Why Don't We Know What Most of the Universe is Made of? w/ Daniel Whiteson

[Music] you have fallen into event horizon with john michael gaudier in today's episode john is joined by daniel whiteson daniel whiteson came to uci in 2007 after receiving his phd in physics from uc berkeley professor whiteson's research is in the field of experimental high energy physics he is interested in probing the structure of matter and the nature of its interactions at the very smallest scales to understand the fundamental nature of our universe he is part of the atlas collaboration which built maintains and collects data from the atlas experiment at the large hadron collider where the higgs boson was discovered in 2014 along with his team he developed cosmic rays found in smartphones a smartphone app which uses a cell phone's camera to detect ultra high energy cosmic rays these particles are nearly a billion times as energetic as the particles in the large hadron collider and their origin is a mystery things have been quite overwhelming lately haven't they with such randomness it's important to have something that can help you keep a regular schedule keeping track of a schedule is extremely important for the work we do on event horizon a good routine makes that possible that's what makes today's sponsor fabulous so great it's the number one self-care app to help you build better habits and achieve your goals with fabulous you can choose from hundreds of recommended habits or even create your own i know our producer ross has been having trouble remembering to check his emails so i went ahead and created a new habit for him on the app this will help him build the habit with timely reminders we love fabulous because features like that use behavioral science principles as well as science-backed content you can use dedicated programs so you can choose a journey that immerses you in your own personal adventure for example you'll receive regular letters filled with inspiring and motivating lessons that help you commit to a positive action for the week new habits get added to your daily routine and you can use fabulous premium to build and improve and unlimited number of habits in your routine start building your ideal daily routine the first hundred people who click the link will get 25 off a fabulous subscription dr daniel weitzen welcome to the program thanks very much for having me on i'm excited to talk to you about all the craziness that's in our universe oh and i found some listening to your podcast especially in regards to one certain event that happened in 1991 the oh my god particle which was discovered a very high energy very rapidly moving particle hit the atmosphere was detected and that ushered in the the the age of studying ultra high energy cosmic rays now give us a sense of that particle what was i mean was it a proton you know what might it have been and how fast was it actually moving it's a great question and a really fun event to make us think about things zipping through the universe at super high speeds we don't actually know what it was it's hard for us to tell what an individual particle from space was because we don't see the particle directly we only see like the impact it has on the atmosphere sort of like an invisible elephant hits a waterbed and we just measure how much the waterbed shakes so in this case the particle whatever it was hit the top of the atmosphere and banged into a bunch of other particles in the atmosphere which banged into other particles created this whole shower of energetic particles like a big cone from the top of the atmosphere that washes over the surface of the earth and we can measure it using detectors dedicated just for that job on the surface this one particle which is the most energetic particle we've ever measured had 50 joules in it which is a lot for a little particle you know that's equivalent to like a baseball traveling at 60 miles per hour except it's a tiny tiny particle so it's really just an incredible amount of energy for one single particle to have if you think about in terms of its speed it's like 0.999 999 999 no no no of the speed of light so almost at light speed about as close as you can as you can get and this represents a piece of matter moving at almost light speed and this piece of matter moving into that because of special relativity would have experienced time dilation on a very pronounced scale right yeah if you are moving quickly then your clocks tend to run slowly now this is an observer effect right so if you see a clock moving past you at high speeds you will notice that clock moving slowly the person holding that clock who's moving with it they won't notice it moving any slower they just know this time going as time goes but you will see it moving slowly and they will see your clock is moving slowly so special relativity sort of confusing that way but in the case of a particle moving this fast if you had for example a person holding a clock moving this fast then in about a billion and a half years they would their clock would only move forward like 1.7 days so it's extremely time dilated like they're moving so fast that their clocks run extremely slowly so in essence this this it almost doesn't experience time within its frame of reference so traveling that great distance is mere seconds to such a particle so it leaves whatever created it and then boom it's halfway across the observable universe in a second from its perspective from its perspective it doesn't take very long to get part of the way across the universe yes now remember from its perspective time always travels time always moves forward at the same pace one second per second it's not experiencing time moving slowly it sees the rest of the universe as having time move slowly because from its point of view the rest of the universe is moving at that speed relative to it because remember velocity is relative you can't talk about an object or a spaceship or a baseball moving at some speed you always have to say moving at some speed relative to something it's a little bit mind-blowing but like if you had an object in a universe and it was the only thing in the universe like an empty universe except for an object it wouldn't even make sense to talk about it having a velocity because it wouldn't be anything to have a velocity with respect to getting something up to those speeds that's that energy the closer you get to the speed of light the harder it is until it eventually reaches at the speed of light infinite energy needed to accelerate so what in the universe could accelerate a particle to that energy that speed nothing that we are aware of you know if you ask astrophysicists what's the highest energy a particle should ever have and they start out with like particles created in supernovas and then you know gravitationally slingshotting around black holes they can get particles going pretty fast having pretty high energy but not within like a factor of a thousand or a million depending on the physicist you ask of the energy of this particle so there's no process we know of that can generate particles of this high energy which suggests that there's you know something new out there that we don't know about that's making particles of crazy high energy now when you