Why Don't Protons Fly Apart in the Nucleus of Atoms? RESIDUAL Strong Force Explained

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Prior Video explaining the evolution of QCD:
• Why Don't Protons Fly ...
SUMMARY:
Since electromagnetism is so strong, multiple protons in the nucleus of any atom like Helium should repel each other very strongly. So how do they stay glued together?...Because of a force that is even stronger than electromagnetism - 100x stronger, the Strong Nuclear Force.
This force is actually a RESIDUAL form of the strong force, and works via a different mechanism than the force keeping quarks inside nucleons. I review the science of quantum chromodynamics. This force not only keeps protons glued together, it is also responsible for 99% of the mass of objects. Only about 1% of the mass of objects come from the Higgs Field.
Protons and neutrons are made of quarks and gluons. A proton is made of two Up quarks and one down quark. A neutron is made of two down quarks and one up quark. Gluons within these nucleons are virtual particles so the number fluctuates, but there are 8 different types of Gluons which bind quarks together.
Both the quarks and gluons carry a color charge. It is analogous to an electric charge but works via a completely different mechanism, and it has nothing to do with optical colors. It is just a metaphor for a kind of charge property that quarks and gluons carry.
There are three kinds of color charges, red, green and blue, which combine to make a neutral charge. So just like electrical charges are conserved - positive with negative to make neutral, color charge is also conserved by either a combination of the three colors to make neutrol, or by color-anticolor pairs. There are anti-colors too.
Gluons bind quarks together by constantly exchanging color charge between them. This exchange occurs continuously. The constant exchange of gluons creates a kind of continuous bridge between quarks called a flux tube.
Electromagnetism, like gravity gets weaker as objects get farther apart. But the force between two quarks actually gets stronger as they get further apart. It works like a rubber band or spring. If you try to pull two quarks apart, the force between them gets stronger the further apart they are. This tends to pull a quarks back into the proton or neutron. However, if the quarks get too far apart, then the rubber band breaks.
When this break occurs, the energy required to break the rubber band creates a new quark and anti-quark pair, called a meson. This is called confinement in quantum chromodynamics because you cannot have free quarks. They are always confined together with at least one other quark. The newly created meson from the breaking of the rubber band is the key to how protons are kept glued together with other protons and neutrons in the nucleus.
What causes the quark-gluon flux tube to break and create a Meson? Although the color charges of quarks within nucleons combine to form a neutral color, such that the net color charge cancels out, quantum fluctuations ensure that this cancelation does not happen perfectly. This is especially true when nucleons are very close together.
Some color charge remains. This imperfect balance of color charge causes a residual strong force between nucleons.
This is called the strong nuclear force. It is mediated not by gluons, but by the exchange of mesons between two nucleons. It is the exchange of mesons between protons and neutrons that results in a residual strong force, also called the strong nuclear force, that keeps these nucleons tightly glued together.
This is a critical interaction because without it, there would be no atoms heavier than hydrogen because 2 protons could not bind together in the nucleus. And life as we know it would not exist.
#strongnuclearforce
#quantumchromodynamics
#QCD
It is called the strong nuclear force. But note that this is distinct from the strong force which works within the nucleons keeping the quarks tightly bound together. The latter is mediated by gluons. But the strong nuclear force is mediated by mesons. Although the strong nuclear force is much weaker than the strong force keeping quarks tied together in nucleons, it is still much stronger than the electromagnetic repulsive force between two protons. So protons are still glued together even though they feel a strong repulsive electromagnetic repulsion.
CHAPTERS:
0:00 The enormous force of electromagnetism
2:18 The particles involved in the strong force
3:59 The mechanism of the Color Charge
6:24 Confinement & how virtual mesons are formed
7:45 What causes flux tube to break?
8:47 Details of quark interactions between nucleons
12:20 Difference between Strong Force & Strong Nuclear Force
14:18 How to learn the fundamentals

[@SabineHossenfelder]

I learned quantum field theory from Weinberg's books. He gives you all the maths and explains nothing about what it means. I wish I'd had your videos back then, you're amazing!

[@sillyproofs]

Oh Sabine! I caught you first! Never imagined Physics superstars like you would also have to go through such grunt work without intuition as well!

[@Darkanight]

I, on the other hand, was lucky enough to be introduced to it by very competent and didatic people such as Sabine, Arvin and Matt.

[@hoola_amigos]

No, You're Amazingg!!

[@NyteRazor]

So happy you exist.

[@andregustavo2086]

up

[@jppagetoo]

I thought I understood this stuff. I missed the subtlty of the strong NUCLEAR force part of it and the mesons mediating it. Thanks Arvin. This was a great episode.

[@ArvinAsh]

Exactly! That 'subtlety' is missed by many. That's why I made this video. Thanks for watching.

[@sinebar]

I always look forward to Arvin Ash videos. He goes into detail not usually seen in similar videos.

[@ceebee]

"Anyone who says they understand quantum mechanics/theory/science doesn't really understand it" Who said it? Someone who's clearly smarter than myself.

[@Youtube_Stole_My_Handle_Too]

@@ArvinAsh You may drop that moronic rubber band analogy. It doesn't work that way.

