 Okay, let's go ahead and get started. I'm going to try to use the full time today to walk you through the course and then motivate what you're going to have for the first assignment today, which is some reading and a little bit of math homework to warm up for the course. Yeah, everybody loves homework on the first day and I'm not sure about giving it. Thursday will be the first real assignment in physics by itself, but I want you to use the next couple of days to kind of prep yourself for this course. So I'm going to walk you through the basics today. You've got a lot of documentation that you should read and I mean it, read it. I'm going to quiz you on some of it on Thursday. Okay, so I want you to read this between now and Thursday. All right, so I want to begin with some introductions here today. All right, so I want you to tell me about yourselves first. I mean, there's one of me, you all get to know one of me, but I have to get to know about 36 of you this semester, give or take. Okay, so I want you to raise your hand if you are interested in medical school MD programs. Yeah, lots of people, not a shock, right? This is the pre-health sequence most of you are gunning for medical school MDs. All right, what about MD and PhD combined programs? Anybody aiming for an MD-PhD program that combines clinical work with research? Okay, what about dental school other important health related activities? Yeah, so what are you doing? So you're single? Yes. Okay, excellent. I bet you're wondering how I did that. So what's your interest after college? Like maxidiofacial surgery. Surgery. Okay, alright, and someone else who else had their hand up? Someone else? Yeah, what's your name? Lori. Nice to meet you, Lori. Okay. All right, so what about something other than medicine? I mean, and that could be you could be interested in doing medicine and something else or you could just be interested in doing something other than medicine in general. Yeah. Okay, what's your name? Ashley. Okay, Ashley, what are you interested in? Dance. Okay, excellent. And what's your name? Jared. Jared? Jared? Jared. Okay, what's your what are you interested in? Patton Law. Patton Law. Excellent. Okay, great. Yeah, so I know that I have a diversity of people in this class. I do try to respect that. I do expect you to learn physics, but I will also try to take the sour pill that can often be physics and wrap it up in a candy coat of something you actually give a damn about. Okay, so I will try to do that. That's that's my part of the contract, but your part of the contract is you have to execute what's expected of you this semester. All right, now I'm not easily offended. So how many of you dislike slash hate physics? Come on, raise your hands. Yeah, thank you. Okay, good. All right, so my job as a teacher is to work on that a little bit this semester. And yes, are you just like I still really, really hate physics? Thank you for raising your hand twice. Okay, what's your name? Elizabeth. Okay, excellent. See, I'm not easily offended. It's fine. You just failed the first time. All right, so let me tell you a little bit about myself. Whoops, probably skipped too far. So I'm Professor Steven Secula. I'm an assistant, hopefully soon to be associate professor of physics in the SMU physics department. I got here in 2009. And so I'm getting a little long at this point. I spend I'm a research professor, so I only teach one class a semester. And this is it. All right, so I when I'm devoted to teaching, I'm devoted to you this semester. All right, so that's the benefit of a research professor. The disadvantage of a research professor is that you research. And that means that I often have to commute to far away places in order to collaborate with the 3000 people that I work with on an experiment called Atlas. Atlas is one of two multi purpose experiments that are located at a laboratory called CERN in Europe. It straddles the French Swiss border. So it's a lovely and less expensive area now that the euro has crashed and the Swiss franc. So that's good for research dollars. So I spend part of my time there like my graduate students are primarily there and I can't leave them alone for that long. So there will be weeks when I have to disappear to go to meetings in the United States or meetings abroad. I will try to let you know as those come up. I tend to have to plan travel about a month or two in advance. I try to schedule exams for when those travels coincide. So there's one in March, for instance, that will be our second exam. And that exam will coincide with me going to a meeting in Seattle, Washington. Okay, so the teaching assistant whose name is Andrew Turvey will be helping out while I'm gone. And because of the style of teaching I'm going to administer this semester, you shouldn't really notice a big difference between the way, well, I mean, apart from that I have a lot more experience. You shouldn't really notice a big difference between classroom styles when I'm away and when I'm not. Okay, and I'll tell you why in a bit. I like working with students. So these are a few undergraduates that I've worked with on research. This is Merriam Ishak who's now in the MD PhD program at UT San Antonio Health Sciences Center. She came back about a year ago now and gave a talk here in the physics department, basically advice for pre-health students about looking at MD or looking at MD and PhD programs. She was a physics major. She was outstanding, but she really knew what she wanted. And so she did her physics major and went off to medical school. And that's fantastic. This is Holly and Tran. They were both in this class in 2010, I want to say 2010, 2011. And Holly is now going to medical school after a couple of years of taking some other courses elsewhere. And then finally, this is some of the students Matthew and Landon that I worked with on research when I first got here. And behind us is my old experiment called Babar. It's only about three stories tall. In contrast, Atlas is eight stories tall. So it's a much bigger camera. And here it is. So this is where I go to work. I don't get to hang out down here very much because when this is actually running, there's a whole lot of radiation. I don't want to be near. Okay, but that's a person. And that's the cavern in which my experiment is located. It is the largest digital camera ever constructed by humankind. It's an eight story 50 yard long 100 megapixel digital camera, and it's capable of taking 40 million pictures every second. What is it taking pictures of? We smash protons into other protons at the center of this long cylinder. And we image the collisions that come out all the debris that comes flying out. We're essentially ramping up the energy of the collisions to recreate the early cosmos about a millionth of a billionth of a second after the Big Bang. And we take pictures of what happened. And from those pictures, we attempt to figure out what the laws of physics were at that time and see if they're any different than the ones that applying now. And by doing that, we learn all sorts of things about the beginning of time, what the universe is like now, and what its fate might be in the future. We also get to see the players in the cosmos at that time. Most of them are subatomic particles you can't see with your eye, which is why you need all kinds of neat materials in order to actually image them in the first place. So this device is essentially creating a picture, a representation that human beings can understand, based on the interactions of subatomic particles in material. Normally, this thing is filled with instrumentation. Here, you're just seeing the magnets. These are just the magnets in our system. Alright, so you're gonna learn a little bit about magnets, a little bit about electricity this semester. And what you'll find is that you learn a little bit about this stuff, and you can think about really interesting questions, really interesting problems that maybe you never thought could be solved before. Okay. Alright, so that leads nicely into why the hell should you care about electricity and magnetism? Alright, so four of the health types in the room. Physics, generally as a specialty can seem in college as if it has nothing to do with the real world, even though it is the fundamental understanding of matter, energy, space and time, of which all of us are made, and through which all of us move, it often seems disconnected from our lives. But in fact, physics and medicine go hand in hand, especially in the modern era, as noninvasive imaging techniques become not only more advanced, but more important to reduce patient risks and try to improve patient outcomes by catching diseases very early on before they manifest into something you actually can feel as a lump or something like that. When it's gone to that stage, it tends to be bad. If you can catch it a bit earlier, that's better for treatment. So here are a few techniques that have resulted from fundamental physics. So the magnetic resonance imaging scan, and you see a slice of a human head here using this technique, including the brain, nasal cavity, mouth and so forth, throat, brainstem, really nice detail in this. This comes from immersing a human being in a very strong magnetic field and that magnetic field is supplied by something called a superconducting magnet. A superconducting magnets were developed by my field for bending particles in circles. That's it. We wanted to bend particles in circles and make them go around so that you didn't have to keep accelerating them along like 50 kilometer race tracks, which is a huge waste of space. So my field developed these and then they were exported to other industries because once you have a magnet that uses superconducting technology, that is very little resistance to the flow of electricity. That has all kinds of neat applications in industry and medicine. And one of those is MRIs. So the reason that most major hospitals now have at least one MRI machine, the reason why there are portable MRI machines, is because physicists were able to cram a really strong magnetic field into a very tiny space and industry developed that into something that's patient safe and user friendly and mobile. Basically what this thing does is by blasting the human body with radio waves when you're in the magnetic field, it forces all the little spins in your protons to flip back and