What Makes The Strong Force Strong?

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Quantum mechanics gets weirder as you go to smaller sizes and higher energies. It’s strange enough for atoms, but positively bizarre when we get to the atomic nucleus. And today we’re going nuclear, as we dive into the weird world of quantum chromodynamics and the strong force.
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Hosted by Matt O'Dowd
Written by Fernando Franco Félix & Matt O'Dowd
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This program is produced by Kornhaber Brown, which is solely responsible for its content. © 2022 PBS. All rights reserved.
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Ivari Tölp

[@gl8689]

I love how the color naming system makes chromodynamics so much more intuitive for those of us who aren’t physicists.

[@Sad_King_Billy]

Yep this was a great demonstration.

[@thalianero1071]

Finally, a rule of quantum physics that is actually intuitive

[@spiralsun1]

It needs to be. Because of higher natural laws. I know because I formulated them. They are under consideration by the journal Nature now. A pre-print will be available in a week or two-up to 3 they say. Thanks 🙏🏻 🥰

[@robm3955]

@@Sad_King_Billy in of so it would take

[@stevenjlovelace]

Agreed. As a graphic designer, it makes intuitive sense.

[@Morilore]

Thank you for explaining the color wheel in a way those of us who aren't artists can understand. It's really complicated, but the analogy "it's just like the SU(3) symmetry of the strong nuclear force" is so helpful.

[@NullHand]

I would like to comment constructively, but the damn Sarcasm detector keeps going off every 3.1415 seconds. Must have forgot to put batteries in it....

[@scumbagnamechooser]

Best comment award

[@rebeccamaracle2878]

Over five billion people are estimated to have internet access, and this only has 20 likes so far? Come on, now.

[@Morilore]

@@NullHand it's not entirely sarcasm! i do remember as a child thinking that the whole "complementary color" thing was weird and complicated and gave me a headache. but R+G+B=0 makes way more sense! now i just need some mnemonic for remembering the English-language names of R+G=-B, G+B=-R, and B+R=-G.

[@Krail1]

@@Morilore It is super handy! That's the main point of complimentary colors, that they just cancel out. "CMYK" is the typical color space when it comes to printing and painting, for Cyan, Magenta, Yellow, and Black (because B was taken). I don't know how well that works as a mnemonic for you to remember the names Cyan and Magenta, or which colors they cancel with, but I hope it at least helps keep the ideas sorted.

[@mckinleycard3065]

this episode is an absolute masterpiece. please do more content like this, i feel like this is real physics talk but a layman can understand it

[@Blackmystix]

Agreed. Masterpiece. I understood quantum chromodynamics more from this short video than I got from Sean Carrols 6 hour lectures.

[@RadioactiveLobster]

If it wasn't strong it wouldn't be called "The Strong Force." Thank you for coming to my TED Talk.

[@davelordy]

Leaves the stage to rapturous applause.

[@Findecommie]

Ok but just imagine if it was named after a scientist named Dr. Strong and didn't have anything to do with strength 😂😂

[@astrophotographyenthusiast5273]

The last three episodes have been exactly what I’ve wanted to learn. So much great information. Happy to have my atoms assembled in this form right now.

[@xEvilRaptorx]

Just wait til there is an AI nano-bot that can rearrange your atoms for you...

[@Khorzho]

IKR?

[@ninianstorm6494]

@@Khorzho i notice fbi/irs/cia/msm all give double standards to political families deeply involved with kill iraq/libya in particular when muller charge manafort for things nothing to do with russia hack but let podesta go for same reason =blackmail dc to support blame russia to cover up fact 2 party system failed since mccain-hillary all did united fruit company scandal 2.0 recall fbi never look at physical evidence just crowdstrike/hillary words, cia break glass 2017 inauguration with media claim russia stolen election 1oo george bush 14y ago said add ukraine to nato foreshadow nuland f eu coup 2014 support = 1. kzbin.info/www/bejne/pIW0ZHdnlpKdaJI 2001 pentagon memo kill occupy iraq to syria kzbin.info/www/bejne/lZ7Ve4V-rMeJfZo current ukraine gov is proxy since obama drew red line just like did in syria earlier arming rebels telling russia not to interfere while zelensky ethnic cleanse donbass region 7y= 2. kzbin.info/www/bejne/qpKclYqImKmIhqM 3. kzbin.info/www/bejne/f3PIg3Vtp7yelZo

[@ghostmailgg]

This is exactly the same comment that I was going write. 😂 (Best channel in the Universe)

[@Mystixor]

Indeed I thought the same. Coincidentally the basics these videos built off are exactly what we learned about in Uni last semester.

[@loganwoodxyz]

Hadrons never skip leg day.

[@osmosisjones4912]

If a simulation is so accurate down to last atom isn't more of a recreation. If the flow of energy can be reversed can that used reverse time. But the space around the area you reversed would be different many other reasons it's not the real past. But what you use contained space recreate the past . And have large system maybe link it to other areas of recorded space

[@loganwoodxyz]

@@osmosisjones4912 inventing time travel to achieve infinite gains. 💪😤

[@BrumbleBush]

@@loganwoodxyz 😂🤘🏻😎

[@osmosisjones4912]

@@loganwoodxyz I don't know if should be considered legit time travel. Or a recreation. More then a simulation

[@Anankin12]

Didn't expect something like this, I died

[@Shortstuffjo]

I feel like this is one of the best episodes you guys have ever produced. Thank you for continuing to make content about what interests you and your regular viewers instead of falling prey to trying to play the KZbin algorithm game. Two thumbs up, PBS Space Time.

