 We might need to step on it for a little bit more. Who's ready for some surrounding? Our first speaker today, you heard right after the neutron star merger happened? Was anybody here for that event? Yeah. Well then, all of you get to hear for the first time Dr. Jennifer Sobeck from the University of Washington. Join me in welcoming Jennifer. All right. Hi everybody. I see tonight is a Friday night edition of Astronomy on Tap which is a little rare for us. So I hope this means that we'll have you more of a rambunctious crowd tonight. But I'd like to introduce you to a series of women astronomers. Kind of tell you why I'm going to do this. I'm going to tell you a little bit of background. There will be some derogatory kind of things they have to push through. But the important thing is that they did and they made huge contributions to science. Today, I'm going to introduce you to the Harvard computers women can map the sky. Has anybody seen a movie in Figures by Chance? Anybody watched the film in Figures by Chance? The brother book in Figures by Chance. It's a fantastic book. I definitely do recommend it if you get a chance. But as you can kind of remember from that movie, basically all the women who performed math, all the women who performed calculations were referred to as computers. So this is actually the first definition of computers. This is what people actually refer to. So not like our MAGS or our PCs or anything like that. It was actually people that we referred to for computers. So I just wanted to say I have a special thanks to Rachel Baton, Oliver Frazier, who is with our department as well. And actually some people at Harvard who helped me out with this presentation, namely Warren Smith. So there's a really great quote from Isaac Newton. It's, if I have seen further, it is by standing on the shoulders of giants. And basically this means that science is accomplished by standing on the shoulders of people who have gone before us, people who performed experiments. There's just no way to do this. And by the way, just thinking about the Nobel Prize and stuff like that, these things are awarded to, you know, a person or 200 people. Really truly today, science is a group of people, and we're all standing on one another's shoulders. So what we need for this talk today is, I was a brand new graduate student at the University of Texas, and I had been given a book by my advisor at the time, Chris Steven, a really fantastic fellow. He encouraged me, and he really pushed me in helping me through graduate school. Anyway, I was given this book, and it said C.M. Moore. I was like, oh great, I'll take a look through it. I'm sure his work is really, really good. And he was like, no, it's not him, it's her. And my eyes just went, I was just so happy. Because I have to admit up until that time, besides Murray and Currie, I hadn't really heard of that many of the stars. I hadn't really heard of that many women businesses who really made a difference to see this and understand this. And so this is Charlotte Moore Steadily. She was a Princeton computer. She did a multitude of things, but she really just was a very precise wavelength and multiple tables. Multiple is a little bit of astrophysics. But she is the one that kind of motivated me to go further, to go deeper and see what other computers were doing. And I think it's really important for us to know that, hey, in science, we're still on the shores of many people, who were these people? And we're some people who kind of left out of history and not mentioned. And it turns out there were a few. So here are the Harvard computers. Basically in the 1860s and the 1870s, the Harvard Observatory was really pretty well established at this time. They were developing a bunch of facilities, both in North America and in South America, so in the Northern and Southern Hemisphere. And they were starting to really collect a lot of data. And so during the 1860s and the 1870s, really could volunteer, such as Eliza Quincy, but they were never given full status at Harvard. So they spent their time, they worked hard, and they tried to volunteer as student assistants. Around the 1875, they fought Harvard when they said, you know what, we're going to pay these women a staff. We're going to lease, you know, employ women on a regular basis, and we're going to kind of set up a staffing type of program. And so some of the very first computers that we've heard of, and they weren't quite given that term just yet, but are Archie Rogers, Archie Saunders, and Anna Willack. And they were just working on, you know, a few basic projects pretty much under the supervision of the Harvard Observatory chief. In 1876, there was a change in the directorship of Harvard Observatory. And it was a man with a name of Edward Charles Pickering. He was a head of the time boy. He supported people, he supported women. And he actually said, hey, you know what, we're going to appoint women officially, we're going to need them in computers, we're going to give them a title, but at the time he said we thought it was respectable. And he remained at Harvard College Observatory for the next 40 years. There we go. And just working hard in decisions leading to how clean the room is and so forth and so on. But the funny thing is, is that they're working on lab notebooks and actually these notebooks are pretty much the same today. So they were using these to kind of catalog the various observations. So this Pickering really does continue this program and he actually built it. So he starts to hire more and more women observers. And in fact, it's his opinion that women do a better job than men. He says they're more meticulous, they're more precise, and they have tiny fingers that can do the work. So anyway, but the women observers, actually the women's computers, pardon me, were a bit of a bargain. As you can see, they are paid 25 to 30 cents per hour. Their Aboriginal colleagues were placed at least paid like 80 cents or a dollar per hour. So it was a bit of a wage gap. And they work roughly about six days a week. Just to give you an idea of these women who are working for Harvard, they're being employed as staff. They've actually probably received a few of them, decreased at this point, but this is before Radcliffe even opened. So in 1879, Radcliffe