 Okay, everyone, welcome back to our session this afternoon. We're about to get started, so if you'd like to take your seats, please. We're about to get started anyway, so if you could keep the noise down. I feel like a lecturer here. We're about to start. So welcome back to our session this afternoon, which is on Beyond Gender. I'm Dr Gillian Butcher from the UK, and I'm the vice president of IUPAP with responsibility for gender. Now we're here celebrating the 100 years of IUPAP, but in a couple of years time we'll be celebrating the 25 years since the creation of the working group Women in Physics. And in that time, as Sylvina has said and others have said, we've seen a lot of changes within IUPAP in progress in gender equity. We have seen the proportion of women involved in IUPAP in the Executive Council within the commissions and commission chairs. We're now at over 40% women representation. We have data from the IUPAP sponsored conferences returned regularly returns data on their gender statistics, and we're seeing that slowly improving over time. So we're seeing certainly progress in gender equity over the last 25 years. But as the gender equity has changed, so too has the whole landscape of diversity. And so in many countries now, what was once a woman in physics committee has evolved into a diversity committee. And it's something that we've seen in the international conferences on women in physics, we have seen we have had workshops on intersectionality. And we've had requests from the delegates to these conferences about why don't we change the women in physics to a diversity committee. And this is something that we've had in the IUPAP as well. And so we are looking, so I have been tasked with setting up a group to see how best we can take the agenda forward on the wider issues of diversity. So this is a starting point. This is an initial discussion about the wider aspects of diversity. But there are some questions that we might want to ask, which are, so what does, so we're talking about diversity of underrepresented or minority groups. What does that mean? What does underrepresented mean in particularly in a global context as IUPAP is? How do we measure it? Can we use the same metrics as we've been using for women in physics? And these are just some of the issues we know that from the women in physics work that many sort of countries and the IUPAP Territory members are at very different stages along their journey of gender equity. So how do we and we know that this is going probably going to be even more of a challenge when we're talking about some of the wider diversity issues. So how do we make sure that we bring territories and countries along with us and it's not just seen as a small sort of privileged group, you know, stamping their authority and saying this is the way that we are going. How do we make sure that it is actually inclusive and we bring everyone with us? So I've got together a great panel here. They have a variety of expertise and experience and that's a broad topic so we're really only going to be able to perhaps touch on some of the issues. I've asked each of them to just say a little bit about themselves to present themselves and then just have about five minutes to discuss a particular aspect of wider diversity issues that is of particular relevance to them. We'll then have some questions but then we really want this to be a discussion so we will certainly open it up. We'll keep the questions to the end after all speakers have spoken and then hopefully we can have a good session and actually discussing some of the other issues that are of interest to you and where you think Pat should be going and how we follow this agenda. So first off I'd like to welcome Lilia to speak to the current chair of the women in physics working group. So Lilia, thank you. So good afternoon everybody. Thank you very much for the invitation. I'm really excited. I'm so happy of being here with you celebrating this centennial and I'm not going to introduce myself because I will be introduced later in the next panel so I better do this presentation. So the gender policy of Ayupapa Jillian has mentioned and also Silvina in the introductory talk is very successful as shown by the seven international women's conferences in physics already held and the programs and actions taken in different countries. The Waterloo chapter as mentioned is recently adopted by Ayupapa. It's another result in favor of building an egalitarian and solidarity community. Since women have benefited from this initiative similar benefits could be extended to some other minorities worldwide. Here I am only focused on indigenous people also called natives and I use the word indigenous as suggested by UNESCO and specifically refer to those whose territories were colonized. According to UNESCO in the guidelines about indigenous peoples issues there's no international agreement on defining them. The indigenous communities are known because of their cultural diversity and occupation in a specific territory. Their number is estimated on from 370 to 500 million population and they use around 22% of the global land area. They share the voluntary perpetuation of the culture through language, social organization, religion, spiritual values, modes of production, laws, self-identification as well as recognition by other groups. They have been struggling with subjugation, marginalization, dispossession, exclusion and discrimination and women take the worst part of it. Therefore for some decades UNESCO quote places the needs of indigenous people and amongst its priority areas for our response end of quote. Nowadays almost every country where indigenous communities are found has been paying attention to their educational, social and cultural needs. It is well known that the knowledge of nature mainly on climate agriculture and medicine is recognized worldwide. Therefore in some countries there are projects to prepare teachers to improve STEM education. There are also programs for science popularization in communities to attract and support children and youth who pursue science careers. Just to mention a few countries Australia, Canada, India, Mexico, the United States have appointed this educational and professional development. Usually those who pursue a scientific career leave their communities. They become part of the underrepresented groups that struggle with discrimination and lack of support for their progress. Frequently they find a job far away from their homeland. In spite of the difficulties they encounter in higher education the number continues increasing. However the number of their participation in our physics community is not known except for a few countries such as Canada and the United States. For example recently some scientific associations have started collaborating to network and support them. A U-PAP can also collaborate with this effort. First creating a friendly and supportive environment for our colleagues. Second supporting their work at their communities particularly for those who move back to their homeland in work in isolation and without institutional support. Just as the working group women and physics did it they can start networking and decide on the actions and activities necessary to give equality as they develop physics in different scenarios. This will contribute to the mission at U-PAP, assisting in the worldwide development of physics and fostering inclusive international collaboration. Our working group expressed the commitment for doing our best to achieve these tasks. Thank you very much. Thank you Lillia. I'd like to introduce yourself. Thank you. Thank you so much. So I'm Chandralika Singh from University of Pittsburgh and I am going to basically talk about some of the things that I've been working on. By the way I'm a faculty at the University of Pittsburgh in the physics department and my background is in condensed matter theory but I've also been doing research for the last two decades on how to improve the teaching and learning of physics and one of my scholarly research areas is promoting and supporting diversity equity and inclusion. So I don't know how to change the slide here. All right. Okay. Okay. Thank you. So you know I mean whatever the word underrepresented means to you you know whether it's women in physics or racial ethnic minority minorities in physics or first generation college students in physics or you know low income which would actually in developing countries mean a very very large number of people but physics has really excluded a very very large number of people right. It has really the worst kind of stereotype and more over the culture of physics is such that people don't realize how they are actually contributing to perpetuating this culture that actually is excluding so many people and if you look at this famous picture you see there's only one woman here and everybody in this picture is white. So you can see already like the signs of exclusion. So let me start out first by actually giving a framework for what equity means to me. Okay. So I think that there are three things we need if we want actually physics to be equitable and inclusive. One is that we need to provide equitable opportunities and resources to everybody regardless of their background. We need to make sure that we have equitable and inclusive learning environment that means that we provide guidance support and mentoring as appropriate to all the students who come and make sure that everybody belongs in our classrooms make sure that they have identity as people who can excel and they leave our classes feeling excited about pursuing further studies in these areas and of course we want outcomes to be equitable. What is equitable outcome? It would mean that students from different demographic groups including these underrepresented demographic groups that we are talking about they all do as well as the dominant group in physics and if we are not meeting these goals then we have to try harder because it's really important that we provide in the resources intentionally to the groups that have traditionally been left out and we also need to remember that this intentional allocation of resources is really important keeping in mind some of the research findings. So let me actually show you one of the research findings. This is from my own study that was published in physical review physics education research and if you just look at for example the right-hand side here what you see is that we are finding that in introductory physics women who actually get an A grade have the same self-efficacy as men who have C grade. Self-efficacy is your belief about how good you are at solving physics problems. Now notice that it's not just your grade that matters but also what you think about how good you are in that discipline. You are not going to be taking up jobs that require challenging things and you will actually not even pursue certain areas saying no I'm not good at it let somebody else do it and notice here that people who are really good we are actually going to let them go and this is basically equivalent to compromising excellence right because you're letting good people go because they are they don't have self-efficacy why is it that they are not they don't have high self-efficacy because the culture of physics is such that it is really not making people feel like they belong and making people feel like they have what it takes to excel. Here I'm showing another data from my own studies and if you look on the right hand side it's all students and if you look at the percentage of students who are dropping out from physics it's highest for all students but if you look at ration and I think minority students 65 percent of the students who are from racial I think minority groups like African-Americans, Hispanic, Native Americans in America they are actually dropping out of physics after declaring a major and going into non-stem discipline. This shows the culture you know it's not about oh if people are interested they are going to stay it's about what kind of environment we are producing these people love physics and they are leaving because we are not really providing them with the right opportunity you can see that it's bad for everybody but it's particularly bad for underrepresented students. Also I wanted to say that this we have done hundreds of interviews my own myself and my own PhD students and one of the things that often comes up is students say when I went to a professor to ask for some homework help the professor said oh this problem is trivial or this thing is obvious or this is easy now if somebody is from underrepresented group there are already so many stereotypes out there that is you know societal and basically if people say that things are trivial it's like a slap on the face of a student who's from an underrepresented group notice that you might actually be doing the same thing for a student from the dominant group also but they do not have the same reaction as those from underrepresented groups and they think that what you are telling them is that they don't have what it takes to excel because they have worked hard on those things and now you're calling it trivial. So you can see that these kinds of things are actually increasing the stereotype threat from orange to red which is a threat associated with being associated with a group that is underrepresented in physics. So what I suggest is that we as students mentors advisors and people who actually are responsible for creating an equitable and inclusive culture not just focus on efficient problem solving and helping students develop a good knowledge structure but you also focus on defense by defense I mean making sure that students actually feel like they belong they have an identity as people who can excel they have high self efficacy because if we do these things then students will also become even more interested in physics and they'll have even greater achievement goals. So just like the way if you were a tennis coach or chess coach you wouldn't just focus on offenses you should be focusing on both because only then will students from underrepresented groups feel safe and they are actually going to feel like they can actually do well in this particular discipline because my own research also shows that if you do active learning in an inequitable learning environment then it turns out that everybody learns more but say for example the gap between majority and minority students actually increases because those from majority groups are disproportionately benefiting from those kinds of things. So I actually wanted to say that we have also done some interventions that have really been effective and this is basically about normalizing struggle and making students understand even Einstein said if you haven't struggled you haven't tried to learn anything new so it's really important to explicitly normalize struggle and tell students that they have what it takes to excel and it's all about working hard working smart taking advantage of all the opportunities and everybody struggles to learn physics but since you know and if they struggle they'll get to the next step and the next step and the next step and it's actually a good thing to struggle so telling students that you should be pairing yourself on the back on the back when you struggle because that means you're on your way and these are data for gender and race that show that if this kind of an intervention acts as water on partial land and it helps those who are underrepresented in physics disproportionately more than people who actually are from the dominant group. So I'd like to stop here. Thank you. Thank you Chandlika. I'll schedule perhaps you'd like to see some some words there as well. Thank you. Sorry. Thanks. Yeah just a few remarks. So my name is Joe and I'm actually from here I'm retired but I work with the American Physical Society and their forum on international physics and an affiliated commission of IU PAP also with Sylvina on the photo contest that'll come on Wednesday and a number of other things also a European Physical Society. So yeah I wanted to say in terms of equity diversity and inclusion I'll get to all those but diversity is actually very very close to ICTP because in normal times if you look around the room almost everybody is from someplace else it's not just a minority so it's very common. But having worked at ICTP I travel quite a bit and there was always a few things that puzzled me and one of them was going places like Pakistan and Iran where I saw so many women students and I'm going to take the case of Iran right now because it actually puzzled me yes just to figure out why there are so many and part of the part of my curiosity is piqued by because of our optics program here and that's Amadouwage is also part of that and so we've usually averaged around 40 to 50 percent women and participants students coming from around the world and a lot of that had to do with Iran so the so anyway I talked with the former vice minister of science research and education technology in Iran Raisa Mansuri many of you probably know Raisa and so he shared some numbers with me it turns out in Iran there are 30 percent more women in physics at every single level undergraduate masters and PhDs and there are men and that includes even if you just look at the PhD student population is still 30 32 percent women however when you look at the employment it's really 30 percent is a really robust number because only 30 percent of the jobs in physics are held by women in Iran so Iran is exporting a lot of women around the world I really had the great pleasure of meeting Vega so anyway now I want to talk about people like Vega so we've I've had a number of students actually almost all of my students here at ICDP have been women I don't know why that is it just it turned out that way some a couple of them from Iran what are the problems just practically speaking because I'm not a policy person is they they they came for a step a sandwich program so they're three months here and then they went back and they come back for three years but the first three all wrote to me soon after arriving home and said dear professor I'm pregnant and and so you know you figure out the math there and that means they're not coming back the next year until later and maybe they have to take a year off and I was really happy that there was actually a lot of flexibility in that particular program that we run with IAEA to allow them to do that and and one of them had not only that but had to learn French so she was out for a couple of years so anyway there has to be a lot of flexibility it was just something we did naturally but if you don't have that if you're really going to stick by the rules these people are going to be lost and that's just it's a natural human thing so that that wasn't quite right the other thing I wanted to talk about was mentoring and I have one and and most of them okay so one of my students was uh and I'll just bring this up because she's also Iranian um and she's not actually she didn't study physics with me her name's Mina uh but she's uh she uh studied nuclear reactor physics in Iran uh she came here for an IAEA conference and and she was kind of the shy one about the group of three and uh and uh so I I started talking to her and asked her what she wanted to do and she wanted