Accused can pick up a copy of the Smithsonian Magazine we publish them every month they are fantastic readings while you are waiting at the Doctors Office or whatever. Theres a handout you can also pick up on your way out and you will also notice tha that weved some post cards on the table. Two Nights Program a program in for science people and not science people and a way for you to curate. If you are curious about that, talk to me or check it out online. A couple of other orders of business, please silence any mobile devices and take the time to do so now and you will definitely want to do that tonight because you will notice we have cspan in the house. Tonight we have a professor of physics at th the university ofe sciences in philadelphia. His interests range from space, time and higher dimension to cultural aspects of science. The recipient of the fellowship fulbright scholarship and the literary award shes appeared on the history channel, Discovery Channel and pbs and is the author of science books including the quantum. Without further ado, please join me in welcoming doctor mohammed. [applause] i am delighted to be here and i think the associates for inviting me back. This is my second appearance for the group. The first one is about someone who may be more familiar to all of you, Albert Einstein. A couple weeks ago i gave a talk about all the einstein and i think it is fair to say that Everybody Knows who Albert Einstein is, so if you see this face on a poster, on a tshirt that everybody immediately recognized as alberrecognizes a, probably the most famous physicist of the 20th century, but im going to be talking about two other physicists tod today. He did some Television Shows where he explained the science to the general public. He was on the bbc and some american programs and he had a knack for explaining science. He was on some Television Shows including a film about Stephen Hawking and the Popular Science shows on pbs and other channels. You see him with the favorite venue he really enjoys drawing the diagrams and explaining them and that was one of his things. They investigate the Space Shuttle challenger disaster. Finally he made a name because he disagreed with the panels conclusion and he thought that it was too light so he thought that there was a direct reason for the disaster that have to do with something called the orings of the shuttle and he thought they were manufactured properly and we see a picture of him and an image of him dipping it into ice water showing that it was brutal when the experience calls which he thought the cause of the challenger disaster and he brought his own report from the commission explaining that. People that knew him knew that he was somebody that was very blunt and was investigating science and trying to get his roots to things. He was known in the 1960s for winning the 1965 guys. So this was the prize he won and heres the more serious picture of him. His favored part was the dancing and he wasnt so keen on being honored. He thought it was an honor to. It was a blessing he didnt want to be known as a Nobel Laureate he wanted to be known as an every maeveryman and common perh extraordinary guests to surprise people, Something Like a magician who could pull tricks out of his hat and he was someone who wanted to be a common person but then at the same time somebody with extraordinary tricks that could surprise and shock people. So he was known in some ways as much for his unconventionality as for his physics. So he wants to drown and he would stay up all night with his own go drums or congo drums and play into the night so people knew that he was around because they could hear his loud drumming and here is a picture of him come a portrait at a Costume Party that was run by his student. She used to have these themed parties and this is one of the. Also its shaped like one of his diagrams. He was in the musical and this one was very special. This one was itself pacific and he played the chief of valley high. The story in this we heard from the doctor a wonderful woman named shirley who directed the play is at caltech and some years before this she was staging a play and needed somebody to play the drums and the student producer said how about Richard Simon and she said who she said okay. If this professor can come and play thdrums he can participatee play and then she found out some more and realized that he was a Nobel Laureate and she got all intimidated and when she met him she said hello, just call me a dick. I dont want any pretense. And in a position like the drummer or a performer he didnt want people to prefer to the specifics but someone different because he wanted to amaze people in so many different ways through acting were drumming or music and all different things. He knew the skill and do it so well. It happened a few weeks after surgery in the early 1980s and he needed more than 100 pints of blood because a blood vessel near his heart burst. He survived in a couple weeks later was the play and he wasnt going to do it. So they talked him into it. It called for someone heroic that would dive into a pool to rescue pearls from him even and come back up and in the process gets bit by a crocodile and thats where you got your scar so he said i guess i should do the play so he got up and only had enough energy to call out some lines. When the spotlight was on him all of a sudden everybody was completely shocked. Here was this guy that famously were disturbingly almost lost his life and blood drive saved him and now a few weeks later he was on the stage and they got up and gave him a standing ovation and then here he is speaking to a commencement address in caltech. He has the mannerism of the preacher and told. Dry jokes. This is john wheeler being honored by president johnson