[@crosbying]

I agree, I was surprised. I dont know what I expected, but this was interesting and exciting

[@HeedfulGibbon]

Everything from the micro to macro is made up of teeny tiny matrices (matrixes) and all matrices have weak points, holes, spaces through, pores, portals.. from the particles that make up atoms to molecules, cells, bodies, water, the cup of water, all our inventions, even our thoughts.. it is 100% acceptable and within reason to suggest that we live inside a matrix of some kind. Our realm/ dimension with space and time/ our world/ this universe (uni meaning one and verse meaning line) is one among many!! The multiverse is all around us.. other worlds beyond the protective barrier.. and the space in between all these worlds is bright, creative frequencies of sound, swirling forces of energetic power beyond our comprehension, spinning moving churning and radiating, bleeding through the pores of our firmament and all firmaments across the multiverse.. raining energies down on the flora and fauna, pushing, growing guiding everything

[@joshoowa]

Matt when you teach me science I feel like I’m tripping balls, which is good because I can’t do that anymore. Thank you for letting me trip vicariously through your brilliant journey.

[@Baileyyyyu]

What happened :

[@hexagonist23]

@@Baileyyyyu Mom took all of my LSD :(

[@ZenithWest169]

I have an off topic fun fact about color perception: tetrachromacy. Humans typically are trichromatic (having three different color sensing types of cones), but there's a special case where certain people can have four. Note: just because you have X types of cones doesn't necessarily mean your brain can interpret all X types distinctively. Apparently humans have a limit of 4 making tetrachromacy possible, so even if you can artificially make an eye with an arbitrary number of cone types, your human brain simply can't differentiate more than 4 as being distinct from each other. So certain people do have tetrachromacy and see colors differently from most other people. The extra cone type isn't outside the range of visible colors (it's in-between the range of two others) so it's not like they see extra colors or UV or infrared. Instead imagine being shown two red pieces of paper. To normal trichromats they appear to be the exact same color of red but if the wavelength of light reflected off the paper favors the extra cone of a tetrachromats then they will perceive the paper as being different shades of red. If your curious how tetrachromacy occurs in humans it's fairly simple. First it can only occur in women (sorry guys, men can not have tetrachromacy). Women have two X chromosomes. That's twice the genetic set of instructions and if you can imagine being given told to the same thing over again, then this is a bad thing to have. To solve this issue at around 20-100 cells old, each cell of female fetus randomly deactivates one of the X chromosomes. So half the cells roughly have the "left" X chromosome and the rest have the "right" X chromosome. A mutation can occur in one X chromosome that leads to development of a unique cone getting made in the eye due to some cells having different instructions from others. We humans don't have skin or hair color encoded on our sex chromosomes but if we did women would have stripes. Calico cats for example do have fur color on there's and that's why only female cats show that pattern. I just wondered how differently quantum chromodynamics would be taught if we weren't mostly trichromatic lol.

[@user-Aaron-]

I thought tetrachromacy stretched into the UV spectrum a bit? Am I thinking of something else?

[@genseek00]

Fantastic. Thanks for this.

[@grayaj23]

I have an ex who says that the some shades of yellow can make her feel anger. She's a tetrachromat who has issues with synaesthesia.

[@ZenithWest169]

@@user-Aaron- I'm wanting to say I remember a famous artist that had it and want to also say that they saw their vision including more of the near UV spectrum. I wanted more to indicate that they still perceive color ranges similar to normal people do but in that specific case where the unique cone activates when hit with UV light, the brain would just interpret it as being violet (so not in a sense a new brand new UV color, like they couldn't say something like this box looks UV-ish and this one looks yellowish but they'd perceive it as being more brightly violet where as a normal person would only see a very dull or faint violet color as we can barely see into that range).

[@ZenithWest169]

But from what I remember when I first looked into the subject, is normally it was a mutation of the green cone being shifted over to more evenly fill out the spectrum.. If you've ever seen the graph of cone frequencies, the green and red are very close to each other. Edit: looking up graphs it's counterintuitive but apparently the new cone squeezes between green and red, making it a green-yellow new cone. So it doesn't fill out the gap but makes it more noticeable. Though I'm not sure if it's for all cases, just first graph I saw showed this: www.quora.com/How-can-you-tell-if-you-have-the-4th-color-cone-receptors-in-your-eye-instead-of-just-the-usual-3/answer/Bill-Otto-5?ch=10&oid=88928484&share=259cda8d&srid=vzzA&target_type=answer

[@tommymclaughlin-artist]

I think the strong nuclear force just became my favorite force! What a mind-blowing intro to quantum chromodynamics. I'm from an arts background so I'm just an enthusiastic spectator here, but I never expected that color theory would help me understand deep physical forces intuitively. All these videos are great but thanks in particular for this one.

[@stephenchurch1784]

I really wish that society didn't gatekeep math so badly. Getting through the classes needed to fully understand the math of QM was a challenge for sure but there's a notion that you need to be inherently "good at math" to do so that I don't agree with. Differential equations is the only class that I think is truly impossible to self teach for someone sufficiently persistent and motivated

[@JACKRAIDEN97]

@@stephenchurch1784 differential equations are extremely easy and can be self taught. Just your personal experience.