build increasingly large colliders here on earth and then potentially on the moon or even bigger solar system size can you start to approach the energies of this particle artificially you can try the accelerators that we build here on earth get within like a factor of a million so they're a million times less energetic than this particle so the cosmic accelerator that created this particle is much much more powerful than ours and in order to have an accelerator using human technology that could create a particle at this energy it would have to be solar system sized it's not something that we can do currently and the energy of these things doesn't scale very rapidly with the size and so you need to be really really big and of course one of my favorite speculations for the potential sources of these particles are alien particle physicists some people like to imagine that maybe out there somewhere there are other intelligent species asking the same questions about the nature of the universe and using similar tools to try to probe them and maybe they have built such a crazy collider and what we are looking at is essentially pollution from alien particle physicists but of course that's just fun speculation but it's still it's certainly fun speculation but it's certainly a uh it would be really interesting if that is the techno signature we find as opposed to a radio signal now you also have a project called crayfis that aims to use the world's cell phone network to detect ultra high energy cosmic rays could you give us an overview of that and is it marginally possible that we won't detect a techno signature from an alien civilization through a radio telescope but rather the world's cell phone yeah about a few years ago we were wondering about whether it be possible to make bigger detectors to spot cosmic rays one difficulty in understanding where these things are coming from is that there just aren't that many of them like this oh my god particle it happened in 1991 we see particles around at this energy you know every few years or so nobody's beat this one so far but for these crazy high energies it's like one per square kilometer per century and so if you want to understand where they're coming from you need to see a few of them you know one basic question we have is like where in the sky do they come from is it from one particular location or all over we haven't seen enough to even answer those basic questions and so if we could see more of them then we could answer a lot more of these questions the difficulty of course is that to see more of them you either need more centuries you got to wait a long time or you need more square kilometers of detector the way you see these things typically or currently is that they make their splash over the surface of the earth and you have a region of the ground that's dedicated for this and there are two big facilities right now the pierre og facility in south america and the telescope array in utah and you know they are pretty big we're talking about thousands of square kilometers but they're tiny compared to the surface of the earth so we were wondering instead of spending another 100 million dollars building a dedicated facility could we take advantage of existing resources things that people have already built and maintain in order to see these cosmic rays and the cosmic rays when they hit the top of the atmosphere they create these showers of particles but those particles are just everyday ordinary particles that exist in cosmic rays you know muons electrons protons photons and your phone the camera in your phone has a silicon chip which is an expert at detecting those particles normally it tries to detect photons coming in through the lens but if you cover the lens of your phone if you make it dark then other particles like muons which can penetrate any cover you put on your lens can still leave a little splash in the camera so if you cover the lens of your phone essentially you are running a little particle detector and if there are enough folks out there running an app which essentially just looks in the camera while it's dark for little splashes then they could detect a huge splash of these particles washing over the surface of the earth and in regions where there are lots of people and lots of phones you can get essentially a snapshot of this big splash it's called a shower and you could use that to figure out how much energy the original particle had and where it came from so we did a little calculation in a paper to see like how many people would it take running this app in order to be as sensitive as current facilities and the answer is a few million people so we wrote a little app and we're testing it and so far it seems to be working pretty well so potentially if we get enough people running this app then we could be operating a worldwide network which could see these cosmic rays i don't know if the first thing we would see would be very energetic cosmic rays from natural sources like centers of galaxies and supernovas or if we'd be getting a message from aliens in terms of high speed protons but i'd be happy to see either one what would they be doing if they built an accelerator the size of their star system are bigger they say there was super civilization and built one the size of a galaxy in order to figure out and probe the universe at extreme energies which we would love to do but we don't it's not the cards for us yet what what would they be doing that would produce you know what what experiment could they do that would accidentally or or intentionally produce such a particle well if you're colliding particles at very very high energies then your goal is to understand like the fundamental nature of space and time when we do that we're essentially recreating moments of the universe early on like from just after the big bang when everything was very hot there's a lot of energy everything was very dense and back then we think that there were lots more particles that were just around floating in the universe like the things that make up me and you are electrons and protons and neutrons those protons and neutrons are made of quarks there's two kinds of quarks ups and downs so basically everything that you and i know everything we've ever eaten are made out of electrons up quarks and down quarks that's the recipe for everything we know in the universe other than dark matter but in the early universe we think that there were other particles floating around other kinds of quarks other versions of the electron other heavier particles and one question we have is like well what other particles are there out there on nature's menu so these aliens might be colliding particles at very high energies like we would love to do to create these other particles that haven't been seen since the very early days of the universe and so if they make these collisions they could see these particles and these particles probably wouldn't last for very long for example in our collisions when we make a higgs boson it lasts for 10 to the minus 23 seconds it only exists very briefly then it turns back into ordinary particles that have a lot of energy so if you are doing collisions at very very high energy then you're definitely generating sprays of particles that