very quiet and conservative in his outward appearance he was much more radical and was extraordinarily light within his ideas. He thought about the whole universe and tried to remake the whole universe fundamentally from scratch. He went through different phases where he thought it is the one element that the universe is made of . Hed become driven by that and try to store the implications of that as much as possible and then see what drove these diagrams and you would see he would fill up a blackboard from left to right including things like black holes and wormholes and things like this to explain and he was a revolutionary in the same. A lot of ideas we see today mike black holes and quantum physics ideas come from so from his clever mind came things like wormholes and connections. No matter what you put into a black hole you see they throw themselves in that it can only tell you three things about itself. Its only these three things so he compared that to Something Like a marine or soldier who could only report his name, rank and serial were supposed like you said they had no hair so that is a quote from him that they are indistinguishable and here we see a diagram of something called the participatory universe. He wrote down his ideas that are preserved today as the American Philosophical Society because if you are a scholar you can go in there and look through the notebooks and see all of the strange ideas that he came up with over the years and the diagrams for them and then this is a portrait of one of his Favorite Places which is an island off the coast of maine where he would sit and think. And he loved the coast of maine where even though it would be that cool chile he would sit there and write and think. He would sit there and think. Let me go back in time now to september, 1939. It is the time that the pivotal papers are publishe were publise journal called the physical review. He worked with him over in denmark. Then he worked with him over the United States to try to unravel the secrets of Nuclear Fission. This was important because once it was discovered in germany and they were worried about the nazis developing an atomic bomb, so somebody named lisa who worked with a german physicist knew about this discovery and told him. He came to United States in january of 1939, gave a talk in princeton and revealed to john and others including Albert Einstein the germans, Nuclear Fission program that the germans created Nuclear Fission and einstein wrote a letter to roosevelt. Suggesting that it be available to the United States research it. That took a couple of years. That is when the Manhattan Project got off the ground. The other paper in physical review aside from the Nuclear Fission paper was a paper by Robert Oppenheimer on black holes they are just cold collapsed stars and oppenheimer speculated in september 1939 that a large star come if it was large enough, would collapse down into something that is so ends. Other physicists pretty much ignored the paper and thought it was kind of a quark or made a mistake and that peter was forgotten from 1939 until the 50s or 60s. The person who discovered it was john wheeler and he discovered it when he looked at the paper again. He looked at the same issue and thought this stuff is really interesting. So he resurrected the idea before collapsed stars that came black holes and today they were a very important part. In the fall of 1938 but then 1939 in the second year was when he got off the ground with his research. When thinking about the prospect of the germans developing, he didnt really think about that too much because he didnt think that the United States would even get involved in world war ii. He was of the opinion that we wouldnt get involved and that people like and rico and einstein and so forth for a little bit too worried about Nuclear Fission and it wasnt something to concern oneself with that time. Later, he regretted this profession and i will explain why in a few minutes. So here he is at princeton and reading a book. He lived in the graduate college and worked with wheeler as a teaching assistant so his job was to be a teaching assistant and he already named a name for himself many times does a brilliant thinker even at the young age of 21. He has three articles already in the New York Times about his work by the age of 21 so the first on21 to thefirst one is wh school. He won a mathematics competition. He was the highest scorer. He was brilliant of calculation. He was always good at turning out results, computing. And then he was in the honor roll and took a competition. He came out the highest individual score in the country for the competition. Harvard offered him a full scholarship to go there as a graduate student that they discouraged because they wanted him to do Something Different so he wanted to go to princeton because princeton had this amazing smasher in his basement in the Physics Building where particles will circle around many times this year to magnets and then just at the right moment would smash into the target producing all sorts of other particles and finally he was fascinated by the idea that he could look at those results and do calculations and make predictions about the particles. He liked to calculate and come up with an answer to a. How does it fit into the bigger picture. It would steal him in that direction. He needed to meet to discuss his teaching responsibilities. He needed this responsibility to look for the mechanics course. So they read a book called mechanics and this text burke antext forpanther with the home assignments. There were a lot of procedures people out there and the other had his offices final and he was painted as a young assistant professor i need to manage my time. So he had a pocket watch and put it out on the