[@armanddicesare7326]

Sure that's it's more exciting than the weak force (maybe because this time i can understand what it actually does not like the weak force lmao)

[@madderhat5852]

That's exactly my background and thought for today's episode. Amazing.

[@stephenchurch1784]

@@JACKRAIDEN97 the difficulty with self teaching diffeq isn't that it's particulary hard. It's more a lack of resources. Khan academy only covers the first couple weeks of a proper theoretical approach to diffeq, the youtube videos tend to be either too conceptual or focused purely on the mechanics of doing diffeq, the people answering questions on math stack exchange tend to be discussing it with math further down the path, and diffeq generally comes at a point in the math sequence before you learn to effectively read a math textbook. Maybe impossible was too strong a word but I still think a person would be better served self teaching the pre-reqs, placing into a diffeq class and having a good guide.

[@brianhinojosa451]

I appreciated this episode a lot. I’m not a physics major, and this hit some basics things I didn’t know. More episodes like this would be absolutely fantastic. Thanks for the work you do,

[@brunofagherazzi9903]

When I started college I read/watched a lot of content on QFT and Group Theory etc but never got very far as I lacked the math. However this video is so well built and explained that my heart actually raced when you said "SU(3)". THANKS for making these videos

[@visionkrypto6760]

I love how the videos are informative and relatively easy to understand while not being too basic on the other hand. Enjoy watching them every time

[@classified022]

The PBS series have always been good at this, infinite series (RIP) also didn't pull any punches when it came to mathematics but in certain subjects where I had no background I could still follow along

[@TheEnzogori]

Exactaly

[@3sc4p1sm]

Easy to forget the world is falling apart

[@realzachfluke1]

@@3sc4p1sm Yeah but no matter how bad things get here on Earth, the Universe never stops being awesome. Matt O'Dowd (the host of this show) said something along those lines at the end of the one of the Space Time episodes after the covid pandemic began (one of the ones where he had to record in his apartment). And yeah, that's pretty much how I feel. I can't even tell you how much the night sky has helped, and continues to help keep me going.

[@klauskervin2586]

This episode had one of the best explanations of quarks I've ever experienced. Thank you for this great content!

[@handleless85]

I found it too similar in structure and content to kzbin.info/www/bejne/fH2WeqCqfMh7p7M which also dives deeper into the math behind it. Would have expected SpaceTime to at least link this video...

[@albertosierraalta3223]

@@handleless85 I was going to link the same video! Great content

[@Nefville]

I'm sure that link goes to a video about quantum mechanics.... right?

[@usernamesrlamo]

Interesting that Anton just posted a video on protons (quarks and gluons) that had a great explanation on how quarks and gluons actual function. I thought it was one of the best explanations I’ve heard. m.kzbin.info/www/bejne/Z5PMhYVjr6-nnM0

[@Mr.Nichan]

@@handleless85 Yeah, I saw that video before this one too. It's on a channel with 531 times fewer subscribers and came out 10 days before this video. Hmm...

[@leenar0sesxc184]

I like it how I have a physics degree and yet recently, Space Time videos have delving beyond the undergrad level into things even I have not seen yet. Keep up the good work, there is never too much physics!

[@hassassinator8858]

Physics degree and you're selling your body? What a tragedy

[@motoshan]

This episode is great! Thanks for taking all the feedback on board from the recent survey. I wouldn't have said I was unsatisfied with recent videos but clearly you have a deeper understanding of your audience and the content you produce because it's clear that you saw a need to produce different kinds of videos. You've been hitting the nail on the head. Thanks for scratching the itch we didn't know we had and really upping your game with these videos.

[@hazardousmaterials1284]

I’m a bit disappointed that the episode named “Why Isn’t the Nucleus Ripped Apart?” doesn’t actually describe how the nucleus isn’t ripped apart. You described how individual protons and neutrons are held together, but not how they hold onto each other. I once assumed it was gluons being interchanged between the baryons, but was recently surprised to learn that protons and neutrons exchange mesons. This explains how the strong force really holds the nucleus together - named the “nuclear force”. I haven’t seen a video ever mention that. Hopefully, this will be described later in this series!

[@DrDeuteron]

that's called "quantumhadrodynamics", and is an "effective" field theory describing the nuclear strong force as left-over QCD effects. The problem is, a proton is 1.6 fm across, and the range of a gluon is

[@lucidd4103]

He did, it's because it's strong 💪

[@shashankchandra1068]

@@DrDeuteron @1:40 Is that blue colour what can be called as a gluon field?(AKA one of quantum field ) and red colour a gluon particle?? Or the lowest energy density which is not shown/render in this image (prf.derek said tht in this video) is what we can call as GLUON-FIELD? Or is that RED COLOR RECTANGLE @1:21 is what can be called as gluon-field(AKA one of quantum field)kzbin.info/www/bejne/Z6KtYaJqiptml9k @1:40

[@hazardousmaterials1284]

@@DrDeuteron - Thanks! That's really interesting to know!

[@DouglasQuattrochi]

Omg I was so enlightened and surprised over the color symmetry explanation I didn't even notice you're right! We only covered gluons!

[@damaliamarsi2006]

The quality of this channel never ceases to amaze. I know it is good when after watching 16 minutes of explanation on something with QCD in the title it only feels like a minute or two have gone by. Everyone I have told about this show has loved it.