come out of the collisions that have a lot of energy and so some of those could be reaching earth or you know if we're speculating about alien intentions maybe that they think that's the most natural way to communicate not to send radio waves or light flashes but to send little physical particles at very high energy maybe in some pattern it's impossible to know how aliens would think is a natural way to communicate maybe that's how they talk to each other back on their home planet yeah um communication via particle accelerator [Laughter] to a cell phone now when dealing with these super colliders you know these big enormous ones that we might someday build could you also probe things like say string theory and see if that's on the table as a viable uh description of the universe it's certainly possible in the future to build really big accelerators that could probe questions like string theory string theory essentially says that our current idea that electrons are little point particles dots with zero volume right no radius no length just like infinitesimal dots that that might be wrong that actually electrons if you zoom in close enough are made of these tiny vibrating little strings and if they vibrate one way you get an electron if you vibrate another way you get something else it's difficult for us to probe that theory because the strings if they are real are so so small and particle accelerators are cool because the higher the energy you have in your accelerator the smaller the thing you can see sort of like thinking about the way you use light in a microscope you can't really see things using a microscope that are smaller than the wavelength of light being used and so as you go to higher and higher energy the de broglie wavelength of the particles you're talking about gets much much smaller and so you want to see really really small things you have to have really high energy particles in order to probe those tiny distance scales so we are you know orders of magnitude away from probing string scales if those strings are real but there's nothing preventing us from building those accelerators and asking those questions and maybe seeing those strings one of the really cool things about particle accelerators is that there is no limit to their power the only limit is money right if you gave us a trillion dollars we could build a very powerful particle accelerator you gave us a quadrillion dollars we could build one a thousand times more powerful and so really money is the limiting factor there's no limit to how much we could know about the universe it's just a question of how much we are willing to spend now is there plans any plans on the table for a future accelerator that's more powerful than anything that we currently have there are always plans though it's never clear what's going to happen it's sort of like space telescopes you know the james webb telescope took 20 years to launch or longer even to plan to build and actually go out into space particle accelerator projects are on the same sort of scale it takes decades of planning and political finagling to decide who's going to spend the money where it's going to be currently our highest energy accelerator is the large hadron collider the one outside um geneva where we discovered the higgs boson in 2012 and it collides particles just under 14 trillion electron volts so 14 tera electron volts and it's um been operating since the mid 2000s and we think it's going to operate for another 10 or 15 years but that means we need to start planning for the future and people are talking about a 100 tev collider maybe in china maybe somewhere else the question is who will pay the maybe 100 billion dollars it costs to build such a machine though the things we could learn about the universe might be incredible and you know 100 billion dollars sounds like a lot of money to me and you but it's really just a few aircraft carriers um if such a thing were to be built you know it might get started in construction in five or ten years and then it would take you know 10 or 15 years so we're talking about decades from now there are also plans for a 30 tv collider perhaps in the same tunnel as a large hadron collider or a bigger tunnel built at cern also there's a wide spectrum of ideas stretching all the way to building a particle collider on the moon that wraps around sort of the the equator of the moon and is just built under slightly underground to protect it from micro meteors yeah the the lunar gardening process the uh and i there there's weird things about the moon you know static electricity phenomena and things like that that i worry about now that we're looking on going back there you know now in the particle accelerator can you probe things like i i know we can't do it at this level but could you eventually probe things with a big enough accelerator like other dimensions as i recall string theory predicts 10 dimensions of space one dimension at a time can this be used to characterize other dimensions if they should they exist it certainly can and even the large hadron collider is big enough to ask questions and answer them about other dimensions of space and time the idea is that you know maybe there's not just xyz the three dimensions that we're familiar with maybe space has other ways to wiggle it if that is true it would be really fascinating it would help answer some really deep open questions about the universe questions like why is gravity so much weaker than all of the other forces if you hold up a kitchen magnet you can overcome all of the gravity of the entire earth right with just a tiny kitchen magnet that's a way to think about how gravity is so much weaker than the other forces but we don't really know why that is it seems strange to us the other forces have sort of similar strengths and gravities like 10 to the 37 times weaker well one explanation for that is that maybe gravity isn't actually that much weaker maybe there are other dimensions of space and gravity sort of leaking out into those dimensions you know that gravity gets weaker by the distance so you don't so you feel the force of the earth more strongly than you feel the force of jupiter because the earth is closer and as things get further away gravity falls off well if there are additional dimensions of space then gravity would wiggle through those dimensions and our dimensions and so it would fall off more rapidly than like one over distance squared which is newton's idea maybe would fall over by one over distance cubed or one over distance to the fourth if there are other dimensions and if these other dimensions are not like infinite dimensions the way that our three are but they're small circular dimensions that loop over around themselves then these effects would only be visible at very short distance scales so gravity would fall off very quickly like one over r to the sixth for the first millimeter or first centimeter and then after that it would fall off like one over r squared so that it agrees with what newton has seen and the operation of galaxies and solar systems this is something that we could probe at the large hadron collider because we can get to very small distances so if gravity is really powerful at short distances then if you collide two protons