forth. And looking at the frequency of the flips, you can figure out what material that little region of your body is made from. And so you can look for normal material and you can look for anomalous material, material that's not supposed to be there. Here is another example of a technology that's a byproduct of fundamental physics. This is something called the PET scan. How many people have heard of the PET scan? Anyone? Yeah. Anyone ever had one or know someone that had one? Yeah, it's a fairly common thing these days, more common than it used to be. Basically what happens is that we won't study this in this class, but I'll mention it because it's cool. You get injected with a radio isotope that emits antimatter. Antimatter when it means matter does what? Does anybody know from science fiction or other means? Yeah, boom. Right? Now, it's pretty dramatic. You watch like sci-fi, Star Trek, something like that. And any time they have to eject the warp core, that thing really goes. Like in the Abrams Star Trek movie from 09, when they blow the warp core at the end to get away from the black hole, yeah, I'm a nerd. Okay, so we'll just deal with it. You know, that's like a tremendous release of energy that warps space-time and then they're able to surf out of the black hole. This is a bit less dramatic than that. This is like a radio isotope that every now and then emits an anti-electron. And your body's made of lots and lots of electrons. So it's bound to hit somewhere nearby an electron and when they meet, they turn into two particles of light. And that light travels out of the body. It's basically x-rays or gamma rays. And you put a big detector around the body and then you can figure out by doing a little geometry where the light came from in the body and you can pinpoint where the radio isotope was collected at that time. It follows the path of blood. So you can use this to identify regions of large or obstructed blood flow in the body. Alright, so for instance, this is the distribution of the radio isotope due to blood distribution in the brain in what's considered a normal brain. This is a person who is pre-sum treatment suffering from Parkinson's disease. And you see that there's a greatly restricted blood flow in various regions of the brain compared to a normal brain. And then this is post-sum treatment that the patient was given. So probably some experimental drug or some new approved drug on the market. And you can see that blood flow activity has increased. Didn't have to cut open the brain to figure this out. That's a good thing because cutting it into the brain is really risky. And then you can combine these techniques. You can combine MRIs and PET scans to get all kinds of information about blood flow, material distribution, and so forth. There's also now functional MRI imaging, which is real-time MRI imaging. So you can actually watch changes in the body as they happen. Alright, so this is all a relationship between physics and medicine that's evolved over decades and is to the benefit of patients now. And so what I always say is that physics is the fundamental study of energy matters space and time. It's about asking curious curiosity driven basic questions about the universe and then trying to find answers to those questions. And you never know how it's going to pay off. You might have to invent some new technology to answer the question. You might have to do some calculation that no one's done before to answer the question or both. And inevitably that spins off into the world around us. The World Wide Web. The World Wide Web exists because particle physicists at CERN wanted to share papers. And now it's a platform on which hundreds of billions of dollars of commerce happens every day. Alright, the World Wide Web was invented by CERN. And now everybody uses it. Okay, so you never know. You never know when something is going to be beneficial that spins off from just curiosity. And so what I want to teach you in this course is how to use curiosity to turn that into action. Alright, so physics is about turning curiosity and questions into action. It also has some useful side effects. So for instance, this is data collected by the American Institute of Physics, which is one of the organizations that does a lot of statistical analysis of teaching and outcomes and so forth for the field. And one of the things they looked at, ranked by the average total score on the MCAT, was if you major in physics, how do you rank against other people and other majors? So for instance, here's biology down here. Physics is up here. Okay, yeah. Right, but let's take a look at the breakdown. So average biology scores on the physical sciences, no big surprise, are a bit lower on average than if you major in something like engineering or physics, mathematics, neuroscience, right? Okay, where you're just going to get more physical science, biomedical engineering. You're going to get more physical science in a program like that. Alright, but just straight biology, you may not be required to take physics or lots of physics or engineering and so forth. And so physical sciences score tend to get dragged down by that. But what's also interesting is that the biological sciences scores are a little bit lower on average in majors like psychology, biology, and so forth, compared to physics. Of course, verbal reasoning, English majors are off the charts, which is what you'd expect. That was my control. If this wasn't true, then I weep for our species, but I'm glad to see that English majors do the best on verbal reasoning in the MCAT. Okay, so the MCAT's evolving as an exam, but the takeaway message from this is it never hurts to get a little bit more physical science in your life, because physical sciences are about, in general, and that goes for biology too. Okay, they are about setting up and solving hard problems. And in physics, you will learn to set up and solve hard problems and you will use the language that nature appears to respect mathematics to do it. Okay, I would love it if math could be used to pass a language requirement in the new undergraduate curriculum, but that's a losing battle we found out at SMU. We'll try again in a few years. Okay, so other institutions allow that. Okay, if you care about money, if you major in something like physics, the range of salaries coming out of college offered by recruiters spans something like, what is that, 40k up to about 62k or so, you know, something like that. Okay, ostensibly money making majors like marketing don't have quite the high end of the range that people with a physics degree get coming out offered by recruiters, but that, you know, whatever, that's a big spread. So I just encourage people to find something they're interested in and then do it really well. That's all that really matters. Okay, so if you're passionate about science, do science. Just sort of a curious thing that we've been doing is collecting statistics on our own program, looking at BS and BA recipients from physics. And, you know, naively you'd expect, well, everybody who gets a BS or BA in physics goes into physics, and actually nationally that's just not true. And it's also not true at SMU. Most of our students are part of dual degree programs with engineering. So something like 37% of our graduates go into engineering, not a big surprise. But what I thought was interesting was about 16% go into finance, business, and marketing. Only 13% go into some physics related thing. I looked medical physics under medicine because it's there's more medicine involved than just physics. But that's a roughly equivalent number of people that get degrees in our program go off to medicine and physics, other natural sciences like chemistry. And then we have some, you know, occasional students that go into law. One went to seminary, art, music, and design, and education. So we have a mix of students in our own major program. They're not all going into physics. And so when I teach, I try to keep that in mind that not everybody that comes through a physics class is going to be a physicist. And that certainly applies to most of you. Okay. All right. So why should you care about physics? Because it's everywhere. It is quite literally everywhere. It is present at the beginning of time. It's present now. And it lets us understand the evolution of the universe and maybe ultimately its fate. Every time you tap on a touchscreen device, that's physics. That's circuits. That's capacitors that we're going to learn about this semester. It's resistors. It's light. It's optics. It's all the stuff that we're going to try to cover this semester, at least in some level. The humble light bulb is just a wealth of physics information. And we'll play around with some of them this semester. The GPS system. So the fact that you can use your mobile phone now to figure out where you are and where you're going and how to get there, all of that is made possible by something called Einstein's theory of relativity. How many of you have heard of Albert Einstein before? Okay. He's one of the more famous physicists in the history of the field. And he came up with a beautiful, very simple understanding that still works to this day as far as we can tell of space and time as a single entity. Without that simple realization, the GPS system would lose accuracy by 11 kilometers every day. So if we didn't understand space and time as a single entity through which we move, then we would have put satellites up into orbit, started trying to triangulate our position on Earth and every day been off by 11 kilometers, even if you just stood still. The next day, you'd be 11 kilometers over there. The next day, you'd be 11 kilometers over there. We just keep drifting. And it all comes from fixing that, comes from a very fundamental understanding of the universe. MRIs have covered the fact that you have all of these beautiful bonds and bonding mechanisms that make up living organisms. At its heart, that's all physics. It's fundamentally, it's Coulomb's law, which you're going to start learning about this week. The pumping of the heart. The heart is a huge muscle, but it's powered by a really regular and predictable electrical system. And it's when that system becomes irregular and unpredictable that you have problems. All right, you never want to get into that state. The eye is really an amazing piece of optics, although terribly