[@KendraAndTheLaw]

And it refreshingly stays out of politics

[@brendan1871]

@@KendraAndTheLaw I don't know about that. Matt's claim that dark matter shot JFK (as opposed to the rival claim that Elvis did the deed) and his denial of aliens building the pyramids is about as 'political' as one can get.

[@dimitargueorguiev9088]

Kudos to Matt for attempting to explain QCD with simple terms and definitions understandable by the laymen.

[@jestermoon]

I understand quantum mechanics 🎉😮 Mmm Yeah I know. Noble Prize to the usual address thx for confirmation of my bias and relativity speaking 🔊

[@pmamonthero6641]

​@@jestermoonI'm a fart queen

[@ReivecS]

Man these recent episodes have been excellent. I could honestly be happy with about 20 more vidoes that just keep deep diving in this direction and then talking about how various ideas would effect other theories and assumptions we have. For example the past few videos have left me a bit confused about how important (or not) the Higgs boson really is, so a deeper dive into that would be great.

[@cinemaipswich4636]

As a Cinematographer, Editor and Graphic Designer, I can see more sense in Quantum Science than I originally figured. Since Anton's post yesterday, the Gluon's have risen in stature as the "energy potential" that cause/creates/forms Mass and with it the Gravity and SpaceTime itself. Richard Feynman's "If you understand Quantum Physics, then you don't" is less of a mystery these few short years later.

[@nixdorfbrazil]

Yeah I saw the same Anton's video. But I got confused now. On Anton's video he claims that a recent paper has proposed that the rest of atoms mass come from gluons energy. It's pretty recent find that will need more discussion. But if gluons are responsible for the atom mass and the more massive an object is, the more gravity it "has", this is spooky! I don't know. I'm complete amateur and I don't qualify to be talking about this. But now I really think I have a question.

[@Mr.Nichan]

Gluons are not THE '"energy potential" that causes/creates/forms Mass and with it Gravity and SpaceTime itself'. MOST of the mass of of atoms comes from the binding energy of protons, and neutrons, with the related inter-nucleon "nuclear force" being responsible for much of the rest. All that mass can probably said to come from the gluon/strong field. However, the quarks themselves, as well as electrons and other charged leptons, also have mass that derives from their weak-force interaction with the Higgs field, and apparently the mass neutrinos must comes from something else that physicists haven't figured out, though they are sure that neutrinos have mass, simply because they know neutrinos experience time. (The proper time between emission and detection must be greater than zero if the neutrino changed in the way that "neutrino oscillation" demonstrates between emission and the detection interaction.) There's a PBS Space Time from 2016 about how mass comes from massless particles you should probably watch kzbin.info/www/bejne/nYSuq5qmqZl7eLc You might also want to watch the videos released immediately before (about how the Higgs field creates elementary particle mass) and after it (about how massless particles create time when they create mass). Also, it's questionable to say that spacetime itself is created by gravity, rather than just that gravity is created by curvature in spacetime and mass/energy and it's position/motion curves spacetime, though it is interesting to note that massless particles kind of don't have time or space other than their interactions, due to infinite time dilation and length contraction. As for how/why mass distorts spacetime/creates gravity, I don't think that's fully understood without a theory of quantum gravity.

[@nixdorfbrazil]

@@Mr.Nichan Thank you. I watched this video some years ago, but I forgot about it and misunderstood some of its implications.

[@leenar0sesxc184]

I think this has to be one of your best episodes so far. Really good and complete explanations, great information, and not too fast so it's possible to follow everything without pausing. Way to go, Matt!

[@nickjones5641]

I've been watching the last few episodes several times for the concepts to stick. I appreciate how deep this channel goes. Thank you!

[@pmamonthero6641]

I've hidden a carrot inside of myself

[@renderproductions1032]

Scientist explaining quarks: The strong force is strong with this one.

[@invisiblekincajou]

may the Strong Force be with .. it

[@Nulley0]

Stronk

[@3sc4p1sm]

Hes talking bout it cus scientists figured out mass is a derivation of the strong force interacting with quarks, prob the next video

[@invisiblekincajou]

@@Nulley0 qwak stonk!

[@douglasauruss]

I was waiting for the very good reason for scientists to use red green and blue colors for this property... to be because it had to do with light sabers. Two light side colors and one dark side color (red).

[@CaptainCuttlefish74]

I've been waiting for an episode like this for so long! QCD is, as far as I can remember, the only fundamental force you haven't really covered, so I'm glad to see this.

[@binacharya]

After years of watching PBS Space Time every week, finally this episode made everything "click" in my head....for the time being at least.

[@Dr.RiccoMastermind]

Would love to see an follow-update video for a deeper dive into Quantum Chromodynamics, including the fact of the presence of Complex Numbers to describe Hadrons. What about all the other possible neutral states In the middle of the 6 others? There are technically more than 2 possible

[@Alex_Deam]

I don't know all the details, but aiui, what you have is an 8-dimensional vector space (a special type called a Lie algebra), and those 8 are the basis of that vector space. A basis of a vector space just means that you can take any finite linear combination of those 8 to make everything else in that space in a unique way. As a simple example, every vector in the 2D xy plane can be written uniquely as some linear combination of the basis vectors (1,0) and (0,1), e.g. (4,3)=4(1,0)+3(0,1). That's what's going on here with su(3) but at a higher level. So presumably any other state you can think of can be written in terms of the 8 we already have.