together at very high energies then when they're very close together their gravity might get very very strong and might get strong enough to create a mini black hole so if you could create a mini black hole using these collisions that would be a good sign that the gravity is much stronger than we think it is over very short distances and that would be a strong clue that there might be these extra dimensions of space and time that are weakening the power of gravity on our sort of distance scales like meters and kilometers and astronomical units and light years and so that's what one thing we're looking for at the large hadron collider and at future colliders the higher energy you have the smaller distance extra dimensions you can probe so far we haven't created any black holes that we are aware of now it's worth noting too that this isn't a dangerous kind of black hole this isn't a super massive stellar mass black hole this is a tiny one created from two protons that doesn't last very long but it does last long enough to study it now spooky action at a distance does that in itself imply some other dimension you know a link through some other dimension between these particles well spooky action at a distance is just a statement that particles don't need to touch each other in order to communicate or in order to affect each other and you know in modern quantum field theory we have these things called quantum fields that fill all of space so the way two electrons push against each other is not that their surfaces touch but that they extreme but that they exchange wiggles in those quantum fields those wiggles being photons in the case of two electrons pushing against each other so it's really just a description of our current understanding of quantum fields to say that particles can influence each other without physically touching in fact that's sort of what touching is like when your finger touches the surface of a table your particles aren't physically touching those particles remember your particles have zero volume electrons have no space to them and what's really happening is that they're pushing against each other and so there are forces involved there so your finger doesn't really touch the surface of the table in the way you might imagine it just sort of pushes it away the way like two magnets can push away against each other without actually touching it's a good thing the universe works that way or else you you would never be able to set anything on a table falling through but i guess there is a non-zero chance that you could set something on a table and it passed through it right i mean it's very unlikely but it's non-zero yeah and in quantum mechanics everything that's possible can happen if you try often enough and you know the world is opaque to us we can't see through it we can't pass through some substantive feeling things but other particles can like the sun also produces billions and billions of neutrinos and those pass right through the table and right through the chair and even other kinds of photons x-rays and gamma rays they can pass right through objects that we think are substantive and not because they're like dodging those atoms and wiggling through them or because they're so small but because they just don't interact with them you know neutrinos don't interact with these particles because they don't have electric charge so they just pass right through they they see the universe is looking very very different from the universe that we see and they feel it differently than we do so you know the fact that something feels substantive to you doesn't mean that it actually is necessarily in a universal sense it's just the way it feels to you now that brings up another point in that when you look at a neutrino a very weakly interacting particle or almost non-interacting except the gravity and i think the weak force too if it gets close enough right but um that starts looking a lot like perhaps dark matter which may also be a weakly interacting particle do you think that the neutrino family is a good place to look for the answer as to the nature of dark matter well we know very little about what dark matter is so i think that we should be looking everywhere you know we know that dark matter there's a lot more of it than there is normal matter we know that it's responsible for the structure of the universe as we see it that it created these gravitational wells that led to the formation of galaxies and stars we also know something else about dark matter we know something about its speed we know that dark matter is fairly cold meaning that it's fairly slow moving so it's more likely to be like a slow moving massive particle than a very very high speed low mass particle we know that because of the structure of the universe the reason we have galaxies where we have them is because there was a big blob of dark matter that gathered together the hydrogen and the helium and forced it to create a galaxy like if you had a universe without dark matter you wouldn't get galaxies forming this early in the universe it would take another 10 15 billion years before you had galaxies so the reason we have galaxies is because of dark matter and so we can look at galaxies and we can understand something about where the dark matter is and because the dark matter seems to sort of clump together in these big blobs we can do some calculations and discover how fast it might be going if dark matter was going much much faster than it is currently than we think it is then those clumps would have spread out more and so we wouldn't have as much clumpiness in the universe the universe would have formed differently so what that means is that dark matter is probably not neutrinos probably not one of the neutrinos that we know because those are all very very low mass very high moving particles people thought originally maybe dark matter is just a bunch of neutrinos but we know now that it can't be because it has to be pretty cold in the other hand you know as you suggest there might be other weird kinds of neutrinos people speculate about additional new neutrinos maybe they're even heavier that could explain the dark matter and i'm totally in fan of thinking about crazy ideas for dark matter because it's such a big mystery you know we know that we've only studied a tiny portion of the universe and i think that that tends to make us sort of blind to other ideas about what the universe might be like as humans we're always over generalizing saying well our experience is like this and so everything must be like that so we need to be work hard to sort of push the boundaries of the box of our thinking and and allow ourselves to to consider crazy ideas that includes weird new kinds of neutrinos you know these sterile neutrinos that maybe don't interact with the other three could be out there in the universe if they are slow enough and heavy enough to be cold enough to explain the dark matter that we see could dark matter be much more complex than that could it be a mirror of normal matter and there could be an entire universe of dark matter stars and things like that that we simply cannot perceive because it doesn't interact with our our frame of reference in normal matter could it be that complex or is that too