flawed in certain ways. And I'm hoping we'll have a lecture at the end of the semester on the human eye that we can take a look at. And of course, you live here in North Texas for most of the time. Lightning, lightning and thunderstorms are a fantastic electrical and magnetic phenomena. And we'll study that a little bit as we go through the course. Okay, so let me back up here. So just to show you kind of the synergy of... It'll be interesting to see if this actually works. The synergy of physics and medicine. Let me show you just a piece of a short video here. You know, or not? I bet I know what it is. Yeah. Let's go back one more time. This is called people messing with my stuff. Ew. All right, let's try this now. The Radiation Therapy Department is a division of the Cancer Institute at Greenwich Hospital. We use the latest technology along with highly skilled and trained board-certified staff. Radiation Therapy Department was designed with the patient in mind with calming, soothing music, colors, furniture, constantly embracing the patient during the course of their treatment. The Radiation Therapy team has comprised of a number of specialists, a physician who helps determine the clinical need for radiation and essentially helps map out the target of the Radiation Therapy, the tumor, and the cancer cells. This is followed by the physicists who are in charge of quality assurance. We make sure that the treatment machine is delivering the radiation as planned. The nursing staff who would assist patients with any potential side effects and the therapists who are involved with daily positioning of the patient to ensure that the radiation is delivered precisely. I am the nurse in the Radiation Ecology Department. I see all patients when they initially come in for their radiation treatments and I follow them throughout treatment. I see my role as a patient advocate, empowering them to get through treatment with as little side effects as possible. Cancer is very frightening and what we try to do here is bring more corporate to the patient through a lot of support. I've been a Radiation Therapist for 18 years and I wouldn't want to do anything else. I love working with the patients. I love the technology. It never gets boring and just the feeling of knowing that every day you've done something for that patient to make their life better is the best feeling in the world. A medical physicist assures the safe and effective delivery of radiation treatment to patients as prescribed by the Radiation Oncologist. We work very closely with Radiation Oncologists to produce a computer-generated dose distribution plan which ensures the best treatment for each patient. The Nivella STX has the ability to focus in on the tumor beyond the capacities of other radiation machines. It allows us to attack the tumor cells while sparing the normal tissue. It allows us to precisely target tumors in the body even in locations where the tumor could move. The patient has more precise radiation treatment delivery, fewer side effects and sometimes shorter treatment times. Okay, so let me pause it there. But I was driving in Long Island for some meeting and this ad came on the radio for Greenwich Hospital and they were advertising that they were the first to have the certain class of linear accelerator in the nation in a hospital. I was like, who says linear accelerator in an ad for patients? That's jargon from my field. That's not radio ad quality material, but there it was. So I browsed their website and found that video and they very proudly, very proudly in their propaganda piece advertise the fact that you have the medical expert, the supporting staff, the nurse that actually works most directly with the patient and the physicists all working together to do these treatments that are very difficult and scary for patients. I've worked with several medical physicists just on the side. They're an interesting group of people. They don't think the same way that my field thinks. They have problems that actually if they screw up involve killing people. No one's going to die if I do a bad calculation, but someone could die if they misjudge the breathing rate of the patient if the tumor is by a lung while they're putting the dose treatment plan together using a computer simulation. Okay, so they're either writing software, implementing mathematics, or they're using off-the-shelf programs to try to come up with a dose plan taking into account the fact that that patient might move because they need to breathe while the beam is firing. Okay, and the goal with radiation therapy is never put radiation somewhere it's not supposed to go because anytime you do that you kill good tissue and you fail to kill the tissue that's bad. All right, so these are very delicate issues. They involve life and death and I think it's fascinating that physicists get to play a part in that of any kind even if it's small. All right, so the other reason that I find electricity and magnetism kind of a fascinating subject is something I think we forget about if we don't think about it daily we ought to. There are a lot of diseases that have to do in the human body with disruptions of the electrical systems of the body in one way or another. And it's a reminder when you see things like I'm about to show you here that we are electromagnetic beings. We are not immune from the laws of physics. We obey them just like everything else and everything, all our thought processes, our vision, our hearing, our ability to speak. All of these are controlled by an underlying electrical system, memory and so forth. And so this is just a nice reminder that it's a delicate balance. At any moment any one of us is inches away from falling off the precipice of all the stuff firing in the right sequence. Humpty dumpty sat on a wall. Humpty dumpty had a grave problem. All the king's forces and all the king's men couldn't put Humpty together again. Humpty dumpty sat on a wall. Humpty dumpty had a grave problem. All the king's forces and all the king's men couldn't put Humpty together again. It's a magnet. Place at the right location on the brain pulsed and it disrupts the electrical currents in the brain. And in this case it knocks out the speech center. All right. Now what's cool about this is that some of you probably already know this but the center of the brain that we use for speaking and the center of the brain that we use for singing are not the same. And so there's I'll probably show this video later in the semester when we come back to magnetic induction which is basically what's going on here. It's a disruption of electrical systems by magnetic fields. You can sing Humpty dumpty but you can't speak it with that magnet pulsing. So he can still sing it. He can add a tune to it and turn it into a song which he does. But when he tries to say it just flat no singing involved he can have his speech center knocked out. It's pretty wild. Okay. So inches. All of us are inches away from some magnet mishap somewhere in a building that just knocks out your speech center changes the color of your vision. Okay. It's tough to be reminded of that right that we're frail. Okay. But but I want you to learn a little bit of physics. I want you to learn a little bit of respect for the frailty of our condition because we are slaves to the same laws that all things in the cosmos are slave to. All right. Let's see value added. So some of you should have this flyer. This happened last semester for the first time. It's continuing again this semester. If you weren't part of this last semester you can talk to the instructors who I believe are Professor Fetalness for this semester. Actually there's an email address if you have questions. We have a zero credit hour honor section. It appears if you pass the section it's one night a week that it meets and there's a light a bit of work that goes along with that. Emily you were in that last semester right? Are you in it again this semester? Yes. Okay, great. So how much homework was there? Okay. All right. So it was kind of like as semi-promised. Okay. All right. So it's mostly a chance to get outside the classroom and kind of engage with faculty and other researchers and other students that may have interests that go beyond just the basic stuff you're going to learn in a course like this. So it's a chance to get together and hear some interesting stuff and find out how physics is connected to other things. So this week Professor Fetalness is going to give an inaugural spring lecture on Wednesday night. So this is tomorrow night called Alan Turing the Imitation Game the Enigma Pirate Codes and Monty Carlos. And if you want to know what the hell that's about you can go tomorrow. Okay. So you can contact there's an email address or phone number for contacting with questions or you could drop by the main office. It's just down the hall in 102 just down that way and ask if you know how you sign up for it if you're interested in it you just want to test drive it this week go ahead and test drive it. There may be pizza for the first meeting I was told but no promises on that. That's something that's something I always want to watch out for is I don't know if there's actually going to be pizza or not. There was pizza mentioned in the email but if it's not on the flyer then it's not law. So it's like if it's not on the syllabus it's not law. Okay. Any questions about that? The question you can also talk to Emily if you have questions. Was anyone else James you were in that last semester so Emily and James anyone else was in the honors section last semester? Yeah. Okay. So and what's your name again? Gloria. Gloria. Okay. All right. It takes me at least three trusts. All right. Okay. So let me talk about the course. So all of this you can follow along with on the syllabus if you really want to. I'm not going to read this word for word. I'm going to give you the broad broad brush picture. Okay. So of course there's the university curriculum and I have to put these SLOs on here. So go ahead and read those. They're all boilerplate. They all match up with this course in one way or another moving on. Okay. What are the actual goals of this course? I want you to be able to explain the nature of electrical and magnetic phenomena. Okay. So I want you to understand what is electric charge? What is the force between electric charges? How is it described? What