How the Higgs Mechanism Give Things Mass

[@pbsspacetime]

If you really want to know about the W boson mass measurement at FermiLab, your favorite W-boson-mass-hunter, Don Lincoln, has you covered. kzbin.info/www/bejne/rYPLco1vgpKff5o

[@ahothabeth]

I, too, like Don Lincoln and it is well worth subscribing to the Fermilab youTube channel kzbin.info/door/D5B6VoXv41fJ-IW8Wrhz9A . It has great content.

[@carryingautoclicks7501]

thanks mr time spacema

[@theredturtle4471]

What would happen if there wasnt just one single mass for a W boson, and it could vary in mass. Just a throw-out-there idea.

[@HenryCristo]

Fermilab channel is awesome, so it is this one.

[@curtissharpe7084]

The title should be 'How the Higgs Mechanism gives'.

[@Josecannoli1209]

I feel like this channel started out late high-school level and has slowly pushed us into late college level stuff. As some one who’s been here from the start its great and I feel like I have received a valuable education minus the deep math

[@pacotaco1246]

They're simplifying early grad school stuff in this video

[@Redfizh]

Schools never have data this new. This is fresh 2022 stuff straight out of the oven.

[@TestTestGo]

@@Redfizh the fermilab measurement is new, but the meat of this episode, the mathematical origin for mass in these particles is something that has been around for a while. Higgs came up with his prediction of the Higgs boson decades ago, before we had the equipment to confirm it actually existed. These concepts are taught at university level.

[@PetraKann]

Math whether it’s shallow or deep is not related to Science which is primarily a tool or method which was discovered by Eratosthenes over 2,000 years ago. Mathematics is field of inquiry that belongs in the Arts Faculty like logical Philosophy, finger painting, sculpture, dance and acting. In fact, mathematics is one of the purest forms of Art. Music and marketing are closer to Science than what mathematics is. This is not to say that Art doesnt talk to Science - it does! Everything we do and think of is interrelated in some way - often in subtle or obscure ways. We need to be careful when coupling the claims, theorems and discoveries made in one field or discipline with those made in another field.

[@szamszatan]

@@PetraKann beautifully written, are you an acedemic?

[@antonovcharenko8759]

That’s one of the most challenging recent videos. Wish I could say I learnt something, but it doesn’t click yet. Some learning and re-watching to do first! Don’t dumb it down, it’s entertaining to be pushed to learn.

[@erinkarp]

I agree completely

[@literalantifaterrorist4673]

I'll be listening intently, and then realized I phased out for 2 seconds and need to rewatch a few minutes, lol.

[@Number16BusShelter]

I think I’m going to need to watch previous episodes mentioned in the video to understand this one

[@anexesstormlord7193]

I hate to break it to you, but I guarantee you this *is* being dumbed down. A lot. There's a reason this stuff is an entire scientific field of its own. (Yes, I also went back and watched all the referenced videos and no, I still don't understand like 60% of it lol)

[@antonovcharenko8759]

@@anexesstormlord7193 sure it is, but I think there’s still a lot of room for further dumbing down. I appreciate the current level of accessibility.

[@Robert_McGarry_Poems]

I love being talked through the hieroglyphics.

[@osmosisjones4912]

why can't photons count as negative mass

[@TheoEvian]

easier than the chinese characters, let me tell you that!

[@meowmeowmeow594]

@@osmosisjones4912 because photons have no mass

[@literalantifaterrorist4673]

@@osmosisjones4912 Why would they?

[@clementngai370]

@@TheoEvian 永遠不會放棄你

[@crowlsyong]

This show is one of the best things I’ve ever come across. Thank you PBS, Matt, Editors, Effects, Audio, and all the nameless folks who bring this freely to us all. What a time to be alive.

[@JB-gi5ph]

This was excellent. The 3-D mapping of the "Mexican Hat" really helped me understand how a symmetrical field can still have random elements. That "ahh, now I get it!" moment.

[@ketsuekikumori9145]

Matt: Don't worry. It's not on the test. Some physics teacher somewhere: Oh, but it is!

[@osmosisjones4912]

the higs field sounds like negative mass

[@pierfrancescopeperoni]

@@osmosisjones4912 Get out of my Lagrangian you negative mass, or I'll use imaginary velocity to defeat you.

[@gertjan1710]

@@osmosisjones4912 If you stick the higgs field to energy then it doesnt become more heavy

[@revenevan11]

Then the music at 17:48 plays 💀

[@Aaron-Fife]

I can usually follow along and understand each episode, but this one went way over my head. Guess I need to refresh my memory with a few more episodes... Of SpaceTime.

[@PK1312]

I'm glad I"m not the only one. I kept having to skip back because I was getting totally lost, usually I'm able to follow without a problem haha. Not a criticism, mind!

[@nilborne1]

I want to understand, but sadly I do not. Most certainly NOT our host's fault.

[@victorfranca85]

It comes down to how particles interact with the substrate and each other. And how different patches of space interact with each other. As things at the smallest scales seem to be quantum and come in discreet slices. The math is just measurements. What we can observe.

[@slashhack1463]

@@marcosolo6491 I really want to dive into the math on this. Are there any books you can recommend?

[@LuisSierra42]

Yeah, this builds upon a lot of difficult concepts that hey have explained earlier like symmetries and transformations

[@tretolien1195]

This is probably one of your more difficult episodes to grasp for non-physics majors, yet also one of your most fascinating, it will be exciting to see whether the Fermilab result holds up to scrutiny!

[@osmosisjones4912]

the higs field sounds like negative mass

[@sherryfax]

I am an electrical engineer, fimiliar with the math and most terms and I find this incredibly hard to understand.

[@paulbennett7021]

Don't know about that, I'm not a non-physics major - whatever that is (musician & linguist) - but I sort of got this.

[@Deltexterity]

@@paulbennett7021 well im also not a physics major and *extremely* confused, you have to understand that not everyone is you.

[@DrDeuteron]

I think Fermilab data are the scrutiny. Also: this is difficult for physics majors, too.