opened as a university and it was the women's section, or the women's college of Harvard. In 1882 Pickering really picks up the pace. It's really become a huge scientific endeavor from Harvard into Victoria. And he begins these photographic stellar investigations. He starts creating the plate collection. That's something we're really going to focus on today. So these plates are basically either images or spectra of astronomical objects, things that we're very, very interested in. And then finally, the last person besides Pickering to really get this program is a woman by the name of Anna Draper. Her husband, Dr. Draper, they actually had an observatory, their own personal observatory. This is still kind of in the era where you could be a quote unquote gentle woman observer, or a gentleman observer. They're basically your front of your own science, your front of your own observatory. So her husband, unfortunately, passes away but he's doing this huge stellar catalog just starting to starve and start to starve. He's walking throughout the sky, trying to give them identifications, trying to map the sky. He passes away during this time and she issues a call. She said, hey, please help me finish this catalog this work with my husband. Nobody answers it. So she goes up to Pickering and she says, hey, can you help me do this? She gives them instrumentation. She gives them money. And from this, the actual whole observatory is her computer core is actually formed. So we're very, very thankful. By the way, just to let you know, Harvard College finally got a good one in students in 1977. All right. So what are these plates? What do they look like? And what do these computers actually have to do with? And so basically, Harvard College Observatory houses one of the largest collections if not the largest collection in the world of plates. They're like flash emulsion plates, right? So we're not quite at film, but we're basically using like a photographic emulsion to develop images or spectra of astronomical objects that we're interested in. And so you can kind of see here on the left. Here's an actual spectrum. And if you're a little familiar with your physics slash astrology, this is H beta, which is basically a spectral line of hydrogen. This is H alpha right here. And this is what they're working with star by star by star in looking at these equations. So you can see this particular plate. There's lots of spectra. And each of these actually represents a stellar spectrum of a cluster. So basically this is a collection of stars. So they're spending a lot of time getting really deep into this. And they're looking at each one of these spectrum. And this is the tool that they use to do this. It's called a fly swatter. But basically we're sitting there with the magnification, the magnification glasses. They're putting them up to their eyes and they're just more featured by the feature of what they're going for each of these stars. So it's really, really interesting. As you can tell, as I mentioned here, there's about 20 hundred telescopes. So all of these telescopes are collecting data in the West, Peru, South Africa. And then basically this program with computers can analyze 480,000 plates. Roughly 100,000 plates of spectra. So we're talking over half a million plates that we were able to accomplish over the period from 1890 to 1940. So 15 years. It's a really odd fortune. So our first woman, and I forget to tell you, I'm wearing a t-shirt. And it features the computers actually. So who's seeing the NASA Lego weapon set? I'm so proud that it has actually been released. It's something that I definitely participated in with my fellow colleagues that have been giving this release. Well, there's Legos now of all sorts of astronomers collect the series. But anyway, so I have a Lego weapon set. That's what I'm wearing a t-shirt and it's featuring some of the computers that I'll talk about now. So the first of these is Henrietta Swan-Leven. She was really one of the initial computers. So she had that full computer title in the observatory. She was very much interested in variable stars. And so what it featured here is just a really nice nearby variable star. In fact, it turns out to be a sappy and I'll talk a little bit more about that more in just a second. And here's one of her actual plates. And if you can't see it too much when you zoom in, you can actually see the identifications that she made on this particular plate. So she graduated from Radcliffe and she started volunteering. Eventually she got that computer title. Her thing was classification. So she's looking at the spectrum and she's going through and she's classifying all the lines of the spectrum. She was basically looking at these things from superposition. So you have one plate and then another plate taking in just a little time later. And she's super-employed, too. To really understand that there was variability in the stars, meaning if the positions of the lines shifted back and forth. She discovered roughly 2400 variable stars. Half of all the new variable stars at that period of time. She was prolific. So in 1908 she publishes a catalog of roughly 2000 variable stars that had been identified in the large and small Magellanic clouds. Anybody familiar with Magellanic clouds? No? But basically these are satellite galaxies on Milky Way and one of the reasons you're probably not familiar with them is because you can see them over here. So when you get a chance and you're done from Peru or Chile or Brazil, you look up into the next sky and you'll probably see people in the small and large Magellanic clouds. Anyway, these images were more sensitive than any images she had previously made and then these was really starting to be something of a pioneering discovery. So here's her plate. It was taken with a small Magellanic cloud and at this point she's actually this is something pretty, pretty special. And so she does have an issue of publication like mentioned and she starts to talk about these faint variable stars. And then what she mentions in particular a really nice finding that she arrives at is that taking within two to three days of each other, so plates taken within two to three days of each other have equally interesting results showing that the periods of many variables aren't