to come out of Iran actually everybody wants to come out and find to find some education in Europe she wanted to go to IAEA etc etc so she had a whole list and I and so we started talking about careers and so it didn't really matter that we didn't do the same physics what mattered was that she needed just somebody to to mentor her and then and help her along with the with her career choices the kind of things that she should look at and we started with her CV and and worked up from there uh and I should say right now she's really a real superstar at IAEA she's appeared with the director general on women in nuclear that program she's one of the uh one of the five I guess outstanding women young women uh advocates of that so any rate it's it's not because of what I did it's because these are these are people women and and there could be anybody that really are self-starters that really want to do it and all you have to do is help so I'm a real advocate of mentorship I think everybody should do it and in every physicist actually mentored one student probably a lot of great things that happened so the last thing I wanted to say is uh they're you know here there's economic we heard about economic barriers uh to inclusion uh that that applies to developing countries but they're also developing communities uh even in very rich even in the United States they're developing communities if you want to look at the most developing community as the Native Americans uh they're at the low end uh sorry to say this the totem pole but they really are uh and and you can find uh these kind of communities all around the world and I think that that also something we have to address in terms of underrepresented uh peoples they're they're many and I think we heard that earlier there's too many um but especially in developing countries even in China which surprisingly is a developing country because it's based on GDP per capita you'll find many people that are really not out not in this game and that's a lot of minds to lose so anyway that's that's all I wanted to really say thanks if you'd like to introduce yourself thank you thank you so much hello everyone my name is Dr Pega Masumi at the moment I am a lecturer at Swinburne University in Australia and um my involvement with women in physics started as um I studied my bachelor and master degrees in Iran and as Joey said I was surrounded with more than 50 percent of my classmates as a female and then I came to Australia and in a group of 30 40 PhD students I was within the handful of women and I started teaching in Australia and in the bachelor degree there was a few women and it was really possibly why in a western country with this much freedom there are not many women doing physics so um I take up their role as a chair of women in physics in Australia and we did some good job in Australia just promoting women and just trying to get more female students to come to physics um one thing that we did in Australia was that um we I actually initiated to changing the name of woman in physics group to DGAP which is a diversity and equity group in Australian physics and myself I was always observing that um as a woman who is coming from another country and starting a career in um in a in another country which is completely new does it mean I am under representative because I as as my colleague says um we're not exactly fitting in and we have to try harder we have to do lots of volunteer work lots of networking lots of hours to put in although we are an early career to be able to succeed and another thing is I'm coming from a to the end of my early career transitioning to my mid-career and I'm always wondering do I make it to stay in academia I will I be forced to go outside in Australia we have about um the 5 to 10 percent of the whole PhD students can end up being in academia in a full-time position or somewhere in between um industry and academia and I think the female physicists who decide to go to industry and we really need physicists to go more outside academia into the government and into the industries to make have a full impact um is that are we representing those people too if I don't happen to transition to a job in in my mid-career in academia do I still become presented as a woman in physics group or will be I will be forgotten so these are the things that puzzle me and I think about them all the time and I would like to hear your thoughts thank you thank you to our panel here for sharing some of their their thoughts and some of the expertise we've heard quite a variety of sort of different different thoughts and different aspects of diversity but I wasn't thinking rude if there are any questions at this point or any comments so this is supposed to be a sort of panel and it's a discussion so if you have any questions either directed to to one of the the panel or to the panel have any questions for each other they I we got have we got someone too but I could just shout this would be nicer to be able to hear you so my question is it is for peg up because it seems to me that you have a perfect test case if you compare Australia to to Iran we often say perhaps it's an aspiration or a hope that if we reach a certain critical mass a certain critical percentage of women in physics then everything's going to be okay do you think that's true actually I um I had the pleasure to work with Kathy Foley who is now a chief scientist of Australia and I really believe on what she said once to me that I think women who are very has a very running a whole house and also doing work and has a full power of multitasking if we can get them to work it's especially in Australia that lots of the working force has been women not in academia or not in high position but has been run by women if we can get to that point of 50 50 that's a pure potential of Australia so I do believe yes if we can get more women to that's there is a different part so when you are a kid in Iran in Iranian family you will be inspired by your family telling you that physics is great engineering is great indeed Iran has the most number of engineer females in the world so we really get this support from the family and we wanted to Iran is a man dominated country in Middle Eastern country and we wanted to take our freedom so we go for a study but when we finish physics unfortunately you are not necessarily end up in high-end jobs or in academia as a female the reason is the country is a religious country and to be able to be in the system working the system you have to change yourself and that's probably one of the reasons I left so in Iran that 50 50 change when you want to get a job so even if you decide to stay in even if you decide to go for interview to stay in academia you need to they will ask you to read religious books and answer religious questions which has nothing to do with me teaching physics so unfortunately they won't get to the full potential but if if they they would have it would have been a better country thank you yes I think you said something interesting what is it culturally that in Iranian families pushes you know parents to insist on a scientific education for their daughters or maybe for everybody what is it it doesn't seem to happen you know there is anywhere else there is actually not a push it's a pride so for families they they actually are so proud to say my daughter is studying physics or my daughter is an engineer they have a certain pride saying that like your dad supports you to become an engineer supports you to study physics I remember my mother is a midwife and she was taking me to to science seminars and I was curious from a very early on what is science and the first gift that I get as a inspiring me to do that was a telescope to look at their stars so they they inspire you they support you there is no female male in terms of what you are able to do you can do whatever you want but I had a very interesting experience when I came to Australia I was teaching and they were decent students coming from higher school to Queensland University and I was demonstrating some experiments for them and they said they really enjoyed it and I went to them and asked one of those female students I said oh that's really cool would you like to be a physicist and then she said no the boys will take I'm crazy and I'm ugly and I was really like well so the society is really different um we also have some questions in the zoom so if it's all right I'd read one the next question is a bit pivoting from gender toward a more economic aspect it's thank you for the wonderful panel may I ask the panelists um think high tuition costs resulting in student debt coupled with minimal stipends in graduate school often discourage under uh represented groups are there any suggestions in solving this just Joe did you want to see yeah reduce the tuition costs just eliminate them I don't know California used to have free undergraduate education I don't know what happened Europe is not anything like the United States I think the United States is probably the outlier isn't it Bill yeah so oh yeah in many countries the solution is the public education which is free and we don't have to pay any tuition and just for example in the our national university the tuition every year is like I don't know maybe 50 cents dollars so that's another solution yeah and in in countries including the United States it's a huge problem right and especially at the undergraduate level where students have very different privileges and some of the students I mean even if they have full tuition paid they still have to actually support themselves you know because they have to pay their rent they have to pay for their food and so if they really don't have all of those things covered then they're going to be flipping burger at Burger King or something and then those things can be extremely tiring and students have to do their physics chemistry math and everything else along with that and so it's really not the level not a level playing field and so if we really want to make sure that students you know the things that are equitable not only do we have to make sure that we academically support students and mentor them and and provide opportunities in our classes but also provide support you know so that students don't have to do those kinds of out of class you know those kinds of jobs that can take up a lot of time and make them really tired then they won't have time for homework and things thank you I would like to add some comment because there is a debate as to what higher education is because many Latin American countries think that higher education is a right so it's like public education at other levels and in other countries they look at higher education as a commodity so that you have to charge for so there is a huge debate on how you perceive higher education which in at least in my country most people think it's a right so you have very good public education and public universities where you pay nothing because it's the way to get underrepresented well at least it's not so easy for underrepresented groups because of economic problems even if university is free to go to university but it's it's perceived as a right so the government supports universities and people can go. I'm going to make a controversial statement about as to whether we think that we actually do want to encourage more underrepresented groups into into physics when it's such a it can be such a toxic environment as you were saying Chandralika that they are leaving should we be trying to fix the the environment first before we try and get more in and just try and keep funneling them in. So I think that that's a really good point but I think I would like to connect that to what Bill you were asking which is that you know is there any advantage to having a critical number of women so I totally agree with your answer that you know I don't think just having a critical number is good enough you know you really need to change the culture also because culture of physics has been really toxic and underrepresented people are really not wanting to stay as you saw two-thirds of the the racial and ethnic minority students leave after declaring a physics major also my research shows that women are leaving physics and engineering that significantly higher grades and going into non-stem disciplines than men this has to do with cultural issues in physics so I think that we need to work on both fronts on the other hand you know like we also have done research in courses like for algebra based physics physics courses in which women actually are majority these are pre-meds and in those courses what we find is that you know men with B grade have the same self-efficacy as women with A grade so it's not as bad as the ones in which women are underrepresented the one that I showed you but we also see that there is differences in self-efficacy between men and women in those courses and at the end of the semester even though men are underrepresented in those courses for bioscience majors the physics courses for bioscience majors their sense of belonging goes up but women's sense of belonging does not so there is something about women do not feel recognized even in those kinds of courses in physics so there definitely is a cultural issue in physics that really needs to be fixed so it's not really and and I think that having a critical number of women is really important to also push for wanting to you know see the culture change because otherwise you know people who are not like underrepresented people they might not even understand what the real issues are and because they have not faced the same issue and as I said it's not really people's intentions that matter but the impact that they are having because of the way that they are doing things. Okay thank you for these discussions I'm Reza H. Thadde from Physics Society of Iran and just to make the conclusion of the this talk more clearly thanks to Pega for explaining everything very clearly but I would like to say that it's not only matter of physics the number of the women are higher than men in the all the fields of the inside the university in Iran and we have a section of women in physics in Physics Society of Iran as we monitoring the number of the women that studies physics undergrad graduate and schools in all of the country and according to data we know that's even in the other fields of the research of Saudi like medicine or art it's they are more attractive for women and there are some kind of the restrictions by the country that's reduce the number of the women in that fields of the sudden and at least at the time we haven't seen any sign of the any kind of restriction of the number of the women in the physics that's could happen could affect the number of the women in this field of the physics but just to say that it's not a kind of the attraction just only for the physics that we have the same statistics for other fields of their side and if I would like to go to the comment of the resume and suri that's show mentioned yes we have very a smaller number of the people women working in the even in the academy right now what's because the this trend of the not in graduating of the physics women in the country now the number of the physics women inside the academy is also increasing for example in the department of physics in sharia university that's i'm working in the last three years the number of the women that's higher are more than the number of the men that's the number is about 10 or 15 years ago just only one woman was working in the physics department now we have about six or seven from 30 that's something that is rising that's it's come some kind of the output of the system that we have right now that's anyway so just to make it clear thanks i was going to add to your point it's actually very true i wanted to i'm actually wondering how we should practice the positive discrimination for women and promoting and having the role models because you talked about the self-esteem which is really low and my experience was i was applying for a postdoc and they i got the postdoc and then when i went to work there some students and some other people in the group said you got it because you're a woman so this is actually the worst positive discrimination for me because not only i will doubt my abilities and the skills i will also just feel horrible that people think that they got me just because i'm i'm a female so it is it is actually important we also think how we should do this support is it actually doing good to frankly and putting in the position that we are looking for a female or should this be behind the scenes and just by raising awareness that we are aiming for a role model of physics in the department so that was my comment as well thank you okay just a very brief comment and i think in the beginning of the career physics is a dream i think i really believe that so if it is a dream you have you have to have in your mind the possibility of dreaming and that is very difficult if the culture influences in the opposite way for underrepresented people for also for women so i think if you want to change the culture you have to discover how to give that dream to everyone and i think that if you do that you could get more people from underrepresented sector of the society my experience in physics is women in physics that my country are less than 20 percent are very outstanding in physics maybe you say because they're a lower number now because they they actually dreamed to do science that's my comment thank you thank you for that hey chandelier yeah so i have a couple of comments to make about this you know so notice that there are several issues here so first of all there are people who actually don't come to physics because they look at shows like big bang theory and they're like no i don't want to be like these people right so they're out even before they but then there are people who come and we provide a really horrible environment right the culture of physics is such that it repels them you see that they're underrepresented people are quitting after declaring a physics major those were us data so you can see that there is something wrong with the culture right and i'll give you an example of this woman you know her name is eileen pollock she was the first woman to actually major in physics at Yale university and she wrote her memoir called the only woman in the room in 2016 and so she says that you know she had basically um measured in physics and nobody encouraged her to go to grad school and she said that an undergraduate thesis was mandatory for her at Yale university and she did a theoretical project with somebody and she said you know when i saw that project that problem i ran to his room because i was triumphant and i thought you know when i told him when i show him that i've solved this problem he'll be so excited he'll say i mean you should go to grad school and so not she knocks on his door and she shows him that she has solved the problem and he's like yeah and he goes back to doing what he was doing and she went from being triumphant to feeling like she was at the bottom of the ocean notice that she doesn't have any role model she's already questioning whether she has what it takes to excel and instead of recognizing her instead of validating her instead of affirming her and saying yes you should go to grad