[@ModMINI]

These videos help me to be able to sleep at night without brain being totally full of questions. It's only partly full now.

[@NoahFriedman]

I never realized the strong nuclear force and strong force were actually two different things, but this was a clear explanation. thanks!

[@1495978707]

Well that’s not exactly what he said. The strong nuclear force is still the strong force, but it is interaction between white particles due to them only being white on average, but fluctuating around that. It’s just like the Van der Waals force is really still the electromagnetic force, where charge neutral atoms are attracted because the distribution of charges fluctuates around the average

[@JoshWalker1]

@@1495978707 This was a useful comparison, thank you

[@sadovniksocratus1375]

ATOM. Atom = electron (active) + proton (passive). In simple atom, 99.9% of the space is empty, because the distance between electron and proton is 10^-10 m. But if one electron tied two protons, then the distance is 10^15 m. (closer to each other by as much as five orders of magnitude). The more complex the atom, the shorter the distance and its outer space tends to zero, while the inner field increases and becomes nuclear. All interactions (EM, nuclear, weak) are the result of the connection between electrons and protons and depend on the distance (and conditions) of interaction. These interactions obey Pauli's law: "There can be only one electron in an atom: simple or complex."

[@neps4th]

Only 1 electron ??

[@dimitriosfromgreece4227]

Yes yes super AMAZING 😊❤️🙏🙏💗

[@L2p2]

As a layman it took me this video to understand "strong force" and "strong nuclear force" are different ~~~ Thanks Arvin !

[@taloweryus]

This was by far the clearest explanation I've seen of the strong force and how it works to bind nucleons together. Thank you!

[@BananaTie]

That was amazing! You are true to your channel's tagline to take something and explain it in a way the general puplic will have a chance to understand. This is the first time I believe I understand Feynman diagrams, thanks to your detailed animation. Suddenly I see myself in posession of an understanding of the strong nuclear force and its implication. On top of this, it explains to me the the existence and purpose of gluons and mesons. You make it look easy - in the same way acrobats in the flying trapeze make it look easy: It is thrilling to watch and looks great, but I know I would never be able to do what you just did. You don't just recite sciense news - you translate it and is able to teach the rest of us. Thank you Arvin!

[@ArvinAsh]

So glad you found it helpful. Thanks for your kind comments.

[@KalebPeters99]

I wholly agree with your sentiment. Brilliant work as always, Arvin 🙏

[@sidgar1]

Just for perspective, a proton weighs approximately 3.68x10^-27 pounds. 20lbs of force pushing against this mass is about 5.42×10^27 times the mass of the proton. That's 5.42 _octillion_ times the mass of the proton pushing against it. The mass of the Earth is approximately 1.3 x 10^25 pounds. Imagine a person weighs 130 pounds (1.3 x 10^2) The forces pushing the proton are roughly equivalent to having 10,000 times the weight of the Earth pushing against a person. It's mind-boggling how much energy is contained in the nucleus. It's no surprise that nuclear reactions release so much energy. (In this example, I'm using pounds but in KG or grams the ratios would still be the same.)

[@Mernom]

The fact that there's a LOT of nucleons out there also helps.

[@Ebenezer456]

Nice example!! But where does the force come from? I mean, how does it come about in the first place?

[@JV-pq3qn]

Wow and I thought an ant was strong, who or what make this kind of thing

[@MiroM84]

I am guessing that as people weaponised fission and fusion very soon there will be some strong nuclear force bomb and also a strong force bomb that would allow us to test the limits of physics

[@JV-pq3qn]

@@Ebenezer456 Science tells us more and more about how it works, but the who, what, and why and if there's some kind of intelligence or reasoning behind it remains a complete mystery

[@chbrules]

I love this channel more than any other science channel on YT. You explain these extremely complex ideas in very understandable ways. I always learn things. Feynman would be proud!

[@virt1one]

very good explanation. I didn't quite "get" all of it but I did learn a lot. I think I now understand why protons stay inside the nucleus together, thanks for the video!

[@blueckaym]

Great explanation! What I find really helpful is to show the different levels of the strong force and interactions - from the strong force itself, thru the strong nuclear force to its effect on the stability of the atoms. I've always thought that unless you're going to the field professionally you most likely don't need all the math of these forces. For the ordinary people like me, what's the most important is to grasp the concept of the forces and interactions. And for that purpose videos like this are really priceless!

[@lahma69]

You did an excellent job of quickly and concisely explaining this relatively hard-to-digest theory. I can't imagine how it could have been explained more quickly or how it could have been explained in more depth or details in such a short time. Striking a balance between explaining the theory in enough depth to actually conceptualize it and not getting carried away with the details and complexities is not an easy thing to do, but you pulled it off superbly.

[@douglasboyle6544]

This was a great video, I never grasped the difference between the strong force and strong nuclear force. Thank you!

[@parapeciarz7472]

That's a wonderful explanation! The best one i've seen so far

[@xxwookey]

That was quite a lot to take in! I'm glad you tried for the simplest useful explanation because it's already moderately complicated. I was aware of the existence of those particles and forces but this is the first time anyone has ever explained to me how they interact. Now I want to know how on earth people worked this out...