table. Simon looked at it he was a little sneaky and went to find a store and bought his own watch. A friendship was born at that moment. And from that point on, they had a friendship based on joking with each other and also being very honest with each other and inspiring each other to spire the most farflung ideas in physics but then to try to make something of it to come up with a calculation that would make sense and match reality. So, you can guess whose job was the idea and then to do the calculation was simons job. It made an unusual pair and simon would wear Shirt Sleeves and have a very thick accent, spoke very loudly sometimes come at it an,didnt use the best la. He was very genteel, always watched his words very carefully. But the two of them got along very well. He admired his ability to be a little while and not care what other people think. He admired his family life and was nice to people, so in a late life interview, simon said i wish i was as nice as we are inviting students to my house and being really kind of two people. Well, simon was kind of people that he also could be kind of moody. Wheeler was always very, very straightforward with people. And if youre a kind person. Now of course simon also had his bongo playing side which go brot him a lot of press. The. He was much wilder. This was between september, 1939 in december, 1941, which is summer 1981 is when a lot of physicists were recruited to work in the Manhattan Project including wheeler and simon. They both took on roles in the Manhattan Project at this time. So, when you look at this timeframe, it is Pretty Amazing what they got done in this period with less than two and a half years. Simon did all the work that he needed for his thesis, for his doctoral thesis and in less than two and a half years. So, let me talk a little bit about the Research Together. So, the Research Together became known as a wheeler signed an observer theory. Well, which was all that about . Well, that had to do with how electrons interact with each other using electricity or the electromagnetic action. The standard picture at the time, which is now the picture today is modified is that when an electron interacts with another electron, they share another particle called a photon which is the carrier of the electromagnetic force. So, one elect john oscillates and then it gives off a photon and that its another s survey y dont sit bacbalance it back anh each other kind of like to volleyball players might dont they volleyball back and forth between each other and that creates the interaction between the two. So, you need the intermediate particle just like you need to e volleyball in a volleyball game to create the interaction. So the great physicist calculated how an electron could interact with itself to create kind of a ball of charge, so the model was imagining this as a ball of charge and these charges are going to interact with themselves using the photons ph, and if you calculate this using direct fear he which was developed in the 1930s were the late 1920s and early 1930s, if you do this calculation, you get a very strange answer. Also if you compute the energy of two electrons interacting with each other, using that you also get an answer of infinity. And many different calculations, using direct method give you an answer of infinity. Which is very unsatisfying. It is a crazy answer so in order to address this, Richard Feynman thought of a radical idea. He said well, the problem that youre getting infinity with disasters can be eliminated if you just eliminate the intermediary. Eliminate having a photon or a light particle exchange between the two electrons. We all know that there is light out there and it will be produced by the electrons themselves. Through their mutual interactions which would take place over a distance. This is known as the action at a distance theory. The action at a distance theory was not new. Isaac newton when he was talking about the plan is going around the sun, use the action at a distance theory to explain why earth and the other planets are gravitationally attached to the son. Newmans idea was that there is Something Like an invisible threat connecting hours and the other planets with the sun. Well, later, maxwell, the great scotchman says in the 19th century, wait a minute. Lets come up with an idea of intermediaries like something called a field which would be an intermediary, which would convey a force from one thing to another. And in the case of electromagnetism, that field was called the electromagnetic field. Which would be kind of like a wave going from one to the other. The quantum version of that is to say in quantum physics, a weight is the same of the particle. A wave is like a particle going back and forth. And that particle is known as a photon or light particle. And this is called technically known as a wave packet. Kind of like imagine, a little wave like an ocean wave but find to a small region so it is a little bit like a particle. Just like you took part of an ocean wave and created and if like a ball around it and then that is a wave packet. So that is the idea that quantum physics was considering. And this is what feynman decided to eliminate just to get the right answer in a calculation. So he was going back, it was a little bit retro. Going back to the idea of action in a distance with one modification. There needs to be a time delay because as we know, electron interaction with another electron must do so at the speed of light. So he built in a time delay. And once he had this idea is lets come up with the idea of direct interactions between electrons and maybe we can get somewhere with this. And wheeler pointed out a conundrum. He said well, if you have any electrons going through space, theres something called radiation resis