school this is amazing job that you have done you know he didn't affirm her at all and so she she said that i locked up all of my physics books in my dad's locker and i decided to do grad school in English and now she's an English professor at University of Michigan in Arbor right so the interesting thing is that when she went back to Yale when she was writing the book this person was still there and so now 30 years later she's so much smarter in terms of like her experiences so she's like let me have breakfast with him and this time she asked him point back what did you think about my undergrad thesis and he said Aileen not that many people do theoretical work i must say you were your work was exceptional and she said i was cheery i because physics was my first love and i said really why didn't you tell me then you know i could have still have been a physicist you know do you ever tell anybody that they're doing a good job that they should go to grad school is like no i don't want to give people the wrong impression you know they should decide for themselves but the point is that if you are not recognizing people if you're not affirming people then people who are questioning themselves because they don't see other people like themselves you know they don't have role models they are the ones who are first likely to say i don't like this culture i'm leaving and so we are you know there's so many aileen polox who won't write their stories but we we can already see from those statistics that under represented students are leaving the discipline at much higher percentage and because we are creating this culture that is not really helping so we need to recognize our own responsibility and i wrote in yeah um so i just wanted to offer a slightly different perspective i think uh which i want to preface by the fact that i'm from denmark and the university of kopenhagen where i think on the undergraduate level maybe five percent at a good year are from non-white communities um and then i think we start off with 30 women and end the year with 15 percent women on the first year of the undergrad um but the reason why the majority of women leave the undergrad in at least in my university is not the professors or the teachers but the male students who continuously don't believe that their fellow students can do physics and continue to comment on it throughout the year um and then when you continue further if you survive the first year of undergrad so to say and you meet professors they are always at least in my experience very encouraging um but you just got to sort of survive your fellow students for the first year so it's a slightly different perspective but yeah thank you all right we have several hands i don't remember i think i'm just going to go in this circle so yeah i i just wanted to say in response to yours that you know like we have a paper coming out in a couple in a month or so uh in physical review physics education we said that shows that it's not just your instructors but also this you know male peers who are actually creating this toxic culture you know like some of the people are like oh you are not able to do this you know i'm i'm in you know i'm already at the grad school level or you know they run around with a spring theory book on their chest or something like that so you know no there there are lots of issues like that also that are actually so you're right that you know it's the overall culture but many a times you know this those those students are taking lead from other people you know like that they look up to so i think that definitely there is some something about it and the important thing is that it's not just your intentions that matter but the impact that you are having on the students chandra i have some comments from the morning we saw a picture in which there is a number of nobler leaders sitting and only one woman was there but only this one woman went twice time never press so if we providing an opportunity to the woman in terms of scholarship so might be in a future we produce more and more manicures but that is the problem of the opportunity which we not giving to the woman i'm not talking about the whole world but the specifically in a south asian region where the people yeah the poverty is so if we provided them a separate type of scholarships in the every branch of physics might be we produce a future cutie thank you anisa thanks you have been looking for the theory of everything for a long time but you know think about all the underrepresented students whose talents we have lost out on you know we could have potentially had the theory of everything if we had really used everybody's talents but so that's another thing that we should be thinking about can i hello hello everybody i i want to thank my panelists for the interesting talk concerning uh uh sub-saharan africa the the question is not the question of under representation that it is a question of access to education access to education for for many many people for women for for boys and so on and and i know in many of these countries there was a special program to encourage girls to go to school okay they go to school but at the end of the primary school you cannot find a lot of girls at the secondary school at the university why because in in many places there is a lack of of energy a lack of water and many of this job is devoted to women when they have to go to for for for firewood they have to go for water they have to go so they have not time to go to to to school and to and to learn physics the problems that we don't think that women cannot do physics we think that everybody can do physics even from my my own experience in my university the best student in physics are girls you know so it depends if i if i if i learn that in the united states there is a problem of under representation in africa it's not this question really okay this is what i want to say thank you for that anyone want to sort of follow up on on that i think about having access yeah thank you and i just wanted to make another comment related to what you said which is that you know oftentimes when students who have less privilege they come into physics they also are interested in knowing you know how can physics contribute to the society you know something that we don't always think about what we should be because this is true for a lot of students from underrepresented groups you know because physics actually has really played a key role in revolutionize you know our world but we don't really emphasize any of those things that are really important for people who are who have some who are not as privileged so i think that that is another thing that we as you know physics mentors and physics educators should keep in mind that you know students you know like who are underrepresented are more likely to care about these kinds of issues i think that's a very good good point is we have another question any yes i think we also have questions online so i'm just trying to sort out but i think the two of you were first and then i would read a question from zoom if we still okay so i have a question so regarding the underrepresented groups my minorities so okay we all agree that the that this is the root of it is a cultural problem there is no question on that but of course there is also institutional behavior that sometimes may i can i say exacerbate the things so the question i have for the panelist is do you think that in this moment institutions are trying to correct this curse or do you think that the action that are taken at the institutional level are not enough because of course acting on the cultural level of academia and changing the culture is important but i also think that an institutional action has to support this otherwise might be not as a as efficient as it should be yeah i was going to make a comment about that that not also the not only the persons are i mean to change the culture but only also the institutions so much pressure pressure over the students over the so focusing and getting numbers and things like that that causes several problems i remember one of my colleagues complaining about why one of the students got brain yet and then she said he said no it is the she cannot do she cannot have both she has she has to choose what she wants and i think that because this has an impact on the results of the projects because you have a timeline and things like that it's also a problem besides some others so yeah i agree also i consider very important to change the institutional culture also also is that is very competitive and also there are studies that women tend to be less competitive like they don't in that sense that and they want to be more collaborative and then there is these things that they think they are thinking about physics to do some supportive to do something to support the community so yeah to have there are a lot of things to do like also studies that showing that many of the tasks which are more time demanded in many menos less prestigious are women are mandated to do those those kind of things so there are a lot of things to do not only changing the culture of the person but also the institutions that's what i'm not sure we've got time they go wanting to sort of come in and this as well i think it is up to every one of us we have supervisors in the school that they get only men and male students or we have supervisors that they offer a hourly rated for a postdoc to a female PSG students who just finished but then go get a full-time male person as a postdoc so it is also up to students and it is also up to anyone who observed this kind of behavior to go to the head of a school and say you need to talk to this person and say why do you just have male students why do you not provide these female PSG students with a full-time job other than just take the labor so i think it's up to all of us me as a PhD student so that if i see my supervisor is doing this i have to speak up yeah i totally agree with her so i definitely think that the institutions are not doing enough and you know there was a study that came out from joe handelsman group in at gl university like about five seven years ago which shows that you know they they gave a survey to 150 or so faculty in sciences and they asked them you know that only the name was different jennifer or john but otherwise their cds were identical and they asked them to rate them in terms of how likely they were to hire them how likely they were to mentor them and how much they would pay and all of these were lower just because the name was jennifer for some of those people as opposed to john and so you can see that there are all these biases and stereotypes that people have in mind just because somebody is a female like you said and this is all about the culture i think we just have time for one well in fact we probably don't have time but we will take one last question yeah hello thank you for all talking um so i'll start with a comment um it's studied in the uk and um chandra lecker's things uh comments and speeches um really resonated with my experiences oh no uh sorry um i'd never seen a female physicist um until after my first year of university and um i've had problem classes with i whereas the only female in the uk and then i went to a conference uh for women in physics at the end of my first year where for the first time i saw inspirational female role models and that made me realize i'd completely internalize these biases about women uh about my peers about myself and uh so say uh having role models makes such a huge difference so if things that could be changed making sure that our female female lecturers in the first years right from the start like what you're doing making sure that there are there's diversity on panels and talks and things like that um my question is about something that's often overlooked within the physics community um so young people are addressing a lot more but inclusion of other types of genders um so uh inclusion um this i i don't see in lots of big physics organizations i was wondering if any of you have any comments on why if that's changing thank you i perhaps that i'll sort of just comment on that and i mean that is something that yes we do actually want to change i and i think we'll be doing that for certainly the i you perhaps sponsored conferences and perhaps doing just some of the even just some of the basic things i think you're starting putting our pronouns on unnamed badges things like that small starts but i think that's something that we we definitely want to move so move beyond not just this woman and gender but moving beyond the the non-binary uh is that the right way moving it's moving moving moving beyond the binary gender to the to non-binary i we've already overrun and we've got a next panel on i want to thank the speaker so much for sharing all their experiences um and i i hope that you in the next 100 years that we'll look back at this session and people were saying i can't believe that they actually had to discuss this it was it was it was so obvious at the time so i you know i think as we move into the the next century we are a you pat you know i think there's some reason to to be hopeful that actually we can we can make real change and we can actually make physics new inclusive for everyone if we just thank you the panel uh and you for your your questions as well just thank them once again thank you the morning i you pat pays a lot of attention to trying to promote physics in developing countries and so we wanted to have a panel to discuss the situation of physics in latin america and so we have a fine set of panelists coming from different countries uh rodrigo capaz from the brazilian nanotechnology national laboratory and also the uh his professor at the federal university of Rio de Janeiro and his vice president of the brazilian physical society he's from brazil then is arturo martí sitting by him he's from uruguay he is the past president of the federation of iber american physical societies feya sofi and he's a professor at the universidad de la republica in montevideo uruguay then louis huerta he is from chile and so he's a member of the nuclear energy commission there but he's also now the director of the latin american center of physics which is based in brazil actually and was founded a with close ties to ictp 60 years ago is that right so this is the 60th this year is the 60th anniversary of this class and here is lilamisa montes whom you you've just seen here before in the previous panel she is a the current chair of the working group on women in physics of ayupap she is a professor at the aben emerita universidad autónoma de puebla in mexico and she was a co-founder of the network of science technology and gender previously known as mexican network but now it's more widespread i think so i leave the floor and i think the first one to speak is a tourist that right i whatever order you want okay thank you very much silvina for for inviting me i am arturo martí from the universidad de la republica in montevideo and i was the the past president of the federation of iber american physical society so i'm going to to speak about our federation and about the the physics in in our region so the the phoesophy has 20 21 physical society physical society from all the latin american countries plus spain and portugal and the the foundation was in la plata in argentina in 2005 as the at the union of at the fusion of two previous institutions the phoesophy and the unisophy so the federation governance is given by an executive committee by seven members the actual president is the doctora maria sanchez from cuba i think that uh maria is is in not in not present now but she's connected by by by the zoom uh i don't know maria if you if you if you if you if you want to add or to comment something just tell me so in addition we have a general assembly from all the the president of the legate of the society which used to to to celebrate his meeting every two years however in the during the pandemic we we had more more virtual zoom meetings so this is our website here we can find document histories and and several and several documents so let's take a look at physics in our region so as we are physicists i would like to to make a parallelism with a physical phenomenon like turbulence so as we know turbulence is an autonequilibrium phenomenon uh it has a wide range of special temporal scales present high diffusivity and predictability and it is an open problem so the same uh the physics in in our region are the same characteristics for the the heterogeneity in human and material resources we have we have physical societies with a few thousand uh members to to add larger with several thousand of of members we have a region we have some location or with very prestigious institution there is other places in which there is almost almost no physics at all so the the heterogeneity is also among the physics fields developed for example there there are more theoretical than experimental groups in the region there are also some uh gender issues and the usually physicists uh work in in in academics institution and and much more or less in industrial or or companies so the temporal scales also affects also affect the the uh the science the science funding there are strong strong fluctuation in the science funding uh related to the crisis and prosperity cycles these uh these aspect weekends the intra intrarational collaboration on project and it is difficult to to to maintain a long-term project in addition there is a brain drain problem uh both from the from the region to to more developed countries and also inside the region uh i would like to add that there are few systematic studies about the physics in the region and also there is a problem of unpredictability in the in general so what what we're doing in in phyosophy we're we're trying to to to to share information to strengthen traversal initiative and collaboration we try to to connect with other institutions like like UPAP, CLAF, EPS, APS and many others we are we are supporting outreach programs like physical Olympia both iber-american and uh physical olympias and also latin-american university university physical olympia and and other activities like other activities like the international year of quantum science we are we are thinking about that so this is the contact information and and thank you for your attention now is Luis Huerta from the latin-american center for physics well thank you very much i i appreciate this invitation for this important centennial symposium i think it is a very important moment to review the history and what i want will do here is to review the history of the latin-american center of physics that this year is uh celebrating his 60th birthday so CLAF as we call is a latin-american government agreement in established in 1962 60 years ago uh the objective was to foster regional cooperation in promoting physics to link research to the economical and social development of latin-america and the foundations of this is that research in physics is the basis for economical and social progress that's was the idea to establish with CLAF uh in numbers physics 60 years ago when CLAF was founded uh in physics maybe there there were seven to eight physicists per million in in habitants in latin-america uh that means um more more less more than 1000 physicists