[@bengoody595]

Arvin .. thank you so much. Confession, I had to keep skipping back over the second half multiple times for this to sink in but thanks to you I now know what is meant by an unstable element and that it decays quickly. The strong nuclear force between protons is too far apart and thus the neucleus becomes unstable. This visualisation you've put together I am guessing is in it's simplest form but yet conveys exactly what you're trying to get across. Awesome video, keep up the good work! 😊👍🏻

[@Li.Siyuan]

Clearest explanation of basic QCD I've seen yet. Thank you!

[@mrcalico7091]

Wonderful Video Arvin! You were articulate at simplifying these complex interactions and still covered enough of the details to make it understandable. Love this one!

[@jamesbond_007]

This is GREAT! Thanks for explaining this so clearly Arvin! After decades of thinking I understood this stuff, my eyes are finally opened that the strong force != strong nuclear force, and now I understand what mesons are for (at least one of their uses). I always suspected there was leftover (residual) strong force, and posited that it may be responsible for gravitational attraction. And I never knew that the net color charge neutrality was a requirement. And, I thought the gluon flux tube would continue to be reinforced by the creation of more gluons -- I did not know that quarks could appear from the separation energy trying to pull a quart out of a nucleon. It's an interesting parallel between the strong force keeping things together because the color charge is constantly changing within the nucleon, and the strong nuclear force keeping nucleons together by an analogous mechanism of meson exchange.

[@MaxxTosh]

Are you considering a video to explain the weirdness of Technetium, and why it is never stable despite being such a light element? I’ve never heard a satisfying answer!

[@ArvinAsh]

Interesting. I don't know much about this.

[@jarooko]

Thanks, Arvin, for these kinds of videos. Explained wonderfully, and incredibly clear.

[@88888888tiago]

Best explanation about the subject I've seen. Finally understood the subject 🙌 Thank you sir

[@gringo1723]

Compliments! Exceptionally expressed and displayed, also Your Feynman diagrams explanation is easily the best I have seen on recent KZbin postings. 😎

[@paysour1]

Thank you so much it's been 40 years since I had physics and this wasn't a topic that was covered. It's the first time that I had it explained in such a way that it all makes sense. Thank you

[@Jezee213]

I was trying to picture the process in my mind and was struggling however, the analogy of Velcro on the magnets was brilliant! thanks for that visual aid it's helped me so much!

[@happmacdonald]

This is a great explanation, thank you Arvin. :) The question this leaves me with is why a nucleus only tends to be stable with a mixture of protons and neutrons. It's like there's a "sweet spot" in the ratio of how many protons and neutrons can make a stable nucleus for any given proton count, with a handful of less and less stable isotopes surrounding that preferred ratio, and then if the ratio is too far off the nucleus just isn't going to form in the first place.

[@Mernom]

I think that's because of there is too much positive charge in one place, it's a more energy stable configuration to eject the positive charge. Such interactions can happened without tossing out protons.

[@happmacdonald]

@@Mernom that only helps describe the "not too many protons" direction though. What stops us from having Hydrogen with dozens of neutrons in it though? 😁

[@sethrenville798]

Why are Oscillators within Conway's game of life only stable in certain configurations of squares? If you subscribe to the Wolfram physics project model of the universe, in which information is Fundamental, And all things within existence can be described as different confirmations of information that a fundamental, sweeping computation calculates from a probabilistic waveform of the future into a specific incidence of physical reality, generating information and turning the energy that used to make up The portion of the wave form that existed in all other possibilities into mass, driving our linear experience of time and entropy, both as by products.

[@BruceD1776]

"information is Fundamental" What exactly is information? Information about what?

[@garyfilmer382]

Great video! I had forgotten some of quantum chromodynamics too. It’s still awesome to me, that the electromagnetic force, which is incredibly powerful, is kept held there within the atom by the strong nuclear force. It is the reason, of course, that nuclear fission, the splitting of the atom, releases the greatest energy known to humanity. It is still mind-blowing that everything, in the world around us, and also ourselves, we are all atomic matter, literally made of atoms! It’s like sometimes I have to remind myself that this is actually our reality, not something separate from us.

[@michaelhansen8959]

Yes, it's not us and the kosmos. It's just kosmos.

[@contessa.adella]

Wow! I had no idea HOW the quark type, gluon and force jigsaw fitted together….You have explained the mechanisms involved with lucid clarity…Thank you so much Arvin.👍

[@meneerjansen00]

Thank you for explaining this in as way that I _finally_ understand it.

[@hansweichselbaum2534]

Absolutely amazing! For me, as a chemist, the smallest things in the universe are protons, neutrons and electrons.

[@DavidCarter-ib3vw]

Is there a way to make water out of hydrogen and oxygen? In case we establish a colony on the moon or Mars? Where will the water come from?

[@jimmyzhao2673]

@@DavidCarter-ib3vw I heard asteroids and comets contain a lot of water. Maybe lassoing and deorbiting them down to the colony could work.

[@jimmyzhao2673]

These animations are *fantastic* It helps me to understand things better.

[@radar536]

Amazing explanation. Thanks!!!