[@nice3294]

This was such a great explanation beyond the classic "the particles bump into the higgs field slowing them down" explanation.

[@jacksonstarky8288]

I completed the survey before this episode came out... and this episode was almost exactly what I asked for in my survey responses. I loved the deeper mathematics here... and I'm going to have to watch the episode at least once more to completely absorb the equations. Thank you!

[@sencoptico]

Finally an explanation of the higgs mechanism that answers a lot of my "ok, but where did it come from?" questions! I love this episode.

[@kingeternal_ap]

Quite mesmerizing

[@kingeternal_ap]

The amount of self confidence to say mass just "math'd out into existence" is why physics are for wizards.

[@Soken50]

@@kingeternal_ap Hippity Hoppity There goes gravity Mom's Spaghetti

[@drankenstein5241]

@Daniel E. 556⁵⁵⁴

[@dchappy6985]

Heh explaination please? The thumbnail said "Explaination... of Mechanism" not a more detailed possible "description".

[@genericytprofile852]

It's episodes like this that make me wanna go rewatch the 10 or so episodes before. I find it's like a new layer of understanding being revealed every rewatch. Goes to show how info dense these things really are!

[@jaredf6205]

I’ve been thinking of starting from the beginning now that I understand more.

[@jaredf6205]

I just rewatched all the videos in the playlist in the description before rewatching this one and it helped me understand this video much better.

[@viscinium]

There's something akin to cosmic horror in this, but it's also beautiful

[@gljames24]

It's quite literally existential so that makes total sense.

[@doublejazz]

Yeah thinking that we only exist thanks to some weird quirks in the universe symettries that cause things to have mass is kinda spooky

[@Xeridanus]

Someone recently described cosmic horror/madness like this: Imagine you're an ant walking along a computer board. The landscape is made of a strange material and various things are humming around you. Suddenly, you understand what it all means. It's using lightning to do math (whatever that is). It's communicating with others like it in places so far away you can barely comprehend. Giant alien beings are playing "games" another concept you don't even have a word for. And then just as suddenly you're an ant again, desperately trying to keep this knowledge in your head and experience it again. So yeah, this is cosmic horror/madness. Getting glimpses of the true nature of things we're not made to understand.

[@nice3294]

15:37 theres also something about the way he describes the weak bosons

[@Sorrowdusk]

@@Xeridanus Or maybe not an Ant but a Moth. Then the world opens up and *He comes* to remove the 'bug' in his machine.

[@supermendi0078]

I’m studying these at university right now and I gotta say you did a great job summarizing the most important concepts. Explaining symmetries is quite challenging, and those animations really help to better grasp the ideas involved.

[@KerbalHub]

I'm not supposed to be in this class...

[@alaska4joe]

😂😂

[@RealmsSMPStudios]

You’re supposed to be the Class…

[@DylanOLeary1163]

As as non-physics major, I really like seeing these episodes which explain the formula and then show how it gets converted to some kind of real world representation. It's a gap I often have a hard time bridging in my head.

[@monkeywrench2800]

Can't get enough of this channel !! Super educational and helps me to feel like I know something now.

[@Leptospirosi]

me too, except I really have no idea what I know now...

[@osmosisjones4912]

the higs field sounds like negative mass

[@osmosisjones4912]

can photos work as negative mass

[@UncleZopity]

Y'all ever take a crap so big that when you go to sit down the next day, some of it squirt out onto your legs & back?

[@majinvegeta9280]

I love this channel but some of the stuff is way out my wheelhouse but thats one reason I'm here I guess

[@jogandsp]

I normally understand your episodes, but most of this one went over my head. I'm sure that just reflects what a complex topic it is. Thanks as always for putting out amazing content! Even though I didn't understand a lot of it, I'm glad to know that these exciting developments are happening!

[@pawelparadysz]

at first quantum mechanics was super complex also, it just took a looong time before we learned how to explain it, and this topic is relatively fresh

[@jasonp7091]

We've been looking into the details of really small things, and we've been figuring out more and more of it. Some things make sense, and parts of the theory predict each other. Kind of like if you hear a mooing sound, then you can look and you'll find a cow. Likewise if you see a cow, you'll probably hear it moo. They predict each other. It seems like most of the universe should be like this, and largely, this is what we find. They give the example of a bowl with a ball that can roll up and down any of the sides in the bowl, and it's always symmetrical. You see the ball roll up one side and it should roll down the other. But if there's a bump in the center? Then the ball can't roll evenly from one side to the other. It picks a random direction from the top of the center bump and gets stuck down that side. It's no longer symmetrical. There are moos with no cows and cows with no moos. When you do the math, that part matches the bit where the particle's mass should come from.

[@dlrosbury]

I really like Matt as a presenter. His grasp of the material here is impressive. To hear him able to lay it all out in what sounds like such a clear and logical progression and all the while I'm near totally lost. It's a beautiful thing to listen to, but really, in the case of this episode, it's more like I'm just dazzled by an awesome display of the aurora borealis. I can't touch it and I just can't stop watching, or in this case listening. Bits of it do make sense, nevertheless, in the end it's all quite satisfying to hear it all come down to another fascinating aspect of... Space-Time. Ditto, over my head!

[@DustWolphy]

Is it hard to say that it's just explained a bit unclear? It's hard to follow if you have limited understanding of the topics, because he moves from concept to concept before you have time to get your bearings. There are other youtubers who make it easier to understand. It's also worded a bit colorfully on purpose. I suppose that's what most people here are after, it's like a form of poetry.

[@thatsreallyamoon]

This topic isn’t easy. I have an MS in applied physics, for perspective. Some things are just hard. I don’t get a lot of it either.

[@APieceOfThePast]

I think you just blew my brain. I completely concur with everyone else - this channel started out with A/S to A Level Physics and we’re now well into University level. That’s to be expected (and excellent). Amazing work… but I somehow feel like I skipped some chapters in the textbook somewhere! Is this just a clever trick to get me to rewatch all the past videos for a sixth and seventh time?!