[@Dr.RiccoMastermind]

@@Alex_Deam yes, this sound reasonable and might also be comparable to forming any color and shades by using values for R, G an B between 0 and 255, for example. Thank you!

[@Dr.RiccoMastermind]

@@hyperduality2838 Although I love duality in the world, depicted also as Yin and Yang, not everything is just dual in the world - besides the fact of much grey between black and white in every aspect of life and nature. Like there usually never is a choice only between A and B offered, better find C and D sometimes 😎 However, very nice listing of yours, although much is put together a little arbitrary. Proofing quantum physic dualities by classic physics equations might not work so well

[@Dr.RiccoMastermind]

@@hyperduality2838 your getting a lot of things mixed up without clear structure or direction. Don't even understand what you want to say with 'dual to entropy' with you 4. Law of Thermosynamics (actually the 3rd I assume, ranging from 0. to 3.)

[@SuperVstech]

The universe is so complicated, AND simple… complete comprehension may never be possible, but it is amazing to me all the forces that just make sense.

[@gert-janbonnema]

When we reach complete comprehension, the simulation will end and we will wake up in the even more complicated universe that simulated this one. It's a neverending puzzle.

[@ryancarter2146]

This episode was new info to me and made so much sense. Sometimes it goes right over my head. Well done Matt!

[@mbmurphy777]

As the universe approaches heat death and is dominated by the expansion of space, could it be possible that expanding space is enough to pull quarks apart, snapping the gluon flux tube- creating new matter (effectively from dark energy)? Could that happen fast enough to create something like a big bang?

[@ruddyxmax]

Yes, is expected all kind of matter become photons, even Black hole evaporates due hawking radiaton, will be the last kind of matter to exist.

[@Chipchap-xu6pk]

That is a really cool thought. If I understand correctly, you're essentially saying that maybe the tube breaking mechanism explains the creation of matter at the big bang. It was just a consequence of rapid expansion. I'm also getting a hint of cyclic universes - big bangs from the rapidly expanding cold universe. I'd love to hear the thoughts of physicists on that. Is it right? Wrong? Already known?

[@alphavasson5387]

I'd highly recommend looking up "the big rip" - it's a theory on how the universe will end and it somewhat matches this idea

[@k4kev]

Another great video on QCD! I just so happened to read David Griffiths "Introduction to Elementary Particles" recently, and WISHED so badly that PBS Space Time had videos on chromodynamics. What a lovely coincidence as the first video on the topic was posted only a week or two following my wish. This follow-up visualizes the SU(3) so well for me. Thanks for continuing to create top quality content consistently. Well done.

[@RedNomster]

This is the first video I've watched from PBS Space Time where I caught myself going "That makes complete sense," or "That answers my question" at nearly every turn. Ya'll mentioned quark-gluon plasma in your *how many states of matter are there* video and I just nodded along, but this video connected a few strong force dots for me. And explaining how this 8-fold symmetry of maths is coincidentally synonymous with RGB and Chromodynamics, and not some "similar analogy" was the cherry on top. Great video. I'd love to see if there's other fold symmetries present in the quantum world outside of 8-fold - perhaps a species who relates colors differently than us would be more likely to stumble upon an understanding of forces unrelated to the strong force!

[@kstxevolution9642]

yes! finally an episode about QCD. i volunteered on a research as the "algorythm/programmer guy" to implement some calculations involving QCD. been in love with the subject ever since

[@semidemiurge]

I have been trying to grok this for two decades. This episode is one the best yet. Extremely well explained. I can't thank you enough.

[@Cliff86]

Was really looking forward to this episode and the talk of SU(3) You guys really outdid yourselves with this episode

[@felipemonteiro5877]

This is probably the most inspired episode you guys have ever done. Congratulations!

[@Cettywise]

Dude, I have been struggling to grasp color charge for a while and this video finally brought me to a very basic understanding of the ideas behind the strong force. Thanks for everything you guys are doing to breakdown some very dense ideas and raise our understanding of science!

[@jakobknudsen6864]

This was amazing! I hope you can find the time to do an episode like this on the weak force, as good information on that force has eluded me for so long. Regardless, excellent content as always!

[@osar7664]

Question: your explanation of the nucleus repeats something I’ve heard elsewhere, that is, certain things can’t happen because of the Pauli Exclusion Principle. It would help to understand how we know that the Pauli Exclusion Principle is in fact true rather than just taking it as a given. Love the show!

[@SalivatingSteve]

I like to think of it more like, two identical particles can’t occupy the same physical space at the same time. When you go subatomic the electrons behave more like a standing wave vibrating around the nucleus, not a point particle “orbiting” like a planet.

[@StefSubZero270]

In quantum mechanics when you have to describe particles, you have that a wavefunction describing fermions is an antisymmetric one and when you have bosons it is a symmetric one: in general for particles these wave functions can be described by something called a "Slater determinant" whose components are the various states( (n, L, m , m_s) in which all the different particles of your systems are and you have that this determinant vanishes completely for fermions, in particular when you have that two or more fermions have the same spin-coordinate a.k.a. they occupy the same (spin) state (if it can be helpful, this happens when the states are linearly dependent). Thus you have that the wavefunction simply is 0 and thus you cannot have one that describes multiple fermions being in the same occupation state

[@ivarwind]

I think this is the first time I've seen any attempt at a pop sci explanation of what is meant by SU(3) - and it was a good one! (I.e. simple, makes sense, relatable to something we know very well, and very clear that there's much more to learn)

[@ingmeisterk874]

Long expected episode and it was absolutely worth the wait!! Very well done Matt & Team!