[@IncompleteTheory]

This is a fantastic explanation. Thanks for uploading!

[@KF-bj3ce]

The only time this was explained so clearly. It is now no longer a mystery. Thanks

[@MrWildbill]

Thanks for another great video. One of the things that I have never been able to wrap my head around is why neutrons decay into protons 14-15 minutes after they leave a nucleus and yet the proton will essential last for ever (at least as far as we know)? What is going on in a nucleus that allows neutrons to last essentially forever like a proton, that changes once they are free? I have read numerous answers but they tend to just gloss over it or go into deep math and gobbledygook, can you give a very high level explanation?

[@ArvinAsh]

That's a great question which gets into quite complex QCD. But let me attempt to answer that in two way. The simplest answer is that a free neutron has more energy stored up in mass than does a proton plus an electron plus an electron antineutrino, which is what the neutrino decays into. A neutron, like all processes in nature, is always tending towards its lowest energy state, and so the lower energy state of the free neutron is to be in the form of a proton, electron and antineutrino. A bound neutron actually has slightly less mass than a free neutron. It becomes more stable in nucleus partly because of the mechanism I described in the video, which is due to the color charge interaction between nucleons. Here is the above stated in a slightly different way by another contributor: There is a subtle difference between the binding energy of one up and two down quarks as compared to the configuration of two up and one down quark. As a result, mass of a neutron is slightly higher than that of a proton so a free neutron “tries” to drop to this bigger binding energy configuration with emission of electron and antineutrino. The situation becomes more complicated in the case of a nucleus where inter nucleon interactions enter the game, so some configurations of neutrons and protons become stable.

[@ProfessorBeautiful]

@@ArvinAsh ".... which is what the NEUTRON decays into...." ?

[@ArvinAsh]

@@ProfessorBeautiful A free neutron decays into a proton, electron and an antineutrino.

[@MrWildbill]

@@ArvinAsh -- Both of those explanations were great and compliment each other well, thank you, I think I am starting to get it better. So a neutron in an atom has a lower energy state because it is always exchanging gluons and a free neutron does not exchange gluons, when it leaves, is stops this exchange and the mass increases slightly and the neutron then drops to it lowest energy shape by emitting an electron and antineutrino. Is that close?

[@korakys]

@@MrWildbill After reading Arvin's reply that is exactly how I would rephrase it too. This was a very interesting question and a good answer.

[@Posesso]

Really really good. This I didn't know, and you explained very well, being a complex topic. Hats off.

[@djelalhassan7631]

Beautiful Explanation

[@terrifictiger]

Arvin Ash is brilliant as always in explaining complex ideas in physics in such a lucid manner. Thanks Arvin

[@ProactiveForce]

Amazing!

[@suyapajimenez516]

You explain everything beautiful. The art work beautiful too. Thanks Arvin

[@MichaelBurnsGuitar]

Well I'm glad somebody understands it! Great videos, very clear with good visuals

[@nHans]

I like it that whenever you say "fundamental forces," you immediately clarify that they are "fundamental interactions." I too have started calling them "interactions." I now use "force" to only mean Newtonian force, that is, things that cause a change in momentum. Physics becomes a bit less confusing that way! Oh, and I've started saying that there are *_five_* fundamental interactions-the fifth being Higgs. After all, it accounts for fully 1% of the mass of baryonic matter-about 600g for an average human!

[@prich0382]

Gravity is not a force so it's quite confusing saying it's one of the fundamental forces aha

[@ivoryas1696]

Niranjan Hanasoge I was gonna ask what the Higgs Boson _does,_ but I feel like _he's got something for that!

[@nHans]

​@@prich0382 Here we go again. A lot of other people have said the same thing in the comments. And Arvin has replied to many of them explaining why we call gravity a force nevertheless. To save you the trouble of searching through the comments for his explanation, I'm copying and pasting his reply below: ❝ In physics, every force can be described as a gauge theory, which is a form of geometry. Gravity is unique among gauge theories because it is universal - it applies to everything. This is different than electromagnetism for example, because the gauge theory, or geometry describing EM, applies only to charged particles. This leads to interpretations by people who may want to impress you as "gravity is pure geometry." But it is still a force. Stand on a scale, look at what the scale says - 180 lbs? That's a force. Drop a weight on your foot (don't actually do this). What do you feel? That's a force. Furthermore, we know that General Relativity is incomplete. GR breaks down at quantum scales. Most physicists believe that a more complete theory of gravity, which would also explain its mechanism as quantum scales, would show gravity to be no different than the other three forces. And so gravity is typically referred to as the "force" by nearly all physicists. ❞

[@nHans]

​@@ivoryas1696 Arvin has uploaded several videos about the Higgs Boson (which includes the related Higgs Field and Higgs Mechanism). As have several others. You probably remember: The Higgs Boson - dubbed the _God Particle_ - was a big deal a decade ago, though now it's just another boson in the Standard Model. In short, all the particles of the Standard Model-except photons and gluons-have mass because of the Higgs Boson, Higgs Field, and Higgs Mechanism. Without Higgs, they would be massless and flying around at the speed of light. That's why I consider it as one of the fundamental interactions, alongside Strong, Weak, Electromagnetism, and Gravity. Note that the photons and gluons don't interact with the Higgs field. Consequently they are massless, and do fly around at the speed of light. However, the mass due to Higgs is only about 1% of the mass of the atoms and molecules that make up everyday matter. The remaining mass is due to the Strong Force. When the quarks are held together by the gluons to form protons and neutrons, and those in turn are held together by the various mesons to form atomic nuclei, all that confined energy manifests as mass. There-I just summarized several hours of watching Arvin's videos! You should still watch them though.