being short. She's just now something a little bit special but she knows it. She knows that she's discovered something really, really special. And what she discovered is something called seconds. And seconds have a really well-established luminosity period relationship. So understanding their brightness of luminosity as a function of their periods, which is basically a period thinking about how fast the star is fluctuating or how fast it's varying. And so this is her original plot. Yeah. And so what you can see here on the y-axis is luminosity. And it goes from faintest to brightest. And then on the x-axis right here is the period of time, so very short period fluctuations versus very long period fluctuations. And this is actually her plot right here. And so she gives this relationship, she publishes it, she establishes it, but it's a pretty darn kind of item. And what she said is showing that there's a simple relation between the brightness of the variables and their periods. So that's actually a quote from her publication. She went on to provide the first calibration of the slope of this relationship, but as there was no known distance to the MCU and we knew it was out there, but we didn't know how to establish a distance, she wasn't actually really able to calibrate it. And just before she was able to give this information, she actually passed away. So, we have Edwin Hubble here. They both, of course, are familiar with Celsu, the next generation, which is going to be the Jane Duet, say Celsu, but Hubble was still definitely operating at this point. And Hubble pretty much stood on the shoulders of Henrietta Leavitt, but we didn't know it, right? So Hubble went in and he examined you know, various seconds, so he really well understood the varying stars, right? And examined them in a small Magellanic cloud image you can see right here. Here's an image, an actual image, from part of the observatories of the Magellanic cloud. And he was able to sit there and look at the seconds, especially in the Magellanic cloud and in drama, he was able to establish, using this period of the mass relationship, that it was a galaxy way external to the Milky Way. So first, we didn't understand, you know, if it was just something like some sort of satellite or if it was indeed its own external galaxy. He continued this idea and eventually he was able to measure the local rate and the expansion of the universe. This is a fundamental finding for all the Hubble constant. And it's something that today we can investigate and we actually try to calm down and understand because it's related to the expansion of the universe. For a hundred years, Hubble used, you know, for a hundred years, Hubble was actually credited with this idea. He was credited with this period of the mass relationship and then heaven and hell he lived in the community. So now we have Annie John Cannon. Annie John Cannon is one of my parents. She's a spectroscopist. She's a full-fledged spectroscopist studying the normal stars. She works pretty much for a long period of time. And what I've kind of shown here is just her working at a desk. She's one of these women that made the transition from being a computer to almost being like a staff photographer. I've shown here in the middle, spectra. And of course those from Woy-Gee Bibs. I'm going to know what Woy-Gee Bibs is. Okay, well, you've got enough questions for tonight. I'll ask you later. But anyway, it's the spectra of all the stars of high eddies, which is an open cluster in the disk of our galaxy. And this is an actual notebook from the period that is currently stored at Harvard. So she begins volunteering at the observatory where she's taking grad classes at Bradley. She's actually deaf. So she's doing this work. She's accomplishing this in all the time you're in here. So it's very impressive. And just impressed by our work. And he starts to promote her. And as you can see in 1911, she kind of goes to a second curator of the astronomical photographs. But at the time, the president of Harvard University did not want to allow her to be listed as staff. So you won't find her name in the staff directory at Harvard. Eventually she was beyond this and in 1938, she's finally recognized so a year, 27 years later. She's finally recognized as Harvard staff. And she becomes the official curator of astronomical photographs. She averaged three stars a minute. She averaged three stars a minute. And she was able to classify over a quarter of a million stars during her career. That's just the normal. I can't do that. So she was incredibly impressive. She basically did retire. She did retire eventually and her position was left open for anybody to actually fulfill her position with that level of just efficiency and experience. So Canon is really nice because of course she started this spectral classification and the understanding of the whole stellar sequence. So I'm looking at stars and I really said they have characteristics of properties but how do I begin to understand this? How do I begin to type these stars and try to prove them and make sense of what I'm seeing? So she was able to refine the classification systems of front and body. She reduced the number of categories and made it really straight forward to understand, hey, this star is here before we see this side. It has this temperature, so for this on. And so there's this, if you've ever taken the Astro 101 class, there is an acronym that we use to help people understand the stellar classification system. And it's O, B, A, F, G, K, M. Anybody knows what the traditional acronym stands for? O, B, a fine girl and kiss me tonight? There's that. That is not my favorite acronym. So in my own Astro classes, I've asked for people to come up with ideas substitute acronyms. I took these from a class that Stony broke but Old Bald and Fat Generals keep messages. Oh boy, an F grade kill scene and only boring astronomers find gratitude to knowing the models. So she found this classification system it was a huge step forward and kind of what I've shown here in the middle plot is just a prism sector. So this is the first time that we were able to break apart light to a spectrum we used to prism. So something that, you know, I think we're kind of all familiar with. And here's the actual stellar sector's