[@Jm-wt1fs]

Love the channel As you guys get into particle physics, I’d love to hear your take on emergent space time and more fundamental geometric theories about particle collisions and scattering amplitude. Many theoretical physicists like Nima Arkani-Hamed have been famously saying “space time is doomed” when trying to unite quantum mechanics and general relativity.

[@rmdodsonbills]

I'm no physicist, but knowing how intimately tied the concept of spacetime is to general relativity, that intuitively seems like a very plausible outcome.

[@ninianstorm6494]

@@rmdodsonbills i notice fbi/irs/cia/msm all give double standards to political families deeply involved with kill iraq/libya in particular when muller charge manafort for things nothing to do with russia hack but let podesta go for same reason =blackmail dc to support blame russia to cover up fact 2 party system failed since mccain-hillary all did united fruit company scandal 2.0 recall fbi never look at physical evidence just crowdstrike/hillary words, cia break glass 2017 inauguration with media claim russia stolen election 1oo george bush 14y ago said add ukraine to nato foreshadow nuland f eu coup 2014 support = 1. kzbin.info/www/bejne/pIW0ZHdnlpKdaJI 2001 pentagon memo kill occupy iraq to syria kzbin.info/www/bejne/lZ7Ve4V-rMeJfZo current ukraine gov is proxy since obama drew red line just like did in syria earlier arming rebels telling russia not to interfere while zelensky ethnic cleanse donbass region 7y= 2. kzbin.info/www/bejne/qpKclYqImKmIhqM 3. kzbin.info/www/bejne/f3PIg3Vtp7yelZo

[@rafakordaczek3275]

That was so well put together. It is an excepionally easy to understand video.

[@matthewwriter9539]

2:00 A periodic table except for partials...which was the original idea of the periodic table. I wonder what Armin Shimerman knows about quarks. Maybe you should have him guest star on an episode to talk about it? 5:30 Nice diagram 13:00

[@LVGamerCats]

It would’ve been all too easy and tempting to cover this topic in broad strokes, but in the last two episodes you sketched and colored many details of QCD. Bravo! I can’t wait to see what comes next. A calculation of the mass of a nucleon perhaps?

[@joz6683]

Physics class is now open. Will be late to class today as I am in the middle of life stuff. However, I cannot wait to watch. Thanks in advance for all your hard work.

[@CircuitrinosOfficial]

I would be interested in seeing an episode about what experiments were done to determine the properties of quarks and gluons.

[@BronzDano]

I love these videos. I only understand…or barely keep up with a 1/4 of it. But still…some of the best content on all of KZbin 👏🏽👏🏽👏🏽

[@elaadt]

This was the best explanation for the strong force and related particles I have encountered. Thanks for this episode.

[@ortnamus]

I find it interesting that the colors add up to zero, just like 1+w+w^2=0, where w is a cube root of -1. This is analogous to how sqrt(-1) has such significance and use in so many other areas of physics.

[@Eulers_Identity]

wait but wouldn't that particular equation give you w = (-1 ± √-3)/2 ?

[@johnrizzo9111]

Ok, but it seems the main question still stands: Why doesnt the nucleus fly appart? We now know why quarks stay together, but what about protons? What did I miss?

[@luz_reyes_676]

strong force overcomes the repulsion of the electromagnetic force. thats how strong the nuclear strong force is.

[@garethdean6382]

An entire theory, hadrodynamics: en.wikipedia.org/wiki/Quantum_hadrodynamics In short, the nucleus is held together via packets of quarks and gluons being shared between nucleons. The video sadly didn't cover this and so was quickly renamed.

[@LIGO-LHC]

@@garethdean6382 Thanks.

[@ayanpeace]

The bigger picture is amazing - I didn’t know it was also from PBS :) great work!

[@daconssc]

I have watched or read many explanations of quantum chromodynamics, but this was by far the easiest to understand. Thank you!

[@jeffreymartin8448]

One of the better ones. Been struggling with QCD for awhile. But, made many steps forward after watching. Really dig this series. I can spend most of a very enjoyable evening with them.

[@stevesurprenant1005]

I so agree. Watching this video at 2 am.

[@bencushwa8902]

I'm a physicist by training and a photographer by choice. I've always found the link between QCD and how our vision works to be fascinating. Thanks for the link to The Bigger Picture. I hadn't heard of that channel and I'll definitely be checking them out.

[@zacharywong483]

Such great, eloquent, yet understandable explanations! Great visuals as always! And fantastic video overall!

[@sameddington9072]

This is the first explanation of this that's really clicked for me. Thanks so much!

[@ThatCrazyKid0007]

Incredible episode guys, can't wait to see more deep dives into various quantum theories and models, math included.

[@DanHarkless_Halloween_YTPs_etc]

I realize this is a sentiment that's been expressed here a million times, but just wanted to say that I'd never been able to get a good handle on quantum chromodynamics from my readings on it in the past (indeed, when the subject was introduced here, I said, "Uh oh…"), but your video finally made it all snap together! Thanks again for all your layman/hobbyist-accessible deep dives!