[@1495978707]

I think it may have been helpful to analogize the strong nuclear force with the Van der Waals force, as it’s a very similar thing. Neutral charged objects still interact because of fluctuation around average

[@LuaanTi]

Absolutely. There's a lot of residual forces out there. You don't even need fluctuations; all you need is an uneven distribution of charge, regardless of whether that's a static or dynamic distribution.

[@sadovniksocratus1375]

ATOM. Atom = electron (active) + proton (passive). In simple atom, 99.9% of the space is empty, because the distance between electron and proton is 10^-10 m. But if one electron tied two protons, then the distance is 10^15 m. (closer to each other by as much as five orders of magnitude). The more complex the atom, the shorter the distance and its outer space tends to zero, while the inner field increases and becomes nuclear. All interactions (EM, nuclear, weak) are the result of the connection between electrons and protons and depend on the distance (and conditions) of interaction. These interactions obey Pauli's law: "There can be only one electron in an atom: simple or complex."

[@VicMikesvideodiary]

@@sadovniksocratus1375 " These interactions obey Pauli's law: "There can be only one electron in an atom: simple or complex." Sorry what?

[@sethrenville798]

I find it's almost better, I'm conceptually speaking, to explain the whole hadron system as being the real world corollary of an oscillator within Conway's game of life, Meaning that singular courts can't exist on their own because they are not actually a coherent object, but rather, are simply a portion of A computationally bound system that is functionally a single object, With the constant, unbelievably high speed exchange of information within them causing The energy from their probabilistic existence-as being simultaneously all 3 color charges, with varying probabilities-being collapsed into mass when they interact with one another and force an irreversible computation as to which color they currently are to occur, which we call spontaneous symmetry breaking.

[@barbaraolson6783]

You tube has really improved my understanding of math, Physics and many things.

[@owaisahmad7841]

Very effectively explained. Brilliant.

[@BryanWagner]

People like you, Sabine and others are my favorite educators. You make it so accessible!

[@cjtymczak4687]

Actually, the strong force holds quarts together, and it’s known exactly. The same is true for an atom and the electromagnetic force. The residual force is what holds nucleons together analogous to the residual of the electromagnetic force which holds atoms together forming molecules (chemistry). It’s a very complicated force which is still not exactly known. Now I do research in quantum chemistry, where we can calculate the interaction between atoms (essentially) exactly. The same framework needs to be attempted for nuclear interaction (lattice QCD is, but it’s an extremely hard problem)

[@ArvinAsh]

Thank you. I'd appreciate any other insights you might have through your line of work.

[@cjtymczak4687]

@@ArvinAsh Your welcome. Thank you for being an awesome science communicator and educator. Your always welcome to ask me questions, my specializations are many-body theory and electronic structure. Dabbled a bit with nuclear theory, but using empirical potentials which never seemed to work well. 😊👍👍

[@chriskennedy2846]

The 2 protons and 2 neutrons of a helium nucleus are packet pretty tightly. Makes me wonder if the flux tubes within each nucleon work like a subatomic version of the bonding orbitals between two atoms? In other words - in a water molecule, we can see the difference between how an H is connected to an O within the molecule itself (sp3 overlap with s to create a molecular orbital where the bonding electrons can reside in a lower energy state than if they were not bonded) vs. how H is connected to an O of a neighboring water molecule through hydrogen bonding. There appears to be a distinct difference in the two types of connections with Hydrogen bonding being the weaker of the two. And when we put enough heat energy into a pot of water - the weaker hydrogen bonds will break and the stronger molecular orbital bonds will stay intact and the boiling water will send off individual units of intact H2O molecules. So an H will feel the difference between its connection to an O in its own molecule vs its connection to an O of a neighboring molecule. So given the close proximity of a down quark in a proton to one of its own up quarks and a similar proximity of that same down quark to the up quark of the neutron right next door - how does it know to gluon flux tube with one and not the other and to meson exchange with the other but not flux tube? Is there a distinct difference "felt" by that down quark (much like the H in the water molecule) or in reality is it more like a molecular resonance structure where they diffuse out equally the gluon and meson interactions and form an energy equivalent grid much like how a resonance structure in an SO2 molecule doesn't favor one S-O bond over the other and we have 1 1/2 bond for each connection?

[@ajeethsuryash5123]

You got me subscribed. Awesome explanation. Elegant narration.

[@COTU9]

That video was great! Thanks for putting that one together!

[@sacredkinetics.lns.8352]

Great explanation. 👶 Thanks a bunch.

[@JustaReadingguy]

Very well done. Now could you give the experiments supporting the theory? That would be very amazing.