inputs. This is for main sequence stars, so basically even stars that are in the prime of their lifetimes. And you can see here there's a nice temperature down to the lowest and there's actually change what you can see with this spectrum. I'll show you more in just a second. And she had a really great applying of distinction. Anyway, she has a really nice quote. She says each spectrum is a gateway to a wonderful new world. And so here is her stellar classification system and this is of course a modern day version of this where you can see O stars at the top and M stars at the bottom. They have a disservice temperature of 44,000 Kelvin roughly. M stars are pretty cool at 32 in the 40. Our own son is a G star and our own son has a temperature of roughly 5,800 Kelvin just to give you an idea. So Canon's system was so stable, so robust that it was adopted by the IAU. And today it's known of course as the Harvard spectral classification system of the Canon, but the Harvard. So there's one other woman who I found really fascinating and her name is Sillian Payne, the author. She's Sillian Payne. Sorry, I don't have a bunch of them. But anyway, she is just phenomenal and she really, out of all these computers, she's the one to achieve the most in the greatest transition in her career. So she was around for Harvard pretty much primarily during the 20th century and she tried to initially study at Cambridge for the paper to know we don't accept women. So she went to Harvard at the time. People found her to be so fascinating, so intelligent that they actually allowed her, they created a special degree category for her and she's the first person to write a story from Rise Left to Women PhD. So she was that impressive. And it took her about 30 years though so she gets the PhD, she goes to work for Harvard with so many toys. It takes her about 30 years and finally they give her a professorship. Just to not let you guys know today she was assigned for most professors transitioning from like a postdoc so a period after her PhD to professorship is seven years. It took her 30. And eventually she became the first woman to head the department at Harvard. So she was a third department head but the first one to do so and she's just amazing. So what I've shown you here is a view of the sun because this is one of her primary research topics and I just love this view of the sun. This is from NASA which is brown-based and space-based images of our sun at different wavelengths. So each wavelength between piece of information in this picture clearly shows that and it gives you a different view of the sun. You get an idea of the s-tactivity and you get an idea as to content and this is just a really beautiful view of the sun. And these are her notes. One of the things she worked on is line streams and identifications. And so here this is her at the telescope right here. She's taking data for her doctoral work and then what she discovered at the time is that the sun is made primarily of hydrogen and foam and only 2% of the sun is heavy elements. So it's basically hydrogen and heavy elements and this shows people because people thought, hey, the sun and the earth they should be the same. They should have the same composition but she was the one to prove it. She saw a connection also between atomic physics and the understanding of these lines that we see in the absorption spectrum and she was really able to make that connection. And she was understanding to understand this as a function of the layers of the sun and her single exploring law on atomic physics was the layers of the sun. She was able to show that the many differences of lines in the spectrum were due to different atomic ionization states. Sorry, that's all we are with physics. Let me get you guys. We haven't added up here without much physics, I don't believe. And that basically different temperatures it was related to different temperatures and different elements of the elements. So here is an actual spectrum of our sun and I want you to be impressed because each of these dark spaces right here so basically the black body spectrum wanted to be the rainbow and so there's a background of the rainbow that comes from our sun. And essentially each of these dark places right here is where some sort of element has taken out light from that background of the rainbow. And each of these dark spaces corresponds to a different element. So that's how we're able to understand what's in our sun. Not just what's in our sun but what's in stars all throughout our galaxy. So her work was solely pioneering. And of course I've given this nice little periodic table of elements something I referred to in my last talk but basically shown that all these things in this periodic table of elements are actually kind of representing this one segment of the solar spectrum. So her finding was so revolutionary that Henry Norris Russell said no I don't believe you. No, I'm a rabbit. And so he went down, he was actually Princeton too so I won't lie a little bit of the Harvard Princeton dynamic came in there. He took his own observations he said, ah because this finding is true he published it and actually he was credited with finding your simple, simple decade afterwards. So... Exactly. So I want to point you to two references tonight and I really want to highlight that these women succeeded through kind of adverse and tough times but they really did persevere and the thing is, is that even though history did forget them at times but their work still came through and I'm so grateful to know that because they're an inspiration to me. And so what Harvard has done is actually started to invest in these computers these women that gave 50 years of time to figure out the astronomical science and really truly the work in before. So one of these is called Project FEDRA which is preserving Harvard's early data and research astronomy and one of the reasons I'm pointing out to you is I know everybody has a time of a London time but I really believe in citizen science and this is one of the ways that you can contribute. So you can go to Project FEDRA's web page and what you can do is perform transcription of the album, you're going to know what's in your air just so you're actually helping science and archiving to move forward for these women. So