PSW 2370 Particles and Nature of Nothing | David Kaplan

I now call to order the Society's 2,370 a--the meeting in the 140 v years since its founding in 1871 good evening everyone my name is Larry Milstein I am the president of PSW the oldest scientific Society of Washington DC committed to providing a forum to further scientific understanding and inquiry welcome to our members and guests to tonight's lecture by David Kaplan we will begin with a few announcements followed by a reading of the minutes of the 2,360 ninth meeting and a brief recounting of the 32nd meeting of the society that took place in 1872 we will then turn to this evening's lecture followed by a question and answer period thereafter I will present a small thank-you gift to our speaker make a few closing announcements and then adjourn the meeting to the social hour but first please join me in thanking the sponsors of the fall 2016 and spring 2017 lecture series the policy studies organization in cooperation with the American public university and a generous sponsor who has asked to remain anonymous I would like to note that this lecture in particular is sponsored by our friends at the policy studies organization and the APU in conjunction with their DuPont summit that just ended and for those of you who came over from the summit a special welcome and I don't know if Paul rich or Daniel Gutierrez are in the audience but if they are thank you very much Paul and Daniel for your support of PSW are you here ah I think I tired went home it's been a long day I understand they start at 6 a.m. on the Dupont summit I am pleased to announce that the following new members have been elected Debra Bell a museum specialist retired from the Smithsonian and a fellow of the Explorers Club broadly interested in the natural and physical sciences Jessica Rosado a next-gen sequencing project coordinators serving the NIH particularly interested in genomics neuroscience and quantum mechanics Cameron Moy a senior at Kenneth Island High School an Eagle Scout and Honor Society member particularly interested in planetary and space science physics astrophysics and mathematics Bradley skates a chemist with the US Navy interested in the relationships between biology and chemistry and David Kaplan tonight's speaker whose interests will no doubt be clear from his talk tonight please join me in welcoming them to the Society [Applause] if any of our new members are present in addition to David Kaplan please see me after the lecture so I can give you your autographed copy of the first volume of the bulletin of the philosophical Society of Washington in which you will no doubt be fascinated to read why the society is called the philosophical society and why it really should be called the scientific society the minutes of the previous meetings lecture on NASA's explained program by jae-hwan shin and now be read by external communications director Preston Thomas at the cosmos Club in Washington DC on November 18th 2016 president Larry Milstein called the 2369 'the meeting of the society to order at 8:30 6:00 p.m. he announced the order of business and welcomed new members the minutes of the previous meeting were read and approved president Milstein presented a summary of the thirty first meeting of the society held in 1872 president Milstein then introduced the speaker for the evening jae-hwan shin the associate administrator in the Aeronautics research Mission Directorate at NASA his lecture was titled exciting possibilities for 21st century aviation NASA's explained program dr. shin began by reminding the audience that the precursor organization to NASA's Aeronautics mission was founded in 1915 a few years after the Wright brothers first flight thus predating NASA's better known space mission by decades dr. Shin explained that NASA Aeronautics research is responsible for many of the advances that helped bring civil and military aviation from the Wright Flyer into the modern era dr. Shin then showed a recording of the current daily commercial air traffic plotted through US airspace comprising up to 5,000 planes at one time he explained that every flight needs to be managed within defined Airways with strict separation and precise landing and takeoff times modern aviation safety and air traffic control procedures have made flying so safe that an individual such as our president could expect to fly a three-hour commercial flight every day for nine thousand years without experiencing a fatal accident making it the safest mode of transportation in the world another area that NASA is collaborating with private sector to research is ultra efficient environmentally responsible aircraft technologies such as composite wings and fuselage --is Sawtooth exhaust nozzles and non circular fuselages provide substantial weight savings as well as improving fuel efficiency and reducing noise dr. Shin explained that the near-term development and adoption of these technologies could decrease the fuel consumption of the US commercial fleet by billions of gallons of jet fuel by 2050 dr. Shin NEX discussed which he called the dawn of a new era of aviation using composite materials to move beyond the performance limits of the current tube and wing airframe designs future designs being investigated include very long truss braced wings with non circular fuselages and flying wing designs all to maximize the effective lift Arian and engine size while mitigating engine noise unusual engine configurations such as placing them at the top rear of the aircraft may further increase efficiency by consuming the boundary layer air that is closest the fuselage and thus creates the most aircraft drag if engines can be made to operate using the disrupted air dr. Shin noted that the increasing demands for high efficiency low emissions and reduced noise mean that aircraft designers will soon need to find ways to incorporate electric based propulsion into their plans although the weight of lithium-ion batteries is currently prohibitive early hybrid designs may be ready for flight tests as soon as 2018 dr. Shin then discussed the polarizing subject of supersonic flight the 20th century landmark for commercial supersonic flight the Concorde was incredibly loud dirty and expensive if supersonic flight is to be resumed these problems must be addressed indeed due to due to the disruption and potential damage from sonic booms commercial supersonic flight Overland is currently banned in all countries NASA has modeled variations on wing designs to create low boom aircraft and is targeting 2020 for the first flight test dr. shin also addressed the parallel development of unmanned aerial systems or drones and the race for safe integration of UAS into the National Airspace UAS policy issues include not only safe operation noise and wireless spectrum but also privacy and security concerns and simple social acceptance dr. Shin noted that the stakes in this race are enormous because whichever country achieves such integration will reap enormous and economic benefits through the availability of new services and efficiency gains as well as the sale of UAS hardware as the rest of the world follows suit dr. Shin concluded by repeating that the sky is the limit as myriad new aircraft design and propulsion technologies are poised to assure in a new era of flight and new opportunities for US leadership after the conclusion of the talk president Milstein invited questions from the audience several questioners asked for more information about hypersonic flight dr. Shin explained that Mach 5 or five times faster than the speed of sound is traditionally considered the threshold to hypersonic speed the current air speed record for jet propelled aircraft is held by not NASA's unmanned x-43 which achieved Mach nine point seven or approximately 77 thousand four hundred miles per hour for ten seconds one major application of hypersonic engineering would be building spacecraft that can take off and land horizontally like airplanes creating tremendous efficiency gains and lowering the cost to orbit after the question and answer period president Milstein thanked the speaker made the usual housekeeping announcements and invited guests to join the Society at 8:00 at 10:37 p.m. president Milstein adjourned the 2316 at meeting of the society to the social hour temperature 11c weather clear attendance 68 respectfully submitted preston thomas external communications director I thank you Preston are there any Corrections additions or comments on the minutes well wait a minute because I have a I have a I think a correction you said that it was adjourns of the social hour 1037 I think it's 937 since we kick everyone out at 10:00 I was simply misinformed I transcribed as I was provided okay because I was in Thailand at the time you were out of town you managed to find a turkey in Bangkok I did a black market butterball one of these days you'll have to tell us about it thank you do I have a motion to accept the minutes with that one correction we'll have second all in favor all opposed the minutes are accepted unanimously as read and will be posted to the website in due course the 30-second meeting of the society was held on Saturday October 19th 1872 President Joseph Henry was in the chair The Bulletin does not report the time of day the meeting was called to order or the location Joseph Henry was a primary founder of PSW and it's the longest-serving president leading the organization from 1871 until his death in 1878 he was the preeminent American physicist of his time known internationally for his pioneering work on electricity and magnetism particularly his work on electromagnetic induction work that incidentally led to the invention of the Telegraph he and several close colleagues found it not only PSW but also a variety of other institutions to support scientific endeavor and facilitate the communication of field and experimental results and new theoretical and mathematical works among these organizations are the Smithsonian Institution which Hamre served as first secretary the national geographical society the Washington Academy of Sciences and the cosmos club all still active today at this meeting Harry himself gave a talk on the fluctuations of the Nile River the bull does not report on the contents of the talk as some of you may know the Nile was formed by the confluence of the Blue Nile and the White Nile at Khartoum in Sudan the White Nile originates at Lake Victoria and Uganda some 3,400 kilometers upstream of the confluence the Blue Nile originates at Lake Tana in Ethiopia and flows 1,400 miles before joining the White Nile both of these rivers undergo very large annual cycles the flow out of the Blue Nile for instance varies over 50 fold annually from about a hundred cubic meters per second in the dry season to over 5500 in the wet season as a result peak flows on the Nile went undergo annual 40 fold variations from roughly 500 cubic meters per second in the dry season to over 8,000 in the wet season the Nile flooding that the ancient Egyptians relied on for their agriculture was the result of these annual cycles today the flow of the Nile is controlled not by nature's annual cycle but by the Aswan High Dam we can only wonder what mr. Henry would have thought about a dam that controls the flow of water from the vast Nile rivers watershed covering about 20 percent of the African continent and the and most of the mighty Nile itself mister jhc coffin presented maps prepared for use by an expedition to observe the transit of Venus that was them being planned for December 1874 the maps were prepared by GW Hill and were published as part 2 of papers relating to the transit of Venus which I'm sure everybody's read several members of PSW at that time were involved in expeditions to observe and measure aspects of the upcoming Venus transit they plan to use their observations to determine the size of the solar system among other things an effort in which they were actually quite successful Charles s purse and it is pronounced purse made a communication on stellar photometry the bulletin doesn't report on the content of the presentation but notice that the paper on which it was based was to be published in the annals of the Harvard College Observatory and purse did publish a monograph a few years liq years later on the subject Charles purse was a very important American philosopher and scientist of the 19th century he made notable contributions to the fields of geology astronomy mathematics logic and philosophy he founded at least two particular fields of thought pragmatism and semiotics he was something of an iconoclast and not an altogether easy personality and he ran afoul of another PSW member Simon Newcomb for reasons I may discuss at another meeting leading to Newcomb's lifelong animosity to purse in fact so deep was Newcomb's disliked that he intervened personally to purses professional advancement and block appointments that first otherwise likely would have secured finally he beat eliot meets some geek reported on some details social investigation need undertaken on the invest adjustment of census returns a topic of some interest today i presume that he was reporting on methods of statistical analysis but the bolton does not report on the content of his talk we hope nonetheless that his presentation was met with dispassionate analysis and we note that a PSW general committee member Eric Epstein sitting in the second row there is working for the 2020 census to ensure the cybersecurity of their operations and data collection we wish him the best and with that we turn to tonight's lecture