[@bonniedavis4601]

I second the motion!

[@OGIslingr]

I responded to the episode idea survey about a week ago and requested that the higgs mechanism explained episode be revisited and here it is! Thank you PBS Space Time! Thoroughly enjoyed it! :D

[@simesaid]

Yeah, the 'further explication' eps are always welcome. But each episode takes weeks to produce, plan, shoot & edit before they get to our screens. They don't just knock one out within a few days of a viewer suggestion.

[@simesaid]

...but good suggestion anyway!😀

[@OGIslingr]

@@simesaid I was simply stating that I wrote the same topic as a response in the previous weeks survey. I did not say that they used my suggestion and created this video because of it lol. It was exciting to see the topic come up after I had been wanting it revisited.

[@pk10006]

I come here for the heavy puns. So far i'm massively impressed.

That's a good topic because we can all weigh in on it

[@brothermine2292]

I prefer to keep things light.

[@TheRealSkeletor]

Some of us are just too dense to pick up on the good jokes.

[@inamdarsaquib9528]

I come here for iq dose. Biology and chemistry are dumb

[@Kwauhn.]

You've just gotta tap that notification banner when it says "PBS Spacetime"

[@Josecannoli1209]

I feel this personally

[@Ziltzoder]

I disagree. I can't just dive into these whenever. I gotta set the *mood*

[@zhangalex734]

Wow more of these videos that go into the math, please! I have to stop multiple times to cross-reference text books but wow these overviews with a bit in depth explanations are awesome.

[@LuisSierra42]

There are tons of videos where they explain the actual equations, in fact i think this is the only physics channel that does so

[@sluggdiddyyddidgguls]

I am shocked at how much this sparked my memory from my modern physics and quantum mechanics courses from 12 years ago...thought I had lost most of that math and information.

[@themudpit621]

You don't lose it, it just sits there taking up neurons, occasionally laughing at your university fee debts. Bless it.

[@talesmusic739]

I'm brasilian and I'm learning English. This channel is very good 👍🏾

[@protestifications]

Me: ok time to sleep SpaceTime: Why does the W Boson’s mass matter? Me: 🤔

[@n0rie9a]

me too, started the vid with only 4 hrs of sleep left till work

[@chrislaws4785]

Watching this channel and learning about the things that scientists are ACTUALLY doing and learning, has been the ONLY thing that has given me hope for the future of man kind. The very opposite of what watching main stream news channels do.

[@Seraph.G]

The middle made my head spin, but the end brought it together in a way that actually gave me an approximate (if simple) understanding!

[@Rastasandrainbows]

This was one of the more fascinating and rewarding videos to follow. Our universe’s mechanisms are beautiful even without being able to see the whole picture yet.

[@jamesmnguyen]

It still blows my mind that this is how the universe works at the quantum scale. Yet it seems so natural with the aforementioned symmetries

[@viliml2763]

It's *kind of* how the universe works. We know all our current theories have flaws, and in the worst case scenario they might all just be approximations that just happen to work really well. But the relationship between forces and symmetries is certainly a great discovery and a big step towards the truth.

[@jamesmnguyen]

@@viliml2763 That is it true, but I believe the Standard Model is close to the "true" theory of everything similar to how Newtonian Gravity is General Relativity when moving slow.

[@Alorand]

What I appreciate the most is the feeling of "lossless compression of information" Often helpful metaphors are used to explain science, but there is a nagging feeling that crucial details were glossed over.

[@lud3269]

I swear I'm addicted to this channel, I've discover it a few weeks ago and since then I've watched dozens of videos, the quality is awesome and the script of the videos too, I'm not fluent in English yet so the subtitles help me a lot, sometimes I have to search a word he said but this is great cuz I'm learning new words while watching educacional videos, so thank you for feeding the curiosity of this curious being(If I have made a gramatical error in this comment pls tell me💀).

[@Austin-bk9qk]

I know this is eight months later, but I would have thought you were a native speaker of English if you hadn’t mentioned you were not fluent. If all your written English is like this then I would say you are fluent, or at least incredibly close. For context, I’m very adept at English even among native speakers. I read constantly online, and a lot of older generation Americans who speak English natively don’t come close to your level of quality in this comment.

[@bloobushviper5709]

I expected something light to just listen to while I was stressed. Definitely gonna come back to this video when my head is clear and I can pay attention because this looks like it's answering my questions about the Higgs field and stuff!

[@slevinchannel7589]

Atheist-KZbinrs, Conspiracy-Debunkers and Science-Channel are basically blood-related; to the point where they even overlap in what they cover... all the time. So many cover Problems with Religion, even if we exclude Cult-Experts like Telltale from said Family of Channel.

[@calebderochea8304]

As someone who is just about to graduate with a BS in Physics, I'm glad that I'm now at least able to follow along with 90% of what's going on in this video. To be fair, I am not a particle physicist and am focused more on astrophysics, but I can still at least figure out what's going on.

[@Haannibal777]

My physics degree was over 20 years ago. I struggle to remember if they taught me some of the stuff I watched but just forgotten it or if I didn’t learn it at all. Nonetheless given what I do now has nothing to do with physics, my passion of it has only mildly diminished.

[@marcellisrobinson]

Take a grad level QM course, plus QFT using Peskin & Schroeder. Otherwise, we'll have only a qualitative feel for the video, based on our understanding of undergraduate QM

[@andrewandcubes]

Thank you for this, I’ve been hoping you would cover the details of this news since I heard about it. Pleasantly surprised that you were able to cover it so soon!

[@jessstuart7495]

I propose a new class of particles called bozoffs, which carry anti-forces.

[@darikdatta]

I'm picturing Mr. Miyagi teaching physics.

[@danieljensen2626]

Honestly bozoff is 100x better than the names of all of the super symmetric particles. You're unironically much better at coming up with names than any actual particle physicists.

[@davidparadis490]

The world is full of bozos

[@Doomclown]

The union of physics theories is broken by bezos.