consequences does it have? We're going to come back to something that you should have seen in the first semester. You learned about gravitational fields. We're going to come back to the field concept. It's a very useful concept for explaining forces that don't involve physical contact. And in fact, as far as we can tell, the field concept works all the way down into the subatomic realm. Giving us a picture of the most fundamental interactions in nature, the stuff that happens way below where we can actually see it directly. Then there'll be a corresponding, as there's a gravitational potential energy, there's an electric potential energy and electric potential. And all of this will be needed to kind of understand electrical phenomena. And then we want to get charge moving. So we want to start moving it through things and getting it to do mechanical work in the same way that water moving through a pipe can do mechanical work in your plumbing system and power a generator or move a paddle wheel or something like that. Electrons and other charges moving through piping for them called conductors and I'll play around with the conductor in a bit today. They are able to do mechanical work by smashing into other things and generating heat and light and all kinds of other neat stuff. So we're going to learn about basic electrical circuitry conductors, batteries, resistors, capacitors, all right words you may have heard before we're going to play around with them a little bit this semester. I want you to be able to explain the nature of magnetism just what the heck is magnetism caused by and then I really want you to be able to describe the magnetic phenomena how it behaves what are the forces involved and then finally we'll have kind of a very broad lecture on light and how light connects to these other concepts and finally I want you to be able to understand the basic working of simple optical systems. I want you to finally be able to explain and hopefully we'll have a little capstone thing at the end how does electricity, magnetism and light set the stage for the 20th century revolution that we're really still living through today. A lot of things happened at the beginning let's say the first quarter to first half of the 20th century and we're still reeling from the consequences of that today. There's just as much fundamental physics just as much curiosity about the universe today as there was then there are many mysteries right now about exactly how the cosmos operates and what are the big players in the cosmos and those will no doubt set the stage for similar revolutions in the 21st and 22nd centuries. We're living through that now. This is a very exciting time for physics. There has not been a time like this since Albert Einstein did his work in 1905. And then finally I want you to be able to set up and solve quantitative problems in these areas described here and be able basically I want you to be able to apply these ideas. I want you to show me that given a situation you can work your way through that situation using the principles of physics and the language of mathematics. Those go hand in hand. And I also want you to understand how to apply these ideas to areas other than physics such as medicine, biology, chemistry, electronics, everyday life. Okay. And then finally I want you to demonstrate through performance on homework and quizzes, in-class exercises and discussions and exams a clear understanding of the principles and application of electricity, magnetism, light and optics. And I'll get to what I mean a little bit more about that in a second. All right. So what's the structure of the course? Well, you're here now you're in class. This is an in class period. Most of them won't be like this. The in class periods are going to be used to work with you as individuals and as groups to set up and solve problems in physics. This semester I'm trying something called the flipped classroom. And the flipped classroom firmly puts the burden of learning on the student which is where it's always been anyway but now we're really kind of like doubling down on that. All right. So in class you'll have quizzes on the readings and lecture videos that were assigned in the previous class. You'll have to do problem solving and one of the things we've been missing from this course for a long time is a clear demonstration of the whole class of how one even begins to set up and solve physics problems. I have never been able to do that in class because I have all this lecture material I want to cover and have demonstrations I want to do. I'm mixing it up this semester. There will be a little bit of lecture and some demonstrations in class but mostly I want you guys to interact. And so I will show you how to set up problems. I will give you problems to start working. When people get stuck I want everyone to stop. I want us to discuss the sticking point and then see how to get past it. And I'm hoping that by doing this you'll get more practical hands-on engagement in the physics ideas that you've been reading about or watching on YouTube videos. Okay. Demonstrations are often best done in person. I will try to do a couple today. So there may be I'll probably cut them out of the lecture videos and then and save that will save time on the lecture videos. And then of course discussion. I want you to feel free to ask questions. If you're not sure about something that you read I want to talk about it. I want to use the class as an interactive period not just me chalk talking like I'm doing now. Okay. A modern chalk. I have slides for you. Okay. I'm trying not to lecture to you. I'm trying to work with you so that we can learn this physics together and get through the hard stuff together and you can draw from each other's strengths. Because all of you have strengths and the key is that each of you needs to find what the strengths of the other people near you are and work together to solve problems. That's how the real world works. And so I want to emulate that as much as possible in a college class. All right. There will be assigned reading and lecture videos. All right. And I will show you the web page for the class in a second. Those will they're all laid out on the web page already. Okay. So all you have to do is look at the class material site on the course website. I'll show you where that is. And it's all there. All right. So you can start now. There will be assigned homework roughly every week. But you know sometimes just give it because we'll have exams and stuff like that. It may be one assignment over two weeks or something like that. So that'll get mixed up a little bit as time goes on. There will be four exams total. I like to spot check all of you as frequently as I can. So they're once a month. The first one will be in February because this is a short month. The next one will be in March. The third one will be in April and then we'll have our final exam on May 7th, I believe. Eight in the morning in this class. Great. For morning exams. Now previously in this course I've given a cumulative final exam. That will no longer be the case because to assess you globally across the material in the course I've introduced a new feature to the course. The final exam will merely be incremental and only the material that we talked about since exam three that wasn't covered on exam three. And it will also include material from something called the grand challenge physics problem which I'll get to in a moment. And then of course there will be help sessions and office hours. I'll get to office hours in a second. Okay. All right. So lectures. Oh lectures. These are the class periods. Tuesdays, Thursdays. This time. This place. The style as I said will be quizzes near the beginning of class. I'll do a little exposition at the beginning to give people that are coming from far across campus or something like that some time to roll in maybe a couple of minutes late but probably by you know 935 we'll start the quiz. I'm guessing they'll be about 10 minutes in length and then we'll move on to problem solving and demonstrations and things like that. So every non-exam period so the classes will be during class the exams will be during class periods. We'll have quizzes on assigned reading from the previous lecture day and lecture video material. Okay. So there'll be short simple questions. You either know it or you don't you read it you watched it or you didn't. Okay. So you know don't fake it if you didn't just save yourself the effort. These are quizzes are worth 5% of your total grade. Okay. You're going to have like 30 something of these so just relax. And I dropped the lowest two. So please don't freak out. Okay. If you miss a quiz if you have an excused absence by the way and I have a whole policy for of course you know official university excused absences but if you're you're barfing on your roommate because you have a norovirus please don't come to class. All right. All right. You know I dodged a norovirus over the Christmas break but I have to take care of a very sick spouse for 20 12 hours and and I hate it when people get me sick so don't come to class don't get your friends sick don't get your peers sick say home there'll be lecture videos you know when things need to be recorded I won't record them like it's happening now you know multiple cameras and so forth to use here if the setups are reliable then it all works great or just come and talk to me after class and find out what you missed all right there talk talk to a friend in the class but if you're sick just let me know I'll know if you're faking being sick all the time it'll be pretty obvious that you're never showing up to class because you always have the flu or Ebola or you know some kind of whooping leprosy or something like that so I'll know I'll think I'm not stupid I can see patterns okay I'll do demonstrations in class because some stuff is just more fun and threatening in real life there'll be opportunities for discussion and of course problem solving how to set up and solve problems because that's really what I need you to be able to do all right reading the pace will be about one chapter every one to two weeks the first chapter is a little bit light so we're gonna finish that basically between now and Thursday I basically expect you to spend four hours outside of class periods reading and watching lecture videos I'm serious about that