as you can see right here, here's the Project FEDRA FEDRA results where Anna Jump Cannon Cecilia Payne and then Henrietta Swann Newman and so by the way, Henrietta you need some help here. But if you do get a chance, even just taking a look at their notes is absolutely fascinating and realizing what they understood over 100 years ago. It's just amazing. And so I gave a few just links down here and by the way, these women were so prolific that all computers behind generated 2,400 notes. The other really cool thing and this I think people relate to too is big data. So the funny thing is for a long time we had these photographic plates and roughly in about the 80s 90s we transitioned to CCDs. So basically like your iPhone, all these cameras they work off the CCDs. So we had these plates and they were in storage for forever, collecting dust and hey, there might be some information on them. And the way that we really understood that these plates were valuable is they actually found an old photographic plate from about 70 years ago where the first exoplanet was actually damaged. So it was really quite fascinating. So what they did is they built a device and said hey, we're going to upload all these devices into a scanner. We're going to collect the information from the scanner as you can see here and then we're going to make all this available to scientists. We're going to make all this available to scientists. And so essentially all of this data it was taken roughly 80 to 90 years ago it was being used now in current research so it's really, really fascinating. And I just want to point out too that I've talked tonight about 30 minutes. There were so many more computers and by the way there were so many more computers throughout various institutions and various laboratories. And so right here this is the rocket with it. So again kind of thinking about that these are also women who worked on various programs that NASA had established. Here's an image of them right here. There's one whole book that goes with the rocket women and I highly suggest you take it out and probably be a good movie too at some point. So I just want to end this really quickly. I think I've been really great but I doubt it. Anyway, but the quote from Jenna Dyer is learned she's a fantastic astrophysicist and she's a whoops whoop. She's a great advocate for stuff. And one of the things that she says is so if we want to get to know our best possible discoveries, we want to get to these best possible discoveries then everyone has to have a seat at the table. So my presentation tonight is just to the iceberg and I hope I can encourage you to look into this and kind of see who are the people that really made our scientific discoveries. Thank you very much. And there's a question. Like where did I get this awesome shirt? It doesn't come in men's sizes. You see women. Good question. So basically she asked whether or not we see when you see a lot of publications when you see a lot of mentions of these women you see initials as opposed to their names. And so I will tell you that we do I refer to myself as Jay Stowek but I will tell you that's a little bit of a dodge. You're right. It's really interesting to maybe pursue just those first stages. Yeah, they definitely refer to themselves by their initials. I also have to tell you guys I hope it's not too negative. I hope you can help me out here to feel positive about this stuff. But looking for images for these guys and it was just fascinating and I'm so thankful because by the way this presentation stands on the shoulders of so many people. But this particular image is known as the paper doll image. Every a lot of images that I found are figurines. So if you search for the very first search terms that you'll come up with a bunch of women who are doing absolutely for not really worth any other questions. What is the recognized definition of an exoplanet? Nice try. So you ask what is the definition of an exoplanet? I know the answer. But no one comes to my phone. It's actually going to come in a few minutes because there's a break between me and the next speaker who's by the way absolutely fabulous. She's written a book. I highly encourage you to say I highly encourage you to have another beer. But are there any other questions? This is a really good question. So basically do the plates decorate over time? And the answer is yes for some of them. They try to hold a variety of different emotions so basically different chemistry to get the plates. Also they try chemistry which is really kind of interesting to see which emotions were more sensitive to red light versus which emotions were more sensitive to human life. So basically you move the piece of information when you're looking at a star and when you're looking at an other one. And so yeah, unfortunately some of them because of the differences of emotion they didn't agree and actually some of them were trashed. In fact any of my department trashed a bunch of their photographs. It's important. Short time. Anything else? Yeah. Good question. So basically I had mentioned that I also planned to actually do the scene in a photographic plate. So yeah, there's a study on it. And especially thankfully to this dash project the one that I mentioned the digitizing of all these Harvard images. Yeah, there's that dash to see it again just based on current specter if we go back and see hey was this perhaps seen maybe six years ago maybe eight years ago. See if there are different kinds of all that up. All right. The question is really high school to give these talks. Not yet. I think I'd like to very much I'm involved in the mentorship program because I had somebody mentor me actually so I want to kind of repay that and so I'm involved in one mentorship program right now. I'd like to be involved in more so maybe this is an opportunity and I'll make this talk really hopefully and really find out. All right. Hey guys, I hope you have a wonderful Friday night. I'm so glad that you came out and I will keep on coming out to our Astros sometime. Thank you. Thank you. We're going to have to take a 10 minute break. Everyone can use the restroom and get more beer. And then we're going to give you trivia results. So come on back next 10 minutes. To tell us whether or not we have discovered the