[@JorgetePanete]

bozos

[@lookoutforchris]

Looking forward to a compilation of this channel's content in book form. There's so many videos at this point, with deep interrelations, that I feel like a Space Time encyclopedia makes sense.

[@FOR-VALOUR]

Very informative video and extremely enjoyable to watch. I'm very happy I found your channel.

[@cyancoyote7366]

"So far... so bad. But let's forge on anyway and hope it all gets sorted out" Every physicist in history ever.

[@BunnyOfThunder]

This is going on the "rewatch a few times" list :D But it's fun to puzzle through the challenging stuff sometimes. Doing so with the General Relativity playlist is what got me into this channel.

[@amytaylor1054]

Hello there👋how are you doing today? Hope you stay blessed as you’re already.God bless you🥰

[@concernedspectator]

The last time I was this early, electroweak symmetry hadn't broken yet

[@2Sor2Fig]

7:50 - When he said "don't worry, this won't be on the test." It just reminded me that he's got a PHD and is also a professor, so for a few people out there, this genuinely was on the test. Poor bastards, should have been smart and jumped ship to biology while you had the chance. Real talk, the math was delightful. Watching Spacetme has, oddly, greatly helped improve my knowledge of math more than anything else. Edit: 11:00 - Just realised Leonard Susskind did a popular lecture on this 15 years ago that's floating around on KZbin. I'd watched it but never really got it, this helped a lot. Link to the Susskind lecture: kzbin.info/www/bejne/gKKxmGtnbrWckLs Edit: 16:45 - I've always believed that you're either born a scientist, or shaped into one. I was definitely born into it. I've always counted myself lucky to have been part of this... thing, to get to understand at least some of the beauty, if not all of it. Statistically speaking, a little African kid shouldn't. Much Love from Zimbabwe. I think this was your episode so far.

[@kindlin]

Biochem is my arch nemesis. I went civil engineering and then had a good dose of math, for the first time, in master's structural. My passion for physics, that Spacetime has helped to foster and expand, has been growing for a long time, but this is the first episode of any program, ever, to give an intuitive understanding of the what it means to have a symmetry break, and the math bears that out. This is astounding, and it makes me want to go get a physics degree even more.

[@2Sor2Fig]

@@kindlin Clearly, we should have all just done pure physics, lol. I feel you on the symmetry breaking, this is the best explanation I've heard of it.

[@elysiumdevice]

I love this show, thanks Matt at PBS! Its like a strangely therapeutic escape from the drama and turmoil of news and world events.

[@DanHarkless_Halloween_YTPs_etc]

IKR! The spacelike backgrounds, the gentle synth music, and Matt's supernaturally calm and wryly amusing presentation style really hit the spot for me too. (Not just world events, but life events, in my case.)

[@eliasgermer8762]

I remember mexican hat potential.

[@oisnowy5368]

One of the important things in science is that where experiments can be used (you cannot repeat the exact same earthquake, or a nova), those experiments should be reproducible. The multitude of W-boson mass measurements made so far tend to lie (as in not-sitting or standing) quite some distance apart, the latest disagreeing the most. I'd love to see some more W-boson mass measurements and other measurements of bosons. And explanations for why some of the other experiments had produced their lower values. Taking measurements is hard and there's lot to learn about that, perhaps even more than there is to learn about W's mass.

[@GeoffryGifari]

i don't work in experimental high energy, but knowing that scientists primarily pushes for originality, wonder just how much effort is expended in reproducing other results? does CERN allocate some timeslots per year just to confirm the finding of others?

[@supersonictumbleweed]

How come Matt looks like a character from The Long Dark? I appreciate this another take on explaining Higgs Matt. You're the best!

[@slevinchannel7589]

Atheist-KZbinrs, Conspiracy-Debunkers and Science-Channel are basically blood-related; to the point where they even overlap in what they cover... all the time. So many cover Problems with Religion, even if we exclude Cult-Experts like Telltale from said Family of Channel.

[@NeoCyrus777]

Matt, please, mercy. This video melted my brain.

[@alaska4joe]

😂

[@falconmediaworks9479]

Planck Yeah! This is a fantastic channel truly refreshing and something different. Thank You!

[@elenalaloca3880]

As I was watching this episode, my husband comes up to massage my shoulders (I love that), watches with me for a short stint, and walks away saying "How can you understand ANY of that!?" ... It helps that I've been watching PBS spacetime (and other lectures etc) for the last several years, spiral notepads full of notes and equations... and having a passion of learning physics and quantum mechanics. It's actually thrilling to know I was able to follow the video, and now I have a few more hours ahead of me to dive back into many of the references that was mentioned. I wish videos like these were available 30-40 years ago when I was in school, it would have made such a difference to my future. At least I enjoy this all now as a hobby. Keep up the good work!

[@Ni999]

Shout out the late, great Steven Weinberg who surely deserves to be remembered by name for much of this episode.

[@derpderpington100]

rip Mr Peter Higgs, thanks for everything

[@FausterZ]

It would be nice to have an episode discussing the Higgs coupling to the Fermion fields for a hopefully simpler example. Also, that Chi-cubed term looks like an anti-Hermetian term, which is usually bad when you are talking about potentials.There is one that pops up in the Dirac equation, but it is resolved if you expand the electron field by expressing the positron field as a relativistic expansion of the electron field. Is something similar going on in this case?

[@DagonExcelstraun]

I have watched this episode five times, and it is just now starting to come together

[@Rishikotenkirama]

PBS is a national treasure! I love PBS Space Time and all of the free knowledge!!!

[@overanalyzed5258]

Watching this feels like the crossover scene in avengers endgame where all these different characters and pieces fiinly come together

[@djbslectures]

Awesome episode. I really appreciate the non-dummed down math!

[@MrDino1953]

Pity about the spelling though.

[@djbslectures]

@@MrDino1953 🤣

[@djbslectures]

@@MrDino1953 Spelling = dumbed over, math = not dumbed down.