okay I will not always try to assign up to four hours because that's crazy but I do expect that you know if you're it's not good if you're spending less than an hour a week on reading and lecture videos you're either not watching all the lecture videos or not doing any of the reading or both okay so and if you're struggling let me know and we'll see if we can figure out a some kind of you know strategy for for getting through this all right please take notes as you do these activities because these notes you should bring to class and if you have questions you should ask them something wasn't clear in the reading you should ask I want you to take this time with the book and the videos as real like reading learning time okay so find a quiet spot put your headphones on and just lose yourself in the science all right please read your notes before coming to class they may help you with the quiz all right so the assessment of all this is as I said these reading and video lecture quizzes they're worth five percent of your final grade I use them to check your pace and comprehension they're in class near the beginning of each class again to give people time to get here from across campus do try to get here on time though because when I started the clock is ticking okay and if that's going to be a problem getting here by let's say 935 please speak to me and let me know the two lowest reading quiz grades are automatically dropped all right so don't be shy about missing one of those or bombing one of them it's okay all right homework this is now worth 10 percent of your final grade I expect you to spend about four hours outside of class working on homework because we're going to be doing things in class to learn to set up and solve problems I'm hoping that that that will help to mitigate a lot of the office hour learning that seemed to be going on in previous semesters I've taught this class I'm very generous with my time usually outside of class and I think that means that people don't spend a lot of time sitting down and trying to figure out how to do the homework themselves so I'm going to try to force your hand on that by actually making you do homework style problems with me in class okay this will be assigned weekly through Wiley Plus so I'll show you the course website there's a link to our Wiley Plus course page you did you have Wiley Plus the first semester okay so you all should have codes those codes are still good so you can just use those codes register for my section all good to go if you don't have a code you can register on the site and buy one I really recommend you just get the digital only copy of everything because it's generally cheaper as a bumble and you don't have to work on reselling the textbook which we may not even use in another year or two anyway okay and I'm going to have the system assess your answers on your homework and I'm going to have the teaching assistant assess your methods for solving problems so you'll get homework assigned primarily through Wiley Plus it's due Thursdays by 9 30 a.m. so it's assigned on a Thursday typically it's due on a Thursday answers are submitted in Wiley Plus but I expect you to make good quality written solutions to every problem as if it was going to be graded because randomly the teaching assistant will pick one of the problems from your homework and grade that on form did you write oh yeah go ahead do we have to type it into the Wiley Plus system or do we have to type it on paper? No no into Wiley Plus you enter only numerical answers I don't like the whole let's enter a bunch of symbols into Wiley Plus business no that's what teaching assistants are for so I mean human beings are still better at that stuff entering it writing it and reading it than computers so I would prefer to take advantage and save you the time all right so yes you should be writing a good written solutions in pen or pencil as you go so I have a homework in quiz policy I used to give more numerical quizzes I tend to give more concept quizzes now but nonetheless this is what I expect from you and I have a link to an example on the website of a good quality written solution what should that look like from a previous student who generously donated their solution okay so I expect good quality written solutions in English classes they think that they're the only ones that are the arbiters of structure and content and form and method nonsense in science it's just as important to be able to tell a story with math as it is to do it in any other area of life and I expect you to get good at writing good clear linear solutions with words explaining things that need explaining and otherwise using good handwriting and written equations and step by step because the teaching assistant is going to look at what steps you put down and if you have you know equation number one equation number two answer what I joke is then there was a magical operation in there called a miracle occurred and you get no credits for miracles I want to see what you did between equation one equation two and final answer and the teaching assistant will grade accordingly okay and if your written solutions are suffering then I want to talk to you because we need to figure out a strategy for you to make that better all right so half of your homework grade five of that 10 percent will come from just getting the numerical answers right that are assigned to you the other half comes from a full assessment of your solution not the answer the process all right so the teaching assistant will not grade you on your numerical answer you don't get dinged for that twice you could get zero on the numerical answer because you were one decimal place off because of a calculator error and a hundred percent from the teaching assistant because your process was fine but you just had a calculator bar for the end right so you got to get the habit of double checking and triple checking your calculator methodology I'd say seven times out of 10 last semester and in previous semesters it was just punching things into a calculator in the wrong word otherwise everything was fine and the student was totally stressed for no reason okay so build a tense but understanding relationship with your calculator don't trust that thing trust but verify that would be my advice with a calculator okay it's like that friend that's going to stab you in the back at the worst possible moment that's what calculators are okay so exams as I said they're four per semester they're in class they're 80 minutes long so they fill the class period and they each cover a specific subset of topics and they're each worth 15 percent of your final grade so exams are worth 60 percent total of your final grade okay so we've got 65 and 10 what's the remaining 25 percent well I'll talk about that in a moment comprehensive physics knowledge will be assessed separately in another method so the final exam is not cumulative it merely covers material that wasn't covered on exam 3 that's different from previous semesters okay the grand challenge so you should all have a form and a problem all right the problem is the same for everybody in the class and I'll just read it out loud this is an open-ended non textbook problem okay there is no textbook answer to this question so you have to think you have to be creative you have to invent and then you have to calculate a patient bored before their MRI exam rubs their feet aggressively on the shag carpet of the waiting room shag carpet my waiting room is this also a bit nervous they unconsciously scratched the small dark blue circular tattoo on their left arm soon after they were placed in an MRI machine describe at least three interesting things that could happen to this patient when the MRI machine is turned on okay now you can google and in fact I encourage you to google if you're confused about where to start on this that's perfectly fine but what I want you to take away from the policy on this is that any source that you use to get inspiration any whether it's a person a website whatever start keeping notes about what you looked at I want you to start documenting your sources all right you as an individual all right this the answer to this okay and you have to identify three things that could happen to this patient and document them with mathematics and numbers as needed it's due no later than five p.m. on the last day of classes all right so you have from basically next week officially to the last week of classes to work on this piece meal through the whole semester it will seem overwhelming at first but there is a structure involved and you can please please please please read the grand challenge instructions to see what I envision for this to help you okay it's a group exercise random groups will be constructed in week two that's after the ad drop date I want you to give your team a name please how did I say this now I want it to be something polite and nonoffensive I was I was very politic in my way of saying oh yeah choose a name for your team be creative but also polite and respectful with your choice make sure everyone on the team agrees with it okay all right so you're working teams of we'll see how many people are left after Friday but let's say five to six people okay I expect you to meet as a team outside pick a time pick a restaurant whatever pick a cafeteria you don't have to meet for very long 15 20 minutes and otherwise you can just ignore each other's presence and text or whatever for the rest of the time but I really want you to meet it's what I do and I'm in a group situation what do you do all right I want you to meet outside of class as a group and just talk how did that week's lecture material maybe get the juices flowing on a possible thing bad or otherwise that might happen to this poor patient when the MRI machine is turned off okay and I've dropped a few clues and they're about directions you could go and but you are free to go in any direction you want with this that's the beauty of this you can take the little clues about the shag carpet and the tattoo if you want that's up to you but if you would rather go I wonder what happens to the protons and this person's body go for it just have at it okay it's perfectly fine anything is fair game as long as it can be physically defended and justified so I want you to think of this as sort of combining rhetoric with physics you're going to come up with