on particles and the nature of nothing and it is my pleasure to introduce tonight's speaker David Kaplan David is a theoretical physicist and professor at Johns Hopkins University before joining the faculty at Hopkins he held postdoctoral positions at the Stanford Linear Accelerator Center the Argonne National Lab and the University of Chicago among other honors he was named an outstanding junior investigator by the Department of Energy and a fellow of the sloan Foundation the Cavalier and the American Physical Society as many of you know David also created and produced particle fever a documentary film about the Large Hadron Collider he was nominated for the award for best producer by The Producers Guild of America for his work on the film and he wanted to pot Journalism Award for it among other accolades David also has hosted science programs for the History Channel and National Geographic in online videos for quanta magazine he strongly recommends not being a filmmaker and physicist simultaneously but by his own account he continues to ignore his own advice and tell you the truth I would do if I could get away with it and do as good a job as he has it both he and her Navy at UC Berkeley and a PhD at the University of Washington please hold questions for the question and answer period at the end of the lecture and join me in welcoming David to the podium hello thanks for having me what a great honor and what an illustrious audience I'm speaking to as far as I can tell I mean I I need enough data before I make assertions so you know you try to aim these talks so you you hit the average person in the audience but I think there are no average people in this audience so I may miss completely and I apologize but there is time for Question and Answer afterwards I am a particle physicist there are two types or theorists and experimentalists and as a theorist I'm not allowed to touch the equipment but I am supposed to come up with organizing principles for what we've understood and so I am going to talk to you not about the most speculative possible things that are out that we talk about that are gonna be end up wrong and no one will talk about in 20 years I'm going to talk about things that we already know usually when you're asked by journalists about the latest and greatest in thing you know that that journalist doesn't know anything about quantum mechanics or even how magnets work and so you think well I'm gonna tell you but it's gonna but this is a waste of time let's go back and learn something first so I'm going to tell you things that are known very well and the English language is limited in how you can describe them but I'll do my best it's obviously better described in mathematics I've done the best with analogies analogies always fall short you can call me on things you can mutter to yourself if I've done something of bad taste but feel free to bring it up in question and answer particles and the nature of nothing the first thing you learn when you you've gone past the threshold in learning about physics where you feel maybe I can do this maybe I'm good enough to accomplish something you realize to mistrust your instinct and the biggest discoveries come from assuming that your instinct is wrong in making a leap of some kind and and of nice well-defined moment where that happened is of course the Copernican model of the universe take the Sun and you shove it in the center and we're moving around in some ridiculous speed and of course your instinct tells you that's not happening you're standing still everything's nice and calm and you see the Sun move past you across the sky that's what the instinct says but the great thing about that about mistrusting your instinct and coming up with some kind of guess is once you guess even if you don't feel good about it the next morning it's irrelevant the theory is outside of your body now it's like a song you write no longer it belongs to you I mean maybe ASCAP maybe kind of belongs to you but it doesn't belong to you in the sense that people can internalize it and with scientific proclamations of course you can test it and and that that is the great for me and I'm not the first one to point this out I read this in a nice book by Richard Rhodes this was in a sense a moment in in Western culture where as scientific proposal and in some sense this is not much of a scientific proposal it's just a reorganization of an understanding but a scientific proposal now can be tested lives independently of the scientist nobody has to believe it you can just try to figure out if it's true the other thing you learn when you do research and you internalize it and you forget it's a thing that there is there are two things happening there things and there are laws and what I mean by that is best described by Kepler's desire to understand the universe of course the universe - Kepler was a the Sun and the six planets and the moon and he wanted to come up with the theory of the universe namely a theory that described the six planets and their locations and he noted that there were five platonic solids five perfect three-dimensional regular objects and if you circumscribe those objects inside and outside of each other with spheres in between and you do it in the right order perhaps you can predict the radius of the sphere in which every planet is embedded and so these planets are moving around the Sun because they're embedded in these cosmic spheres and they turn and that turning and that the radius of those spheres can be described by something perfect something else three-dimensional and perfect and to his credit he believed in the data he believed in the data of Tycho Brahe hey his the guy he worked for and the data as far as he could tell was accurate enough to say that his theory didn't work as beautiful as it was he could not get a theory to match the data and he gave up on it and of course even worse he could interpret from the data the planets don't move in circles they move in ellipses and in ellipses not it's now it's not a sphere that the planets embedded in it's rotating around it's some free body in space but he did come up with Kepler's laws namely that the motion of the planet behaved in a very special way special in the sense that no matter which planet you looked at you could say something about it you can say something about its dynamics a is the distance from the Sun to the farthest the planet can be T is the amount of time it takes to go around and then on the other side is some parameter it's the same parameter for every planet it's interesting that they all follow this rule what that suggests is that if another planet was discovered and of course another planet was discovered and then an eighth planet was discovered and then the ninth planet was discovered and then the ninth planet was demoted and then there's arguments and who knows what's a planet anymore and of course other stars were discovered with planets too so how many planets was irrelevant this was something about the history of the formation of the solar system that's not a deep scientific part of scientific research that people do with the deeper part of scientific research became the laws what are the rules if I took I'm God whatever that means and I take a planet and I and I kick it around our Sun I can tell you something about its orbit there is a rule associated with this and this of course leads to perhaps a deeper theory say the theory of gravity and that then is the dist you you can be very attached to something he was attached to his theories he was disappointed and discovered that this we defied these things from dynamics in kinematics or dynamics and the history of the process to create the thing you're looking at so what is fundamental and what is just an artifact of where things started in the first place of course you need data and this was the thing taking the data back then and this is a thing taking data right now it's called the Large Hadron Collider it is a machine that lives about 300 feet under the surface of the earth mostly in France a little bit in Switzerland and it is colliding particles protons parts of the hydrogen atom simplest atom at extraordinarily close to the speed of light and it's colliding them within a large enough structure that you can see what happens when you collide it it is made of bizarrely intricate components components that had to be invented for it these objects their electromagnetic calorimeter x' but do you see they look like a crystal they're transparent but they're actually 99% tungsten which is a metal however they're transparent they don't do anything with visible light but the higher energy particles that go in there can deposit energy and can be read out and a very large number of objects like this and other materials were invented and used and put into a machine some of the parts very big and they were trucked they were flown in or trucked across Europe and through Geneva and placed in that tunnel which is 100 meters below the surface the components became very large and they had to be lowered very slowly so this was it was lowered 300 feet it took 10 hours to lower it because it weighs a significant fraction of the Eiffel Tower so you obviously don't want to move very fast objects like that and once they're put in you have 17 miles of magnets and other equipment to attach and you have to move things very slowly through this 10 so it takes hours often just to put the part in its place within those tubes is a near-perfect vacuum throughout the 17 miles and that has to be maintained large electric currents will be going through this tube to twelve thousand amperes and you need so that the copper wires or the wires don't disintegrate you need to make them superconducting and that requires tons and tons of liquid helium operating at temperatures a couple degrees above absolute zero and so they have a very large supply of liquid helium and then the machine runs they take the data and the data requires a very large array of server cores or computer cores they have ten thousand eight core machines at CERN and Geneva and then they have another ninety to a hundred thousand across the world at data taking centers and the data is taken and is distributed in parallel over the world and then of course it needs to be accessed by thousands and thousands of people these thousands of people this is a 10% of one of the four collaborations associated with this experiment they all need access to the data the world wide web was invented by an engineer at CERN in order for people like this to access the particle physics data from anywhere and of course the world wide web is used for other things too and then all these people they come from a lot of places many countries including countries that don't normally collaborate on anything else China and Taiwan Russia and Georgia Israel Iran Serbia and Croatia Pakistan India Cuba the United States you can ask why why go to all this trouble to build that monster just so complicated took so many years had problems went over budget people thought it would create black holes and destroy the planet all kinds of painful things about why takes an entire almost career to build this thing that the original plans are written down in the late 80s and it really started running in earnest in 2009 why do we do it we say we are trying to understand the basic laws of nature actually when we talk to the press we say we are trying to turn back the clock and see how the universe was created okay that's not true that's actually a difference between history and dynamics we're trying to figure out the rules you look at the universe you look back and you can try to figure out the history but it's a lot easier to understand the history if you know what the rules are so we say we're recreating the Big Bang or other people do I don't say that we're not we are going to energies at which collisions at the early universe happened it's true but we are trying to understand the structure and because of deep reasons associated with all of physics itself something called renormalization the laws of nature operate on all length skills the size of the universe the size of this room the size of an atom why don't we go why do we bother to look at the tiniest things and it's because the action of the laws are the simplest at that level and we're looking for those simple structures and the simple laws that manifest all the complexity that's in this room but building a Collider like that is asking like asking how it was an automobile work and you think oh create an experiment I'll take two vehicles and I'll collide them into each other at high enough energy so that when everything's flying out we can reproduce what a carburetor does okay so that is obviously not an effective way to there are other things you can do because we have tools that are smaller than the components of the vehicle we do not have tools that are smaller than the components of the proton our tools are made of protons so there must be a different way and of course there they're deeper reasons why it's complicated than just that you can say we're trying to understand the contingent constituents of matter what is all matter made of well you all know we say if you take say anything physical matter a glass of water and you look closer at length scales 10 million times smaller you see that there's structure to it here there are molecules there's h2o hydrogen and oxygen and if you just go up a factor of ten smaller you see there's another structure it's an atom here's a picture of an atom which is obviously to those of you who know