[@craigsimpson9561]

Silly question,: If there are a ring of valid vacuum states available, and the universe has settled upon one of the many, then is there any reason for the "interior" of a black hole to also settle into the same state, or could a black hole potentially contain another one of the many possible options? Likewise, as the curvature becomes increasingly more extreme around and inside the event horizon, is it possible for several vacuum states to exist in discrete boundaries further and further within the black hole without conflict? If so, would this lead to varied values for the Higgs boson within each level, leading to nested shells of increasing (or decreasing) vacuum states? If so, what consequence would this have for the "mass" of the entire system? Presumably, the confined surface (volume) of a black hole would not only permit different values to the infinite and flat external spacetime of the observable universe, right? Feels like I'm definitely missing something here... probably means that I need to rewatch the entire series again, eh?

[@adlockhungry304]

What I thought you were going to say: “If there are a ring of valid vacuum states available, and the universe has settled upon one of the many, then is there truly one ring to rule them all?”

[@RibusPQR]

The inside of a black hole is a region of spacetime which has indefinitely delayed transmitting any information to the rest of the universe, except through "gravity" or deforming spacetime itself. Speculations about the nature of that interior can never be proven nor disproven, and so are unscientific.

[@garethdean6382]

This largely depends on what the interior of a black hole IS, which is currently only theoretical. For example, if matter compresses and increases in temperature during collapse it's possible for the space within to reach a higher energy state. Possibly all of a black hole's mass\energy is stored in a sphere of high energy vacuum. Other theories invoke wormholes or loop quantum gravity. So the answer to your question is a definite maybe, we have yet to find the theory or experiment that will answer it for us.

[@Caspenar]

This video made me realize that somewhere along the way I completely stopped understanding what we're talking about here. I need to go back and rewatch the old stuff so I can get a hang on things.

[@uiteoi]

I just don't have enough knowledge to be able to appreciate this episode. But it did give me some hints as where physicists are going in their quest to unify the laws of physics. Fascinating even if I can't understand it.

[@KekusMagnus]

I think I can safely say this is the most complicated episode you've done to date. I have a physics degree but I didn't take that many QM courses and I found it hard to keep up at times. I can't imagine what ordinary people must see

[@OwenDavies83]

To quote Socrates, All I know is that I know nothing.

[@superguy183828]

Personally, (as a math teacher) I liked the video a lot, and I am somewhat interested to hear about the proof/details. Although honestly, PBS Spacetime has earned my trust to the degree that I'm only really interested in the nitty-gritty to better conceptualize the *conclusions* about what it shows us about our current understanding of the universe and the direction of where it's pointing to look next. In other words, I'm mostly interested in @15:07 but I need to watch the whole video to better visualize what I means, even if don't fully understand the maths along the way.

[@aaronmicalowe]

I only took physics to highschool level so there are parts of this that fly over my head, but with a little effort I can keep up with the gist of it and for brief moments have a clear understanding.

[@semaj_5022]

Yesss new Spacetime! Now... let's see if I understand any of it. Edit: watched twice now, and some of it kinda makes sense? Which is mostly a testament to Matt's ability to explain high level topics to the hobbyist or layperson.

[@so_dumbshu]

same lol

[@zhangalex734]

Good luck!

[@andrekz9138]

Thank you for engaging us with this level of complexity. Too often will physicists give up on us.

[@Timesend]

Is usually struggled understanding most of your vids especially the ones about the fields , particles etc. however this one gelled with me and increased my knowledge greatly , thanks for this awesome content

[@artyompopov9990]

The moment when you show first lagrangian is the thing reminded me why I respect physicists so much. The second one was the moment I recalled why I will never become one.

[@3More140]

RIP Peter Higgs ):

[@heisenbergstayouttamyterri1508]

The last "Space Time" is one of the few things that dispel my monotony and enable me to do anything! Thank you Matt for everything!!!! ❤ from Bangladesh!!!

[@jacovawernett3077]

Namaste and L'chaim from Jerusalem. Salem.

[@dillbourne]

8:47 If it's true that gauge fields shouldn't interact with themselves and shouldn't have mass, why do we consider the gluon to be mass less when it has a 3-gluon vertex, interacting with itself?

[@FermionPhysics]

It’s possible to have a mass gauge field. I don’t think this video was trying to contest that. Maybe they used a poor choice of words. The part where Matt said that the phi^2 term represents a self interaction was not correct. That is what the phi^4 term is supposed to be. So you can have interactions for a massless gauge field

[@Rudol_Zeppili]

Your correct, the gluons interactions with themselves give them mass. It’s what comprises a large portion of the mass of a hadron.

[@evilotis01]

that's a really good question and i hope Matt answers it!

[@FermionPhysics]

@@Rudol_Zeppili gluon self interactions is not what causes mass

[@Rudol_Zeppili]

@@FermionPhysics source?

[@JohnsTrainVideos]

When I watch this channel when I'm well rested, I learn so much. When I watch this channel when I'm tired, my brain breaks.

[@crazybear1489]

Thank you so much for this. Thank you for bringing this to those who can't attend formal school

[@denisfolcher4480]

a new PBS video, direct auto like :)

[@FerrisMcLauren]

You are the reason physics is dying

[@davidgarofalosteachingcorner]

Nowadays we often hear particle theorists discussing the beauty of the Higgs mechanism, often invoking it to show how elegance and beauty are good guides to understanding nature. Yet, when Peter Higgs was asked about his early interaction with colleagues, he pointed out that Heisenberg criticized him, saying that the mechanism for giving mass to particles showed that Peter Higgs did not understand physics.

[@stylusapteryx1490]

Sounds true to form. Wasn't heisenberg that doubt-inducing headmaster guy? The uncertainty principal?

[@davidgreenwitch]

What I never understood: If all those particles we see come from a broken symetry like with the analogy of the iron gaining/loosing magnetism at a certain temperature. What is the actual difference between all particles/forces? Or to stay in this analogy: wouldn't all particles have the same temperature? Why isn't everything the same but some have properties and others not? A block of iron would cool down equally, too.