and women were less than 10 percent in that moment nowadays the the of course there is some difference you see in these bars these are the scientists not only physics uh very different from in in each country uh physics is very very under underrepresented in in the entire domain of science i think there is now the scientific survey of this but we we think that we are 25 000 physicists in all latin-america country but it's uh this is about the two percent of the physicists in the world more or less but latin-america have the seven percent of the world population so we are closely as a strongly under underrepresented women are about more than 60 years ago but not too much is about 20 percent with a very very strong difference from one country to the other one so in one countries are close to 30 percent but uh in other 10 percent inversion is low well the foundation of CLAFS was the idea of Jose Leite Lopez uh brazilian physicist who convinced the uh the ambassador brazilian ambassador to UNESCO uh to uh presented idea to that organization actually the ambassador presented idea and that was the inspiration because uh visiting mexico and visiting uh argentina uh Jose Leite Lopez saw how how physics has evolved in that time finally it was founded it was uh an agreement between governments that was ratified one country another one uh the three person mainly in this uh endeavor was Jose Leite Lopez uh Marco Moschinski the Mexico and also uh Juan Jose Llanveaje the Argentina the three uh latin-american physicists promoted uh CLAFS and we can say that i would like to say something about the environment the political environment there i think it's closely it's close to what Arturo said before about turbulence that the time these uh endeavors were implemented latin-america uh lived uh several dictatorships uh strong stability but because of those some governments with where uh which implemented social reforms economical reforms that uh wasn't uh uh please send please send to the the rich people in the society and also to the united state in that time united state in intervention in latin-american countries was strong these uh years were a contradictory years and in one part some scientists were persecuted and also put in prison but like in argentina or in brazil you see there the record of Jose Leite Lopez when she was put in prison after the coup uh in 1964 brazil uh uh mexico was rather a style stable in that in this sense you see uh a graph uh with the economical growing but followed by the stank stankamiento of the economy um but a lot of uh uh movements of students you you you know about the history of platelolco that that that was what that was what uh going on in latin-american state however these uh naturalist governments were also uh support were supported also some uh initiatives in science uh i give only one example of the institute of theoretical physics in brazil which was created with strong support from the military in in the government in that moment i think what what we learned about that is even uh those who are in the other side of the of the street in some uh aspect coincide i think nationalism was uh good for this but very bad for most of things so i must i have to say but also in Chile uh was turbulent uh moments in the 60s uh was the revolution in freedom of uh president frey who makes uh great reforms and but in that moment connoisseur was created then came agende and after that the military coup in 1973 and uh but in during the military dictatorship was created from the seat the main fan to uh for the basic science in Chile until now is the the best uh instrument to fan science well that moments were uh in that moment uh nuclear and particle physics uh were uh dominated the scenario of physics uh after that other areas grow grew and in that also in that decades especially in the 60s the first astronomical facilities uh international astronomical facility were established in Chile you see three examples in Chile and also in in latin america in general you see a recibo in Puerto Rico in 1962 Cerro Tololo and La Silla in the also in the 60s i think this was a very interesting beginning of uh of of course astronomy were uh funded with us class have not this line of action we contribute to political recognition of the importance of science for natural development uh we elaborate the global and integrate ambition avoid in balance in scientific development different countries and regional institution that was what we want to do to form a solid and interconnected regional scientific community and make class the glue of the latin american physical society uh today we have an in latin america uh important facilities some in operation and some projected i have some uh examples here i i omitted observatories for just for astronomy but we mentioned the the the serious uh project in brasil the hawk observatory and the high-amplitude water sharing observatory in mexico the pierrot that was uh uh inaugurating the 80s the observatory for cosmic rays the just uh who's proximate to be uh inaugurated is a chelonkov telescope array for observantio on high energy gamma ray in paranal also the the project of the swg o that is looking for a country and between argentina chile and peru is an important observatory establishing in in chile and useful for astro practical physics and also a very wanted project in chile and argentina the underslav in the possible tunnel awanegra that will join chile and argentina in the north of the country and there they'll they'll may be i don't know if if we is that tunnel will be built but it will be the first uh underground laboratory in latin america so we see uh an evolution of physics in our the continent uh from turbulent uh years in in terms of the political stability but you you know that in our days these days these years our country suffered the variation of our economy especially the the main countries in in physics in latin america well physics is an uh is and today participate in ifton and multidisciplinary science we have a lot of areas we we can show in chile medical physics nanotechnology sorry uh quantum information also system biology astro practical physics of course and also astronomical instrumentation and uh there are some other areas where physics is also important and it it is now used by other scientists and engineers so we we think class our institution in order to promote interdisciplinary science and to involve our scientific community that especially young people that look for a position in the the academy where positions are now very low very very few very few positions in that in this so they have to look for another areas also because of we want to develop our country physics is very important to develop technology and this is the country are the and the sorry the the continent uh those are the countries that participate in class we put in bold the letters that the countries that are actually participating in class and the other part the other countries mentioned they are not in bold letters are countries that were in the foundation of our class so class is an institution that join commitment of the governments of the of the continent and nowadays our challenge the main challenge is to get that that commitment be renewed thank you so thank you luis when i move to lilia thank you very much for the invitation again so for this i have a presentation okay so now i'm going to talk about the the impact of the ayupat gender policies policy in latin america and that also will give us an idea about the impact in some other countries um so i'm just going through a brief introduction of the working group was mentioned before and then how these regional networks are become so important in in our region and then emphasize emphasize the impact in latin america and how we have gone beyond physics and creating multidisciplinary networks and finally some conclusions so it was mentioned here mentioned before but silvina and so no it's about the multimodification but that there was as you well known there is a low proportion of proportion of women in the field in most of the countries there is also uh in iniquity because there are women usually participate in the lower salaries and also as we ascend in the uh academic scale we find less and less women surprisingly also there were regional differences like uh finding that the developed countries have lower proportions on women in contrast to some underdeveloped countries so the working group number five uh women in physics was created in 1999 and was charged to survey the situation of women in the uh around the world and to submit a report to the consulate and the liaison committees and suggest means to improve the situation for women in physics so the first international conference women in physics which we call i think with a lot of love uh equipped uh was held in uh fist in paris in 2002 and we have already seven organized and they often they ask what are we doing there so many women talking about what so we have plenary talks workshops post post representations both about the the situation of women in each country and also about scientific work and cultural and social activities population popularization of outreach talks recently and the proceedings are published by the american institute of physics and one example is shown here one example is shown here this is a typical front cover for the uh they are open access so i uh recommend if you are interested in following the situation in on your country you can find here a lot of information so there are also there are also regional meetings and um during the last conference in australia which was weird well due to the pandemic there were 377 delegates which is a record so far and because of it was more or less easy it was open so there was no no so much restriction about the participation and there were also 64 countries participating for for the first time so uh there are these networking networking sessions in regional meetings are you and you see here the our first uh regional with marcia barbosa and also silvina is here i am here with silvina and some other colleagues from argentina brazil colombia cuba mexico so in the first conference there were five countries from latin america and during the last conference there were 10 already with chile and ecuador el salvador honduras and uruguay joining the group so here is our traditional group photograph which you see there was a higher attendance because of this virtual conference more precisely about the impact on the situation of latin american physicists um we have observed how the number of activities organized by the team has increased has been increasing and then some of them have already permanent activities around the year for example the mujeres físicas peruanas which is a female scientist no female peruvian physicists uh they are very active now and also we have noticed that the associations are more open to address gender issues which in the past it was really not easy but now they are more open and then i for example they're now in mexico we have adopted and adapted to our legal conditions the protocol um similar to the one uh u-pop has adopted and also there are some programs like these many nas nasciencia in brazil that means um girls in science and for the first time we have the conference for undergraduate women in physics this year and i would like to mention that it was not organized by the mexican team but by another group of young uh uh colleagues and i'm very happy about that and also uh we have created multidisciplinary networks like the mexican network of science technology and gender where we interact strongly with especially with social scientists also the red colombiana de mujeres científicas colombian network also a women scientist which is also very important and in some of these associations uh uh conditions from gender and diversity has been created like uh in argentina mexico and brazil so we can see a lot of advance advance here so i just want to focus now on some activity that we are organizing um regionally silvina and some other colleagues and it was inspired by the networks i'm sorry and the works of workshops and organizing during the equips we and some reports of another uh teams about this professional skills workshop so during the second conference in Rio de Janeiro a group of um uh latin americans uh we're talking about organizing something similar in our region because we knew that trying to do this in each country was going to be difficult because not only because as i mentioned before it's hard to get money to do science and then you add the world women and then they say we don't have money for that so uh we organized instead we were managed to get some support for the pan american school institute and organized the nanobio 2010 in Puerto Rico and this was organized by Puerto rican argentinian and mexicans you see the group photo here and as a part of the program there was a networking session and then when talking with the students we noticed that uh not only professional skills were necessary but also is emotional support so this um convinced us more than we have to do something and so finally we were able to organize the our first first professional skills workshop in mexico with the support of the our national agency my university and the mesoamerican center or theoretical physics which is based in mexico so we organized the first one and then and then silvina was able to get some money from coni set organized one in Buenos Aires and uh we have been moving through different countries like in colombia peru uh brazil when we are were asked to address uh the ethnicity in physics which was a very interesting experience and uh there were also and it was planned to do the one in Chile but then it was really difficult because due to the pandemic in and in two weeks we have the next one in honduras okay okay so this is our inspiration you can see uh the participation of very enthusiastic students and early career scientists and see really have a great time not only um trying to share our experience but also learning from them so then there was the global approach to gender gap a project which already was mentioned by silvina and as a part of this program this project there were there were the regional meetings with the one in latin america took place in bogota and as a result we have a this book which you can download in our web page and with different experiences and there are also uh there is also a website with best practices in latin america so recently we have a launch a website which is called withdrawal ciencia dot org and withdrawal is a Chilean word yes i'm a pooch word which means wave it refers to our some with some texture that that's what we feel that we have been waiving within this network so our mission is promote equality inclusion and gender equity in the stem so we are promoting meetings meetings and discussions and enhance social economy and cultural changes and well so just to conclude we definitely can say that the gender policy is has a very positive high impact in latin america we still have many things to do like uh according to the united nations there are 30 53 countries in latin america so and you see that we only have 10 teams so also we need to motivate more our colleagues to participate because usually they consider that this is only for women and it's not true and also get more support of local associations also them as well as mentioned before many of the our colleagues don't know anything about doesn't know about a you but and of course always funding for for the activities so that's my conclusion thank you so thank you li milia now we we have rodrigo barbosa capas from brazil thank you very much i'd like to thank the organizers for the investment especially silvina and all the other organizers of this session uh i'm rodrigo capas as silvina mentioned i'm wearing two hats here one is a vice president of brazilian physical society and the other is the director of the brazilian another technology national lab i will briefly talk about brazilian physics just one slide but i was told that people really wanted to know about the the serious project so i will spend most of the time talking about the cn pen which is brazilian center for research on energy and materials where the series is so really briefly this is a brief timeline of brazilian physics so one could say that physics in brazil started you don't have a point so in 1851 this was the when the first article was published on the fuco pendulum this was the first actually in the first year in the same year when fuco did his experiments in france a brazilian engineer candid olivera did experiments on the south hemisphere of the procession of the pendulum then we jump to uh 1916 when the brazilian academy of sciences was founded in 1951 brazilian brazil joins the iopop today we have eight shares and four votes but only in 1966 the brazilian physical society was founded and today we have more than 2000 members well these are only the ones who are paying their dues but we have more uh and we hold 12 uh area commissions uh 13 annual meetings and schools uh we deliver four annual prizes and we take care of the national physics uh olympiads at different levels uh well there's there's there are too many a lot of uh uh things that i could add to this timeline but let me just close that just by mentioning the latest development that this year brazil uh joined cern as as an associate member step okay so uh this is cnpan uh cnpan is a misnomer because it holds four different national labs but if you compare to the national labs in the us i would say that cnpan is a is a is a national lab and uh four national labs are more smaller smaller centers and this is the ln nano the the uh oh okay ln nano uh this is where i come from uh but in the same center oh they we are located in the city of campinas near san paulo uh in the same center we have the the lnls uh the brazilian synchrotron uh light national laboratory where eve petro was the the director before uh and that it's the the basically the the the national lab that takes care of the series and this is the older synchrotron light source the uvx the second generation uh synchrotron light source the series is a fourth generation uh we also have lnbr the brazilian bio renewables national lab uh the brazilian bioscience national lab and as i said the the nanotechnology national lab we is a very unique uh r and d ecosystem and we try to work together uh in a synergetic way in different areas as health renewable energy renewable materials uh agri-environmental and quantum technologies so the uh cnb has four different uh axis of activities uh first uh and this is uh very strongly in our dna it's an open access facility for external users from both from brazil and from abroad we do our in-house research uh we do support for innovation and education and dissemination through workshops and and courses and training um this is just to give you an idea about the the international our international users uh this is in the last 10 years uh the uh international users of the whole cnb facilities is basically 10 percent we can we should increase this number 90 percent of the users are brazilian but from those like 8 000 proposals 10 percent roughly 800 are from abroad and you see the more than half are from argentina and this is a list of uh countries