any atomic physics or quantum mechanics completely wrong but every child learns that that's what an atom is even though that's not what an atom is fine there's an electron and a proton will agree at least on that and then you'd say okay let's go smaller I'll interesting things are happening as you go small let's take the electron for example and go a hundred times smaller and we've done that and ask what is the structure of the electron and we go a hundred times smaller and we see a dot and we think well there's got to be more to this so we go a hundred times thousand times smaller you go a thousand times smaller to the electron to look at the structure and you see you acted well you don't see anything so then you keep going out a thousand times and this done you actually you don't see anything either but the LHC see we've done this in the about the year 2000 we got to here and the LHC is going another factor of 10 and what do you think we will see yeah we do that's right so right so that's not the reason why we build the LHC although of course it's possible you know you don't know when something might come up so it's possible you do exploratory physics because it's there that's part of it but that's not the motivating feature we know an enormous and morphs about matter we know we say we learned the child same child who gets the wrong picture the animal learns everything is made of atoms everything we know about physical matter is made of atoms that's astounding and the things that make up the atom have a structure and we've studied that structure in great detail we know a lot about it we know a lot about matter the LHC is taking it what looks like a very small step in that scale but the scale of the experiment is enormous how could that be is that really what we're up to no it's not everything's made of atoms we understand everything what are we looking for what are we looking at at the LHC we're looking nothing and we're looking very carefully we do not put this in our grant proposals but we do we underline what we do is out this is how we think about it now let's let me say what I mean I just being glib here of course but I mean nothing is not nothing what I mean by nothing we don't say nothing in particle physics we say the vacuum what is the vacuum the vacuum of space time what is the vacuum in which all matter lives what is the nothing nothing being the medium in which there are atoms what is it and is it important and what is the structure of it stuff is made of atoms the nothing the vacuum is made of something else so the Higgs the Higgs bosons you may have heard of discovery a few years ago at that Collider is associated with understanding the vacuum of space time and that's what we're going to get to in this talk first you need to know some quantum mechanics so I'm going to teach you quantum mechanics I think I have three or four slides which should cover it so studied quantum mechanics and one in the in the context that we care about here is in a sense study of waves not real waves although knowing how real waves work tell you something about how quantum mechanics works something you know about real waves is this is water this is top down a photograph of water and water waves impinging on a surface with two slits in it and as the water waves move through the holes they spread out they spread out in this circular pattern and because they emanate from two points they interfere with each other and you see very important things happening here there are places where the interference cancels and the waves essentially disappear in their waves were places where they get enhanced that's how waves work we're okay with that they use something called superposition they add to each other and since waves go up and down they can add or subtract that's okay particles don't you wouldn't think billiard balls don't tend to do that you throw two billion volts at one spot they collide they add to each other they're in the same foot there's more stuff they're here it's not true with waves you add you take two waves you send it to the same point they could subtract they could cancel it could be nothing there that's interesting water is a way water you can produce waves in water it's a medium light is a wave light is a wave that lives as far as we can tell in a vacuum meaning it's not a wave in something it's just a wave somehow it propagates like a wave it acts like a wave you take a flashlight or a really monochromatic light and you shine it like a laser you shine on two slits you get the same pattern light is going through both holes but there are places where there's no light where the light perfectly cancels from the two holes so you cover one hole light shines everywhere you have two holes open and they're places where they're dark the light gets subtracted it's a it's a non-intuitive aspect of how waves work and the weird thing is that that works with light but it also works with for example electrons take take well this is a case of light but take the case where you have that laser light and you turn down the brightness so tiny that you discover the light is in fact made of particles and you allow one particle of light to move through those holes at a time so you wait a day and you get a few dots and you wait a couple of weeks and you get many more dots and you wait months a year and you get a pattern you give all the places where the photons hit and they illuminate it on their photographic plate and now you discover even though the particles were coming one at a time you still get that same pattern there are places where the particles didn't want to go but remember in order for the particles to no they didn't want to go here they needed to know there were two slits and you interfered with each other but somehow one particle it looks like one particle on the photographic plate but one particle knew to interfere with itself didn't somehow go through one slit or the other it knew about both slits this is weird but to explain this we don't think of particles simply as particles it has properties and you sometimes hear in the popular literature it has wave particle duality that it's just that we don't have a good language to describe what they actually do this is what they do see it this weird pattern means that even what we think of as individual particles behave in a way where there's mutual interference or in self interference they look act like waves there's a beautiful set of lectures by Richard Fineman called the messenger lectures that he gave at Cornell and it strongly encourage you to watch them it's more than three slides on quantum mechanics let's talk about real atoms not the fake atom that's easy to draw the teachers show this is what it's not an app electrons are waves - they're particles but they behave as a wave so when they're not hitting a photographic plate they're in an atom they're moving around an atom how do they move in an atom well those who know chemistry or physics know that waves like in a hydrogen atom the electron is described as an electron cloud it essentially lives everywhere at once in this ball you can think of it as if you have a glass of water and you and you tap it against the table then on top of the water you get these standing waves so the water is vibrating on top there's a some kind of vibrating wave in some internal space that's what the electron is it's a standing wave in this ball it's a ball of something fluctuating but in an internal space that's what an electron is you know for example a hydrogen cannot possibly believe an electron going around a proton because you ask what is the angular momentum in the ground state of a hydrogen atom it's zero and there's no preferred direction it can't possibly be something going around there's nothing moving around there's no angular momentum stored in it it has to look different but how do you imagine a billiard ball moving around here in this stable way with zero angular momentum and zero direction it's not it's a cloud it acts like a wave in the atoms so understanding atoms understand particles is understanding the behavior of wave-like properties because when they're in their quiet state that's how they're acting are there little bits that are very important one is that higher energy means higher frequency waves so your particle moving faster and faster has more energy and that more energies associated with when it's you're asking about its wave-like properties it's a higher frequency wave blue light is a higher frequency than red light and blue light contains more energy per photon per particle than red light does the other thing is about the uncertainty principle if a particle is like a wave that means it's no Sun in one location at any one time it's spread over space when we measure it we measured it at certain point and that wave turns out to translate into the probability of seeing that particle measured at any one point and that's that's a core part of what have you've heard of the uncertainty principle now that's quantum mechanics or the part that I thought would be useful now let's talk about investigating the vacuum we're investigating nothing what does that process mean how do we investigate things and I we're talking about small length scales so when we investigate something that's very small we take a wave like light we bounce it off of the object and we allow that light to bounce into our detector known as our eye we put it through lenses so we can see it more clearly but there's a fundamental limit to how small you can get and that fundamental limit is the wavelength of the light itself light can't resolve something tighter than that wavelength and so if you want to look at something smaller you need shorter wavelength you need higher energy particles are waves so the particle is going around the LHC we go a higher higher energy so we can see something smaller and smaller but like I said we're investigating the vacuum we're investigating nothing how do you bounce a wave off of nothing that is a problem let me describe the experiment that was there at CERN before the LHC there they were colliding electrons and positrons positrons are the antiparticle of the electron has exactly the same properties of the electron except that it's electric charge is opposite and if you take an electron and positron and you allow them to collide as they did they had 17 million successful collisions of it certain type electron-positron came together and once in a while two other particles would come out I had some font issues here but the two particles are the muon and the anti me one the muon and the anti Mew and have similar properties to the electron so electron it's antiparticle came in what came out are two different particles a muon and it's antiparticle and the weird thing about it is that the muon is 200 times heavier than the proton the electron so you've put in an electron and an anti-electron and what you've gone now to something much heavier so that defies some instinct about thinking while I'm breaking out part the electron I'm looking inside what's inside the electron maybe the muon is inside there but wait a minute the muons much heavier how is that possible does that make sense is there some sense in which that makes sense there are two things you infer from an experiment like that or at least have to question the first is that mass itself is not fundamental mass the masses of the electron its antiparticle don't sum up to the mass of the particles coming out so mass must not be a conserved quantity there are processes where the mass of things change normally in low energy processes like everything we do in life for the most part except when you're building an experiment mass is basically conserved but we have found processes where that's not true and that's because this equation that fits on a t-shirt which is not the correct equation the correct equation relates energy to momentum the kinetic energy of an object and mass which is in a sense of potential energy it's some storage of energy in the particle which means if mass is not conserved in for a single particle you could convert mass to momentum or back and forth and keep energy conserved so in that process when two particles collide and heavier ones come out we conserve the energy in that process but the mass of the particles are different because mass is simply a form of energy and like potential energy turns into kinetic energy when a ball rolls down the hill two particles colliding and creating heavy your particles is a conversion of kinetic energy momentum to Mass with conserved energy so mass is not fundamental and we understand so how two lives in the bigger picture of our description of energy so the electron come in with large energy and large momentum and go out with smaller momentum same energy but a bigger mass but it also means something a little bit more disturbing which is that matter itself is not fundamental matter material objects can disappear or appear or become something else in fact you can collide the electron and positron and what comes out are two particles of light which we don't consider as matter consider as a particle but it's a massless particle so if matter itself is not fundamental you can ask what are the fundamental objects can I create any random thing when I collide two things together it's just randomly producing garbage that we have to put labels on and there were periods of time in particle physics where that's what was happening in the 1960s the theorists didn't know what the hell was going on and they're producing particle new particle every week and we