[@HimanshuSharma-eg5li]

This was an amazing episode. I would definitely love to see a follow up deep dive into the strong force. Waiting for that future episode

[@queuerious]

Watching these episodes, I am forming the opinion that this is perhaps one the best accessible insights for non-experts of physics and cosmology on KZbin. To parallel a more simple time, it is never a good idea to base ones understandings solely on one good book - lots of books, lots of reading, rounds out ones understanding and ability to filter good arguments, ideas and logic from bad. But one remembers the good authors. And indeed, you and the PBS team are one such modern example. Thank you!

[@Rajdeep007lol]

Always happy to see you Matt.

[@spectator5709]

I am applauding here! 👏😃 What a great episode! Great explanations and excellent graphics to go along! Five stars! ⭐️⭐️⭐️⭐️⭐️

[@mkhachfe]

I've watched almost every PBS space-time video and this is absolutely one of the best episodes

[@crosbying]

One of your best videos! I am sad I skipped it when it first came out. This was just stellar explanation of this topic

[@rogumann838]

Amazing video. Please do one on the weak force too!

[@taybagoogy1162]

It seems to me that it very step of progression in scientific understanding we understand older, smaller, and the forces that govern each scale. All the while we have interactions and orbits. I wonder if the universe will eventually evolve to be some hire form of orbit or interaction, or if it already is and we don’t know it yet.

[@Eireternal]

Alright! Suggested this episode a good year ago. Super excited to learn more, thank you!

[@carmenosorio1315]

I like the back screen , it's so ilustrative, and the explanation so clear, I love you all. Thankyou

[@eddieperez3145]

Absolutely loved this episode. This was a fantastic video Matt; I feel like the strong force is never really discussed, or at least in great depth. This always puzzled me, why the heck wouldn’t we wanna talk about the STRONGEST force in the universe?! Maybe because it’s super complicated 😅

[@CATinBOOTS81]

Other people: "Wow, this video is super easy to understand and clearly explains the fundamentals of QCD!" Me: "Wow, SU(3) is amazing... these kind of patterns are exciting! Please tell me more examples about it! I want to be able to better recognize them in the world around me..."

[@Szergej33]

Such a good explanation, great video. I remember first learning how there are 8 types of gluons, not 9 that the 3 color * 3 anti-color suggests. Very cool symmetry trick, that one.

[@kirk001]

This is the most fascinating presentation of the most fascinating physics topic I have ever seen in my half century life-time. Thank you.

[@jesusdesanto432]

I just read an article saying a study measured quantum leaps and found they were not instant. You had mentioned that there was such a study in progress in a previous episode. It would be great to revisit quantum leaps and what this new finding suggests about their nature.

[@MR.MUFFIIN]

Great TV show too

[@kameronmaclean678]

Great education Matt

[@stefanblue660]

I thought Arvin Ash was the best explainer, he is known for great visualisations, but you bring it on the point explaining things I haven't really understood before after hundreds of videos. I am very thankful for that! 🙏

[@Krail1]

This was a huge help in understanding the behavior of quarks in hadrons. I feel like most discussion about quarks gets so into the weeds about superposition and spin and wave functions that we don't really highlight this core behavior that defines how they form larger particles! I remain mystified about how the Strong Force works to keep individual nucleons together in the nucleus, but I assume that's a subject for the next couple videos.

[@Astromath]

Really great and easily understandable explanation of quarks, gluons and the strong force! To anyone more interested in that topic I recommend a video about the strong force as part of #SoME2 I don't remember the name exactly but you should find it when searching "SoME2 strong force"

[@1224chrisng]

oh yeah, that's a good video, he does a deeper dive into the maths of SU(3)

[@mrgadget1485]

Hi! Thank you for interesting topic as always! Do quarks "live" in the same quark-field, or do they all have different fields which interact with others?

[@DrDeuteron]

I think that's a matter of taste [no pun intended, ...wait for it] Before the Higgs turned on, quarks were massless, and so-called "flavor symmetry" made sense to have one quark field with different 6 flavor and 3 color dimensions: now, not so much.

[@rileyschroeder8560]

I can't overstate how much I appreciate this channel

[@mateoconk]

4 mins in and this already better taught for me than anything on Chromo Dynamics I’ve seen yet.

[@deusexaethera]

So, gluons are color charged and therefore can only interact with other color charged particles like quarks, but electrically neutral photons can interact with other particles that feel electromagnetism _regardless_ of whether those particles are electrically charged? Why aren't photons limited to interacting with electrically neutral particles?

[@garethdean6382]

No, both gluons and photons can interact with neutral particles, through magnetic effects. (electromagnetic and chromomagnetic. Most of photon's interactions with matter are with charged particles, neutron-photon or neutrino-photon interactions are pretty rare. But most particles of matter larger than a quark are color neutral which limits gluons' effects. if electrons and protons had no charge then photons too would be ghostly particles that did little.

[@Dr.RiccoMastermind]

Very interesting topic and well explained and arranged. Bravo! Now, for the analogy to the RGB System. Several experiments show that technically black, as Grey, is just a shade of White, even if the darkest. Do the 2 "neutral but unbalanced" states of the Hadrons exhibit the same connection as between black and white?

[@SuperStingray]

The metaphor is strictly based on the "hue" property of colors, and doesn't really account for brightness (i.e. light vs. dark.) The neutral state is considered "colorless" rather than black or white because that distinction doesn't really exist in the context of the strong force.

[@metaphysica9984]

This is the coolest explanation ever! Very bombastic episode! Thank you for being the best!