with the largest number of uh proposals in the last 10 years so the series uh i should say i'm a theoretical condensed matter of physics and i'm not i don't work at the series so any technical questions you should direct to if petrov but i'll do my best to explain to you uh this is a piece on nature in 2013 basically discussing these uh a new generation fourth generation uh synchrotron initiatives all around the world at the year before we were planning at the at cnb to to uh upgrade our second generation uh facility to a third generation for the facility and we were provoked by our international committee to be more ambitious and to try to go for a fourth generation synchrotron and um this was done uh actually in 2016 the the first fourth generation uh synchrotron was uh uh finalized in sweden and and this is our our what we did they started in 2014 to 2017 these are different snapshots of construction of series and in 2017 it was it was basically finished uh well i'm running out of time so i will not explain to you how the synchrotron works so i will skip that sorry and and but basically uh we had uh there's one figure at merit that which is the lateral size of the uh so electrons go around a storage ring right and and when they make a turn they emit radiation in different wavelengths and and a good uh figure of merit is the size of of the uh lateral size of the electron bunch which should be as small as possible and this this uh defines the different synchrotron generations so this is our old u of x uvx uh synchrotron most of facilities around the world are third generations and the the series now is in a fourth generation with lateral sizes of 10 micrometers and there's also the max four and the and yes yes our f in France okay let's skip that so this is a movie uh and you should feel like the electrons going around the ring uh and the there's no sound in this movie but you should be able to read so there's an inner ring which is the booster ring and then there's an outer ring it's the storage ring where the different beam lines come from and you do experiments uh with the light coming off these uh several beam lines so the electrons they're blue and this is the series from above and these are the beam lines let me talk about the the different beam lines uh in the first phase uh uh there they are uh there should be a 14 uh different beam lines covering different spatial resolution and covering different subjects from from biology from living matter to functional matter to quantum matter these are different techniques uh if you need more details you can just visit this website these are these beam lines are in different stages of development oh this is a more uh let's say comprehensive and and with more technical information the names are interesting they are acronyms for the different techniques but they also uh uh correspond to animals or plants from from Brazil so there are now eight beam lines already working in commission stage these are the ones in green uh three of them are in the process of installation two of them are being assembled and there's a project of another one for the first phase in the second phase there will be two sorry eight more beam lines in the total of 22 beam lines during the first and second phase so this is another movie sorry this is in portuguese so you can take your opportunity to learn some portuguese uh but uh well just just to show you uh oh this the movie there is not so good uh just to show you some some of the beam lines and and instrumentation in uh on them this is a emma is a extreme conditions been lying high pressure high temperature i think it's the ricks beam line imbuya has a nano uh infrared uh facility and let me just skip that because we're running out of time this is the first paper that came out of course it's about covid 19 as as uh as expected on the crystallography of of of covid 19 and this is actually a new uh project uh we are going to uh have in uh cnm pen the first bsl4 laboratory maximum biological uh contention laboratory in in latin america it will be located right here and will be the first one in the world to be connected to a synchrotron beam light so actually you're gonna have three beam light beam lines through this uh bsl4 facility and this is uh some i mean uh technical plans for that i think i should also mention that an important part of the project was most was developed in brazil and in specifically this x-ray detectors they are based on the medipix technology of developed in cern and we developed with a brazilian company phytek and it was licensed to it uh and and uh i think it's important to mention that uh most of the instrument or a good part of the instrumentation uh of series was developed in brazil actually 85 percent of series was developed by brazilian companies and these are all companies involved in different parts of the project and i think i should stop here and thank you for your attention thank you so i think we have time for a couple of questions so leave it michelle thanks thank you i have a question which might not be politically correct oh my goodness but which is connected to the previous panel on inclusiveness why do you say latin america and not south america this south america would seem more uh inclusive towards indigenean indigenous no is it true or not mexico is not in south america i see yes but latin america does not sound very inclusive latin so the way we call it is latin america and the caribbean and so in that way we include a islands that speak english basically or maybe other languages which are not latin but that's the uh the name that the region is known by really and it's inclusive my question was actually um connected to the previous one i was rather curious what's the situation about all those things you were discussing in the countries that are not latin american basically the english-speaking french-speaking and dutch-speaking countries in that region south south america central america caribbean uh since some of them are pretty undeveloped have no uh so um some of them are uh underdeveloped they don't have many physics programs or in some cases they don't have any at all so how are there any activities to maybe try to spread more physics into those areas where there's actually no physics unlike in the cases that you were presenting where you have already many physics programs and now you want to improve them even further so maybe louise can can you answer if you see the name of the latin american sector of physics is written in three languages including french so uh the idea the original idea of latin america comes from 60 years ago but also we are not actually now that present including all the countries of speaking spanish not because we want to do that but because the policies of the different countries uh have not uh um supported the the incorporation to the latin american sector of physics but our idea is to include every country from Mexico to the south and Chile or Argentina so actually we are working with the countries that are not in in our center they are not state members you have to know that our institution is an intergovernmental agreement so each country who join must have the commitment of the government uh also it is the government that they membership use uh we want to maintain that but it's difficult in this world that multilateralism is difficult because for our scientists it's very easy to talk to first world researchers uh individually so what we're doing what i what we want to do is actually to make more close the different countries in latin america all the countries in in every language spoken in latin america uh to make some horizontal exchange between researchers we have some phd programs within latin america with two countries involved and the idea is to promote that so what the idea is to promote regional cooperation between our countries we have you see you you saw the presentation of rodrigo barbosa but also i talk about cta and other initiatives i'm talking about the big initiatives but also there are a lot of of physics now in latin america enough for young people to make their careers okay so i i guess we can take one last question if please i have a comment on the when the first single drone radiation center was building brazil in the 80 uh he was a two other force he was built by a small number of people with a ridiculous budget now everything was done in the laboratory because at that time the industry in brazil has no capacity to produce high vacuum chamber or power supply with the normal i will say noise level now for the new one this has been built in very small parts in the lab almost everything was done in the brazilian industry magnet vending magnet protocol example everything was done by vex which was the big brazilian company and quite successfully i also mentioned that it's a sector which has been shown i know only there are 60 single rotation laboratory in the world there is only two that have been able to do that and that was only less than five years now you should know that this kind of detector costs about one million for one point the big one 1.5 million europe uh so it's very important that was only in the laboratory with a small company pi mega and saving a tremendous amount of money now so it's a very good transfer of technology from a laboratory to the brazilian industry now i have a question for all the telescopes which were shown on a private slide i would like to know i mean as was pointed by rodrigo about 86 percent has been built in brazil now my question for the telescope how much is built in argentina in chile and so on from my point of view this is fundamental it's very important that the industry and the science of the country be strongly involved otherwise you don't benefit too much i can only mention a little bit about piero je as far as i can tell all the uh the detectors that were deployed a lot of that has been developed in argentina and also all the civil construction and all of that or je had a huge impact local impact in the region where it's placed mendosa for also for outreach and but the technology i think it was mostly developed in the country so for for roger yes yes that's the about the telescopes i have no idea to have a good number about all these telescopes because there is something which is very important i could like to do a comment uh i do agree i don't want to talk about our fellows in astronomy but the first telescope were established with the country only receiving 10 percent of the time to observe that's fine that's very good for astronomy of course but no more than that nowadays the agreements are different we are including technology transfers and the possibility of some not only in Chile but all in the in the region industry can participate in unless in maintenance or some activities but also in the construction but the history of these telescopes is that and our community uh is uh promoting the you the transfer the tenorio transfers now the history was like i said okay so i think we have to adjourn to have the coffee break and sometime if i'm just can can say one last thing i think it would be good if these panels also address the point what ayupa can do for you i mean are we uh you didn't really answer that question are we meeting your expectations is there anything that we can do better i think it would be important for us to know that do you want i don't know if someone wants to commit well for yasofi now is an observer to our general assemblies and i think that the projects like lamp could have a great impact that's why i invited rodrigo basically because i would like serious to be involved in lamp and but of course we can keep on thinking of how to reach out to regions sunil gupta was having some ideas for asia that maybe we can we can share with other regions yeah too but i mean to help organize networks but through projects i think it could be very useful and lamp is in particular a very good example i think it should be expanded more in in our region lack which is latin america and the caribbean to accommodate the other countries you know thank you all welcome back and thank you the for the panel have a seat please we're going to start this session excuse me so good good evening everyone my name is robert topini i'm from florist italy and uh in up i serve as the chair of c-17 on laser physics and photonics it's really a great pleasure and honor to introduce today professor william daniel phillips he received in uh 1997 the Nobel prize in physics together with claude cohen tannogy tannogy and stefan stefan chou for his contribution to laser cooling a technique to slow down the movement of gasses atom in order to study them at the national institute of standards and technology and especially for his invention of the ziman slower uh coming from his career since the beginning he was graduated from the uñata college i don't know if i'm pronouncing it in 1970 summa cum laude and after that he received his physics doctorate from the massachusetts institute of technology and then in 1978 he jumped the the nist and he received many awards and honor from starting from outstanding young scientist award at the mario land academy of science in 1982 the Nobel prize in 1997 the shovel of prize in laser science and then many other it's a very long list phillips william daniel phillips is also a professor of physics at the university mario land con college of computer mathematical and natural science at the university of mario land college park today he is going to give up a talk whose title is a new measure the revolutionary quantum reform of the motor modern metric system thank you thank you thanks very much for that that kind introduction so is the is the microphone well positioned because i'm wearing a uh a clip on microphone because i'd like to move around and i can't uh stay close enough to the the podium microphone to make it work okay so i'm here to talk to you about about the new metric system as you heard i'm uh from the the national institute of standards technology that's the the national metrology laboratory of uh of the united states and uh i'm also from the joint quantum institute which is joined between uh nist and the university of mario land and at nist i'm part of the laser cooling and trapping group and i'm very pleased to recognize my group leader who is gretchen cambell and uh also a professional colleague and uh paul letre porto ian spielman ida teetsinga charles clark and nicole younger halpern who are the the other permanent members of that group and with whom it's a pleasure for me to work on a daily basis i really want to say how honored i am to be able to address this centenary meeting of the union of pure and applied physics iupap because almost from its inception iupap has been a leader in the establishment of an internationally agreed system of units and we've already heard about how that was one of the original motivations for having iupap and iupap really did do things in the early days um the uh the first commission after the uh the the one on administration and finance was at that time called the the uh the s un it was for um symbols units and nomenclature and that is now commission c2 uh which is uh su namco for symbols units nomenclature atomic masses and fundamental constants um in 1948 iupap made a recommendation to the uh general conference on weights and measures uh that started the process to establish the international system of units that we all use today it was iupap who made this happen and what iupap wanted was to have a system that was based on uh the meter the kilogram and the second plus one absolute electrical unit which turned out to be the ampere so that system that we use today some people call it the mksa system that was because iupap was pushing it in 1948 now it took until 1960 uh before the international metrology community adopted uh that system but uh iupap was the original motivation and iupap has continued to play a major role in the development of the international system of units or the si as we call it and uh myself as a past member of commission c2 uh it's been my pleasure to be promoting this new development in uh in the si around the world and uh i'm very happy to tell you this story here at this uh centenary meeting uh i want you to think of questions as we go along because i'm going to provide prizes for everyone who asks a question uh now it has to be a substantive question which means that it can't be what's the prize but any other question is uh is is welcome and you will you will definitely get a prize and our our students will uh will deliver not only a microphone but but but actually more than one prize so so so be sure to think of questions okay so uh a revolutionary quantum reformer the metric system what am i talking about well the metric system really came into being with the the french revolution at the end of the 18th century and uh this exciting picture by Delacroix uh i think gives some of the spirit of the that revolutionary fervor on the 20th of May 2019 so not very long ago which i'm sure as you all know is world metrology day uh uh we have experienced the greatest revolution in measurements since the french revolution the international system of units uh expresses all physical quantities in terms of seven uh base units we have the uh the kilogram for mass uh we have the meter for length the second for time the ampere for electric current uh the kelvin for temperature the mole for amount of quantity and the candela for i forget what it's called uh uh luminosity okay uh anyway um you know if i'm honest the candela is the most hated unit in the international system of units but there it is okay now the reform that i'm talking about is that now today every one of those base units is defined by fixing the value of a constant of nature and i'm going to tell you about how that is possible by beginning with an example that has been for quite some time defined by uh a constant of nature and that is time and so with apologies to the late great steven honking i'm going to bring you my version of a brief history of time so since time immemorial the second has been defined as a certain fraction of a day there's 24 hours in a day 60 minutes in an hour 60 seconds uh in a minute so the day uh has 86,400 seconds and that's what we have used to define what we mean by a second the problem is that since the around the turn of the century we have known that the rotation rate of the earth is not constant uh there are changes due to seasonal changes the fact that the earth's orbit around the sun is not circular and the the uh the axis is inclined but there are additional changes for example the tides exert a frictional force on the earth and slow down the the rotation of the earth the um every time you have an earthquake you redistribute the mass change the moment of inertia of the earth and this changes the rotation rate um if ocean currents change if there are storms this changes the angular momentum of of that part of the stuff and so the the earth has to change its rotation rate so this has been known and measured since the beginning of of the 20th century using mechanical clocks that were exceptionally good uh around the middle of the 20th century we started to have atomic clocks this is the first atomic clock it's not really an atomic clock it's molecular clock but you know what's the difference between a few