didn't know we didn't have a good theory of what was happening we have a better picture now now I'm gonna take a few slides to teach you quantum field theory but because that's such an intimidating sounding thing I'm gonna call it lake theory and the metaphor hopefully works to a degree let's talk about Lake what is Lake theory well let's take the surface of the lake two-dimensional surface that's the surface is what matters here we take a rock and we drop it in the lake and a wave travels across the lake now I told you that particles in their evolution in space and time behave like waves have wave-like properties well let's call our wave a particle just to be a little defiant so the particle what does the particle do it moves across the the lake at a fixed velocity depending on the temperature and density of the water in the lake and it it carries energy from one place to another sends information one side to the other that's what a particle does fine so let's say that's a particle now let's set up an experiment let's say I have a theory deep down in the lake below the water there's another material it's also a liquid maybe it's molasses it's something very thick and that molasses I bet if we can excite it put enough energy into it we can cause it to vibrate and vibrations will come through and we can prove that there's another surface down there we just need enough energy to do it so we take two big law rocks and we put them on either side and the two big rocks make waves that crash into each other and the the excitation created here is so large that it causes the molasses itself to vibrate and from the molasses two waves and I look my special light and and equipment and I can see look there are waves moving in either direction on some lower surface it's a thicker surface I needed enough energy to produce those waves but that tells me that there's something else down there there's a surface of molasses when there's no rocks thrown the water is there the molasses is there we don't see the ripples but we'd say that that's what's fundamental the waves depend on whatever I throw into the lake or how much energy I put into it but they're not the fundamental piece we describe the fundamental piece as the surfaces and what we then imagine in space-time is that these aren't two-dimensional surfaces there are three-dimensional surfaces meaning they fill all of space and therefore they live on top of each other they're all accessible locally but you need enough energy to access all of the lakes or all of those three-dimensional surfaces and what we imagine is that there's some stack of surfaces these are what we'd serve all the degrees of freedom of space-time itself this is the vacuum this tells us what is possible and if we had enough energy or a sensitive enough detector maybe we can see the whole thing maybe there's a story associating them all maybe there's a mathematical structure that makes it complete and gives it a single origin that's quantum field theory that's what we teach in my course that's it it's one lecture and then we go out for beer after that I say I'm just admitting you know I'm omitting the math their consistency conditions initiative there are many issues of course but you know that's the that's the sort of physical infrastructure of it this standard model is simply a list of those Lakes those fields we call them that fill all of space or just it's a terrible description of it but they fill a space time that's a slightly better description it's just a list 217 particles the fundamental fields in nature and they and they live in a nice relatively beautiful structure with some crappy parts to it and we're trying to clean those up you know and see if maybe there's something more fundamental it's that it's in a sense a list of numbers which describe how the the lakes interact with each other the particles interact with each other and then it's quantum field theory with is all the machinery of quantum mechanics and special relativity whose rules you follow to extract predictions from all of this some of this is matter we know and love the electron the photon is the particle of light and U and D are two of the quarks and they're in a sense the structure of the proton and the neutron and therefore the structure of all atoms we don't know why the rest of this crap is here but it is and we so we're trying to understand it this is the particle that mediates the strong force so it keeps the proton and neutron together these two particles are responsible for some certain kinds of radioactive decay otherwise they're kind of lame these are neutrinos which are produced a plethora of them in the Sun they're going through your body right now billions and billions of them every second as it was pointed out to me earlier today yes it's true they're also kind of crappy because they're not the dark matter the universe they don't explain anything so but maybe they turn out to be important you never know you have to just basically take down everything and this of course replaces the old standard model which is fire earth air and water but so this obvious looks simpler but the math is much harder to extract from this alright let's talk about nothing and nothing's not nothing again the vacuum shouldn't call it nothing but I do because it's the vacuum is where there are properties it's where of the surface of those lakes are it's the it's the untapped part of space-time itself and the Higgs which is that particle I put in the middle actually might the editor of our film put it in the middle he invented that he's not a physicist but he he sort of hobbyist so he's reinvented how we draw the standard model and a lot of people now use it so that quantum the quantum theory fields includes the Higgs field in the Higgs field like these others are degrees of freedom and space-time but they it plays a special role in the standard model you guys have experienced fields you know what fields are field for example if you take magnets and you bring magnets close to each other without touching you feel the force between them or you bring it close to a refrigerator it jumps out of your hand into the fridge there's something action at a distance but we can describe the theory without having that action at a distance we describe the electromagnetic field that's sourced by the magnet the magnet has a magnetic field say we call it a dipole field dominantly and it falls off it gets weaker and weaker the farther you go from the magnet it has a direction associated with it and so when you bring two magnets together it deforms the field deforming the field costs or adds energy and in doing so when you change the energy of the situation in this case you create a force there's a direction associated with it and there's a strength of the force depending on how close the magnets are we describe magnetic fields as a dormant field which if sorest is turned on and near a magnet the electromagnetic field the magnetic version of it turns on near the magnet gets weaker and weaker and goes to zero far away but we a particle physicists would say the electromagnetic field is simply there but it's there's energy stored in it when you're near a source that's a field you've experienced field the Higgs is a field - and the only difference is that eggs a field who's turned on everywhere it seems to be sourced by the fundamental nature of space-time itself so unlike the magnetic field which is sourced locally Higgs field is turned on but it's turned on uniformly in all places now if you turn on a field uniformly what does it do the Higgs field can't create a force because it forces a direction associated with it but it can do something and what it does is it gives inertia to particles or namely mass mass is something that satisfies the symmetries of relativity it's invariant it's the same everywhere in space-time and so doesn't have directions from it but it is a dynamical effect that the Higgs has on particles that interact with the Higgs field without the Higgs you would take you could take an electron in principle an electron which has no mass no inertia associated with it it goes the speed of light if you looked at that energy and momentum equation if you set em to zero you'd see that energy and momentum are the same in the units where the speed of light is one so if the electron is going the speed of light it would pass by the proton it can bend its trajectory but it will not be trapped by a proton in order to be trapped by proton the electron needs some mass and so if the Higgs field is turned on and that's what this green tint is the electron now has a mass in the electron moving towards the proton it will get trapped it can lose energy in the form of massless photons and it can go less than the speed of light and get trapped in an atom and so the Higgs turning on the Higgs field in the existence of it is to say that mass is given to some particles and that mass allows matter to form structure to form it created matter when as we imagine in the description of the universe that the Higgs field turned on at some early time due to the temperature evolution and when that phase occurred matter could then exist remember that you take a field and then you throw rocks in it and so we threw rocks in the field and we excited the Higgs boson we meaning the people who are allowed to touch the equipment not me but I say sort of euphemistically we discovered the Higgs boson the Higgs boson was predicted by the existence of the field so we knew the field existed at least the theory was that it existed but we didn't see the particle and that would confirm that and the belief in quantum field theory confirms that the field exists so people were looking for the particle not because they care about the particle but because they care about the structure of space-time and this is the indicator that it exists and by measuring its mass the energy stored in that particle we get additional properties of the field and so what the plots look like when you look for a resonance which is what an energy to specific value is it looks like a bump and we saw a bump and then we got very excited and they put it on the New York Times and and then some crazy fellow made a movie about it even somebody who risked his career to film this but he did okay now he's here this was obviously very exciting what was exciting as again not the particle not the god particle which thankfully it doesn't say it in this title but the the fact that we knew one more piece of the puzzle but it's a it's an a big piece it's an infrastructure of of how particles work and now the LHC is turned on again and they're running again they're taking data in the next nine months they may just find more details about the Higgs clarify the theory better measure things more precisely or we could discover something else the standard model is is a semi complete it's mathematically complete for the energies that we're probing so we're not guaranteed anything else but we could see something else and there are things out there that we we speculate about that exist we just don't know their detailed properties and the the clearest one is something we call dark matter dark matter it's an unfortunate name it makes it sound very mysterious for particle physicists that the bet is a dark matter is something prosaic it's a new particle or new set of particles now the more exciting way to say it which is true so you can I feel something when I say it too so it's not bad to feel something dark matter would is matter it's the one matter we have evidence of that we know is not made of atoms it's made something else and it's roughly 80% of the matter in the universe and we don't actually know what it's made of so you're told everything is made of atoms and then you were given a picture of an atom and it's wrong and then you actually discover that atoms are not everything that there's other things and most of the universe is not made of atoms that's something else but since we don't know what it is we ignore it and we talked about the atoms and patter cells on that so dark matter it could be particles it could be more exotic ideas but if it's not even particles it requires even crazier things but the simplest statement then is if dark matter is a gas of particles that dominate the universe creates the structure of galaxies etc that means there's a dark matter field we can create it or perhaps dark matter has interactions other than gravitational and we can detect it so dark matter of all of the sort of mysteries that we point out in fundamental physics dark matter is the most physical it's a dynamical thing that we don't understand and we know we don't have the theory for it almost all other mysteries and fundamental physics are about very strange numbers or initial conditions of the universe which are deep things but sound a little philosophical this is not philosophical we don't know what it is it's most of the universe some people think that's embarrassing I think it's exciting okay many many years ago it was it was noted that there was a problem in galaxies they're called rotation curves if your Aruban is very famous for having cataloged these and pointing out that that if you look at a galaxy you can detect using the Doppler shift as things move towards you away from you how fast things are moving and because you can get a rough picture of the mass of stuff in a galaxy you know that stuff that's farther away and going in a circle must be going slower because the gravity force is weaker out here and because it's weaker out here you have to go slower to stay in orbit but