a bunch of ideas but you need to defend them and you need to defend them using physics and math I expect you to write words too but I expect you to show me that your words have meaning by using mathematics okay um I know group exercises oh great I'm going to be graded as a group yes and no 80% of your grade will be the grade that your group gets on the write up 20% of your grade on this will come from questions that are given to the members of the team that handed in that write up on the final about the write up because I want to know that each and every person basically understands what was in that write up I don't want one person to be pulling all the damn weight and the rest of you to be doing nothing okay and no doubt I'm going to get in your full about that anyway during the semester so and so is not showing up at the meetings and then we'll have a little talk with so and so okay so so the nice thing about this is there's group shame which is great right and then there's there's professor shame which is even better so I expect everyone to pull their weight in some way and there's very clear instructions you know there's a title page for the write up a collaboration page you name your teammates and then you list their contributions next to it this is what we do in physics so why should it be I mean it's what all scientists do you have collaborators you list what they did okay medicine you do the same thing so you know you'll have an alphabetical author list for your team name and then what they did and then the write up that everybody contributes to I'll talk about this more next week but I want the teams to pick an editor a lead editor that person's job is to really collect everything into a document they don't have to do all the writing you should delegate okay but you know there's some tips in here a pro tip use a collaborative editing system like Google Docs or whatever Microsoft's Skynet thing is or whatever so sky cloud whatever you like okay use use what's convenient for you to to get some work done all right so I expect you to synthesize work from the first semester with work from this semester now we're going to learn as we go so you might not have any ideas right now about where to go with this that's cool it's fine I don't expect you to have three answers in the first day but I do expect you to pay attention as we go through the material and reflect back on the question and then think of anything that we might be helpful for getting to some solution okay I'm also going to provide you with a written an example of how I expect the written solution to look still kind of working on that because I'm writing it alone I don't have a team to rely on here but I picked another question that I didn't give you guys I'm going to try to answer it so the question I'm looking at is what happens of all the electrons in the solar system suddenly move to the sun explain three consequences of this okay so the first thing I have to do is calculate how many electrons that are on the solar system and I didn't realize how difficult that was going to be so I'm still working on that all right it's okay I'm going to teach you about approximations this semester too I will check you once per month so we're going to meet me and each of your teams we're going to meet we're going to talk you guys are going to tell me where you're getting stuck you're going to tell me I don't understand this problem I'm totally lost I hate this class fine we'll just get that out of our systems and then we'll see if we can find a way forward okay and again I want you to see the handout for full details on this this is a new feature for the class I'm pretty excited about it I think it's going to be better than having a big cumulative final that you're all scared to study for you can work on this piece meal through the entire semester and I expect you to draw from three different areas of the course I don't expect you to do all electrons and then more electrons and then something else happens with electrons I want you to do this something electrical that happens something magnetic that happens maybe this magnetic phenomenon or that electrical phenomenon and then kind of pick your way through it and then come up with three things that might happen to this poor patient when that machine is turned on and nothing is not an acceptable answer okay unless you can defend it all right so any questions on this all right well you'll all go home and then go like in about an hour okay and then realize what I've just asked you to do all right so don't get stuck get help I have office hours Monday to okay how many people can make Monday two to three p.m. all right let's do it this way how many people cannot make Monday two to three p.m. raise your hand high high high high high okay how many people of the people with their hands raise keep your hands up hands up hands up how many people cannot make Wednesday 11 to noon put your hand keep your hands up if you can't make it okay so I think I got a majority of people the teaching assistant is also going to arrange office hours and we'll likely do this by poll okay so the poll I will send up to the whole class but I will at first I would like people who can't make any of my office hours to respond to the poll for the teaching assistant and then we can have other people kind of lump it all right so I'm going to expect you to be honest I'll explain what I expected and email all of you all right so the TA led help sessions will be announced my office is very tiny for any of you that have ever seen it before I cannot possibly fit all of you in my office even just the people that raise their hands the varsity is where I like to have my office hours so I just pick a table and then it's just a nice place we don't kind of spread out and sit down okay so I find it's much more relaxed and my colleagues tend not to drop in and think that they're owed a chat with me you know when I'm meeting with a student I'm meeting with a student but my colleagues expect me to interrupt what I'm doing they leave me alone this is great so you help me I help you how's that sound we'll go to the varsity and we'll talk physics there's also of course the learning enhancement center it's in 20 I think it's still in 202 Lloyd that's the northwest corner of Ford Stadium behind Meadows Art Museum there's a link there in the slides which I'll post after the lecture physics tutors are available they often are drawn from our physics majors or minors they tend to be excellent so if there isn't a physics tutor let me know and I'll talk to the director of undergraduate studies and we'll see what we can get set up okay and of course you can always get a private tutor there are physics majors and minors who might be interested in taking cash and teaching physics as long as they don't have a conflict of interest it's okay for them to do that so the TA can't be your tutor can't take money from you all right don't let them do that hungry little graduate students we pay them they should know better all right so all right so here's what a typical week will probably look like I didn't list the four hours of stuff outside of class and the four hours of homework out of class but on Friday what I would recommend you do is take that homework that was assigned on Thursday and make sure that by the end of Friday before you go out and have a nice weekend you look through each and every problem assigned and just make notes which ones do you think are going to cause you problems which one is just a WTF I have no idea what's going on in this problem okay as the course goes on I'll have to start cursing like a sailor so just get used to it Saturday Sunday have fun but also please really work the homework okay I would just really try just try just try a problem like here and there and don't pick the ones you think are going to give you problems pick the ones you think are easy get those out of the way okay get the low hanging fruit by the end of Monday so you know office hours on Monday let's say Monday afternoon you should have at least tried to submit answers to the online system for any problems where you felt good okay if those are right you're done all right you understood it move on go find the difficult ones and come speak to me at office hours about problems you're having okay and of course repeat rinse and repeat Tuesday Wednesday keep trying if you get stuck talk to the TA talk to me and then Thursday morning 9am that's when everything has to be sign sealed and delivered on Wyler Plus you're graded on whatever is in there at the time and then you bring your written solutions to the class and you put them right up here okay and then I'll give them the TA and Andrew will randomly choose a problem of his own liking because it's evil or whatever and then he'll see how everybody did okay and then rinse and repeat exams will always be on Thursdays so we'll squander three class periods doing exams during the semester okay and that's what I've already told you basically I mean so the range of hours I expect people to reasonably put an outside of class outside of these things is six ish to nine ish hours that's what I would expect for a three credit hour course okay so roughly four on learning and roughly four on homework so four on learning four on doing yep well I'll give you example exams before the I'll get to study from and to practice I'll give you sample exams before the actual that's going to be pretty similar identical in style yeah yeah yeah yeah no I don't like surprises you shouldn't like them either so yeah okay good that's the right attitude no I don't like surprising people I mean yeah you won't know the exact content of the questions but the format is typically something like five multiple choice concept questions and two to three kind of depending on how intricate the problems are two to three problems to work I mean you got 80 minutes what kind of reasonably expect from people right I can't go crazy here so and that seems to be hard enough I mean I would say students give me the sort of right range of reactions to that exam that I would expect people who are struggling struggle people are not struggling don't struggle so that's surprise right okay okay so there you go if you like pie charts 10% homework 5% quizzes 25% grand challenge 60% in class exams most of your grade is coming from individual performance by the way for