atoms among friends so uh 1949 the first atomic clock using the ammonia molecule uh a few years later at the uh the sister laboratory in uh in the united kingdom they made the first cesium clock now uh the basic idea of an atomic clock and i don't have to tell this to most of you is that you've got an atom like in the case of cesium it has a nucleus it has a valence electron and there's an energy difference between uh the relative orientation of the electron uh uh relative to the nucleus and that corresponds to a certain frequency and in sodium that frequency is is 9.19 some gigahertz and the idea is that if you start with the atom in one state and shine in microwaves at exactly the right frequency the atom will change its state and you can tell whether it changed its state and then you know that the frequency is exactly that number and if the frequency is wrong then it doesn't change its state now i've given you an oversimplified version i assure you the truth is more complicated please feel free to ask me about the truth i love to tell the whole truth but it takes a long time and so i'm not going to do it during the talk okay so uh in 1967 they defined the second to be the duration of 9 billion 192 million and so on periods of this radiation that corresponds to the frequency that makes the spin flip in the in the cesium atom so that is atomic time and ever since the first clock uh at uh in england the performance of uh of these clocks has been getting better and better uh because people work very hard and make it better but it it's stalled out at about a part in 10 to the 14 now you might say a part in 10 to the 14 who needs to do better than that well at the national institute of standards and technology we are never satisfied and the same is true of every metrology laboratory in the world uh and the problem was that um the cesium atoms were moving too fast they were moving at uh over 100 meters per second because it's a gas at uh a temperature a little bit above room temperature and that's how fast those those atoms were moving so then we had to invent laser cooling well i didn't invent laser cooling but we worked on how to make it work and in my group we developed a lot of the techniques that made it possible to make atomic clocks uh that used much slower cesium atoms cesium atoms they were only going one centimeter per second and here is what happened as a result uh the improvements uh continued and that was because of laser cooling and now these clocks and here is a picture of one of them that's uh don micof and steve jeffords who built this clock and they cool cesium atoms down to one micro degree above absolute zero so at one micro kelvin these atoms are moving at less than one centimeter per second they launch the atoms up into uh this vacuum tube they fall back down and if you launch them about a meter high they come back down after about a second so instead of only having a few milliseconds to look at your cesium atoms when they're moving at 100 meters per second you get a whole second and that improvement is what makes these atomic clocks so much better along with a lot of other things which i'm not going to tell you about unless of course you asked me questions so this is the most accurately measured quantity in the international system of units the second good to a few parts in 10 of the 16 and so this is really important what has happened we went from a definition of the second that was based on something quite arbitrary the earth well i mean it is our only home but it is pretty arbitrary nothing uh keeps the rotation of the earth constant because you have all of these effects that can change the rotation of the earth and we replace that definition with a constant of nature the energy level in an atom as far as we know every cesium atom in the entire universe uh has the same hyperfine frequency and will for all time uh and so this is the spirit of what we're trying to do with the international system of units is to replace artifacts with constants of nature so these are the kinds of questions you might like to ask but you know i'm sure you can think of better ones yourself now it gets even better in history so my next interlude is a short history of length now time was important in ancient times but length was really important because it had to do with commerce people sold things in units of length people built buildings that had to be measured and so this was a really important thing now the early approach to length was no we'll have questions at the end but keep that question in your mind please okay i mean i'd love to stop and ask questions but we'd never finish okay uh so it was easy a foot you know it was a foot uh uh a fathom was the distance between your your fingers uh so this was wonderful because you always had the standard of measurement with you the trouble was it wasn't very consistent if you were buying fabric from a short fabric merchant you might not get what you wanted and so uh in order to make things more standard the um uh the body referred to was a particular body typically the body of the monarch in in ancient egypt it was the body of the pharaoh and the distance between the pharaoh's elbow and his forearm plus his his palm was what was called a royal cubit and uh that's not a quantum bit that's a a unit of length measure and um uh now the trouble was of course that uh while this was was better than having it be just a random person the pharaoh was not always at hand and of course he might gain weight and he might die and there might be all sorts of problems so uh they made an artifact uh this uh piece of granite was the royal cubit standard for egypt and then people out in the field building pyramids would have wooden standards and they would have to calibrate them every month against the stone standard and the penalty for not calibrating your cubit was the death penalty these people were really serious about metrology and the results were astounding uh the baselines of the pyramid are good to a tiny fraction of a percent they're square to 12 arc seconds they really knew what they were doing because they were good metrologists and this idea of length artifacts was extremely widespread but often it would vary from one town to the next so here in the german town of regensburg you can see this tourist is measuring her fathom against the standard fathom and it looks like this would be a good place to buy fabric because you'd get a good a good long uh fathom of a fabric but if you were to go into the surrounding towns uh you would have different levels uh different standards of measurement so this is rather annoying um and uh during the french revolution the revolutionaries figured they would fix it well how would they fix it by defining a new standard of length the meter and the meter would be 110 millionth of the length of the meridian passing through paris going from the pole to the equator excuse me that became the new the new standard of length 110 millionth of that distance so what did they do they sent out astronomers and um uh surveyors to determine what that length was from barcelona to um uh uh dunkirk and uh they extrapolated they knew enough about the shape of the earth that they could do that it took them several years it was during war they kept getting thrown in jail you know you show up in a town with a bunch of telescopes and measuring instruments in the middle of a war and the first thing they do is put you in jail uh but nevertheless they eventually finished uh they came back uh to paris with their measurement of what that meridian was in in units in the old units and now they knew what the meter was in the uh uh in in in terms of the old units well that's wonderful uh but of course you can't go and measure the earth every time you want to have a meter so what did they do they made an artifact uh oh first i wanted to tell you that that they were very proud of themselves they thought that they had come up with something that would be good for all time and for all people and you'll notice they have this uh in this metal that they used to commemorate this they have this mythological creature is measuring the earth and that's exactly what they did they measured the earth but then they made an artifact so that is the meter of the archives it's uh was stored in the archives of paris in 1799 and it became the standard of length for france uh from that time forward very much in the spirit of the old egyptian royal cubit uh and uh uh but an artifact now a few decades later uh the countries of the world got together and decided they would adopt the metric system themselves oddly the united states was one of those original countries that uh that agreed to adopt the metric system so the united states has been metric at least since 1875 uh just no one has noticed and um uh and and they made a new meter stick and this meter stick had uh had scratches on it and the distance between these two scratches was one meter and it was made to be as close as possible to the length of the of the meter of the archives uh now 1875 the end of the 19th century scientists had been spending the 19th century proving that light was a wave and making devices like this interferometer designed by michelson that could interfere uh waves of light and could measure to a fraction of a wavelength of light uh so you see if you send light in here and onto this beam splitter some of the light goes to this movable mirror some goes to the fixed mirror the light comes back combines again on the beam splitter and produces this beautiful interference pattern which uh is from a different apparatus and all you have to do is move this mirror by one quarter of a wavelength of light and this central fringe changes from dark to light and so that means that it's easy to measure a distance that is smaller considerably smaller than 200 nanometers this is to be compared to a scratch that is on a metal bar and the scratch is 10 or 20 microns wide uh so soon it was easier to measure lengths uh with uh interferometry so people uh used uh light as a de facto standard for decades it wasn't until 1960 which was the year the laser was invented it wasn't until 1960 that they redefined the uh the unit of length to be based on the wavelength coming out of this uh this lamp which has krypton in it and you want to discharge it and produces an orange light that uh uh whose wavelength now defines what we mean by a meter but almost as soon as that was done it was clear that the purity of the light that came from that lamp was not as good as the purity of light that came from a laser a good laser it didn't take long before people made really nice lasers and here's a picture of one of those lasers a helium neon laser that whose wavelength can be stabilized to an absorption in uh iodine molecules and pretty soon everyone was using these iodine stabilized helium neon lasers as their de facto standard of length history repeated itself you had a better technology to measure wavelength you started to use it instead of the actual definition of wavelength and so it was time for a new definition because people were using a de facto definition that was not the international system of units definition so the obvious thing to do would be to define the meter in terms of the iodine stabilized helium neon laser this is what had been done in the past whenever there was a new technology then you would uh uh adopt that technology as part of your new definition that would have been the obvious thing to do fortunately they did not do the obvious thing what they did instead was something beautiful and brilliant they defined the speed of light why does that give you a meter the new definition of the meter is that the meter is the length traveled by light in a time interval of one over 299 million blah blah blah uh that defines the speed of light to be this number in meters per second and you see the beauty of this is if you can measure the frequency of light which they had just learned to do in 1983 to do really well then if you define the speed of light and you measure the frequency you immediately know the wavelength and it doesn't matter what color the light is so if someone invents a better laser at a different color uh that you can measure the frequency of you have immediately incorporated that improvement into your definition of the meter it's already there because you defined the speed of light you didn't define the meter in terms of some specific wavelength some specific color of light if someone invents a better way of measuring frequency and they did and they did make better lasers and these guys got Nobel prizes for inventing new ways of measuring the frequency and making lasers that were more stable and by the time their Nobel prize was awarded people were already using their techniques to realize the meter better and better so here's a very important concept we start from artifacts we go to a constant of nature krypton and then we go to a fundamental constant of nature the speed of light and the beauty of this is that we should never have to change again no matter how many improvements are made we shouldn't have to change the definition again now this meter definition i consider to be both brilliant and beautiful and even more beautiful than the definition of the second uh and what i'm here to tell you about is that on the 20th of may 2019 the international metrology community brought this same beauty to the definition of the kilogram and for that matter to the ampere the kelvin and the mole well why was that done why did it need to be done and how is it done that's the rest of the story but here's a few questions you might think about if you want to uh at the end of the talk okay uh why do we need a new kilogram well uh a light history of mass so since ancient times we have had standards of mass uh and they were artifacts so in ancient Babylonia uh these polished stones were the standards of mass and mass standards were pretty important because things were sold by mass money was uh denominated in mass one of these stones is called a shekel um now come the revolution the french revolution they figured let's end this artifact business uh we know the problems with artifacts they differ from one place to another uh what's to to keep them from changing let's make the kilogram the mass of one liter of water so you take a cube of water that's uh one tenth of a meter on a side and that is supposed to be equal to one kilogram well that was great everybody has water uh we've got this new meter that's that's uh the measure of all things wonderful uh use it to define what we mean by kilogram the trouble is it's not that easy to measure out one liter of water uh water sticks to things and it's repelled from other things its density changes with temperature uh all sorts of of problems with water and so they did what everybody has always done they made an artifact this is the kilogram of the archives what an amazing experience to hold that box in my hand in 1799 this object this platinum cylinder you see how small it is because platinum is among the densest of materials and so you don't have a big buoyancy correction so that was another problem with water because there's this big buoyancy correction so not so bad with with platinum uh and this became the the standard of mass for uh for France and a few decades later again in 1875 at the time of the the treaty of the meter uh they decided to make a new kilogram this is called the international prototype kilogram you see it's held under three glass domes it was chosen as the one of all the ones they made that was closest to the mass of the kilogram of the archives and that became the standard of mass not only for France but for the entire world and has continued to be the the standard of mass for the entire world until just a few years ago this was the last of the artifacts now this is the definition up until a few years ago the kilogram is equal to the mass of the international prototype of the kilogram what could be simpler than that but think about this it's the 21st century we are defining what we mean by mass for the entire world using an object that was made in the 19th century based on an object that was made in the 18th century this is deeply embarrassing and it's a real problem what if somebody leaves a fingerprint on the on the kilogram it means that all of you would lose weight uh now people don't go around leaving fingerprints on the kilogram but the fact of the matter is that its mass appears to be changing here is a plot of the uh the mass of various copies of the kilogram made at the same time in exactly the same way relative to the kilogram well it's only a few points because they don't take that kilogram out very often uh but you'll notice that almost all of the other kilograms are going in the same direction now a reasonable person might conclude that it's the international prototype of the kilogram that's going in the opposite direction but it can't because legally it is always a kilogram well this is this is a scandal to have this kind of a situation we must have something to change to change this situation and the thing we're going to do is to change it in the same beautiful way that we change the meter we're going to do it by defining a constant of nature so what constant of nature shall we use for the meter it was the speed of light what should we use for the kilogram well to motivate that uh i want to remind you of what is certainly the most famous equation in all of history right uh this tells us that the energy of an object at rest uh is equal to its mass times the square of the speed of light now there's another equation not quite as famous but well beloved by physicists and that is that the energy of a photon is equal to its frequency the frequency of the light from which the photon is is is taken times Planck's constant and you can just think of Planck's constant as being that that proportionality constant now if i combine these two equations and solve for the mass uh i now find that the mass what is this mass that i'm talking about imagine an an object like a an atomic nucleus that is radioactive and it emits a gamma ray which is a photon and you can measure the frequency of that gamma ray if you measure the frequency of the gamma ray there it is somewhere uh divide by c squared which is defined multiplied by h which i propose that we should define you now know the mass change of that nucleus in kilograms okay now we don't actually weigh photons i mean we could in fact we can we just don't do it well enough but we can still use Planck's constant as a way of defining a kilogram very well using an electromechanical device which is known as a kibble balance and that's brian kibble the genius who figured this out so in this little movie i want to describe how this works the first i want to invite you to remember how you weigh things normally in your youth you all weighed something by taking an unknown mass on one side of a balance and putting known masses on the other side of the balance until it balanced and when it balanced then you knew what the weight on the uh uh of the unknown was because it balanced the weight of of known masses this is the way everybody measures mass now i want to invite you to think about another way let's say that instead of putting known masses on this side we put a coil of wire and we immerse that coil of wire in the magnetic