second dirt or not. Yes or no. Please join me in welcoming Elizabeth. I'm Brett Scott. Because I too have a women in astronomy legged t-shirt which I almost wore but then I was like it's cold. So I guess my regrets are 50-50 because I was worried about that second part. So how have we found Earth 2.0? I'm going to start our story with what I hope is a relatively familiar system of planets. This one. So on the far left we have our nearest star the sun and then moving outwards we have our rocky planets Mercury, Venus, Earth and Mars and just in case anyone has had a few too many beers you're here. Beyond that we have our gas giants which are predominantly atmosphere and kind of masses. So Jupiter, Saturn, Uranus and Neptune and then some of you might be saying Pluto. And what we say to you is that we don't talk about Pluto. Our sun is not the only star with planets around it. Now our story begins in the early 1990s or we found the first planet around a pulsar which you all know from doing your quiz earlier. So these were two planets initially discovered around a pulsar in the early 1990s and everyone ignored them. A pulsar is a freaky dead star and people were like yeah, too weird. Since then we have discovered over three and a half thousand exoplanets I believe the count was this morning 3,605 and roughly one third of those are approximately Earth sized by which I mean that physical radius is less than twice as. So this has led to an obvious question could any of these Earth sized worlds actually be Earth like? Well let's do the obvious thing and check the news. So we have headlines like Earth 2.0 NASA says scientists have found the closest to it outside the solar system or we have NASA's discovery of a solar system with seven Earth-like planets will change how we hunt for alien life. Or we have Earth-like planets around Proxima Centauri that's our nearest star. It must be just like us, right? So, oh yes and then spotted are alien neighbors. NASA found a group of Earth-like planets that could host alien life using Kepler. So based on this, I would say well, I mean this is just Earth everywhere. I have to tell you we're about to do a bit of ice bucketing. So let's wait a minute and do something more controversial and ask what we know about these planets. So 96% of planets so basically all of them are found using one of two techniques. The first technique we call the radial velocity or sometimes the doctor wobble because it sounds cooler. So this involves the star making a bit of a wobble because of the planet's gravity. So we normally think of the planet going around the star and that fortunately is true but the star also responds to the planet's gravitational pull which is a titty bit of all. And as it does it wobbles towards the Earth and further away and that causes its light waves to get stretched and compressed so we see a red and blue shift in the light and that indicates the planet. The second one is a little bit more intuitive. The planet simply passes between us and the star and blocks out a bit of the star light. Now we call this the transit technique. So what do these methods tell us? Well the doctor wobble tells us the planet's minimum mass. The reason it's the minimum is we do not know the orientation of that orbit. If it is exactly edge on, then we get the mass. If however that orbit is tilted we underestimate the mass because only part of the star's wobble is in our direction. And we have no way of knowing from this technique alone what it is. Transits gives us the planet radius. Not the minimum radius, it does give us the legit radius. And there's no small print to that one. So this means that typically for any exoplanet discovery we know a sum total of two things. We know either something about the planet's extent so either it's radius or it's minimum mass. And we know something about how far from the star so we know how much radiation, how much star light that planet is receiving. And the problem is neither of those actually directly relate to what's going on on the surface. So why then do we get the following news announcements? In 2014 a planet with a very catchy moniker, GJ832C, was discovered. And this has a minimum mass because it was found through that radial velocity technique of five times that of the Earth. So it was a super-Earth. However, when the research paper came out, see how professional that looks, the abstract says the following. No, no, I'm not even going to bother reading the paper. I am looking at that top abstract section, the introduction, the bit that really everyone reads. And it says the following. Given the large mass of the planet, it likely would possess a massive atmosphere. And therefore, GJ832C is more likely to be a super Venus, because Venus has colossal absences. Surface temperature of Venus, anyone? Yeah, it is 460 Celsius, and I don't even need to translate that into Fahrenheit because it's really irrelevant to this stage. Longest is spacecraft has ever survived on the Venetian surface. Any bets? Well, it's a bit better than your guesses, but really it makes very little difference. It's about two hours. So this is vanilla 13, and that temperature is hot enough to melt and melt, so that spacecraft didn't survive all that long. So, likely to be Earth 2.0, we're going to go with another one. So we got Newfound Alien Planet, GJ832C may be able to support life. GJ832C is the best candidate for supporting life. I'm guessing whoever wrote that was in Arizona in the summer. GJ832C potentially habitable super-Earth discovered a mere 16 light years away. Or maybe this potentially habitable super-Earth is just 16 light years away. So, you know, really we should be packing our bags right now. It's clearly around the corner and it's a big holiday. So where the hell did this happen? I mean, I didn't even read the paper here. I just read the abstract. So how do we go from... Are you going to read any part of the paper? It's going to be the abstract. So how did we go so horribly wrong? And the answer, at least part of the answer, is something called metrics. I think the most people have heard of. This first metric I'm going to introduce is the so-called habitable zone. So the habitable zone, the official definition, is where an earth-like planet can maintain liquid water on its surface. So