crazy and i have an idea there's no idea too crazy when it comes to dark matter the short answer is yes though there are some caveats right we do know something about dark matter you might start out and say well we don't know anything about dark matter so there might be dark stars and dark planets and dark life and dark podcasts talking about you know what is the missing five percent of the universe that uh that we're made out of but we do know something about dark matter we know that it doesn't have interactions with itself the same way we do like if you have an electron passing through the universe it's going to bounce off of protons and interact with all sorts of stuff and that's why matter that's why our kind of matter forms planets and forms stars because it tends to it's because it's sticky right when matters bangs into itself it tends to stick together and dark matter doesn't do that dark matter we think passes right through itself you know we've seen for example the bullet cluster two huge clusters of galaxies passed through each other the gas in the dust smashed into itself huge explosions and ripples and x-rays produced but the dark matter passed right through even though it has gravitational interactions it didn't have anything stronger which would prevent it from passing phasing through itself out to the other side so it's unlikely that dark matter has strong interactions that would allow it to build complex compact objects like stars and planets on the other hand right there is a lot of dark matter there is much much more dark matter than there is normal matter so it could be that there are many different types of dark matter and maybe most of the dark matter is some big fluffy non-interacting thing that has you know controlled the results of our experiments but there's still plenty of room for there to be a portion of the dark matter to be different to be weird to be sticky with itself in a way that we haven't yet detected and to form complex functions and and objects and maybe dark physics and dark chemistry and dark biology and dark intelligent life that certainly is possible it's also possible that even though dark matter doesn't have strong interactions maybe it forms complex objects just at a larger scale instead of planet sized maybe they are galaxy sized objects with complex swirls in them that we just can't detect we should be also wide open to other ideas about how life could form and what it could mean to be alive and maybe streams of dark matter can be organized in a way that one might consider to be life i'm going really far out on a limb here speculating but you know it should be remembered that we know so little about dark matter that we should be wide open to crazy ideas about what it might be hey we exist you know i mean it and think about that if you are a dark matter alien you probably cannot perceive normal matter so we would be it's dark matter and here we are we sort of uh we prove that intelligence is possible in the universe therefore therefore the universe could be stranger than we ever imagined as to paraphrase a an old quote the graviton now what is your views working in particle physics what are your views on the graviton do you think that that is necessary to describe quantum gravity or do you think we just don't need anything further than you know what we understand from relativity we definitely need something else right we know that the universe is well described by quantum mechanics things seem to be quantized quantum particles behave differently than baseballs and basketballs they don't have smooth continuous paths in the way that you know classical objects do so we know the universe is quantum mechanical on the other hand general relativity is not general relativity says that the universe is has smooth and continuous paths and you know that space can be infinitely divided up so one possible way to unify general relativity in quantum mechanics is to say maybe gravity is also a force like the other forces maybe it can be described in terms of the exchanging of virtual particles the way we talked about earlier when electrons bounce off each other they exchange a photon maybe you can describe gravity between two objects is exchanging some virtual particle a graviton that's one idea but there's a whole other class of ideas that says well we know that gravity can also be described not as a force but instead it's the effect of curved space-time so maybe rather than taking gravity and making it into a quantum force let's take space-time and make that quantum mechanical say slice up space time instead of letting it be continuous slice it up into little bits like maybe the universe is pixelated instead of smooth and continuous like you can be here or you can be there but you can't be in between in some weird way and these pixels would be super duper small and so that's a completely different way to think about unifying general relativity and quantum mechanics and it wouldn't require a graviton because it wouldn't make gravity a quantum force it would make space itself quantum mechanical and to me that's a more attractive idea not scientifically scientifically we have no way to prefer one idea or the other but philosophically it seems to make more sense to me i'm attracted to the idea that gravity is not really a force it's just the curving of space and time and that space and time should be quantized like everything else it seems to be quantized and it uh it makes sense to me that space would be divided up into these little pixels and a time could be quantized into basic units um i like that view of the world though i have no evidence to support it well einstein liked it and the the reality of it is that it's much more elegant that way because you're just looking at the physics of a bending trampoline you know things like that tensor stuff as opposed to yet another particle in quantum mechanics which we seem to keep coming up with more and there doesn't seem to be an end and it's rather messy now should the graviton exist though and should we see it in a particle accelerator then could that be used as a further probe in determining the nature of dark matter because dark matter obviously interacts with the graviton should it exist right yeah absolutely if the graviton exists and then it can be considered the mediator of gravity then everything that feels gravity should interact with the graviton if we had a collider that was powerful enough to create and detect gravitons then yes it would also interact with dark matter that would mean for example that we might we might be able to produce dark matter in our colliders create collisions which produce gravitons and those gravitons then turn into dark matter for example so yeah that would be one way to study the question of dark matter is to study gravitons because gravitons are part of gravity one of the cool things about gravity is that it touches everything even if you have a particle that has no other interactions if it's a particle then it has mass if it has mass that's energy and energy bends space time energy contributes to gravitational curvature of space and so everything that's out there can be probed using gravity it's a super cool because it touches every kind of matter now on to the uh the