to the surprise of many astronomers the the speed of material that was going around galaxies maybe is m31 I think the speed of materials going around the galaxies as you go farther and farther out it basically stays the same it doesn't slow down but somehow it stays in orbit which says you can either say wide we don't understand the gravitational force but we seem to understand it in so many other contexts or a simpler explanation is that there is matter distributed you know at a much larger scale within these galaxies and we just don't see it and so there's additional matter here that's being picked up that's becoming more and more important as you get away from the visible matter at the center so this is the proposal dark matter but after doing a lot of studies over long periods of time it became clear that dark matter is literally invisible it does not interact with light at least if it's a gas of particles it doesn't interact with light it's not made of atoms that's a very cursory way to say it but at great detail that appears to be what's the case yes and I'm going to tell you a number of things about it yeah first the way well we know about dark matter is it's a material that interacts with gravity so the theory of gravity is extremely restrictive anything you add to nature must interact with gravity through the laws of general relativity and Laza general relativity said that light bends around matter it's in effect attracted by matter the path of a light beam as it goes through past something heavy will change direction this is called gravitational lensing and so in fact gravitational lensing is now a way that we measure the mass of objects galaxies and clusters of galaxies and so you can map out the structure of matter the universe and you can see even places where dark matter exists something that does not interact with light but does interact with gravity you can weigh these galaxies and the clusters and you can see how dark matter is distributed it really does act like matter that interacts with gravity we speculate about what it could be it could be clumps of non luminous stuff we know so much about the evolution of the universe that we know that those clumps it turns out can't be made of atoms even the clumps if that's what they were they'd have to be in the made of some new material simpler is simply a gas of particles that new material can just pervade the entire universe but still be cold in that it can be moving slowly enough to attract itself to each other and form galaxies it could be that general relativity itself is simply wrong it's right in every other context except in the context of weighing galaxies there has not been real progress in attempts to figure out theories that can match all the successes of general relativity and and still account for these strange movements of stars this in a sense is the most trivial possibility that it is a gas of particles but we just don't know what those particles do or what other interactions they have so people simulate assuming that there is a dark matter it's a gas of non interacting particles other than gravity with tiny perturbations perturbations that you can read off of the Cosmic Microwave Background you say those perturbations also exist in whatever dark matter is and you evolve it on a computer in time and the structures you produce are amazingly similar even at the mathematical level in terms of let's say the Fourier transform of this looks a lot like the structure of galaxies and galactic clusters so in fact not only that dark matter its behavior appears to be something that can create structure and those little blobs where dark matter is the densest our places were Giller matter falls in is attracted and galaxies form this is the so-called millenium simulation this is the biggest dark matter simulation at the time as year 2000 and you're now moving through the end result of a simulation and you see a structure that sort of looks like the universe bright spots which could be galaxies or clusters of galaxies but you see these filaments that run through it and the filaments are not dense enough to attract visible manner so we don't see them but gravitational lensing allows us to see the beginnings of some of these structures so not only do the simulations predict the correct distribution of galaxies it predicts these filaments and the filaments are now things that we can see but using gravity gravitational attraction in that light it still doesn't mean we know in detail what the the fundamental interactions of those objects are that make up dark matter but we know many of the things that it does do and what it what it can't be dark matter if it interacts with particles in such a way that you could produce it up the Large Hadron Collider the problem with it would be that it is invisible meaning it's produced in the collider and it it leaves and it doesn't interact with our detector that's a little depressing so then we say well there's conservation of momentum and we add an arrow there and we say that's the direction Dark Matter must have gone so you look for events where nothing is going in one direction now that may seem ridiculous but we see another particle in this way we see neutrinos neutrinos also don't interact with detectors with with much probability and so we similarly see the invisible implied path of the neutrinos and because we know their properties we can confirm when neutrinos appear the hope is you go to high enough energies you may produce events where again momentum seems to be missing from the event and we can infer that there's a new invisible particle not necessarily that it's dark matter but it gives us some clues a more likely way dark matter would be detected and what I mean by is see the properties of the dark matter is by taking experiments which incredibly sensitive but are hidden deep from all other objects so this is a wimp detector a weakly interacting massive particle detector that's a favorite idea for what Dark Matter could be and these detectors are incredibly sensitive and they're put deep into minds this is the Soudan mine in Minnesota and that's to protect it from cosmic rays and other pollution and you just sit there and wait and you wait for years and take data and see if one of the millions of particles coming through the detector has an odd chance of interacting with the nucleus this is how in a sense different material but does our neutrinos are detected from the Sun you you have a very quiet environment and the neutrino which interacts so weakly that it almost always passes through your detector without stopping once in a while it does hit something and when it hits something it creates a flash and so these are very sophisticated detectors to both see the dark matter and to rule out other explanations for it but so far it has not been seen now there are other deeper seeming questions let's see what time is it 9:20 how are you guys doing it's getting this okay everybody's okay okay take a deep breath oxygen is good for this sort of thing okay so there there other questions that don't have the benefit of having a physical presence that we can't understand and what I mean by understand is know what in detail is causing it one of those mysteries is the mystery of the Higgs mass itself I said that the Higgs is responsible for mass for fundamental particles we don't actually know what is responsible for the mass of the Higgs itself that's something we simply put in by hand in the theory but we can ask where does that mass come from in fact all masses that the Higgs creates are proportional to that number so this is a fundamental number in some sense right now it's one of the fundamental parameters and it's responsible therefore for the size of atoms and it's also responsible in a sense for the size of the disk of our galaxy so we can ask why that where did that number come from is it come from something even more fundamental we can ask those that come from the scale the energy associated with gravity itself maybe that's it Newton's constant is a dimension 'fl constant it has an energy scale associated with it so we can ask maybe the Higgs Mass Connect comes from Newton's gravity or Einsteins gravity that constant of nature and if you assume that you can ask about the full quantum theory all the lakes all the fields that live in space-time and all the quantum effects of those space-time if you look deeply into the vacuum you'd see and we see a little bit of this at the LHC there are quantum fluctuations in all of those fields they're not quiet the vacuum is a actually very violent place and the Higgs has a special property that it's extremely sensitive to these quantum fluctuations and in fact when you estimate you say oh it must come from Newton's gravity or Newton's constant you estimate the mass of the Higgs and you find a number that is C what is this number called billion trillion ten quadrillion times the mass that it actually is in other words this while it's not a calculation it gives you an order of magnitude estimate of the mass scale of the Higgs the bascule therefore of all of fundamental particles and the mystery is why it comes out with a number that seem to ignore the fact that there are these quantum fluctuations this is something that people have tried to understand and I'm going to give you I'm going to explain a model to you that people use to try to understand it and first I'm going to do in a simpler model because the simpler model is easier to understand so the simpler model is to imagine that there are extra dimensions of space this is not the actual model but this unfortunately turns out to be simpler than the one that I'm going to name but not describe very well what are extra dimensions well you have there's no way I can imagine that one can picture extra dimensions so you again you have to analogy extra dimensions of space might be described in the following way let's say you live on a two dimensional sheet and you only know two dimensions it's your whole life and then three dimensions exist but you're not aware of it and objects from the three dimensions can pass through your dimensions and what that might look like is if you're on the surface is a circle might appear all of a sudden grow stop growing and then shrink and disappear that would be the effect of an extra dimensional object passing through it so in three dimensions you live in three dimensions you're standing around and all of a sudden a ball appears out of nowhere grows to some size gets smaller and disappears and that would be an effect of a kind of extra dimension we don't spend a lot of money on those experiments but that has not been seen but I can say we haven't tested it maybe systematically now the extra dimensions of that nature caused many other problems associated with gravity and so more likely versions of extra dimensions are in which the extra dimensions are so-called curled up maybe as a kid you thought I wonder if I go in this direction forever if I come back the other way and meet myself when I can come back to the same spot we would say that if that's true then that physical dimension is compactified it's just it has continuous boundary conditions there are always things you can write down in mathematics that make you queasy in real physical world but there are many things that have been discovered that make us queasy so we just have to get used to it so if there are extra dimensions they could have that property but the length scale associated with them could be very tiny now if that's true remember of particles don't just act like particles they act like waves especially if you're not messing with them so their evolution might not be a particle moving around the extra dimension it would have to act like a wave but if the dimension closes in on itself the wave has to be continuous so there's some rules it's like in the case of a string you have a string that's tied to a pole and you you shake this string it has certain modes of vibration the vibration needs to stop at your hand and at the pole so only very specific wavelengths will fit on this string very specific frequencies frequencies associated with energy very specific Tower of energies are available for this string and also for the extra dimension waves that go around the extra dimension have to have integer number of nodes and that means an integer number of nodes or integer spaced frequencies of the wave which are integer spaced energies when we collide particles if we knocked a particle allowed it to move in an extra dimension how would we see it we wouldn't see something going around the extra dimension we would see well our particles are are big and floppy and low energy and and fill up an atom they can't see something as tiny as these extra dimensions but that momentum in the extra dimension to us will be another form of energy not motion but it will look like mass and so if the electron could go in extra dimensions there would be an electron mode that didn't move in extra dimensions but then there would be modes that had different frequencies and they would have different energies and we'd interpret them as mass and so we would see a tower of particles we'd seen the particles we know and then equally spaced energies of other part of the same property of particles but equally spaced by an energy scale that we can invert and and align with the size of that extra dimension again a toy model the real model is is a little worse supersymmetry which maybe for some reason you might have heard of supersymmetry is a model and it's a model of an extra dimension it's like an