field of of a magnet now if we can measure the current in that coil if we know exactly where in the coil it goes with all the wires if we know what the magnetic field is and we know the direction of the magnetic field with respect to every point in the wire then we can calculate what the force is just using the laws of electromagnetism and we could then uh divide by the uh the gravitational acceleration and we would know the mass now the trouble is that except for measuring the current we can't do any of those things well enough to do it and here's where the genius of kibble comes in kibble says fine we've done that experiment now let's do a different experiment let's take that coil of wire let's take the leads from that coil of wire and connect those leads to a voltmeter now when we move the coil in the field of the magnet this is what a generator does right it'll create a voltage and if we measure the velocity that's why we call it the velocity mode we measure the velocity of the coil at the same time we measure the voltage induced those are the two measurements we do in the velocity mode that gives us all the information that we couldn't measure that i told you about where all the currents go it gives you all the information that you need then you you do the weighing mode you uh you put current through there you see how much current is required to balance the unknown mass on the other side and once you've got all that information you can have a new definition of the kilogram you take mg the force which is the force that you exert using the current in the weighing mode multiply that by the velocity that you get from the velocity mode so these are two different experiments and that has to be equal to the current you got in the weighing mode times the voltage you got in the velocity mode why are they equal because one is mechanical power and the other is electrical power and those two things have to be the same in a proper system of units now i'm going over this a little bit quickly because we don't have a lot of time so this is the new definition of mass now you're going to tell me wait a minute you promise that this would be about Planck's constant so where does Planck's constant come in and the answer is that Planck's constant comes in because we can measure electrical quantities current and voltage actually voltage and resistance by quantum methods using the quantum hall effect and the josephson effect so here are brian josephson who gave us the josephson effect and claus von klitzing who gave us the quantum hall effect the josephson effect tells us what the voltage is across a superconducting junction when there's a certain frequency applied the quantum hall effect tells us what a cross resistance is the ratio of a of a current to a perpendicular voltage under certain conditions and using that voltage measurement which gives a voltage that's proportional to h over two e and using the current by putting a putting a current through a resistor measuring that voltage using the josephson effect measuring the resistance using the quantum hall effect everything cancels out so the mass is proportional to Planck's constant which is what i promised here is one of the apparatuses at my institution mist and i worked on 25 years ago i worked on a much earlier version of this these people have done it beautifully now this device can measure a kilogram to about a part in 10 to the eighth which is better than the changes we're seeing in the kilogram doing to whatever is causing it and we don't know what's causing it because until now we haven't had any stable mass reference these people who did this experiment are incredibly serious about their metrology they have tattooed the value of Planck's constant and the other defining constants in the new reform onto their forearms like those ancient egyptians these people are really serious about metrology well so here are some of the questions you might ask but i want to emphasize that this idea of using Planck's constant is not something that is unique to this kibble balance that i've shown you there's another really beautiful way of doing it imagine that you've got an atom so here is an atom a two-level atom this is an optical excitation and i shine a laser onto this atom and the atom absorbs a photon and it absorbs not only the energy of the photon which promotes it to the excited state but it absorbs the momentum of the photon which gives it a kick so that it's now moving whoops with a certain velocity and that velocity is Planck's constant divided the mass by the mass the atom and the wavelength of the light just knowing what the way what the momentum of the photon is now you see the beauty of this if you define h and if you define c that means you if you measure the frequency of the light you know it's wavelength that means if you measure the velocity which you can do using atom interferometry you can measure the mass the atom in kilograms not in atomic mass units but you measure the mass the atoms in kilograms so now you know what the mass of a single rubidium atom is in kilograms if you've defined Planck's constant now using wonderful ion trap technique you can compare the mass that rubidium atom to other atoms and eventually you can compare it to silicon and then you go to oh by the way another iupap connection c2 gave its young scientist prize in 2012 to Pierre Cladet for his measurements of this atomic recoil this number that we need in order to get the the mass of a rubidium atom but if you now know the mass of a silicon atom relative to the mass of a rubidium atom and at ptb they make a perfect silicon sphere this thing is the most spherical object that has ever been made and then they measure the lattice constant that means if you know and then they measure the dimensions so and it's easier to measure the dimensions of a sphere so that's why they made it sphere so that means because they know the distance between the atoms because they know the size of the object they know how many silicon atoms are in this sphere and they know the mass the silicon atom in kilograms because of Planck's constant so that means that they know what that mass is and that becomes a new way of realizing the kilogram it's not an artifact you see it's it's something where you've measured you've counted the atoms well not exactly one by one but but you've you've determined how many atoms are in that sphere and you know that the mass in kilograms of one atom so that this is becomes a realization of the kilogram and using either the kibble balance or the silicon sphere laboratories all over the world have made these measurements and when everyone agreed to within some preset standard they redefined the the kilogram by setting the value of Planck's constant so at the 26th general conference of weights and measures they officially adopted this this redefinition it didn't become effective until the 20th of May but after the vote of 60 countries that had gathered there a unanimous vote this is the celebratory movie that they showed oh dear okay where's the tech guy we didn't check this out we should have oh dear dear dear okay so what do we have to do to get the sound doing it well yeah that would be great but for some reason I can't unmute myself it says the host is not allowing participants to unmute themselves okay can you please you're the expert yeah but there's something else I guess well okay your volume was down all the way well that's always possible we can okay all right let's go here let's share there let's that's not what I wanted to do let's cancel that maybe I'm already sharing let's share a portion of screen share again there we go okay now what I have to do is figure out how to go back to the to the beginning of the movie now we'll just do this sorry about that so this is the movie they showed after the unanimously it took more than 140 years groundbreaking science and the agreement from the world's scientific community at times it's impossible accurate precise measurements anytime anywhere but we did it we have congratulations Well, I hope you all heard your language in there somewhere. This was not easy. The 60-some countries that gathered had many disagreements about how things should be done, but they resolved them with a wonderful result. Science doesn't always get it right, but this time we certainly did. When we consider how in the political realm, things are not always settled so well. It gives me hope that perhaps in some bright future we'll be able to settle things this way and all remain friends. Well, there's a final part of the story. The ampere. It used to be that the ampere was the current, which when you put it through two infinitely long straight wires one meter apart would give you a force of two times ten to the minus seven newtons per meter. You all remember that, right? Not true anymore. Here's something you may not know. That definition was equivalent to defining mu knot, the magnetic permeability of the vacuum, as being four pi times ten to the minus seven newtons per meter squared. That's not true anymore. So that number four pi that you remembered, it's off by about a part in ten to the eighth now. So well, okay, for most cases, it doesn't matter. But if you care about things, it does matter. So that's a change. So the ampere is now defined by defining the charge of the electron. So the ampere is now a certain number of electrons per second. And we could imagine doing it by counting electrons. It's still not quite good enough. We're working on it. But for now it's done by using the Josephson effect and the quantum Hall effect. They go together in such a way as to make the current be a certain number of electrons. So there it is. You have some resistor. You measure it in terms of the quantum Hall effect. You put a current through it. You measure the current using the Josephson effect and the current's proportional to the charge on the electron. So when you define the charge on the electron, you've done what you need. Now, here is a dirty little secret that not very many even physicists know. For more than 100 years, we have been keeping two sets of books for electrical measurements. There has been what we now call the SI, the absolute electrical measurements, which are based on a mechanical definition of the ampere. Because it has to be because we have to make mechanical work be equal to electrical work. And then, but that was too hard to use because it was really hard to measure forces and to measure where all the wires were. So instead, people developed a wholly different set of units, which they attempted to make as close as possible to the SI called the practical units or the legal units that were based on standard resistors and standard cells, batteries. And every once in a while, someone would measure the ratio of the legal volt to the absolute volt. And that was one of the things that was tabulated in the fundamental constants. So when you said that your voltmeter was calibrated, if you were in the US, it was calibrated according to US volts. But if you were in France, it would be calibrated in French volts and in Germany and German volts. Well, that was pretty nasty. So in 1990, they agreed that they would use the quantum of Hall effect and the Josephson effect and everybody would use the same one, but it still wasn't the SI. And now it is because 2A over H and H over E squared, when you've defined both H and E are fixed numbers and they're in the SI. So now we no longer have two system of units. So that's what this says. Oh, the mole. Remember what the mole was? It was the number of entities that you had that was equal to the number of carbon 12 grams and 12 grams of carbon 12. Now it's just a number. We've defined Avogadro's number and what could be simpler. And then finally the Kelvin. It used to be 1 over 273.16 of the triple point of water. And now we've defined the Boltzmann constant. So the Kelvin is now defined in terms of the energy, the thermal energy of the microscopic constituents. And we love this definition because it really gets down to the microscopic nature of what temperature means. So, so all of these things bring us to a conclusion. The French Revolution gave us the metric system. The convention de metro brought us an international agreement about units. And now on the 20th of May, the anniversary of the signing of the convention de metro. We had the biggest revolution in measurement unit since the French Revolution and liberally leading the people means we're finally free of artifacts standards. And we're finally free of a double standard for electrical measurements. And all the base units are defined by fixing values of constants of nature. And it seems like we've really done what those French revolutionaries dreamed of, that we've created a system of units that is good for all time and for all peoples. It seems for time itself, because time is defined in terms of hyperfine frequency of cesium, a particular atom, a really good atom, but we've got better atoms now. And all these wonderful atoms, strontium and terbium and aluminum ions and mercury ions are doing better than cesium. In fact, they're doing two orders of magnitude better than cesium. And so it seems that we will have to redefine the second. And we're working on it right now and having discussions about what the redefinition, the new definition will be. And only time will tell what that definition will be. Thank you very much. So now we have questions. And I think the first question should be yours, since you wanted to ask it before, and then you will then have charge of giving out. But you will get the first present. So your question. Thank you. So my first, the first question, so I get the first present, is I was wondering when they measured all the cesium atoms for the time, wasn't there any concept, any idea that while they had the problem to reduce the accuracy further and further, was an alternative approach to not go with atomic clocks and the cesium atoms because at some point it seemed like there was nothing more, not more curious and reachable. Yeah, well, that's exactly what happened when when the cesium atoms got to about a part in 10 to the 16, then it, the technology had developed so that these other atoms were, were starting to look good. So let's go back to that picture. Yeah, so you see about the time that the best measurements on cesium, this blue point was happening, then we were starting to get optical clocks. You see, I didn't tell you, but that's one of the big differences. All these red points are optical transitions instead of microwave transitions. And that's one of the reasons why they're so much better. So, you know, maybe it was just luck at about the time that the cesium hit the wall of about 10 to the minus 16, then we started to get these optical, whoops, these optical clocks better than, than cesium. And, but, you know, cesium worked really well for a long, long time. It had a great run. So the prize, oh, there's, there's three prizes, the wallet card of the fundamental constants of nature with the defining constants on the front with no uncertainty. So a whole page of fundamental constants with no uncertainties. The car that just has the defining constants and the world's best periodic chart made by NIST, of course, has, well, I mean, when you, when you see it, which I'm sure you all want. And, you know, if we run out of time, you can ask me during the reception and I'll give you prizes even then. It's got everything. It's got the electron configuration. It's, you know, it's got the, the ionization potential. It's, it's wonderful. So more questions. Yes. Okay. You mentioned at the end that you're trying to redefine the second again. Yes, again. And all of the other constants that you find also face stuff of the second. Yes, that's true. So how will this affect? Not much, fortunately, because the second is so good. You see, the second is good to a few parts in 10 to the 16. We can realize the kilogram to a part in 10 to the eighth, if we're lucky. So that means we've got eight orders of magnitude to play with before we have to worry about whether redefining the second is going to have any significant impact on, on the kilogram. So in principle, it's true, but in practice, we don't have to worry about it. But we need that, that better definition of the second for, you know, a number of, of scientific reasons. And who knows? So you need to get prizes and you have a question. So two short questions. First is since it wasn't there at the presentation, what happened with candela? And the second one is the second one is why do we still use it? Okay. So, so, so the candela is a measurement of luminous intensity. And basically, here's the thing about the candela. It's really a measure of what the human eye perceives brightness to be. So the candela is now defined in a very clear way. It says you take light of a certain frequency, green light, which is near the peak of the sensitivity of the human eye. And it's a certain number of watts of that kind of light equals one candela. Okay, actually equals a lumen is the way it's defined. Now the idea is that a human subject will look at light of some other color or some mixtures of color like sunlight or artificial light and say that's the same brightness as this green light. Okay, that's the way it's done. And it turns out that people all over the world have pretty much the same curve. And why do we have it? Because when you go to the store to buy a light bulb, you want to know how bright it is and you buy it and it's in terms of lumens. And people want to have something that's traceable to a legally defined standard. And so that's what we have. That's why we have a candela, which is related to the lumen just in terms of solid angle and things like that. So that's why we have it, but it's got this human element in it and none of the other. So you can think of that as either a positive thing. It's the most human of the units. Or you can think it's not really precise because it depends on what a person thinks. So that's the story. I love it. Yes. Oh, microphone, microphone. Oh, I'm sorry. Okay, well, let's take that one first and then we'll come back. Thank you. Just two questions. The first one, with the new units of the mass that you have, can you say something about the mass scandal that the prototype that we have really is losing the mass or not? Right. So those measurements are now in progress. They weren't possible before, but now they are. So the answer to that, I hope will be forthcoming, but for the moment, we don't know. Another question. Usually we teach the SI units at the beginning of the elementary courses that we have, with that new definition of the SI, how we can do that. And what does that mean? Okay, my colleague Peter Morini wrote a paper directed toward physics teachers, high school physics teachers, and we had a co-author who was a high school physics teacher about how you should approach this process of teaching the SI in the new way. And I admit it's a challenge because before it was easy to say, oh, a kilogram is the mass of this object. And now we have to say, the kilogram is that mass that makes Planck's constant equal to this particular value. That's not so obvious that that gives you a kilogram. So look, if I were teaching high school students, I think what I would do is to say, in the past, we used to define the kilogram this way. And once