matter the question of mass this involves one of the biggest discoveries in recent years in particle physics the higgs boson that we mentioned before this particle seems to explain mass the as a phenomenon what's going on there how does it do that so the higgs boson is responsible for a little bit of mass in the universe most of the mass of the universe actually doesn't come from the higgs boson the higgs boson explains the mass of some tiny fundamental particles like the electron and the quarks and it does that by changing the way they move through space you know what we think about mass we think about you know how hard it is to push something or how hard it is to slow something down you have a big massive particle moving through space you want to slow it down the more mass it has the more force you have to apply that's just f equals m a right that's what we mean by inertia or inertial mass so what the higgs does is it changes the way particles move electrons move through space because an electron moves through space now because of the higgs field this new quantum field that permeates the universe as it flies through space it's interacting with virtual higgs bosons constantly and it's doing so in a way that mathematically is identical to the electron having mass so fundamentally the electron is still massless but its motion through the universe is mathematically identical to another scenario where the higgs field doesn't exist but the electron does have mass it's analogous to the way we think about gravity right we think about gravity as bending space and time and changing the trajectory of particles and so instead of thinking about electrons as massless particles moving through a higgs field you can instead just think about them as massive particles moving through emptier space so that explains why electrons have mass and quarks have mass and other fundamental particles but like a proton the proton is made up of three quarks but a proton is much much more massive than those quarks right those quarks have a tiny fraction of the mass of the proton the rest of the mass of the proton is contained in the energy between those quarks the bonds between those quarks so mass fundamentally is more like a measurement of the internal energy of an object and some of that internal energy can be due to its interaction with the higgs field but mostly it's not so most of your mass for example doesn't come from the higgs boson it comes from your protons and that energy the net mass comes from the energy of those bonds and then going further we think that dark matter doesn't get its mass from the higgs field we think it must get its mass some other way so the higgs field is one way for particles to get mass but only the fundamental particles get that mass and only the fundamental particles of the standard model the ones that we know it just goes to show the reliance of this universe on energy it really is a universe of energy rather than what we see as matter because matter and energy are equivalent so let me ask you this go to wrap everything around bending space and creating creating a wormhole and i think this this one episodes on your podcast delved into this spending space time in that way to that extreme to create a a wormhole a passageway of some sort between two separated points in space is it ever possible to do that i mean could we ever start instead of crossing vast amounts of space time we just open up a wormhole and go on through or is that forever off the table it's not forever off the table right now relativity says that it's possible what does that mean for relativity to say that it's possible it means that you can find solutions to einstein's equation that have those features that have two parts of space being next to each other even though they're far apart from another point of view and what that means is you know you have to think about space not as just like where stuff is you have to think about it like as a fabric space time can be simply connected where every bit is only connected to the bits near it or can be connected in more complex ways where bits are woven together to the pieces that are near them but they're also weirdly near to something else that's otherwise far away through other paths through space you know so like depending on how you go something can seem far away or next door that's what a wormhole would be the problem is that even though that's a solution to einstein's equations einstein's equations don't give you recipes they just say oh yeah this is a solution they don't say necessarily how to arrange matter and energy in the universe to make that happen you know and they don't tell you how to go from a universe without a wormhole to a universe with a wormhole they certainly don't tell you how to build a wormhole so that the ends are in places you want them to be right you might build a wormhole and have no idea where the other end of it is which would not be very useful so while it's not ruled out theoretically we are many many many steps from being able to say i want to go to alpha centauri let's build a wormhole and go there this weekend pack some nice wine so essentially unless you're able to open it at both ends so you still have to cross space time you just don't know where your wormhole is going to end up and there's also the question of time what time do you end up um because whenever you start messing with this stuff you start messing with time as well as space right yes absolutely and wormholes require curvature of space and every time this curvature of space clocks slow down i was reading one study that suggested that going through a wormhole might be slower than just going there in a rocket ship because the time validation would be so great that by the time you got to the other side you would have taken you longer to get there even though you went through less space your time was so dilated that your trip was actually slower now could a wormhole not be used for travel but rather communications could you cut communications time between two points through a wormhole sending a radio signal through or does the universe prevent that you know that that fast of an information transfer it does not prevent that that would not violate special relativity special relativity says that you can't send information through space faster than the speed of light but special relativity doesn't limit you on how you organize space so if you connect something from here to there so that the distance is small you know even though it through other paths the distance would be large then you can send information through a wormhole that would arrive faster than light would otherwise right it's one of these cool loopholes in special relativity another one being that you can't move through space faster than light space itself can expand or contract and there seems to be no limit on the speed of that happening so that's the basis of potentially building like a warp drive to get from here to alpha centauri though you know theoretically maybe possible we are again many many engineering steps away from being able to understand how to actually make it happen net that is a reference to the alcubierre warp drive and i've had dr alkaveer on the show actually talking about it now if you could