extra dimension except we would say it's a fermionic extra dimension or it has quantum mechanical properties so the extra dimension itself is not continuous it's it's like a discrete variable you're seeing it's not there's nothing you can say so there here's the supersymmetric extra dimension and then and the bizarre properties of it which are related in an interesting way to the Fermi exclusion or probably exclusion principle tell you that actually you can only have one mode and so you'd see the standard model particles and then there's one copy of them and they're all roughly at the same mass and that's the size of the supersymmetric extra dimension and so the proposal for supersymmetry is that there's another set of particles that essentially match the particles of the standard model another set of lakes or fields and they're at a new mass scale and that's associated with the compactification scale of supersymmetry or we would say the super symmetry breaking scale and the amazing property of supersymmetry is it's a symmetry in which these vacuum violent vacuum fluctuations mathematically cancel it's a property of the symmetry and the higgs mass then no longer needs to be ten quadrillion times what it is the higgs mass is proportional to the mass scale of these new particles and so the LHC could probe the Higgs but it could probe also potential other mysteries about the Higgs and one possibility was to see a new set of particles that gave a symmetry structure that explained the origin of the Higgs and the origin of all mass the supersymmetry has enough stuff in it that the simplest version of supersymmetry has a nice candidate for dark matter it turned out so it became even a more popular theory because without asking for it you produce a particle which should have been produced in the early universe and could explain dark matter so people got excited about it and there's no direct hint of this theory and we've looked at the LHC we haven't seen it and maybe in the next nine months when the data comes in with more energy more about will see it well maybe not I suspect not I'm betting against it even though in the movie I was for it I'm Nam again you know in the movie you you need one of the simplifications is each person in a sense personifies a theory so it's a caricature of theory but in fact both myself and Nima solvus and all the other people in her field that debate is happening in her head all the time so you're seeing two sides of our thinking the morning as we get up and believe that there's order in the universe and the other mornings there's no direct hint is supersymmetry this it's this thing with spheres and perfect solids and thing and we're fooling ourselves and we should just end it this super seven degree that the Higgs is not a dynamical underlying part of the theory the Higgs is a historical accident what would it mean for the Higgs to be a historical accident well let's ask another question does the earth need a deep reason to exist in support life in the sense that it's amazing that a earth has all the amazing important properties that we can survive on it how did we get so lucky to be born on a planet where we can survive that's amazing of course not you don't ask nobody's working on that mystery why we're an artifact of the fact that this place is a good place to live and we've discovered six seven eight nine hundreds thousands soon tens of thousands of extrasolar planets you do a rough estimate there are trillion planets in our galaxy and there are a hundred billion galaxies in the observable universe what are the chances that the properties are nice somewhere good they're good it's not a mystery then okay well that that's fine that that's something you don't work on this is a historical accident it's not a mystery it's not a fine-tuning of parameters people talk about something called the multiverse what is the multiverse the multiverse is actually it can be something much simpler sounding so I'm going to tell you that dispel some of the mystery sounding part of it we could only see a finite part of our universe but that's because of the finite age of this part of the universe and the finite speed of light you can't see infinitely far so our patch of the universe may have certain properties but other places in space-time too far for us to detect yet may have other proper things that we think are fundamental the parameters in the standard model they may be different in different parts of space-time in fact the bigger mystery then the Higgs is something called the cosmological constant problem which could have a dramatic impact in the evolution of our universe which in fact is the best explanation currently for the fact that our universe is not only expanding it's accelerating but the value of the cosmological constant turns out to be a hundred and twenty three orders of magnitude smaller than we would estimate from those vacuum fluctuations so that is the worst estimate that we've ever made in history and because of it you start thinking crazy thoughts and so one possibility is that in space time there are patches where the vacuum energy the thing that expands the universe takes on different values and there are places where they that those values are accidentally tiny and if there's enough structure in the space-time so that you can have a finely grained in a sense scanning of parameters there will be places which are anomalies which are aberrant parts of the universe and if the earth is an aberrant planet a rare planet where life can grow then perhaps our space-time the part of space-time that we have access to is also aberrant the parameters are special they're by accident not because of the fundamental theory but by accident because that the parameters change over larger distance scales than we have at least naive visible access to now in order for that to be true this is roughly how many patches of the universe we need so we need the size of our universe at least times this and even size is not a good measure because of size is not an invariant thing and in cosmology so but that means you have it in its same number of universities if you have that you know we get surprised by big numbers we discover if the universe really is that much bigger then there's an at least an argument for this this is not a complete theory there are issues with it there are things called horizons between the parts of this universe some sense different parts of the universe don't exist in the same theory quantum mechanics breaks off different parts it's similar to black hole paradoxes it's not a complete picture they're arguments about this obviously but it's possible or a broader way of saying it it's possible that that answer is beyond our reach that the question of why or did the higgs mass come from is one of those questions that we don't get to know the answer to just like why are there six planets going around her son at the distances they are big actually when I was a kid I remember looking up a dictionary wanting to know are there names for numbers bigger and bigger and bigger the biggest number in that dictionary at the time was a sin Tilian which 303 zeros said until you take the first three you don't ignore those in every batch of three you count one two three million billion trillion quadrillion so sin Tilian is a hundred batches of those so we don't we we need more than that I mean physics means living with the uncertainty principle not just the one in quantum mechanics but you never know if you're on a dead end but of course we all need to be working hard for one of us any of us to get the answer it's all part of the process and you do it because you can't help yourself and I just want to thank you at that last note I think I might have been a little philosophy there but we have time for questions there are people with microphones they'll bring the microphone to you and the microphone pumps you ask the question but first tell us your name and whether you're a member of the society first question here in the third row second question yes you hello my name is Tony I'm not a member yet my question is a lot of data was um at 120 3.5 GeV GeV thank you they they found the Higgs boson how do they know it was the higgs boson and not something else one of these other particles right the there's a list of particles and then there's a list of interactions and those list of interactions are first proposed they they they preserve the symmetries that appear to be true in nature the symmetries of relativity the rules of quantum mechanics and we have a set of interactions and we have to figure out the strength of those interactions amazingly you take the standard model and you add the Higgs if you measured all other properties in the standard model besides seeing the Higgs then you've fixed the theory up to a single parameter which is the mass of the Higgs so once you measure a particle a new particle that you think might be the Higgs and it has a mass then you have a proposal for a complete theory which is to say that I know how that Higgs must behave that Higgs is not actually literally seen as a particle that comes out and then we bounce things off of it to see if it's the eggs it decays instantly instantly in terms of the timescales of the detector so what we knew about the Higgs is depending on its mass we knew how it would decay what would be the property of the things coming out and if you add the energy and momentum of the things coming out from that you get a mass that's that equation e squared equals B squared plus M squared so for every time so we look for the byproducts of the Higgs what they could produce we add for every event we add up the energy and we you supply and there's a lot of random stuff that comes out and then there's a place where at some energy the same thing is coming out over and over again and then we have to match who say the Higgs could decay into photons or could decay into this kind of work etc that's what the theory says let's see if the ratio of the number of times this object decays into this or that the other thing satisfies all the conditions that the standard model requires to be a consistent theory then at that point so it's past those consistency conditions at the point we call it the Higgs why do we call it the Higgs because the the theory that describes everything we know so far has a particle with those properties and it's the haze there's nothing special about that Higgs we call it the in fact Peter Higgs when he wrote down the model of the Higgs is not the Higgs that we discovered it's something completely different in fact he was trying to solve another problem which was turned out to be wrong and and a guy named Steven Weinberg scooped up that little theory and plugged it into what was going to become the standard model and that now is labeled the Higgs for historical reasons but really it's a particle that has certain properties and explains something specific which is how do fundamental particles get masked and because of that you can predict that the Higgs will decay into heavier particles more often than lighter particles because if the Higgs gives mass to particles the heavier particles must have a stronger interaction with the eggs and the lighter particle so the Higgs decays into heavier particles more frequently and we can predict those ratios based on the mass of those particles and so from that we know what it should behave as it we up to let's say 10% accuracy it still satisfies those properties but we keep digging if at one percent it no longer satisfies the properties one percent is enough small enough that you still call it the Higgs well you say there's something else interacting with the Higgs that's disturbing their properties and you're looking for something else but right now it it it decays in a very special set of ways in which the only way we know how to describe it as a particle that gives mass to other part and we call that the Scott Matthews currently not a member but me neither my question actually you are a member now oh sorry sorry one reason recent results in solar neutrino physics specifically a neutrino flavor oscillation seem to indicate that neutrinos have mass they have a finite mass the standard model as I understand it predicts that neutrinos should be massless if the mass of these particles in the standard model is somehow being created by the Higgs does this mean that we need that the standard model needs some ad hoc assumption adding some mass in for the neutrinos or can the mass of the neutrino not be explained by the standard model because of the Higgs mechanism good so yeah the simplest version of the the the standard model includes neutrinos which I disparage and I shouldn't feed all particles the same but the neutrinos in the simplest writing it's an artifact of how quantum field theory is used to think about theories we've dispelled some kind of crappy habits when you were first discovering something you know you don't know what you're doing so you make mistakes the electron for example has a negative charge that's about the stupidest thing I could imagine electron she moves current they thought it was moving this direction but it was holes and they made a mistake so they labeled that Plus but then they discover the fun of my way that's what happens in the same way it turns out that the standard model does allow neutrino masses but it allows them once you add what's called higher order effects or higher dimensional operators it still points to something new the structure is there but it points to a new energy scale and so there is it doesn't mean