[@ArvinAsh]

If you read the History section of this article, it will give you an idea of how this theory evolved including its validation: en.wikipedia.org/wiki/Quantum_chromodynamics

[@lemonke8132]

wow you made this really easy to understand!

[@elliotjones3098]

amazing explanation, kudos !!!

[@mdavid1955]

Very informative...A question, what happens to the Mesons? Would a Quark-Anti Quark annihilate each other🤔?

[@ArvinAsh]

Yes, but they last long enough for the inter-nucleon interaction to take place. The annihilation limits their reach so they are only effective at short distances.

[@NitemareMoon]

Explaining quantum physics in these simple terms is very beautiful in its own way. Our bodies are the result of different colored forces keeping each other in balance at an infinite pace. Like a strange yin and yang

[@theinquiringminded6952]

Amazing explanation!

[@comelytravel]

Great video well explained

[@Whatisthisstupidfinghandle]

Ok, I learned two things today 1. How this applies to Neutrons. Never knew how this worked 2. There is a Strong Force and a Strong Nuclear Force. Didn’t know they were different things. 2a. But now I’m confused. If they are different things then why are there 4 forces and not 5. I don’t get it

[@ArvinAsh]

Strong nuclear force has a distinct mechanism, but it emanates from the same strong force that keeps quarks in nucleons. It is not a different force, just a residual form of the same force. If you see the latter part of the video, I explain why mesons form - it is because of a residual color charge.

[@Whatisthisstupidfinghandle]

@@ArvinAsh thank you ! I will try watching that part again

[@jasonwiley798]

But one big question remains: what exactly is color charge, and for that matter electric charge. Whoever figures that one out gets a Nobel prize.

[@DFPercush]

@@jasonwiley798 PBS Space Time has some good episodes about that topic. "What If Charge is NOT Fundamental?" "How the Higgs Mechanism Give Things Mass" (it connects to the whole symmetry topic) "Quantum Invariance & The Origin of The Standard Model" "Noether's Theorem and The Symmetries of Reality" I'd post links but KZbin is funny about that sometimes.

[@renscience]

Forces are not fundamental. It is typical media gibberish and even technical people get caught up in it sometimes. Forces are results of more fundamental things interacting as this video shows. Forces are an exchange of energy.

[@balazsadorjani1263]

Wow! I never knew that the strong force and the strong nuclear force are two different things. It explains a lot. Thank you, wonderful video, as always! So impressive, how you manage to give an intuitive grasp about incredibly complicated theories! That's exactly why I love your channel.

[@diegofernandez4789]

Thanks Arvin. Complex stuff easily explained.

[@VenturiLife]

This is a great explanation.

[@meltingturret3208]

As always excellent! Higher resolution graphics also? Thanks. But is anyone curious as to why this process seems so complicated? How did the universe come up with such amazing combinations.

[@nurkleblurker2482]

This was one of the best explanations of something extremely complicated. Arvin is a better science communicator than Neil Negrasse Tyson.

[@declup]

N. D. Tyson, I've observed, tends to rely on charisma. I think his primary goal, perhaps only subconsciously, is to spark enthusiasm in others rather than to instruct. And so he often relies on a lot of emoting and imprecise hand waving. (However, to some extent, Tyson is limited by his preferred medium. He seems to gravitate toward interview-like settings, which make conveying the details of complex physical phenomena pretty difficult. Arvin Ash's scripted visual presentations are the better choice.)

[@HeWhoRemenso]

They are both great and do an equally important job within each's personal situation.

[@Eleuthero5]

This video is my favorite explanation of QCD. Thank you!

[@user-bh7uf9ud5p]

Really appreciate your work

[@dianamccandless7094]

I graduated with a Bachelor's in Physics 27 years ago, but I was a very poor student and I didn't understand or retain much Quantum. I'm so glad to be able to be exposed to this in an easy-to-visualize way. The wording got pretty CRAZAY there for a while, with Anti-Blue and Anti-Down and can't help but wonder what this would be like with a little marijuana edible.

[@romaincorthesy6896]

It is crazy great 👌

[@theultimatereductionist7592]

Things I learned in this video that NO OTHER KZbin SCIENCE COMMUNICATOR has ever mentioned and that I never heard of before: 1. There's a distinction between "the strong force" vs "the strong nuclear force". 2. 12:53 imperfect neutrality. (I have to re-watch to understand under what condition this imperfect neutrality occurs.) I am not talking about serious textbooks used by physics majors.

[@alwaysdisputin9930]

Veritasium's video 'Your Mass is NOT From the Higgs Boson' says imperfect neutrality is due to quantum fluctuations. I think maybe what's happening is the gluon field is constantly changing with particles popping into & out of existence. The fluctuations cause the neutron/proton to lose it's whiteness which it hates & so it immediately fires gluons to change the colour in order to restore whiteness but this changes the colour elsewhere & so it's like when I do a Rubiks cube: I do 1 side but it messes up the other side. This leads to a billion gluons get fired all over the place & the energy from these gluons gives everything mass like if you have (this is from PBS:) a box full of particles bouncing around & you try & push the box but as you push a load of particles strike the inside wall of the box & this makes it really hard to push the box.