they're comfortable with the idea of what mass means, then say, but that wasn't sufficient for modern times. It was a definition that was not as stable as we need for modern times. And so we came up with a new definition, and that's how this one works. So that's probably what I would do if I were a high school physics teacher, but I'm not. Okay, now I promised that you would be next, but you have to run. You're young, so you can. Thank you. My question is, how far is the relativistic effect affect to the whole precision of all that and the whole system? Very much. Both special relativity and general relativity come into this. So all these atoms are trapped, the ones that are used in these experiments, or almost all, and even the zero point motion of the atoms or the ions produces a relativistic effect that is a time dilation, a relativistic time dilation. So that has to be taken into account. And general relativity is a really big deal because the lower you are in the gravitational potential, the slower your clock runs. This is sometimes called the gravitational redshift. And back when they defined this, it was not a problem because in 1967, I don't really remember how good it was. It was probably a part in 10 to the 12 was the best clocks. And a part in 10 to the 12 would have been something like 10 miles, 15 kilometers. And we don't have any laboratories, 15 kilometers above sea level. So it didn't matter. Today, the distance that can be resolved is one centimeter. So you have to be extremely careful. And in fact, it's difficult to make a comparison between clocks in Boulder, Colorado, where these really good clocks are in the US and clocks near sea level, the way the really good clocks are in places like Germany and France and China. And so that's a challenge that we're working on. Portable clocks are one of the ways in which that's being addressed. And global warming is changing sea level. And we define where a clock should be to be a second. It should be at a place called the geoid, which is a kind of a mean sea level. It's a little bit more complicated than that. But if the sea level rises and the distribution of mass from the ice caps changes, what do we even mean by time? So this is a real problem. Now, you had a question, right? You need the microphone. Is the microphone on? Because of the global warming. So probably be that the mass of the earth is going to be increased because of what the ice is going to be melting. Then there is a possibility that then we are against it together and then redefine all this because probably it will be changing. Yeah. Well, the problem is so complicated. Because how do we even know that something is changing? What are we referring to? Some people have suggested we should have a clock at one of the Lagrange points. I don't know if that's a practical idea. It doesn't seem like there's any good answer. Putting it up higher. The whole earth is rebounding as the glaciers are melting. So it's really a hard problem. Make sure she gets the prizes. So the question I have is how you go from these type of definitions and measurements that seem based on very sophisticated experiments to something that you can use in your everyday life. Like I still need a stick to measure something. How do you go from this thing about speed of light and frequency to the length of a stick? Well, there's a hierarchy in the metrology community of standards. So for example, now the secondary standards will be platinum. And then there will be tertiary standards that are made out of stainless steel. So for example, in the US, every state government has somewhere some stainless steel kilograms and other masses that have been measured against a platinum iridium kilogram, which is now measured against a quantum device of some sort. And then those masses are used to calibrate other masses. Maybe you go into a store and you buy a set of brass weights for your balance. And then those are used to calibrate the scale in the factory that's loading crackers into a box. So that's a whole hierarchy. And everybody has to be able to show how their measurement is traceable all the way back to the definition. So if somebody is in a factory, they know that they've calibrated their scale against somebody that has calibrated masses that have been calibrated against stainless steel that have been calibrated against. So that's the way it works. I want also a price. So you derive the unit of mass and the unit of length from the second by fixing the value of H and the value of C. Yes. And E? Well, E is recurrent. Value of H and value of C. But instead of this crazy value of H and C, you could fix H equals C equals 1. You could. Which would be much easier to remember. Well, it would be easier to remember, but it would be inconvenient. Because then I think what you're suggesting is something like having only one unit, the second. And so from me to you is about seven nanoseconds. And the temperature outside today is something that will be measured in inverse seconds. Now, you may like that, but I don't think the average person is really going to be comfortable with measuring everything in seconds. Plus, it creates difficulties when we want to make sure that we've done our calculation correctly. What do we tell all of our students? We say, check your units. If everything is equal to one, you can't check your units. I have theoretical colleagues who tell me that they did a wonderful theoretical calculation and then had to spend another month turning their answer, which was assuming that H equals C equals 1, maybe E as well, into SI units so that they could publish it. So what you suggest is done routinely by theoretical physicists, but it drives the experimentalist nuts to read papers where they don't convert into, shall I say, real units. Thank you for a fascinating talk. So I have a question on over here. I was wondering, so imagine aliens have made contact. So how would you use a fundamental constant to establish a basis for communication? Yes. Well, this is good in, I mean, it's a great, it's a great and it's a great question because it's obvious that in the past, we wouldn't be able to tell them what a meter was because it was the length of a stick. We wouldn't be able to tell them what a kilogram was because it was the mass of an object and without transporting those things, we wouldn't be able to communicate with aliens. Now we can. Now there is this problem of the gravitational redshift. It's not that big, right? We could make a pretty good guess about what the difference in our gravitational potential is at the surface of the earth to the gravitational potential in interstellar space, perhaps being able to reference some place that both of us could see. But that would be a problem because of the fact that the mise en pratique, as they say, the putting into practice of the definition of the kilogram depends on it being in a certain gravitational potential because of that we couldn't be as exact as we would like to be with the transfer of information to our alien colleagues. But we could come, I think we could come close. I haven't really done the calculation to see how far off we might be if we tried to describe how much different our gravitational potential was. But what could be the effect of dark energy? Because now it is, of course, everybody, I want to put you in your last corner trying to understand if there is any effect that could be measurable. Of course, we know that the density would be something 10 to a minus 30, which is very low. Do you have any? Well, I don't know. I sort of dream that maybe some future atomic clock will be able to give us a different way of detecting either dark matter or dark energy by measuring the clock shift. Maybe if we send a clock outside the solar system, maybe we'll be able to. You've got another question up there. We have one here. So I don't know, but I dream that maybe these wonderful clocks can tell us things like that, but I'm not sure. Yes, we have a question from Zoom, which is if we started varying the strength of electric or magnetic field, does the speed of light remain the same or does it change? Okay, so you're saying, okay, so if I've understood the question correctly, it is, does the speed of light depend upon the ambient electromagnetic fields? And my understanding is that it does and it's an incredibly tiny effect. And I don't believe that anybody has ever seen it yet. And I think there was an attempt to measure it using one of these big accelerator magnets that had been decommissioned and then to build an interferometer where the light would go in one direction compared to the other. So now don't take this as gospel truth, but I just have this vague memory that somewhere in the theory of QED that if you have an incredibly strong field that you could change the velocity of light, funny things happen. The vacuum isn't empty. The vacuum is full of virtual particles. And if you put enough field on, then those virtual particles can, in fact, separate and you can have a breakdown of the vacuum. Well, if you can do that, then you can also polarize the vacuum. So the vacuum will have a different index refraction. It's a way my experimentalist's mind thinks of it. Probably not a very good theoretical way of thinking about it. But you'll have a vacuum that has a polarization. And I would guess that light would have a different velocity through such a thing. But my understanding is it is extremely small effect. And I know that no one has measured it yet. But maybe in the future people will. I hope that was the question. And I hope that my answer was sort of correct. Does anybody who actually knows about these things have something to say? Do you know something about it? I mean, you're from PTB. Why shouldn't you know? Not only are you from PTB, you're the president of PTB. Actually, I was the president. I'm retired. Now I'm the president of the German Physical Society. OK. Not quite as good. Less responsibility. OK. Good. Yes. Concerning the last questions. Actually, there's an experiment now designed where you have a very intense laser, which is actually polarizing the vacuum kind of. Because as you explained it, positron electron pairs. And then you come with the FAL X-ray radiation into that very intense field. And then there is a prediction that the polarization is shifted on the level of 10 to minus nine. And I think the experiments are just now at the point that you can possibly see that. OK. OK. Wonderful. Thank you. And I have a second comment, actually. Pre-sized clocks. So there was a recent experiment between three countries, UK, Paris, and Germany. Comparing three very different clocks, distant clocks connected via fibers. By fiber, yeah. Optical clocks on the level of 10 to minus 17, 18 even. And they were sensitive on a certain possibility of dark matter, so-called topological dark matter, which moves with the center of the galaxy. And these are kind of clumps, which could have a certain size. My understanding, I'm not an expert here. And this would show up in a different ticking of the clocks. And so they could exclude some specific parts of dark matter so far. Yeah. And another thing that comparing different clocks can do is to test for changes of the fine structure constant with time, which we don't know for sure that the fine structure constant is constant. But measuring different clocks with different atoms can get at that kind of thing as well. And one of the beauties of doing these experiments in Europe is you can run fiber. And these fibers use these wonderful techniques of two-way transmission to cancel out all the bad things that are happening in the fibers. Wonderful experiments. Oh, sorry. And I should have looked to you for who should get the next question. The assumption that the speed of light is constant is a theoretical assumption. There are, first of all, the photon could have a tiny, tiny mass. And so you would have a dependence on wavelength. More in general, quantum mechanical effects, quantum form could generate effects even in the absence of them, because then you could say, well, it's not the photon mass, but the mass of a zero mass particle. Actually, astroparticle physics experiments are studying these potentially these effects and they're searching for effects of the level of 10 to 19 seconds. So you would have photons coming from cosmological distances and different energy would arrive at the difference of a fraction of a second. And people are actively searching from that. So that's an interesting. Yes, and so far. Of course, it's outside your 10 to the minus 16 and so on. The limits on the photon mass are tiny. But anyway, conceptually, I think it's interesting that a physical question is, is the light constant or not? Well, another interesting point is that you can do a laboratory experiment to measure the photon mass by testing Gauss's law. See, if the photons have a mass, then Gauss's law isn't going to be true. And if you look in Jackson, there's a picture of this apparatus that measures the photon mass. And he describes that. And one of my colleagues who worked on the ampere experiment was the one who did that experiment. So it's kind of interesting that a laboratory scale experiment can also get a competitive value of the photon mass. But yes, all those things are. Since I had the microphone, I would like, well, first of all, to thank you. I really had a great time and enjoyed very much your talk. And then actually, I don't deserve this prize because I'm going to ask an outrageous question. But actually, I was confused by your point. And the point is about mass. We are studying and you're teaching about the difference between inertial mass and gravitational mass. And you presented two experiments where, in one, you're clearly measuring the gravitational mass because you were measuring with a force. And then other experiment. So when you're measuring a mass, so your unit of mass is really an inertial mass. No, you're right. The other way that I described really is measuring the inertial mass. And so, of course, maybe you know, when did people first think that there might be a difference? Was it Ed Foch or was it earlier? Was it Newton? Before Einstein, they were trying to measure. There is a whole history of measuring. Yeah, certainly Ed Foch. But then the equivalence principle, decay and so on. But the Tower of Pisa experiment, in a sense, tests that. But I don't think Galileo was thinking of it that way. But anyway, yes, that's absolutely right. And wouldn't it be amazing if some of these ways of thinking about mass revealed a non-proportionality between inertial mass and gravitational mass? And in fact, adam interferometers have been trying to look for that sort of thing already. So because, well, anyway. I have a microphone. Oh, sorry. Sorry. Okay, thank you very much for your interesting talk. I want to go back to ancient Egypt. Some people are saying that they're considered a drop of water as a kind of fundamental unit. So what do you think about that? Well, I don't know. The trouble with a drop of water is that how big a drop is depends upon what it's dripping from. I recently had eye surgery and I had to put drops in my eyes every day, three times a day. And I always wondered, what is the precision with which this drop? How much does it depend upon how hard I squeeze the bottle? And I decided it doesn't matter because it's medicine, not physics. But I think that if you have a relatively stable mechanical object, drops of water can be a pretty good timekeeper at the level of old pendulum clocks. In fact, water clocks were one of the ways in which people kept time in ancient times. So I've never looked into it. But I think that there's a good history with water clocks. So why not? Oh, so you're thinking of the drop of water as being a unit, say a mass or a volume, as opposed to how fast they drip, which is the only thing I was thinking about. No, you're right. And I haven't really thought about that at all. Except for the fact that I wonder, when you drop something out of an eye dropper, how big is that drop? And I just don't know. I don't know what kinds of things determine that. But apparently it's good enough for medicine. But when the doctor tries to adjust the dose of whatever she's giving me, she changes it by a factor of two to see if it'll make a change. So I'm not sure that it makes that much difference in medicine. But in physics, of course, it makes a big difference. So who's next? At the back. Yes. So I have a forward-looking question. The current definition of the second is down to a few parts in 10 to the 16, you said, right? So do you think we will ever have a similar level of accuracy with any of the other 16 units? And if so, which one will it be? Well, probably the closest one is the meter. And you look at the definition of the meter and you think, well, what limits it? And the answer is diffraction. If I want to measure a length using an interferometer, then I have to have a beam of light. And the question is, how big is that beam of light? Well, any size that is smaller than infinity means that the wave front of that beam of light is curved. And the curvature changes as I move my mirror. So there's always going to be some kind of a fundamental limit of my uncertainty about just how that curvature works. I mean, if I measure everything perfectly, then I could figure that out, but I can't. That is one of the key things that limits how good length measurements are. And I think they're on the order of a part in 10 to the 12 for the very best ones. So that's the closest thing. So that's still four doors of magnitude away from a part in 10 to the 16. And we're soon going to have clocks that are good to a part in 10 to the 19. I mean, right now, they're good to a part in 10 to the 18. So I think it's going to be very hard for any other measurement to catch up with time. But we still need those better measurements of time to do things like measure dark matter and measure whether the fine structure constant changes. So we need those extra decimal places for the measurement of time for sure. I mean, this question and answer session has been fantastic, but I did a terrible job. I mean, I was just the last question is how many more questions do we have? Because I mean, six o'clock is when I just looked. Six o'clock is when we have the reception. So if you ask me during the reception, I will try to give you an answer and I will give you gifts. Oh, okay. One more on Zoom. Okay. So last question on the Zoom is, is there any information or implementation plan implementation plan to emphasize the modified unit units in the syllabus of physics in the world? Well, I would think I'm not sure if there's a specific universal syllabus of physics, but I think that anybody today who's writing a book will incorporate all of these these new things into that book. So for example, if you many physics books have a table of fundamental constants at the beginning, and if they're good tables, they'll tell what the uncertainty is on those. And now a lot of those things that used to have uncertainties will no longer have any uncertainties. And I think that all the new books that are that are written will have these new features in them. And maybe they're all already books that have these new features. So thank you so much. And now we eat. Well, thank you so much for your hard work, how you thought it should be.