that's the way that neutrinos get mass it could be even another thing there could be extra particle that mix it with the neutrinos and give them mass but it is possible to take the standard model add mathematically allowed terms and you get a mass and in fact what's beautiful about it is you add those terms because those terms are higher order higher dimensional not not extra dimensions but higher order they're tinier and so by by Fiat they automatically predict that the neutrino mass is much higher or much tinier than the masses of all the regular matter particles it's called this seesaw mechanism it's there's a high energy scale associated that we don't know that physics we don't have a big enough Collider for it but if you assume there's some physics at high energies you have to write down these interaction terms and when you do you discover the Higgs also gives a mass to neutrinos but it's just much tinier and but now it's just labeling some people say no neutrino masses are beyond the standard model other people say no it's a trivial addition to the standard that somebody's between this is just syntax but it turns out Samantha exactly so this it just turns out that it was easier than expected and in the time when that the mechanism for giving neutrino mass was discovered theoretically it was sort of an astounding thing that you could do that now the way we see quantum field theory is very different and but there's an artifact in the language still so yes neutrinos are beyond the standard model written down in 1967 and 71 and 73 but they're beyond a standard model in a very simple but beautiful way and then you can ask well what is the energy scale the new energy scale associated with the neutrino at very high energies something is happening it turns out the neutrinos predict and that had very neat very high energies you'll see something new something beyond the standard model so that's a nice thing it just turns out it's it's probably 10 to the 12 times higher energy than the LHC so we're not going to see it so that's the unfortunate aspect of that that may not be the way neutrinos get a master could be other things and the best way to study neutrinos are neutrino experiments where you you look at detailed properties the high-energy behavior maybe we'll see structure to the neutrino that's interesting or maybe it'll be like an electron you know dot dot dot dot dot Glynn Chenery not a member yet David is there an antimatter complementary particle to the Higgs the Higgs turns out to be its own antimatter it's similar to the photon the photon is also its own antiparticle it doesn't mean there aren't art other family members associated with the Higgs but whatever would be would have to be an extension to the standard model in the case of supersymmetry there's a prediction that there's more stuff to about how long do you think the Large Hadron Collider is gonna be like at the forefront of particle physics and like how long is it going to be keep making these kinds of discoveries and what kind of machine would succeed it yeah 12 months in 12 months we'll get a lot of data and you know we you measure in orders of magnitude so we have a tiny bit of data within let's say you say nine months it'll be an order of magnitude more data and once you have an order of magnitude more data of order magnitude in some sense more sensitivity after that then you instead of a year you have to wait ten years to get more sensitivity and then 100 so then it then it becomes impossible so the in a year we'll have more sensitivity a lot more and if we see something new then the LHC is just at the forefront for the decade after that as they try to work out what the hell we're seeing because the Higgs was anticipated like no other particle but what comes next is not everything else is is now the Higgs may be the tip of an iceberg and if it is we don't know what the birds made them could also just be something floating around in the water so it depends what happens in the next 12 months if they don't see anything it's a 10 years of mop up work now or maybe seeing something you know in the nooks and crannies of the data that are hard to extract in a trivial way then the forefront becomes if you want to go to higher energies it's a bigger machine but the other possibility so they're talking about 100 kilometers in China they're doing often thinking about lots of different possibilities but but because the timescales for these experiments are now turning into an entire academic career people are trying to get more clever and dark matter is a great example of it because dark matter is in some sense very simple it could be a new particle but its mass has a big impact on it it's quantum properties if the particle of dark matter is very heavy it acts like a billiard ball and could interact in interesting way as you could see it in a mine but if dark matter is extremely light its wavelength could be so large macroscopic you could see it as it affects pulsar timing or or vibrational experiments on the earth or things that look for gravity waves but actually much simpler experiments lots of different ways to detect it using lots of different types of Technology and the LHC had had a focusing effect on our community but I think if the LHC is not the forefront in a year from now you'll see a dispersion into all kinds of weird directions and then I can't predict I'll be thinking about Dark Matter I'm I'm already thinking about Dark Matter I'm not thinking about the LHC because I made my bet and not financed on my feet you bet with your time more important and and then I think about slightly more theoretical things they don't have immediate experimental consequences but so broader context so I don't know they really answer as I have no idea I don't know I think there was one in the back my name is Jack I'm not a scientist but since retiring I've read about a half a dozen to a dozen books on quantum physics are you a member of that no sure yeah and one of the bizarre things about the way quantum physicists think is this not at all like the rest of us the two-slit experiment I've read over and over again from well different people and they all just ignore what most of us would consider the obvious explanation that there is particles and that the particles like photons and electrons produce waves in those particles so there's no need to call electron a wave it's a particle that creates waves why do all of these quantum physicists never acknowledge that as a possibility and explain why they reject it I think the main problem with quantum mechanics is language we're describing phenomena in such a way and especially in popular books on quantum mechanics and things like that we say things that sound I think a little trite it's a particle and it's a wave it's not a wave in the way we normally think of waves as something that's fluctuating in a medium what we mean by waves is that there's a differential equation there's an equation with derivatives derivatives are slopes and change in time and space and the electron satisfies that equation the electron evolves in time and space associated with that equation and when you interact with electron at short distances you might describe it as a particle because you see a dot you can you say oh that's a particle it can transfer energy locally in way when your did when you're interacting with an electron in a broader way in a more coherent way it follows that differential equation but the properties look different so you would describe the properties because when you were a kid there was a wave experiment and you understood that wave experiment as look things pass through both and they interfere with each other so the propagation of the electron from one place to another or the photon from one place to another follows that equation the equation of motion and that equation motion predicts interference if you have both holes you close one hole it doesn't predict something different now we try to put labels on it and say it's a particle it's like billiard balls it's not it's like this that it's not it's just not it's not like things that interact at larger scales it's things that interact it's different set of rules and now you saw when I described is the public it's so beautiful in mysterious and you have to use the same English language but it's it's not correct it's not a good description of it yeah okay let me continue the discussion yeah well let me just say something very simple all of those things are simply analogies is trying to describe using metaphors of things that you know about the experience and say this is sort of what it's like it's not it's not like a bullet it's not like a missile with waves and water it's not like any of those things it's just not it satisfies different dynamical equations and now I want to relate it to you but you don't know the math so what am I going to do I'm gonna look for analogies that are as close as possible and those analogies make it seem preposterous but it's just an analogy we know how atoms work we know how material comes together we know how atoms emit light we understand frequencies from distant galaxies we can understand the chemical content of our Sun because we have a spectrograph we can look at the frequencies of light and it comes from predictions of quantum mechanics and the structure of the atom we know that I'm not telling you it's like bullets I'm not telling you it's like a Miss I'm not it's not we don't use those analogies when we calculate things we use the rules and the rules tell us what to predict and we see if it matches predictions and it does and it does to twelve digits it's amazing general relativity to twelve digits it's amazing it's crazy it's not like this it doesn't act like that water is made of molecules lumps it doesn't look like that it looks like a continuous transparent fluid but I show you the atoms it's made of it doesn't look anything like that it's first Posterous that it's made of atoms that's crazy now it just is that's the rich it looks different the rules are different if you don't like the rules you know maybe there are other universes where the you're more philosophically pleasing is fine men with six the other analogy the analogies are always unhappy because you get to a wall and you think that's crazy yes it's crazy because it's not really like that okay here we go with more crazy yeah it is a question are you man first I'm not a member I I haven't no my job up here I have to I have contributed but he does occasionally give one and my name is Kenneth Roth John but I was trying to think of something really outside the box okay what what if our perspective has to really be reorganized in other words because of the evolution of species and and and our brain we seem to go from a theme to trying to get to a bigger concept of the whole thing okay what if each so-called thing is just a part of a field and it's it's a potential within an energy grid so that you're not going from the thing to describing a thing you're more describing potentials within a whole energy field and and it has certain characteristics at certain points does that make him normally do something with that yes it's no I see what you can do it yeah not yet yeah it's something like that it is something like that I mean but these are all descriptions again and we're sort of limited by the descriptions but well let me address two things you said that evolution is broadest up to this point evolution really favors us figuring out how to survive not figure out the history of the universe or the structure of an atom so we are obviously limited in that way and it's it's a miracle how much more we know then we should know evolution doesn't drive us to do the things we do it's an artifact that we know so much about the universe and the structure of matter but yes we're blinded by an intuition or instant it was built up not to discover those things and something else find food to protect ourselves keep warm reproduce so why do you laugh at reproduce you know in Europe nobody laughs at reproduce come on America the other thing you're saying is what if it's that doesn't it I can tell you that the electron field again it's a description these are all descriptions but the electron field we would describe every electron every electron in the room and your body in the universe is a fluctuation of a single electron field and it's it propagates in a way that satisfies equations that look like wave equations and so in that sense they're not all separate they're all little fluctuations in the same thing there's its energy stored in the field and it's everywhere there's no SAR as far as we can tell grid or anything like that because there are properties of the universe like very good symmetries or rotational symmetry what we call translation symmetry motion laws of physics abide by those by translation in time so those things say that if there's a structure it's it's more complicated as to it seems to abide by rules that don't have simple physical interpretations at least intuitive it's our it's our evolutionary upbringing that don't allow us to immediately jump and know the answer so yes I could describe it in a way the sounds like pockets of energy as part of a larger structure that lives all over in space-time but every description is usually practical for the application not even experimental or industrial but application in our trying to understand deeper about the theory itself and so and and the problem is you can write popular books let's say some of those things and they sound great but they're not you know