homework feel free to work with people and if you do work with people just list the names of the people you work with at the top of your homework so I know who's working with whom be honest in science we collaborate all the time we just report with whom we collaborate you should do the same now at the end of the day you need to be able to perform on your own during exams so if someone else in your group is pulling all the weight or if you're working with a group or everyone else seems to know the answers all the time or you're totally lost like the problem I had in college get out of that group bad group move on to some other group find a different group okay and also be cautious if you're getting private help from a physics major you already know they may not remember what it was like to struggle through this class or a class like this and they may be talking up here and you're just trying to understand things down here right and I've seen this happen so be a little careful if you just get help from a friend in physics they may not be thinking like you're thinking to them there are eight tricks that they know like that to solve the problem but that's because they've seen the problem before you never have I try to put myself in your heads as much as I can because I'm getting old so that's getting difficult but I will do the best I can to be sympathetic and empathetic with all of you I know that this is your first time really seeing this material how many of you have physics in high school okay all right this is gonna be a little bit different but that's good that makes me feel a little bit better I do use calculus during the semester okay and so the first homework that you have is really just a let's see where is that this one here is really just a spot check I know some of these questions you're gonna look and go why is he asking me to do this but just do it get it done move on all right this is due Thursday morning 9 30 a.m. okay there is no online for this this is just my own homework that I write up for you guys I just want to see where everybody is strong and where everybody is weak in algebra geometry and calculus because those are the things we exercise that's muscles through the semester I don't expect you to just be calc geniuses we'll get there together okay physics is a way to teach calculus without just having to be all about the calculus all right so again just take a look at this it's due Thursday in class by 9 a.m. so just put a pile of them your answer is up here try to follow the guideline so this is a good excuse to read the homework and quiz policy guideline so you know what format I expect don't write your answers on this and then hand it in that's not gonna get you any good grades on form okay so this is a dry run I want to see how well you guys can follow instructions and also how well you know how to do math okay so I hope you have lots of resources you've got me office hours you can you can you can arrange other discussions with me outside of office hours but please be polite and do that by email about a day in advance before you actually would like to meet with me because I need a plan if I have time free in my schedule I devote it to research I make commitments to students I make commitments to colleagues I make commitments to attend meetings overseas by you know web conference so I need to know not 10 minutes before you want to meet that you'd like to meet because there's a good chance that time is already been scheduled away okay if you waited too long so please please there's one of me and a lot of you so if you need help do not be shy about asking you should ask for help if you're stuck on something I'm your teacher I should teach you okay but I just need a little advanced morning okay the teaching assistant will set up for sure at least one help session per week we may need more than that to cover the people who can and can't make various days but in addition I will ask him to set up his own like office hours he could sorry you could contact him as well I'll give you his email address and if you need help outside of class you can ask him as well but again be respectful of his time too he has other commitments as well besides his teaching so it's just good form to you know give somebody enough advance notice that they can schedule it this is the website okay so again I will host these slides this is the course website let me see if I can bring this up so you see what it looks like okay so this is what the main course site looks like pretty graphics blah blah blah bunch of boilerplate stuff important things that are here this is the wildly plus with Orion course page we're using the 10th edition of the book so it all comes bundled if you have the online learning system it's all in there the book and everything else student solution manual it's all in there for you okay and then there's lots of information here if you're not sure how to sign up for an account about I made a whole folder of wildly plus stuff okay so this is all stuff that the company sent me to give to you guys so it's all here if you need it you can print it and kill trees if you need it all right I feel really guilty about that pile of paper I'm just for the record all right so lots of stuff about you know my office hours and then the TA your grade composition links to the grand challenge guidelines just a bunch of stuff here that I've already talked about and then if you click on class material this is the this is the meat all right so there's a link here to the material that I've handed out today so this is the first day material homework policies syllabus all that stuff okay so you can take a look at that the current lecture is always highlighted in green I did a little programming and made a nice little web page that does this for us and the past classes are highlighted in gray so the gray ones have passed already we're currently on this period of course there's homework assigned so this is a link hopefully to the the homework assignment I'll fix that that's easy enough to fix I know what the problem is there you have a paper copy anyway and now this is your reading assignment for the next class okay so this is the when I say reading assignment this is what's assigned today that you will be quizzed on next time all right so I can make that clearer if you need it but I'm going to say it out loud now this class is what we'll then have quizzes on and discuss with problem solving and so forth next time okay so that's what I expect you to do there's no lecture video to look at for this I just expect you to go and read and take notes and then we'll start playing around with the stuff in this chapter when we get to the to the next lecture okay and then so forth you know march is on keeps going okay questions yes so will there be a quiz yes there will be a quiz and it will be a combination of stuff from the reading and I really do want you to go through these policies so I might throw in one question from one of the the syllabus or something like that just I want you to read please take that seriously because what's going to happen otherwise is in three weeks somebody's going to go I didn't know that that was on the syllabus and I hate that I was wanting to get a t-shirt that just says it's on the syllabus so so yeah there will be a quiz at 9 and 35 ish at the beginning of next class and it will cover conceptual stuff from the reading there won't be any calculations you have to do it's just concept questions to make sure that that you're following along that's all okay yeah the extended access is that a textbook or is it online well the textbook is all bundled into that wildly plus thing online so the textbook is already there is that what you meant or there's a extended access on the textbooks it's like the first one so it's recommend it and then there's another one that says it's just oh the flyer let me go about that let me go back to that see what I said there oh that that's exactly it so that I mean so that required thing is all here it's all in this wildly plus with a Ryan course pitch thing okay so it'll be at wildly plus last last then you you've already paid for it you have it already not last semester but last year oh last year it should still be good try your code and if it doesn't work then I'll send you to the wildly representative for our institution and she'll get it sorted out for you okay all right any more questions okay then let's talk electricity and magnetism all right so what I'm going to do is this going very exciting okay so uh I have here an ordinary PVC pipe okay so this is just plastic can you verify that there's nothing funky about that no batteries nothing like that okay right yeah it's like it's a magic show right nothing on my sleeves okay actually magnets up my sleeves all right I also have here a very simple yes recently cleaned soda can okay so again nothing funny about that right you're not even gonna look this is your terrible magician's assistant here all the shields are in the front row anyway look inside no batteries blah blah blah okay what's your name Alex how okay all the plants are in the front row right that's how that always works so all right and again if I there's nothing funky going on here so if I rest the can on its side all right and I move the plastic around absolutely nothing interesting happens this is just boring as sin right okay well sin's actually quite interesting but anyway we'll we'll get to that all right so all right now I have an ordinary paper back and what I'm about to do is something called tribal electricity so tribal electricity is the inducement of an electrical phenomenon by rubbing that's it all right so how many of you ever played with balloons at a party like rub one on your head and then stuck it to the wall of the ceiling okay great that's tribal electricity it's got a fancy name everything's got a fancy name right uh there's a word for everything so tribal electricity is just rubbing okay and what's going on is that the atoms in the surface of the paper bag and the atoms in the surface of the plastic are passing by each other they're not actually making physical contact in fact when you touch a surface you're not actually making physical contact your atoms are never actually touching each other your electrons don't touch your the electrons on the table the nuclei in the atoms never touch the nuclei in the in