[@peezieforestem5078]

Temperature is not a property of a particle. Temperature is the average oscillation of all particles. Therefore, in a context of a single particle, temperature is meaningless, and your question: "wouldn't all particles have the same temperature?" doesn't make sense. It's like asking: "wouldn't all the particles have the same average oscillation velocity?"

[@davidgreenwitch]

@@peezieforestem5078 But the question is the same. How could the same "source" come to different results? I would assume the "energy level" is the same for all particles since the universe cooled more or less equally. I mean its not like we can find photons only in stars and protons only in space etc.

[@garethdean6382]

All particles DO have (sort of) the same temperature. (Stars are a bit hotter than deep space.) What we see in the universe is the properties those particles have at (essentially) absolute zero, the ground state. Transitions like electroweak symmetry breaking occur at a certain temperature and when the universe cools past it,a ll particles are affected. When the W and Z boson were produced massive, so was the massless photon. The same transition gave us the massive electron, as well as quarks. ALL particles were affected, one way or another. Perhaps the transition might be considered as the cooling of an alloy like AlNiCo, where the same magnetic properties apply but not all the atoms are the same. When the alloy drops below the right temperature ALL atoms are affected by the same phenomenon, even though the effect is not the same for each kind of atom. As for WHY we have these different particles and fields in the first place, both before and after the Higgs mechanism, we do not yet know. Perhaps they are just arrangements of a single basic building block, perhaps not. We continue to seek deeper understanding there.

[@davidgreenwitch]

@@garethdean6382 Hmm, I'm not sure I understand completely. After all the analogy with the alloy only works if the components are different. But from what I understand it is the opposite with all forces/particles. From what I understand at very high temperatures all particles were the same. Then it cooled down and "some" became particles for transferring electro magnetic forces, others became particles for weak force etc. To me that would only work the other way around. Like when different particles (as in the alloy) get heated and they are loosing attributes (like iron that looses its magnetism). So how can this be the other way around?

[@garethdean6382]

@@davidgreenwitch Well that's not quite how it works. For example, at high temperatures the electromagnetic and weak forces are the same, they merge into the electroweak force. Single and united. BUT that force doesn't possess one single particle, it has FOUR. They seem similar, they're all massless for example, but they have different isospin and hypercharge values (++, +-, -+, --) that make them act very differently under the laws of that force. Indeed before the symmetry breaks we have a lot more particles. Every lepton and quark (except maybe neutrinos) comes in two mirror-image types that are fused by the Higgs field in a unique fashion. Things do not become the identical, they become more symmetric. It's harder to see the symmetry between the photon and Z now, but they have always been two different things. Even if we manage to find a GUT force or reduce things down to one particle there will need to be the same variety there, just arising from simpler building blocks in the same way all chemical elements arise from the electron, proton and neutron.

[@vintagelady1]

Almost fainted from laughter when you said "This is a simplified explanation." Not that I doubt that, oh no. I don't watch these excellent videos with any hope of understanding, I watch to marvel that anyone understands & that the Universe is so intricate. Yet every so often, I wonder if the Universe is just having you-all on? Thank you for letting me peek behind the curtain of understanding.

[@Axel123thebest]

This channel is a true treasure, thank you for your dedication

[@cmbaz1140]

i always imagined mass to be space time "drag" created by the particle going through the higgs field... the more "aerodynamic" the particle is the less mass it has ...kinda...

[@Andrey.Balandin]

Yeah, but this analogy totally breaks when you think about inertia... If mass was drag, planets would slowdown and fall into the Sun.

[@davidsalazar13]

@@Andrey.Balandin isn’t that what entropy is though?

[@briandiehl9257]

@@davidsalazar13 You have to think about reletivity. If two objects are getting farther away in space, it is meaningless to ask which one is moving. From each objects perspective, the other one is moving away. If things were slowing down like this, that would give an absolute reference frame.

[@nmarbletoe8210]

@@briandiehl9257 wow good point

[@michaelkeudel8770]

Better question is what gives the Higgs particle mass that other particles don't have.

[@darer13]

from what i understood -- its the interaction or anchoring that makes "mass". its not something Higgs has and chooses to hand out. something that Matt said as well is that there are probably other "mass granting particles" that can account for the extra mass the bosons have that Fermilabs found.

[@richardhosch6073]

Question for Matt or others unrelated to this particular episode: In a previous episode, a question arose regarding distant objects moving apart faster than c due to expansion of space, and whether any measurement (made from a third middleground observer, perhaps?) would distinguish that condition from one in which they were moving through space each sublight speed relative to some mid point but a net greater than c relative to each other. The answer was no, that redshift and any other measurement data would look the same for the two scenarios. I can't sort out this apparent contradiction. Imagine there are only two objects in the universe, distantly separated, and only the void elsewhere (whatever that is). Scenario A, space is not expanding, and each is moving away from the other at greater than c locally, thus >2c cumulative. Scenario B, each object is motionless locally in a rapidly expanding space, with >2c net relative velocity with respect to each other. General relativity prohibits one, and permits the other. Or, maybe just prohibits the crossing of the boundary necessary to reach that condition. Correct? But with only one other object and thus frame of reference in the entire universe, wouldn't relativity also suggest the two scenarios are identical? If B is permitted and not A, then what other frame of reference is used to distinguish them? It seems that would have to be something intrinsic to the local space. Does the quantum vacuum somehow define a local frame of reference even for empty space? Is there a sort of aether after all?

[@rubberduckie3359]

If you imagine gridlines that pervade all of space, GR prohibits moving past these gridlines locally at a speed >c, but says nothing about two distant areas of gridlines having a speed limit relative to eachother, the objects cannot exceed a local speed of c but if the intervening gridlines between the two local areas around the objects are flexible enough, the two areas can move relative to eachother at any speed. (And in GR spacetime and it's geodesics are pretty bendy).