the edges are, if you take our planet and you shove it outwards, there comes a point where all our water freezes and we become a snowball that is the outer edge of the habitable zone. Conversely, if you grab the earth and give it a really big shove inwards, there's a point where all our water evaporates and that is the inner edge of the habitable zone. However, like all real-estate contracts, there is small print. And the small print in this one... Oh, sorry, it's a binary. You're either in or out. Small print in this one is earth-like. So just because you're inside the habitable zone doesn't mean you are an earth-like planet. Indeed, of all the planets we found in the habitable zone around their stars, there are five times as many planets that are very likely to be gas giants like Jupiter that have any kind of solid surface. So a different planet may or may not be able to maintain water in the same location. So for our Glossier 832C, it sits just on the inner edge of the habitable zone. So the question is, is it earth-like enough like is it an earth clone so we can use this habitable zone contract? Well, I mean, we just said it five times on that subject, you know? Like, it's obviously not identical to us. Therefore, we can't apply the habitable zone. Therefore, we're not really talking about liquid water. And I mentioned it's supervenous. I... No. So the second problem we had was with the second metric that is massively falling out of use. I like to think because I keep giving this talk. And that was called something called the Earth Similarity Index. And it looks like this. It looks very professional. However, we can break it down and say all this equation is saying is you take the planet's property and you subtract from it the same property of the earth and you throw into the arbitrary waiting and you multiply these all together. And the properties we consider are density, radius, escape velocity and surface temperature. Problem number one. None of these four conditions actually measure surface conditions at all. And we're missing loads of important factors that are going to control what it's like on the surface. For example, the fact that we have plate tectonics is kind of a big deal. Our volcanoes actually produced our atmosphere if you care about that. The fact that we have a nice circular bit without extreme seasons, I mean again, that might be nice. Our magnetic fields prevents our atmosphere from being stripped by the sun. Our rock type helps the amount of greenhouse gases in our air. And the fact that we actually have water does help us in supporting it. So, you know, it's all points, but none of those are at all mentioned in these four promises. So it becomes a little bit like this Facebook game. Which of your friends do you most look like? So this is the same basic idea. They take properties of your photo. They take the same properties of your friend's photo. They subtract them and they look for the smallest difference. So, this is me. Which of my friends do you think I most look like? Let's have a drum roll for that. So the answer turned out to be this bag of chips. This bag of chips. My buddy Will decided to replace his profile picture with a bag of frasils. Which you are the good chips, I have to say. And this Facebook game was like hally out your twins. Phones, but either we haven't got enough comparison points between me and this bag of frasils. Or possibly we're using the wrong ones. Which brings me to this four list again. The second problem is that we can only observe two things and none of them are actually these. So we can observe either radius or minimum mass. Or we can observe the amount of radiation the planet is getting. Aha! You might think you lied because look surface temperature that must be correlated with the amount of radiation the planet is getting. And yet, it's not. So we've got four quantities based on two measurements and either of them are these four quantities. So, for example, the equilibrium temperature here is what you get from the amount of radiation. It is the temperature at the top of the atmosphere. So the equilibrium temperature for our planet is a rather chilly minus 18 Celsius. Whereas our actual global average is 15 Celsius. So minus 18, the point is everything's frozen. 15, I think we're talking about what is that at Fahrenheit? 60, to me. And as I mentioned Venus is hot, but its equilibrium temperature is about late 80s. Which, you know, seems like a big holiday. But again, its surface temperature is something that that's left, so no, not really. So the atmosphere has a very strong effect in what happens to that radiation when it reaches us. And it's not like a linear effect. You can't just add 33 and call it a done deal. Yeah, I think it goes suddenly doesn't work for Venus. So we have these two measurements and oh yeah, right, sorry. So yes, this planet that we're looking at here. This has only two, so it has the minimum mass and it has the amount of radiation. And what happened was these two were used to make a guess at these four and then the result was a value 0.81 out of 1. And the claim was, well, if you're above 0.8, you know what it's like. So we took two properties, none of which measure surface conditions. We used them to derive four other properties that we can't measure, and we ended up with a value that claimed to be identical to Earth and everyone believed it. So just in case you weren't convinced, what do we think the ESI of Venus would be? If we observe Venus as an exoplanet, as a clue, Venus is very similar in size to the Earth. So I have one who thinks it's 0.5 or above. Who thinks it's 0.8 or above? Who thinks it's 0.9 or above? Yeah, the last group is perfect, it's 0.9. So yeah, Venus, super habitable, identical to the Earth and any volunteers who goes there next week? So yeah, HCs, we hate them. What can we do? Well, we can't yet measure what it's like on these planet's surfaces. So we can't yet tell if we really have found Earth 2.0. All we can do is say something is Earth-sized. We can't yet say whether it's at all Earth-like. But how patience, my young padawans, because their help is a hand. So currently we do know of Earth-sized planets, but we don't know about Earth-like. The next generation of telescopes is going to change that. These guys are going