Why does stuff have mass? | The history of the Higgs Boson

this video is sponsored and approved by curiosity stream what gives you mass that's a very different question to what gives you weight gravity pulling down on your body gives you weight but your weight can change depending on the gravity so on earth you weigh much more than you do on the moon where the gravity is 1/6 of what it is on the earth but you're so made of the same amount of stuff the same amount of mass but what is mass if something is more massive it's generally harder to move think about like people trying to push on a car that's so much more massive so you can think of mass as a resistance to having motion changed and that resistance you know for everyday objects you know we tend to think of it maybe is friction but what about the smaller and smaller objects because a you know everyday objects around us are made of atoms which in turn are made of protons neutrons and electrons which in turn are made from even smaller particles called quarks and on that scale friction doesn't matter so what is causing the resistance for those particles to having their motion changed well that's a question that humans have been puzzling over for millennia today it's the job of particle physicists who literally study the building blocks of nature and their properties now that's not my job I'm an astrophysicist I think about the incredibly large things so I had to go find some experts on this so a couple weeks ago I went to CERN in Geneva in Switzerland to find some particle physicists and talk to them about the history of this question of what is mass and what gives things mass was finally solved first through studying the theory of what gives things mass up until the 1960s in the first video in this series and then a look at the experiments run from the nineteen 60s onwards in places like CERN to try and answer this question of what is mass so whilst humans have really been contemplating this question of what is everything around as made of probably ever since we learned to pose questions like that it really all kicks off in the nineteenth century especially with John Dalton's work who was a chemist who was studying the properties of elements in the periodic table and he realized that every single element was made of a single unique particle these were dubbed atoms from the Greek meaning indivisible because at the time it was thought that they were the smallest things that you'd be able to get down to but that all quickly changed especially with JJ Thompson's work in 1897 when he discovered the electron a tiny particle that had a mass less than any atom measured and of course we had the discovery of this invisible radiation by Henri Becquerel in 1896 which eventually would get dubbed radioactivity by Mary and Pierre Curie they went on to study radioactivity in great great detail eventually finding that the particles given off by radioactivity were smaller than the atoms they came from in 1907 Ernst Rutherford and his famous gold leaf experiment where he shot neutrons at a gold leaf foil to see how many went through and how many were deflected and he found that an Assam is essentially mostly empty space leading to this model of an atom of a dense nucleus surrounded by this cloud of electrons that would pave the way in the 1920s and 30s for the rise of quantum mechanics the study of the incredibly tiny and their properties and how they behaved and would really open up a can of worms in physics for this world where nothing is predictable and everything is to do with probabilities throughout the 1950s people also then started in particle accelerators to accelerate these tiny particles up to huge speeds to collide them together where this bewildering array of particles would spew out that was eventually dubbed the particle Zoo and as particle physicists you know really tried to figure out what all these particles were and how they all fitted together in terms of the model of how we built up all of the stuff around us so yeah at the end of the 50s we knew so many more particles than we did at the beginning of the century you know well more than just electrons protons and neutrons but the question that still hadn't been answered was what gives them all mass and this was very much the focus for physicists at the turn of the 1960s now the problem was if you took the equations from quantum mechanics that have been shown to really nicely describe the behavior of say hydrogen atoms and other small particles and if you try to solve them when things like electrons and neutrons had a mass all of the equations very quickly got very complex and also were completely inconsistent with each other they didn't agree at all they didn't agree with each other and crucially they didn't agree with what had been observed either and people quickly realized that if they set the mass of all of these particles to just equal zero in the equations equations massively simplified they all agreed with each other and they all predicted the correct outcome as well okay Carabas here's we know particles have mass we know that there is stuff here and that stuff is pulled on by gravity to give things weight how do you reconcile what the maths is telling you with what the universe is telling you so in comes Peter Higgs in 1964 and he said keep the equations as they are keep your mass equals zero and let them all consistently agree with each other but imagine that the particles are not moving through empty space they're moving through some different environment they're moving through an invisible field that permeates all of space which might sound far-fetched but think you know one magnetic field is an invisible field and he said it's the movement of those particles through this field that permeates the entirety of space that gives them this drag this resistance to motion and it's that resistance this drag from this invisible field that permeates all of space that we interpret as mass now most of you watching will be thinking that sounds ridiculous and incredibly far-fetched that's the most ridiculous thing I've ever heard and you wouldn't be alone in thinking that because when Vita Higgs first submitted this idea to a physics journal to get it published to the world in 1964 it was rejected for the same reason that they just thought it was ridiculous however Peter Higgs persevered he did eventually get it published and it caused quite a stir and the thing was it sort of ruffled a lot of feathers quite quickly before all those feathers settled back down again and said actually that would explain everything and that's the thing when a theory comes along that doesn't contradict anything that doesn't ignore other observations that we've seen and just sort of sweep them under the rug and say well you know this explains things perfectly and I understand it therefore let's go with it it actually completely explains the difficulties we've had with the maths it completely explained everything we'd have observed as well and so it didn't contradict either the maths or the universe it brought the two together and in just a few years this ridiculous hypothesis that have been rejected by a journal quickly became accepted theory because it was the best theory we had at the time to explain both our maths and what we've seen very succinctly despite the fact that we didn't really have any observational proof of this invisible field that permeated the entirety of space that quickly became known as the Higgs field now if you're still struggling with this never fear because when I was at CERN I made sure to ask the particle physicists there what their favourite analogy was for describing the Higgs field if you're at a party and something like this is out of this one time you walk into a crowd of people and if you're not very popular you're a bit awkward or smell a bit but yes you know people are