[@alwaysdisputin9930]

@@lepidoptera9337 Why would spectra be fuzzy? How do you explain these gluon field fluctuations: kzbin.info/www/bejne/gGTbfaiQg7Cbors

[@theultimatereductionist7592]

@@lepidoptera9337 There. Corrected it to be clear what I really meant. Better?

[@theultimatereductionist7592]

@@lepidoptera9337 Yes you do, dearie. Otherwise you wouldn't have replied with your bullshit to my comment.

[@surendrakverma555]

Thanks for posting useful information Sir

[@lucasjeemanion]

I think I watched this video before when I first started watching your videos and things just kind of went over my head. I came back to this video and I'm watching it carefully but I am figuring it out. Watching your videos has really opened my mind to quantum mechanics, I never ever thought I would be good at this kind of thing I always thought it was out of my abilities but I am actually understanding it and I've discovered it to be a really natural skill and ability. I can sit here all day and watch stuff and so much of it is coming together! For now it's just enertainment but who knows where it might go someday! Thanks Arvin!!! YOU'RE THE BEST!

[@ArvinAsh]

Glad to hear that! QM is not as hard as it's cracked up to be, imo. Glad it clicked for you.

[@lucasjeemanion]

@@ArvinAsh Hey it wasn't me it was all you Arvin! I just sat back relaxed and enjoyed the show! :D

[@monalisapanja6102]

Why can't quarks exist independently?

[@ArvinAsh]

Because of the nature of the color charge.

[@hardik.m]

If a meson is composed of quark antiquark pair, why don't these two annihilate each other as matter and antimatter do?

[@kethernet]

They do! But it takes time. A very short time, which is why they are so unstable, and thus can't interact very far from the nucleons. Also, only direct opposites annihilate this way, so only some neutral mesons do this. The others are unstable for other reasons.

[@ArvinAsh]

Aaha...great question! It struck me that I did not mention this AFTER we finished the video. They do annihilate, but they exist long enough that the inter-nuclear interactions can take place. And because they annihilate in a very short time, this limits the range of the effect of the strong nuclear force.

[@hardik.m]

Thanks Arvin and ethernet for answering my query

[@BRANSKI-1911]

This is great! It is a simple explanation, yet very informative. Thanks for your work.

[@WooliteMammoth]

You are definitely the best at simplifying complex topics for the layman to understand. Appreciate the thought that goes into this!

[@sinebar]

Maybe the Universe itself was some kind of particle that consisted of the four fundamental forces and all the mass of the current universe but at some point became unstable and decayed resulting in a gargantuan release of energy know as the Big Bang. So perhaps the key to a grand unification of the four fundamental forces is a particle model of the primordial universe. The four fundament forces combined in one particle with an unimaginable amount of mass.

[@liquidityjoey1158]

I think so too, but instead of a particle, it's a "flux"-like energy fractal plasma thing. The parameters defining this universe, are encoded in the forces, akin to the Hindu belief of their gods representing forces that make up the universe metaphorically.

[@robertschlesinger1342]

Excellent video, as always. Very interesting, informative and worthwhile video.

[@samiaint8043]

I am glad you kept it simple and will have to watch a few of times more.

[@macronencer]

Never knew these subtle details before. Wow! I sometimes think that the stuff that goes on at these tiny scales is so absurdly complex that it must have been designed by someone who makes tabletop RPGs. What always comes to mind is: could things actually be simpler than this and still give rise to the right physics for life to evolve, or are we in a minimally complex universe for life? I find that an intriguing question.

[@jaybingham3711]

Not likely a someone. But firstly a large team of someones is more probable. Then a small group or a few. After wading through all those possibilities, then a singular someone can be assessed. Even then, what we interpret as 'design' could span numerous possibilities...everything from intentional-less origination to a adolescent alien scientist futzing around with the last gadgets and accidentally causing a pocket universe...oblivious to what it had done cuz pocket universe's are a dime a dozen in their domain and not the slight bit interesting.

[@nbrown6648]

I agree - that is to me probably the most important question in all of science.

[@Matt23488]

So, if quantum effects cause the gluon exchange inside nucleons to never be perfect, what about in a basic hydrogen atom? It has a single proton and no neutrons (yes isotopes exist with neutrons but let's consider the zero neutron isotope). What happens inside the proton? Does the lack of other nearby nucleons cause the color charge to remain neutral for the proton?

[@davidklang8174]

I know Arvin used the term "imperfectly," but it's not so much that the color charge cancellation is imperfect, but that there are always uncertainties involved. At the most fundamental level, this is all interactions between quantum fields which are never completely static.

[@ArvinAsh]

Great clarification. Thank you.

[@x4ms]

Excellent presentation. Thank you.

[@dirkjensen935]

Brilliant video, I did quantum chemistry at uni and so all stationary state solution to the schrodinger equation. I've always been a bit scared to jump into chromodynamics, but this was actually such a good intro.

[@joshuaidugboe214]

If particles tend to do actions that reduce their energy / use little of their energy, why do nucleons create mesons? Shouldnt doing nothing take less energy.