it doesn't really capture it but it's weird it's it's weird it's super non-intuitive the rules I would recommend book by Stephen Weinberg called dreams of a final theory because it's it's the less it's less flashy than the other popular books but it's an honest rendition of what we know and how how we know it that's it so yes something like it's something like that last question over here one there and my name is Jim and I'm a member and I wasn't gonna ask that it asked this question but you brought up the idea of the analogies that all falls short and I want to go back to popular literature again max tegmark and his mathematical universe is there a need for reality or is it truly all just math and the reality is just the analogy that our mind has put together to be able to function amidst all this math or does it matter so you want to know if there's a need for reality ok qualify you smartly blame max tegmark right now as to as separate for mathematics as separate for mathematics I will repeat the question and that I want to answer how about this great is mathematics separate in some way from physical reality as physical reality need the existence of mathematics it is amazing that the laws of physics is something we can learn and we can understand more and more of it's also maybe amazing that it is perhaps a complete mathematical system and if it's a complete mathematical system we call it reality but really this is just a mathematical system playing out we were reducing all physical reality and interactions that to a set of equations and rules and properties of those equations which means maybe there's you know a couple people in the beach drawing you know writing numbers on pieces of paper and passing them back and forth and that's what physical reality is I don't even know what that means we're we're in a simulation maybe I don't know it's not much of a jumping-off point unfortunately the most beautiful thing I've ever read about that was there was a nice biography I like it by rebecca goldstein of Sharona biography short biography of kurt gödel and in the late stages of his life he was attempting to prove the existence of God with the idea that physical reality is completely described by a mathematical system which means there must be truths in physical reality that cannot be known by components of the mathematical system meaning us or anything in physical reality which means there must be something external and that external thing you might call God but he was one one line he was one line away from getting that proof to work so he didn't prove it no he said he was stuck he eventually abandon it that's why I leave that I don't have anything intelligent to say I don't love Max's book last I have a question named number my name is Shivaji Seth I'm not a member of the Association I have a question about dark matter we are looking for dark matter particles like wimp as you explained through their physical interaction with matter what is that basis technical basis for assuming that dark matter particles should have any interaction with the matter that we know good yeah so far the only interaction we know about is is gravitational and we can put limits on the other types of interactions the electromagnetic interaction if there is any it's it's if it if dark matter is a gas of new particles electromagnetic interactions very weak now we know significant well we have significant evidence about the evolution of the universe we have snapshots of the universe at a time which is roughly when the universe was a few hundred thousand years old that's when photons were released from charged particles called recombination Cosmic Microwave Background and then we have another snapshot when the universe was roughly a second old and that was the time when light nuclei were forming in the early universe it's called Big Bang nucleosynthesis so we we've measured in great detail the the abundances of light nuclei we've studied in great detail this cosmological background and from it we can infer the rate of expansion of the universe and from the rate of expansion we can infer from general relativity the contents of the universe the different components how much matter there is how much radiation there is and lately possibly how much vacuum energy there is and then with those contents and with knowing the laws of physics the much higher energies as we do from colliders we can extrapolate back it's a near thermal system which means you you there's a bazillion things in the pot but it's brought to approximately a given temperature and then we know what's happening it's just from thermodynamics so we can go up and up at different temperatures and then we can ask the question if there is dark matter how could it have been produced and how could it have been left over in this universe and so part of that story is well here's a simple model where at some temperature dark matter is being created interacting with the standard model at a regular basis it's thermalized and so you just take a thermal history of the universe with your proposed particle and you ask what is the abundance of the new extra stuff and to get that abundance right it requires both the mass but also an interaction strength which is not gravity something new and then we take the rules of relativity and quantum mechanics and all the things we know about a standard model and we enforce those upon the new sets of particles and we make predictions and those predictions then bear out on experiments we say oh if it was produced if in a thermal way then it should have interactions at least of this strength because of relativity it must be a interaction of this type and because of what we've seen in in particle detectors it must be at least this heavy and that it can't interact with the photon something so we that's the box and so that's the box we could rule out that idea with these types of experiments as long as I get to this sensitivity and then they go after it though the wimp was an example of a particle that came out of a totally different theory which was predicted for other reasons and so it became a hot topic in that we sort of were excited about the other theory and experimentalist say here is something that just automatically gives you the right abundance of dark matter and it has the following interactions and this is how we're going to attempt to discover it or rule it out and so that that was a class of ideas there are something like five known ways so far for the early universe to generate dark matter and the abundance that we see and so each one requires different interactions at least three of them have very plausible ways to discover experimentally the other two are quite hard and we don't know but we're thinking about it and that's how we do it so there's a it's amazing that both relativity and quantum mechanics had so much of a restriction to what new things could be added to the theory that you you once you have dynamics you're put in a box and it's absolutely true that dark matter could possibly not interact in any significant way with us it has to interact in some way besides gravity it seems but it doesn't have to be very strong but a few of the theories it's strong enough you'd predict that you'd be able to discover it if you look in the right way thank you no we're we're done with questions because we talked to you afterwards it's already ten after so an appreciation for your giving this talk like to present you with this framed copy of the announcement of your lecture thank you signed by the members of the general committee on behalf of the membership I just however before we adjourn to the social hour a few closing items PSW depends on an enthusiastic act of incapable membership oh you can't hear me oh dear so I have to start over I don't know why you can't hear me but I'll speak up can you hear me now okay before we adjourn to the social hour there are the usual few closing items PSW depends on an enthusiastic active and capable membership if you're not a member please join if you are please see me about getting involved in carrying out PSW activities you can apply for PSW membership by going to the PSW website at PSW I'm sorry www PSW science org and you'll have no trouble finding the membership button which when you press it will miraculously bring up an application for membership which when you fill out this form which asks you for some basic information so we know a little about you we'll get you down to the pay dues button when you get to the paid dues button and you press submit don't get confused by PayPal PayPal is our merchant banking service they just process these payments you don't need to have a PayPal account you'll see a couple of tabs on the payment page which for obvious reasons I couldn't bring up because I didn't want to have to pay my dues again and you just go to the one that says credit card and you pay with a credit card and it doesn't really have anything to do with PayPal on your side it's really very easy so if you're not a member please join by using our website by the way how many of you are here for Meetup how many of you are here from me up we're willing to admit it no that's great if we love meetup we have almost a thousand members on our meetup group now and I just like to remind people being a member of meetup is wonderful we love to have you come but it's not being a member of PSW so if you are a member of Meetup we would encourage you to also become a member of that I should say if you are a member of the PSW meetup group we encourage you to become a member of PSW itself I would say what else do I have to tell you do you have any questions about membership please see your membership chair James Heelan or myself we did dues payments for due in September if those good members who haven't paid their dues would you please pay up and keep in mind that PSW is a non-profit educational organization tax-exempt under Section 501 C 3 of the Internal Revenue Code least for now something's about to happen our next speaker will be Scott bolt Scott Bolton this principal investigator on the Juno mission which is currently orbiting Jupiter and by the time he comes to speak at the president's lecture on 6th of January in the new year we should have some very interesting results from the Juno mission so I encourage you all to come and I have a question how many of you were here for the movie oh my god how many of you would like to have a similar event for Scott Bolton with a movie on planetary exploration in particular Jupiter okay we'll try and do that look for the notices I had no idea it would be so popular and finally the spring schedule is in a work in progress so you note that after Scott we have Marty Macri at Hopkins who will be talking on medical errors which some of you may know is about the third leading cause of death in the United States which is why I always advise people to avoid doctors and hospitals he will be talking about some ideas he has for how to eliminate them using check checklists transparency and the free market we're working on the tenth the speaker for February 24th will be Brett Alexander who is the vice president at Blue Origin I'm sure you all know Blue Origin is Jeff Bezos is company competing with SpaceX to get us all to Mars or at least until above the atmosphere for a view of the earth and he'll be speaking on the new space age specifically new rocket engines and launch systems being developed by companies like Blue Origin and SpaceX and by NASA March 10th the speakers likely to be astronaut and Hubble repair person John Grunsfeld and he will be speaking on post Webb very large space telescopes assembled and sit - not on earth as you might expect coming from John he thinks that astronauts will be assembling those telescopes there's a possibility that the March 10th event instead will be a set of four lectures in a panel discussion headed by Matt Mountain on very large US terrestrial telescope projects and in that case we'll reschedule John's talk for one of the other open dates finally the speaker on April 28th will be Anthony James professor mosquito expert and molecular biologist at UC Irvine he will be speaking on mosquitoes synthetic biology CRISPR gene Drive and malaria in other words on the use of recently developed techniques for genetic modification to control disease transmission by these biting insects we hope to have the spring semester completely scheduled before the new year so please check the website at regular intervals for updates as it firms up the social hour ends at 10:30 after which PSW members and guests meet at the fairfax hotel lounge across the street if you're not familiar with this please see vice-president lloyd mitchell back there with the white turtleneck or see me for information on how to get there please use a side entrance to exit the building and I will now accept a motion for a German of the 2317 'the meaning of the society to the social our second

Channel: PSW Science

Views: 140,254

Rating: 4.630435 out of 5

Keywords: PSW, PSW Science, quantum field theory, particle physics, collider experiments, David Kaplan, Large Hadron Collider, Higgs, Particle Fever

Id: -4Mz4OGVC_U

Length: 124min 21sec (7461 seconds)

Published: Mon Mar 06 2017

Reddit Comments

[u/easilypersuadedsquid]

A crash course on particle physics, collider experiments, and quantum field theory. The speaker explained the significance of detecting the Higgs Boson particle, its impact on the field, and the justification for featuring it in a documentary film.

[u/easilypersuadedsquid]

don't worry the actual lecture is 1:24