going to avoid you and this crowd could be full of all that is the Higgs field I'm just gonna get out of your way and nobody will stop and talk to you but if you're very charismatic and talk to everybody it'll take you a long time to traverse the room you'll get stopped everything let's do often to talking something with Aaron's analogy that you can also consider that the people who move around the room and stop and talk to a lot of people will probably you know shake a lot of hands or maybe elbow bump them and in that process there'll be this transfer of information from the crowd of people okay the Higgs field with the person moving around that crowd okay the particle trying to move through the Higgs field and that transfer of information is a bosons job specifically in this case the Higgs boson it's the thing that transfers information from the field to an observer or something that's interacting with that field for example a photon is a boson a particle of light it transfers information about the electromagnetic field to us the observer so for example if you set up a nice simple circuit a little light bulb and some wires and you would finally attach it to a battery you're setting up electromagnetic field can't see it but we do see the light bulb come on because photons of light make it to our eyes and exchange information funny thing though about the Higgs field and the Higgs boson is that the Higgs field also gives the higgs boson mass is what we call self interacting and that's always something I struggle with until I met Clara now stern and she told me this analogy but the best analogy that I've heard for describing that expose on is the the snow field so no I heard it from John Ellis who's a theorist here at set and so he talks about how if you have a field of snow the way that you interact with that snow the snow is the Higgs field and the way that you interact with the snow is how you interact with the Higgs field so if for example you've got a pair of skis and you're just sliding on top of the snow then you're either a very low part to call though you have no mass at all cause you're not really interacting with the snow you're just sliding on top of them if you have snowshoes then you're kind of able to go through the snow it's a bit easier so you're having some interaction but not so much so that would be maybe like an electron a like particle and and if you have no snowshoes at all then you're just in some tiny boots that you're really gonna sink in it's gonna be super hard to get through the snow field so that's like a top part that's really heavy yeah and then the Higgs boson itself is is like a snowball it's like the Higgs field interacting with itself that's not cool that's how you can imagine the boson so immediately after hearing that analogy I was like so Legolas is the photons of the universe because they don't have mass so they can walk atop the snow you completely unimpeded you know they're not impeded by the Higgs field which okay it was a silly thought that I had but it turns out it is something we have to think about and particle physicists are always considering and it it's sort of a consequence of the Higgs field that people might not have thought of before but I know you'll all care about after my why can't we travel faster than the speed of light video and you all got very engaged in the comments but say well I'll let Aaron explain depending on I'm master the particle is on depends how heavily interact with the Higgs field so something that's very light a photon not very light but zero mass no masseter oh yeah that's the latest you can be doesn't see it at all so that kind of translates the fact that it's able to go at the speed of light and that's one of its main properties whereas when you start to go up through the mass scale you start to get more and more interactive with the Higgs you can imagine it for a photon it's like traveling in vacuum for something very heavy like a popcorn it's like traveling through treacle you know it then it removes that ability show you to just travel at the speed of light so if you were to turn the Higgs field off all particles would immediately be masters and adopt light speed so I guess why can't we travel faster than the speed of light the easiest way to answer it is because we can't turn off the Higgs field it will always be there impeding our motion and causing this drag and resistance on even the tiniest of particles I don't know maybe most of you will enjoy that explanation more than Einsteins way of explaining it the theory of the Higgs boson really came out of the mathematics in the 1960s and it wasn't until decades later in 2012 that that was even proven to be right even though it was accepted for decades before that that might sound weird to some but it's not a rarity in physics maths is a tool that we can use and exploit to understand the universe and you better believe we should listen to it when it's trying to tell us something it's happened so often in the history of physics in the 1930s Karl Schwarzschild used the maths to predict the existence of black holes way before they were ever observational II confirmed in our universe Paul Dirac in the 30s used the maths of quantum mechanics to predict the existence of antimatter and even way back in the 20s lamare used maths to show that the universe was expanding well before Hubble ever observed the redshift of Andromeda and a fair few other galaxies in our universe to show that they were indeed moving away from us in the universe was expanding but making observations is key to turning a mathematical hypothesis into accepted theory so in the next part of this series of videos we'll be hearing all about how we actually go about detecting something like the Higgs boson the experiments that were designed here at learn to detect it for the announcement in 2012 and what the future holds for our understanding of how everything around us has mass so before we get to the bloopers I just want to take a minute to thank today's sponsor curiosity stream who made this whole trip to CERN happen curiosity stream is a streaming service with documentaries and nonfiction films on any subject that you can imagine the thing is most streaming services these days if you sign up to all of them it's gonna be sort of hundreds of dollars a year usually curiosity streams plan is just 20 dollars a year however with their new stay in and stay curious campaign because let's face it none of us are going anywhere we're all under quarantine right now they have dropped this to just 12 dollars a year and that way you'd have access to thousands of different documentaries and nonfiction shows that go into so much detail on different topics room physics or even history or arts as well whatever the thing is that you love and new documentaries drop each week as well so there's always new content coming online go to curiosity stream comm /dr Becky that's dr b e ck why for unlimited access to the world's top documentaries and nonfiction series and for my subscribers enter the promo code dr. becky d RBE CKY when prompted during the signup process and your membership is completely free for the first 30 days problem is if you start trying to solve the equations of quantum physics then thick but making observations is keep pigs pigs higgs-boson heart cynics oh sorry I think I've been social distancing for vonti like a week

Channel: Dr. Becky

Views: 106,615

Rating: 4.9681439 out of 5

Keywords: astronomy, dr becky, astrophysics, physics, space, science, black holes, cosmology, higgs, higgs boson, higgs field, standard model, particle physics, particles, proton, electron, neutron, quarks, mass, weight, CERN, CMS detector, ATLAS detector, radioactivity, atoms, history of science, particle accelerator, large hadron collider, LHC

Id: vNqQ9_LVCZc

Length: 17min 34sec (1054 seconds)

Published: Wed Mar 25 2020