to be looking at the planet atmosphere. And when they do, if they manage to decipher the composition of the atmosphere, we will get our first glimpse of something that is on the surface. So JWST flies in 2019. Aerial is the European Space Agency's mission flying in 2026, I think. And Twinkly is a little UK mission that they're hoping to get up sooner rather than later. But all of these are aimed at looking at atmospheres and these may be able to tell us what is going on on surface and may even give us the first sniff of life on another planet. And maybe, maybe then we'll be able to talk seriously about Earth 2.0. So my final slide is a shameless plug. I wrote an exoplanet book and if I haven't demonstrated how many wonderful ways there are to die horrifically on these planets in this talk, I mean, I have a lot more options for you guys. So there are hot Jupiters, which are planets the size of our largest gas giant on all bits of last four Earth days. We have Tatooine worlds with two suns, road planets with no star at all, planets with secrets of lava or tar. All of them are horrifying. And they're all in this book. So I have today with me four copies, which I will happily part with for $25 each. However, I also have a bajillion little cards that you can take as a memorabilia to this talk. Because they only come in perhaps a six million, so please do come out with that. And also these bookies at most bookshops on Amazon is also specifically stopped to aid as a cabinet of Hill because I'm giving a top letter tomorrow night and they promise I'll get the book in. So thank you very much. So the question is, our atmosphere didn't exactly come instantly. So could we tell if a planet was going to be Earth-like but wasn't yet? And that actually is a very active area of study where we talk about the Earth as an exoplanet. And what people do is they sort of rewind the clock and say based on what we knew about Earth's development of life what would an early Earth look like if you could see its atmosphere? So often when we talk about the Earth you hear the term pale blue dot but we might have like a pale orange dot because they're hazes or from an early atmosphere. And that definitely is being considered so we hope we could recognise early Earth as well as current Earth. I mean I'd recommend my book. I would recommend talking about early Earth atmosphere as a particular unit or just generally. So let me think some of my head I have to spell her name. There's a girl called Jada Ani who does a lot of work on this but I would check out conference presenters would be one of them I would get. So for instance last November there was a conference called Habitable Worlds in Wyoming and they have a few things online they were actually live streaming I'm not sure whether talks are still available but they definitely have some panel discussions that are available and the scientists on that panel would be a great place to start looking up their papers because they're all studying Habitable Worlds. So what if there's multiple planets? Oh yes, so if we use Doppler effect to find planets what if there's more than one planet in the system actually you can distinguish that so you fit the wobble to a periodic motion of a planet and you can actually unpick multiple orbits in that so you want the wobble to appear periodically every time the planet laps so you can tell if that is changing slightly you've more likely got more and more planets in the system and by matching the wobble to that you can pick out different planets. What are some methods that might be able to detect those various components of actual planets? So for some of them we're a bit mystified we don't know yet how to detect a magnetic field for instance but the presence of an atmosphere detecting that composition is going to be really key and the reason is that the planet's atmosphere is the result of pretty much everything that's going on in the planet like if it didn't have a magnetic field we would expect that atmosphere to be stripped for example the geology, the volcano is going to be adding to that atmosphere life is going to be adding to that atmosphere really the whole planet system the products of which we're going to be seeing in the gases in the air so the challenge is not whether we will see what's going on it's whether we will understand the fingerprints that we're going to get as a result of that Would you be able to determine if there was an atmosphere being produced in the surface but escaping fast enough where the magnetic field wasn't present? So the question is could we tell if the atmosphere was strategically produced but being simultaneously stripped it all comes down to time scales like how fast is stripping compared to the atmospheric production generally speaking the atmosphere is outgassed from the planet fairly early on in this history so you would expect the atmosphere to be there and be about to be stripped or be already lost so you shouldn't get the situation where you miss it because it's actively stripped I think Telescopes, you said you might actually be able to see the surface if these telescopes you could actually find what's the astronomy community doing here is that the huge announcement what would the astronomy formulate that message or based on the media we seem to be announcing it prematurely 10 years earlier I think there will be a lot of steps before we get to that stage so one of the things we're going to see is this complex signature a hope of gases now the big question will be is that definitely biological or can we do it a biologically so for example our atmosphere contains a lot of oxygen does that mean definitely life absolutely oxygen is definitely produced by life but if you look at the atmosphere of some of the Jupiter's moons like Europa they have oxygen atmospheres but they don't have life so it is possible to be able to produce a lot of these would be biosignatures by a biotic means so I don't think there will be nothing nothing nothing shabam we found aliens I think it will be this is the stage we're seeing some interesting signatures what could this mean what are the possibilities so I hope we give everyone a very gentle build up thank you very much our next event is March 28th back on our website I hope to see you there thanks for coming out