[@PrimatoFortunato]

Great chapter! Super well explained, thank you. I dream of a future video on which you rise us up to galaxy brained beings who understand why perturbations in a field are nicely modelled as particles. PS: my favourite colour is olivine. Just feeling like pointing out so many things we consider colours have no associated photon, which blew my mind. Even magenta is a non-spectral colour. Google how the brain dreams up magenta, because it's awesome :-)

[@ez9566]

just a question: Would a big rip scenario for the universe have so much energy, that even quarks are seperated and infinately multiply? Or does the expansion of space not carry any energy to form any other particles?

[@Jop_pop]

This is answered at 13:30 in the Big Rip episode entitled "could the universe end by tearing apart every atom"

[@ez9566]

@@Jop_pop thanks

[@TGears314]

@@Jop_pop that video was published 3 years ago, thanks for having that info handy haha

[@Jop_pop]

@@TGears314 I rewatch these videos to sleep a lot 😂

[@ZGorlock]

When you were talking about how the different combinations of colors cancel out, it made me think of how rotations in 3D can cancel out. Like if you take and object and rotate it 180 degrees about the X axis, it ends up in the same state as if you had rotated it 180 degrees about the Y axis and then 180 degrees about the Z axis. And if you do 180 in X then -180 in X you end up back where you started. With electrons having spin you think they would have jumped on "rotation" instead of color, and arguably easier to explain too. Missed opportunity.

[@DrDeuteron]

SO(3), the group of 3D rotations, is a subgroup of SU(3).

[@stephenchurch1784]

There's another pbs spacetime video called "electrons DO NOT spin" that you may want to watch. Your thoughts on rotational symmetries are important in physics, the link between electron spin and rotational symmetry is just not the most applicable.

[@cnawan]

Does the Big Rip theory of the end of the universe extend into tearing apart quarks, and wouldn't this lead to an explosion of mass-energy creation? It's curious to imagine a second Big Bang resulting from this in one kind of Cyclic Universe. :)

[@cogmonocle2140]

Having just recently watched Highly Entropic Mind's video on the strong force for SoME2, it's strange hearing the exact same "this will be familiar if you're a photographer or graphic designer" line

[@3nimac]

So excited for future episodes on this

[@SalivatingSteve]

If gluons can’t interact with color-neutral hadrons, could that give us some clues about dark matter? That is to say dark matter interactions exhibit a sort of confinement from the electromagnetic force, but not gravity. Perhaps dark matter is confined to inaccessible dimensions? If you think of each of the 4 forces, 3 colors, & 3 spatial dimensions (+time) adding up that’s getting awfully close to the 10-11 dimensions proposed by modern string theories.

[@beanseason6515]

It's the Midi-chlorians

[@dr.layman1623]

Fantastic. Episodes keep getting better (IMO).

[@csb8336]

Despite QCD vis a vis the strong force, the attraction of beard dandruff can be overcome at this (our) scale with an adhesive roller. this is where QPD comes into play IE Qualitative Partner Dynamics:) nice vid as always!

[@noone6454]

Hi, what if there was no matter/mass in the universe? Would spacetime still exist?

[@cashewABCD]

100% Dark Matter & Dark Energy? Yes Spacetime would exist.

[@noone6454]

@@cashewABCD part of my query is whether they too could continue existing

[@linusog]

Is there any reason that as scales get smaller/bigger there seems to be an whole number decrease/increase in the ways that the dominant force in that scale regime can interact? For example, gravity is large scale and only attractive (1), electromagnetism is medium scale and is attractive and repulsive (2) and QCD is small and has 3 charges and corresponding interactions? Is it related to some underlying symmetry in the math or is this a naive over simplification?

[@CATinBOOTS81]

Gravity and electromagnetism are both large scale - the difference is that Gravity being only attractive, literally everything attracts everything else in the universe... while the Electric force being both attractive and repulsive tends to cancel out in neutral structures. That's being the case, the main reason why everything doesn't crash on itself is that Gravity, while being only attractive, it just super-super weak compared to rest of the other forces.

[@johntaylor2683]

@@CATinBOOTS81 There is no consistent quantum gravity thoery, so the the behavior of the graviton, in explaning gravity is lacking. The best theory is General Relativity, which doesn't describe gravity as being attactive, but a curvature in space time, that cause mass/energy to move along geodesics.

[@CATinBOOTS81]

@@johntaylor2683 Yes, I know about General Relativity, but nonetheless Gravity appears as an attractive force.

[@paryanindoeur]

You have the best science presentation anywhere: narrative (metaphor, storytelling) woven into the math & experimental results. Presenters who use just the narrative come off as 'for children' -- I want the hard stuff, even if I don't follow it all. And presenters who just do the technical stuff come off as dry, academic, and not entertaining. You have the perfect blend. I watch your shows avidly.

[@JoseCastillo-wx6jd]

Excellent video. Very very interesting. I can't wait for another video about quantum chromodynamics.

[@HaHa-gy5vg]

Fava Beans 💪

[@darkmath100]

"Don't get caught in the same trap as the...theories of quantum consciousness." Tell that to the 16 color receptor toting mantis shrimp. But seriously if quantum fields permeate the universe and we know animals such as birds can detect the EM field using quantum entanglement....then the quantum consciousness people may deserve a little more credit. Just sayin'.

[@SpecBASStuff]

When Penrose considers an idea seriously, so do I :)