do that and move faster than light by breaking off a piece of space time could that produce radiation levels that would be powerful enough to explain the oh my god particle meaning that it is it would be a signature of an alien coming out of warp that's a fun idea i hadn't thought about that before but it's certainly true that the front end of the warp drive where you're compressing space would generate a lot of gravitational radiation right anytime you change the shape of the fabric of space that has consequences gravitationally and sends out gravitational radiation which basically is just communicating that that gravity that that space has changed and so the gravitational field has changed so that could be very energetic and i know that for warp drives the radiation is really focused in the direction of motion so it's certainly possible that could provide a boost to particles and yeah that might even create signatures like the oh my god particle i think you would expect more than just one particle you'd expect like a stream of them all surfing on those gravitational waves but i haven't done the calculations myself now could that be used as a weapon in other words sending something relativistic it it shoots off you know this giant shock wave of oh my god particles that hit your upper atmosphere or does the upper atmosphere save us from any amount of these things should they come in in a huge burst it's not an infinite shield right for example big meteors or asteroids can penetrate our atmosphere because if they have enough kinetic energy so you either have to be very large or traveling at high enough speeds to penetrate the atmosphere and you know every time one of these particles hits the upper atmosphere even if they just do turn into a shower they don't make it to the ground they're still depositing a lot of energy in terms of radiation so you can increase the amount of radiation that's hitting the surface by showering a planet with very high energy particles even if you know they're not making it to the ground you're still increasing the radiation those muons pass through you and the more radiation there is the higher the chance you have of getting cancer for example so you could definitely irradiate the surface of a planet by shooting a lot of high energy particles at its atmosphere now do these high energy particles like the omega particle and subsequent ones that have been detected pose any danger to spacecraft absolutely spacecraft are in danger from very high energy particles you know a very small particle can punch a hole in a habitat or give astronauts a high dose of cancer that's one of the most dangerous things about being out there in space is that you don't have the protection of our atmosphere and in particular even if they're not very high energy particles if there's just an high enough flux of them if you have enough particles you can really damage the health of an of an astronaut and our sun is unpredictable enough that astronauts have like a safe room in the iss where they go where there's extra shielding in the case of like a coronal mass ejection or some other coronal solar flare that sends a lot of energy in the direction of earth would otherwise kill astronauts if they didn't have that kind of shielding so yes space is a very dangerous place do you intend to go there with the space tourism do you do you anticipate a day where you will you will enter space oh gosh no i have no interest in going to space i'm very comfortable here on earth i prefer to spend my energy making sure that the earth is safe and habitable for generations to come i also don't want to sign up to go to mars you know for example i have no interest in traveling even to antarctica it sounds very uncomfortable to me and i think that mars and space are much much more uncomfortable than antarctica so it's they're further down on my list of vacation destinations i have to agree i i will not be going to space anytime soon but the furthest i i i go as far as space is walmart but now what's what is next in you know now that we've seen the higgs boson which was long suspected is there anything else that's long suspected that our particle accelerators might soon reveal well one thing is dark matter you know if dark matter exists and it's a particle and it's you know made of some stuff then we might be able to produce it in our detectors in our collider and see evidence of it in our detectors because dark matter doesn't interact with stuff we can't see it directly but we might be able to see its absence like if you produce a spray of particles and some of them are dark matter particles then they're invisible you might be able to detect the presence of those invisible particles because they would otherwise appear to be violating momentum conservation like if you add up the momentum of the particles that go into the collision and the particles that come out if they don't equate each other if they don't match up then that suggests that something invisible was produced so that's one way we look for dark matter in colliders that's something we can we're doing and we should we'll keep doing but for dark matter to be produced in our colliders it would mean there has to be some kind of interaction between the dark matter particles and the protons that we're sending into the collisions and it might just be that there isn't any that dark matter only feels gravity so we can't detect it we're also looking for all sorts of other stuff you know we know that we know very little about the universe we've been studying five percent of the of the energy density of the universe in terms of quarks and electrons and stuff we know that most of the universe is a big mystery and so we're not just looking for particles that we suspect might be there we're also for looking for surprises you know if you landed on mars and were looking for life you wouldn't just look for cats and dogs and little green men you would keep your eyeballs peeled for anything super weird and surprising you would try to expand your mind to be open to crazy new things that you might discover we're doing the same thing in particle colliders hoping not just to find you know dark matter but also to see surprises to find something new and weird that makes people scratch their heads and go what why does that exist what does that mean about the universe that's one of the joys of scientific discovery is that it's exploration which means you never know what you might find under the next rock now my last uh topic for today is time travel now we know we can go forward in time and accelerate it in our frame of reference but or opposite our frame of reference i guess so we can go forward in time any hope that we could ever within the laws of known physics go back in time personally i think that we can't go back in time because i don't think it holds together consistently in terms of an idea you know going back in time means changing the timeline but the timeline itself is how the universe changes with time you imagine the universe is a series of snapshots this happened and that happened then the other thing happened those things are causally connected one causes the next causes the next for that to like loop back on itself or for there to be like a transition or