[@richardhosch6073]

@@rubberduckie3359 Right, I get that far in my thinking. But I also thought one of the core principles of relativity is that there is no preferred frame of reference. Motion and time in any one frame can only be measured, and only makes sense, relative to some other chosen reference frame. If the only other frame of reference in the entire universe is that other distant object, then what distinguishes scenario A from B? How does one object "know" in one condition the other object is at >2c because of the expansion of space, and "know" in the other it is not. Or more relevant, how does the object know the speed of it's local space, since at >2c relative velocity it would have no communication with the distant object? I'm tempted to take the easy way out and just say both are allowed, but you can never accelerate an object locally past c to reach that scenario. However, in an accelerated expansion (like our universe apparently is), there will be a point where these objects cross the same apparent boundaries, and the question of what differentiates the two scenarios remains.

[@rubberduckie3359]

@@richardhosch6073 I could be wrong but I think the point is almost backwards, the objects can't know by observation which situation is true, and that lack of communication is what prevents ftl paradoxes, we are told by the equations that only situation B is possible and we know bc we can't accelerate things to c relative to anything local. Not being able to observe the velocity of your local space is kind of what it means to be in that space no? We can just calculate what the current distance and velocity of the galaxies past this c boundary are from light emitted when we were below this boundary and within causal range of them.

[@rubberduckie3359]

I guess that calculation is kind of disengenuous because from our perspective it's not that far away, it's a distance impossible to traverse and see almost by definition. Maybe in your scenario you could imagine other patches of space to be the 3rd person observers and they would exist even without any objects other than the original 2. That gives a kind of reference frame that doesn't have to factor in c because they can move at any relative speed.

[@viliml2763]

The problem is in defining relative speed. The objects aren't really "moving" away from each other, but new space is appearing between them so their distance increases anyway.

[@davidianmusic4869]

Thanks for keeping the level of discourse up. I could take the math for granted, as I’ve done in the past, but following this channel has helped me understand more of it. I’ll be watching this a few times and figuring along.

[@Encryptsan]

Sometimes I think I have a pretty good understanding of how things work, but then I see videos like this and realise that I actually know very little. Great video, 10/10

[@markrothenbuhler6232]

So could Dark Matter just be normal matter that somehow interacts with the Higgs field more to appear heavier via gravity?

[@ВладДок-д8щ]

Most mass doesn't come from the Higgs field in the normal matter

[@Tigtone_85]

The higgs just grants a tiny amount of mass to fundamental particles like quarks and the electron. This keeps them from being lightspeed particles without this we wouldnt have atomic structures to speak of. Most of an atoms mass comes from the binding energy of the gluons holding the quarks together in protons and neutrons. The quarks bounce around and the gluons act like a spring kinda and the mass comes from the kinetic energy of these bonds similar too how a compressed spring has more mass vs a relaxed one.

[@User53123]

@@Tigtone_85 And physicists don't think it's a bit convoluted to have mass given in different ways? Was it just invented to fix their math?

[@editingdude122]

@@User53123 The existence of the Higgs Boson seems to imply that the Higgs field is a "little" more than BS

[@michaelsommers2356]

@@User53123 Physicists don't care whether it's convoluted; they care whether it accurately reflects nature.

[@pinboru_]

Things are getting too deep for me over the last couple years.

[@OldGamerNoob]

Between this and the muon mass both being heavier, is there any way to work backward mathematically and put bounds on the mass of a new particle?

[@PK1312]

(total layman's opinion) probably, but we also don't know if it's a new particle or multiple, smaller new particles. Also I'm a little unclear on how certain we are that the mass discrepancy is real (although I sure hope it is, for the sake of new physics)

[@Xeridanus]

(Also total layman) It could be a massive particle that interacts rarely or weakly or it could be a relatively tiny mass having particle that interacts all the time. I think the fact that we haven't found it in our searches at other mass levels is more restrictive.

[@kmarasin]

(Not a layman) The problem here is with the electro-weak sector of the Standard Model. The masses of W, Z, and Higgs bosons are all linked by a set of fundamental constants; if one doesn't fit the model while the other two do, you have a big problem, because you can't adjust the constants to account for one without changing the predictions of the others, throwing them out of whack. Theorists have made a cottage industry out of postulating new fields and resultant particles, but inventing reasons why the new field is seen ONLY IN THIS ONE PARTICULAR CASE is the hard part, and even if you can invent such reasons they can be hard to swallow. That is, such theories can be technically valid, but they fail a sort of parsimony test: better theories are supposed to be simpler, not more complicated. What's the point of the SM if it can't explain what it set out to explain? The SM started from first principles like classical electromagnetism, relativity, and quantum mechanics. Where are we going to get better principles than those?

[@PK1312]

@@kmarasin Appreciate your insight, thank you!

[@majormelon8855]

This couldn't have came at a better time. Doing a presentation on supersymmetry and unification

[@rayoflight62]

With this episode, you touched the bleeding edge of the current state of particle physics. My compliments for the extreme clarity of your explanations, and the discussion of the current open questions in the sector (I don't want to say "field"!). There is no passing comment I can actually write on the matter, so I abstain - but I keep thinking. Thank you for all your dedication; Regards, Anthony...

[@YouTubalcaine]

The universe isn't really made of things, it's made of relationships.

[@GwynRosaire]

Quantum mechanics is always fun until someone loses an i.

[@247tubefan]

How the heck do you weigh a subatomic particle?

[@rileyschroeder8560]

Carefully and hypothetically

[@smileifyoudontexist6320]

How the “Hecke” ……

[@gandalf8216]

Equations. But that's the short answer. Otherwise, mass is the energy density that remains for the given subatomic particle once all the other charges are cancelled out in said equations. Don't ask me which equations, I'm just a layman.

[@falnica]

If it’s a charged particle we measure how it’s path is affected by magnetic fields, from there we can deduce the mass. For neutral particles we have to wait for them to interact with something that does have charge

[@bobo2.2]

for the ones that decay, like the W and Z bosons, you can measure the energy and mass of the decay products as they smash in detectors. For stable particles, one other comment mentioned the deviation of the tragectory in a magnetic field.