the table atoms are mostly empty space what's going on though is obviously solidity my hand doesn't go through the table even though my hand is mostly empty space and the table is mostly empty space if you actually know the structure of the atom why and the answer is fundamentally electricity the reason my hand doesn't pass through this table is electricity but to understand that you need to understand something about the electrical phenomenon and the force that's associated with it otherwise this makes no sense once you know something about the atom this makes no sense because your hand should pass right through the damn table but it doesn't and that's a good thing all right so if I just rub this the atoms are passing by each other and what's happening is that because these are two dissimilar materials with different chemistry different numbers of electrons in their outer shells some of which are very easily removed the friction strips electrons from one material and places them on the other I personally don't care which is which because I can just demonstrate there are two charges using dissimilar materials but now that I have a charge built up on this I can make the can move why that happened at all is fascinating this thing had no force associated with it originally let me drain the charge off this and me okay I can remove the electrical phenomenon that's called neutralizing the material I can make them what's called electrically neutral where there is no net electrical phenomenon anymore and simply by rubbing I can induce that phenomenon now okay who has hairy knuckles that's the spirit what's your name what's your Jerry all right you feel something the hairs yeah yeah okay so what you're feeling is something called the electric field that's the way we describe this it's it's gone by many names in the history of science spooky action at a distance force at a distance action at a distance basically it's a force that's transmitted through space with no physical contact and the way that we describe this we'll get to in later chapters is something called the field concept but with no physical contact you can feel the force and what happened to the hairs in your hand they stood up a little bit kind of tickled a little is essentially what's happening to the atoms inside of this can so this can is made from aluminum okay aluminum is a very good electrical conductor that means that charges placed on the aluminum are free to move with very little resistance not zero but very little resistance wherever they like and in fact right now in this can if you were to zoom in and could look at an atom those atoms are jiggling around because the room has air molecules and the air molecules are smashing into the sides of the can and that's causing the atoms in the can to vibrate in their little metal crystal lattice positions and so this whole thing is actually vibrating very fast but atoms are tiny and we're big and we don't see that we experience that jiggling as heat all right so when you put your hand on a hot plate on a hot stove or by a fire your atoms begin to jiggle in response to radiation on your skin or if you make physical contact with the metal element heating element the vibrating atoms in the metal and you feel that as heat okay that's the vibration of atoms it's atoms in the material crashing into the atoms in your hand and that can do real physical damage if you're not careful just like electricity can do real physical damage if you're not careful so what's going on is that because this is a very good conductor and charges are free to move inside of it even though this has no net electrical phenomenon associated with it at first if I submerge this in the electric field from the plastic when I put a net charge on it I can make all the charges move to one side of the can okay so I can make the charges that want to be closer to the guys on the plastic come closer to the can and all the other ones move to the other side and then as the can rolls those charges get pulled down and then they move back up and then the can rolls again the charges move back up they really want to be as close to the electrical phenomenon as this is I can possibly as I can possibly get that's the cool thing about conductors charges are free to move and you can do the can you can change electrons and charge into mechanical energy very quickly just by tricking the electrons in here to move through the surface they can't leave the surface I could make them leave the surface by say striking this with lightning that would be a good way to get all the charge off this thing but I don't want to do that that would destroy the can now Ben Franklin was one of the first people okay how many people have heard of Ben Franklin let me start there okay yeah so famous historical figure in the United States founding father of the country blah blah blah but a scientist as well okay scientist statesmen all that good stuff one of the things that you investigated was this electrical phenomenon and you know there are famous apocryphal apocryphal stories about implying kites and thunderstorms he wasn't an idiot he knew how deadly thunderstorms were he would never do that experiment holding a kite okay I mean he might have tried this with the kite staked to the ground but he wouldn't have gone anywhere near the thing it's been Franklin that we can thank for recognizing and then giving names to the two different kinds of electrical phenomena that appear to be in nature there are positive electrical phenomena and negative electrical phenomena and the way that you can see that there are two kinds is what I hope will be this semester a simple and functioning demonstration this didn't work so well last semester but I'll do the best I can all right so I have here an evacuated glass tube sealed at both ends okay so glass and plastic are very different materials so what I can do is I can put this in this little noose try to balance it balance it balance it better very exciting right I get paid big bucks to do this okay there we go so what I'm going to do now is I'm going to drain all the charge off myself what I'm doing here is if I have a net electric charge on me even a little bit I can remove it by touching a conductor that goes into the earth the earth is a very greedy sponge for for extra charge it's sort of part of the problem you have the lightning storms all right but it's this is called grounding yourself literally you are connected to the ground and it's a great way to leach extra charge off yourself it's also what gets you in trouble in dry winter conditions when you roughly are socks across the floor and then touch metal so yeah yeah yeah the car is usually grounded because it's making contact somehow with the ground and so if you rub your butt against the cloth seats and now you've you've had the tribal electric effect you rubbed two dissimilar materials together you have a net charge the car seat has a net charge but unfortunately you're the one that touches the metal shell of the car so you get a little jolt this is also why they tell you that when you gas up your car when you get out of your car ground yourself if you have a net charge on your finger and you go to gas up and the spark jumps into the gas fumes boom this is what causes gas pump fires it's not cell phones right that was a big myth that was propagating in the 90s and early 2000s it's static electricity and it's because people that talk on their cell phones get out of their cars without using their hands because they're talking so there was a mis-correlation with cell phones and gas pump fires it wasn't the cell phones that were doing it it was the fact that you kind of get out of a car and you stand up and then you go over and you get the gas pump and you start pumping it up you never touch something that's grounded when you do that if you have a free hand when you get out of the car you might grab the roof of the car kind of push yourself out all right so it's that that saves you when you're not talking on a mobile phone all right so yeah pump fires actually yep that's what causes that spark all right so what I'm going to do now is I'm going to put a charge on the glass whoa here I should knock that more tight but let's try that again and then all the excess charge off now these are dissimilar materials let's see if I can oh I knew this wasn't going to work in front of you it works fine before class oh there we go what's that doing it's speeding up what if I go to the other side power of my mind there is an awakening in the force the dark side and the light okay excellent I have a tunnel mirror okay great so whatever the electrical phenomenon is here this is an attractive force I can put the plastic which is charged on either side of the glass which is also charged and apparently they're charged in such a way that the glass wants to follow the plastic all right now let's repeat this experiment with and then again grounding things okay let's repeat this with a plastic rod instead similar material to what the the pvc pipe is made from okay so again charge that up all right so the previous one was attractive then you know that charge the dark side the repulsive force it doesn't want to be anywhere near it can I reverse the motion yes fuel the power of the force I grew up the Star Wars just in case so and I really liked Palpatine all right so so what have we we always see we have done what in science is called an observation there is an electrical phenomenon it appears to have two aspects one attractive one repulsive it seems to be related to dissimilar materials and similar materials if I rub similar materials whatever charge I'm putting on the pvc pipe if we imagine that like charges repel each other I'm also putting on that plastic but if I take a different material and rub it with the same material it must be that the charge transfer goes in the other direction and so if this has a negative charge let's say this one has a net positive charge and they attract each other whereas two like charged objects repel each other and it's these kinds of observations made over a long period of time that led into a final mathematical understanding of what was going on here so with that in mind enjoy your reading we'll have a quiz on that on Thursday morning do your math homework this is a chance for us to diagnose any problems in math right now and I'll see you Thursday