where the timeline looked like this and then later it looks like that just doesn't make any sense to me because later means changing which means changing the timeline the timeline itself can't change all that can change are things along the timeline so i think that it comes from this desire to tell stories and time travel itself is this is comes from thinking about time as a location you know that the 1950s are a place you can go or the 2300s are a place you can go but they're not they're a version of our universe that doesn't exist anymore or doesn't yet exist so they're not places that you can travel to though they do they do you know generate a lot of really fun movies i don't think technically it's going to be possible in general relativity there are a few places where it appears that maybe time travel would be possible closed time like loops etc but the current thinking is that those probably just reveal the problems with general relativity more than actually being possible in the same way that we think like the singularity at the heart of a black hole isn't physical there isn't an infinitely dense point of matter there that's a sign that general relativity is breaking down not an actual prediction of it in the same way these closed time-like loops in general relativity probably are just signs that their general relativity is limited in its applicability it needs to be replaced by something else like quantum gravity now this has happened before with eins or newton and you know newton's newton's physics works but it doesn't really reveal the whole story especially in regards to time which he he didn't know anything about frames of reference or anything like that so einstein came up with a more precise theory but general relativity itself also breaks down so it isn't a complete picture even though it it it gives good answers and it was testable now with time travel though and i want to make a distinction here let's say for example it's impossible to go back in time the universe simply doesn't allow it because you can't be messing with the timeline so it's prohibited just by the nature of the universe but does that does that mean that the past truly doesn't exist anymore or is it because of causality does the universe sort of reference back to the past and it tangibly is back there it's just you can't visit it right i think it's more that you can't visit it the past certainly has left an imprint on the present we think that quantum information tells us that no information is ever lost and so the present uniquely determines what the past was meaning if you knew everything about the present that there was to know you could reverse that and say i know everything about the past as well so the whole history of the universe is encoded in the present moment of the universe so in that sense you know the past sort of lives on because it determines the present or at least the wave function of the present universe but it's not a place you can go so not somewhere you can visit you can't recreate it in regards to that can you so you can still go forward though you know just accelerate really fast or sit right next to a black hole so you can actually travel to the future but you can't ever go back but do you are you of the opinion that maybe some things can so i know that this is consistent with relatively that you have things like tachyons that could never slow down to the speed of light that may actually experience time in reverse do you tend to favor those ideas or or does it apply to everything that you just can't go back you just cannot go back in time tachyons are like a theoretical exploration what would it be like if a particle was going fast in the speed of light but it's not something we think exists in our universe it's just sort of like a mathematical playground so it's one of those things like like exotic forms of matter it's not prohibited but probably does that doesn't mean it exists and you know it it's a different thing between existence versus a thought experiment yeah and probably there are just other aspects of the universe we haven't discovered yet that do prohibit it you know as you say every theory is replaced by more accurate theory and that's true for everything you know we never know whether our theory is a true description of the universe or just the closest approximation we have so far to how we think the universe works really just like an evolving mathematical story we tell ourselves about the nature of the universe yeah and then it's you know that that that alone changes you know and that our understanding of the universe may be significantly altered 50 years from now just like it is from 50 years ago i certainly hope so and i hope that in 50 or 100 years they look back at us and they think wow those those folks knew so little about the nature of the universe because that would mean that there are discoveries ahead that will blow people's minds primitives yeah we are just uh we can't we can't have the hubris to say that we know everything we probably don't know very much at all no we are definitely ignorant children in the year 3000 we'll know more about the universe than the cutting edge minds do today now tell everybody about your podcast sure so the podcast is called daniel and jorge explain the universe and i do it together with my friend and co-host jorge chan who's the cartoonist behind phd comics and we talk about all these kinds of stuff we talk about you know are there aliens we talk about the dimensions of space and time we talk about what's at the heart of black holes and we try to keep it accessible but we also dive deep into the underlying theory and try to explain all that crazy stuff um and we you know have a good time we laugh we joke we talk about physics it's a lot of fun and you also have a number of books out where can people get those yeah we wrote a book in 2017 called we have no idea which is all about what we don't know about the universe trying to prepare you for the big discoveries that are coming and then last year we wrote a book called frequently asked questions about the universe which tries to answer some of the most common questions that we get on the podcast you know can you do time travel or could time ever stop you know can physics explain in afterlife these sorts of fun questions answered from a scientific point of view you can get those books at our websites we have no idea dot com or faq universe.com or just google for them they're on amazon alright doctor thank you for joining us today and i hope we can do this again sometime thanks very much for the super fun discussion [Music] event horizon and my channel are now available as a podcast on apple podcasts spotify and youtube memberships early ad free episodes bonus episodes and sleep focused content sign up now by clicking the links below to your platform of choice [Music] [Applause] [Music] you

Channel: Event Horizon

Views: 138,832

Keywords: What Made the Universe?, What Made Us?, what created us?, How Did the Universe Begin?, How Was the Universe Created?, What is the Universe Made of?, Oh-My-God Particle, lhc, higgs boson, physicls, particle physics, new, 2022, event horizon, john michael godier

Id: BpD1sXPcmW8

Length: 62min 44sec (3764 seconds)

Published: Thu Apr 14 2022