[@KeithCooper-Albuquerque]

Great episode, Matt! I finally have grasped a little more of the Higgs mechanism. Even better, I'm more stoked to learn even more. Keep up the great content!

[@amytaylor1054]

Hello there👋how are you doing today? Hope you stay blessed as you’re already.God bless you!🥰

[@mairisberzins8677]

You are horribly hung over. Just woke up and are staring in the ceiling in agony waiting for the pain and nausea to pass. You put on PBS Space TIme playlist and just doze off to brainmelting videos for half of the day. Yes. That was my day.

[@robindao5]

the higgs field is the aether..

[@Ak0rax2]

I've always wondered why a magnetic field is directed counter clockwise orthogonally to the electrical field. Does any videos of this channel give any insight as to why that is the case and why it can't be directed clockwise without changing the direction of the electrical field?

[@bogoodski]

I don't know if he describes why explicitly but I think the reason why can be inferred from Veritasium's most recent video, actually. Which is pretty interesting in it's own right. kzbin.info/www/bejne/pXrCiWWZgq2Bm5I

[@ipudisciple]

It’s just a sign convention. Electricity and magnetism are different aspects of the same thing. Actually, the same thing seen by observers traveling at different speeds. What we call North/South, what we call +/- and what we call clockwise/anti-clockwise can all be flipped, but you must flip 2 of them, not just 1.

[@armchairgravy8224]

Is general relativity an emergent property of quantum physics? Would this explain why the maths between the systems can't be reconciled?

[@jelmerl1458]

As far as we know it is not. The issue with reconciling GR and quantum is quantizing gravity, you would have to quantize space-time itself, which we do not know how to do. Even if we try, by inventing these quantizations as particles (gravitons) we run into big problems, namely that they interact with themselves giving infinities we cannot deal with (non-renormalizibility). In the standard model at this point I believe these forces to be fundamentally incompatible

[@NOLNV1]

It's what many think, I know Freeman Dyson thought it has to be and so left the theorising at that, but for now the models can not be reconciled at all.

[@kylelochlann5053]

The massless spin-2 field we associate with the graviton couples universally and minimally which essentially gives us EEP and Einstein-Hilbert with certain assumptions so it is consistent with GR, but UV incomplete.

[@Guide504]

Keep up the great work. When the crimes and follies of man in the world loom large, the growing knowledge that we as a species are ultimately brief and inconsequential gives comfort.

[@FreedumbHS]

These videos are absolutely incredible. Keep up the great work

[@randalljsilva]

Regarding the masses of the standard model weak interaction bosons: since these particles exist for such a small time, can their mass be empirically measured by measuring their velocity being below the speed of light? I ask this because while gluons have no mass, they account for most of the mass of protons and neutrons, so distinguishing between rest mass, relativistic mass, and massless particles with momentum is confusing to me. :-)

[@DrDeuteron]

Even at the speed of light, it takes 20 lifetimes to go the diameter of a proton...so you can't track them. Instead, the lifetime is inferred from the so-called decay width (which is around 2 GeV). See "Breit-Wigner"

[@UnCavi]

@@DrDeuteron "Even at the speed of light, it takes 20 lifetimes to go the diameter of a proton" What does this sentence mean?

[@DrDeuteron]

@@UnCavi It means a W decays in 3e-25 seconds, which is really fast.

[@StumpyDaPaladin]

Massles particles DO have momentum. Of a sort. Electrons for example do not "spin" like a ball around an axis. they are a near massless bundle of energy that twists the local spacetime around it so much that from a distance the entire area behaves like a singular object with a big amount of what for all intents and purposes acts like what we call angular momentum. But that is just one part or what an electron is at the quantum scale. Pay attention now: Electron is a negatively charged distortion in the "electron field" that behaves much like a wave (as all distortions seem to do). That wave in the electron field manages to strongly distort the spacetime around it in a weird looking twist at a very small range as it moves. The ripple and the distortion it causes are separate events but are indistinguishable from each other at even sub atomic scales. So between the rested (-charge) energy of the ripple itself and the angular momentum energy from twisting/untwisting local space time ... that whole mess is also moving 'nearly' at "c" for some relativistic energy ... You have an Electron But dont be fooled. It is still a massless bundle of energy. 3 distinctly different kinds so far. However Einstein's equation still holds up even here (especially here in the quantum scales) so all that energy (charge, twisty "spin" and relativistic 'mass') is also equivalent to an (tiny) amount of mass. Gluons get their "mass/energy" mostly from higgs field interactions which prevent their energy from reaching an absolute zero rest state. It is a HUGE amount of energy. So much that its mass equivalent is enough to interact with "spacetime" in the same way that actual objects with mass do in larger scales. Or at least that is the theory. When you crunch the numbers there is energy left over that the higgs interaction does not account for entirely. So something else is going on. And while a few ideas are out there as to what those somethings are and why they do it we dont have an experiment that says "look! i found particle x! therefore the x particle theory is likely correct." That is my limited understanding of it. I am not a physicist or a mathematician. I just watch a lot of SpaceTime videos. :)

[@AREALLYBIGSPOON]

it took me an hour using google to understand everything i just watched. Worth it

[@MrPeterPanos]

I really enjoy this channel, I feel ever more enlightened with every episode 👍

[@amytaylor1054]

Hello there👋how are you doing today? Hope you stay blessed as you’re already.God bless you!🥰

[@barravos]

It's insane to me that I literally suggested a video on exactly this topic on my survey a day ago, and Dr. Matt and Space Time Delivered in less than 24 hours. Guys it's now obvious that the Universe revolves around me. I'm open to being studied for the advancement of physics and our understanding of, dare I say... Space Time. Sincerely though, thank you so much for these videos. I truly enjoy them, though I only catch a 64th of what is being discussed, I think it's important to learn about physics regardless of how ambiguous the theories and equations are, you guys do an amazing job of bringing it down to mortal levels. Love you Dr Matt O'Dowd and Space Time Team, keep up the great work!

[@phizzle24]

G'day Mr O'Dowd from Perth, WA. R.I.P Peter Higgs.