[@limbo3545]

I have asked myself the same question. It seems to contradict the law of conservation of energy, but maybe we are missing something.

[@muahmuah4135]

It would take less energy or the energy should be conserved by the conservation of energy, but a particle consists of smaller particles (in simple words) quarks... and a meson is a form of a larger particles consisting of smaller quarks consisting of proton and neutron. According to meson theory of neuclear forces, meson carrying no carge, and positive change as well as negative charge and they are converted into proton and due to proton-proton interaction energy is loss.... this is also the main reason why nucleus of atoms are able to stay together. Its a long and complicated process a and i also have omitted come process or steps but the main point is there. For full detail check out Quantum Physics for nucleus and their properties and meson theory of nuclear forces.

[@thesheldoncooper]

I'm not an expert but i think, it's because the energy apply to it to break the bond is external.

[@thesheldoncooper]

@@limbo3545 energy applied to break the bond = the energy of 2 quark and 1 anti-quark. That's why it's very difficult to seperate the quark from nucleus.

[@tommy-er6hh]

I believe nucleons create mesons because they are highly energized, which is what "causes" most of the mass(e=mcc or e/cc=m) which is higher than an electron. Since they are so energized, bouncing around, sometimes it leads to stretching/mesons. BTW, i believe that Neutrons switch into Protons and back regularly by the exchange of mesons too. Also nucleon is not so simple as shown in the diagrams, it is more of a constantly changing stew of moving gluons, mesons, quarks and anti quarks all intermingled and changing constantly.

[@edwardwood3622]

Hi Arvin, hasn’t there been suggestions that the nucleus becomes stable again at higher masses, what would be the potential reason for this?

[@cariyaputta]

Is this the infamous "island of stability"?

[@edwardwood3622]

@@cariyaputta yes, that is to what I was referring.

[@aleksandersaski5387]

You mean the island of stability?

[@edwardwood3622]

@@aleksandersaski5387 yes.

[@actioncamsports]

If I recall correctly from another video: As you pack more nucleons in, Pauli's Exclusion principle applies. This means that nucleons fill in energy levels. Some energy levels are more stable, so you get a tiny bit of trade-off.

[@SerbanOprescu]

Excellent presentation. I understood a lot, I remembered a lot.

[@James_BAlert]

Good primer Arvin, l've read so much dry stuff over the years about it, that not much of it stuck and it was in many parts impenetrable!!👍😃

[@anxious_robot]

yaaay. glue.

[@johnmckown1267]

I am confused by one thing you said at the beginning. That one of the forces is Gravity. Yet I've seen videos which assert that Gravity is _NOT_ a fundamental force, but it is the observed result of mass warping spacetime so that the "length" of spacetime towards the mass is "shorter" than the "length" of spacetime farther away, so that the path of the particle(s) involved are warped towards the mass. Or was this another simplification so that you didn't make people wonder about "where is the force of gravity"? Just curious. As always, very interesting. Wish I really understood.

[@ArvinAsh]

In physics, every force can be described as a gauge theory, which is a form of geometry. Gravity is unique among gauge theories because it is universal - it applies to everything. This is different than electromagnetism for example, because the gauge theory, or geometry describing EM, applies only to charged particles. This leads to interpretations by people who may want to impress you as "gravity is pure geometry." But it is still a force. Stand on a scale, look at what the scale says - 180 lbs? That's a force. Drop a weight on your foot (don't actually do this). What do you feel? That's a force. Furthermore, we know that General Relativity is incomplete. GR breaks down at quantum scales. Most physicists believe that a more complete theory of gravity, which would also explain its mechanism as quantum scales, would show gravity to be no different than the other three forces. And so gravity is typically referred to as the "force" by nearly all physicists.

[@pwinsider007]

@@ArvinAsh If location of a particle is probabilistic then there must be spacetime curvature probabilities associated with every location where particle has probility to exist and when wavefunction collapses then spacetime curvature probabilites also collapse to get spacetime curvature at a definite location. is this theory of quantum gravity?

[@d3tcovax]

@@pwinsider007 "On the fundamental role of massless form of matter in physics. Quantum gravity" by Kilmets A.P. has a great approach to quantum gravity that doesn't quantize spacetime!

[@iam6424]

@@ArvinAsh Sir, by more complete theory of GRAVITY do u mean a search, in theory or experiments, of "GRAVITON"?

[@____uncompetative]

@@pwinsider007 Look up 'Delayed-Choice' experiment

[@etownrule]

Learned something new today! First time it was made understandable to me. Thanks!

[@danielduarte5073]

Great information and great communication of complex subjects Thank you.

[@gene51231356]

Is an "antired quark" (one of the two quarks in the exchanged meson between two nucleons) the same as a "red antiquark", or is anticolor and antiparticles (opposite charge) two different things?

[@ArvinAsh]

Thanks for the question! Antiquarks are associated with only anti-colors. A meson which mediates the strong nuclear force is composed of a quark with color, and anti antiquark with an anti-color.

[@iam6424]

Is color a quality or a quantity in particle physics ?

[@infpail7232]

@@iam6424 Background: Bachelors in physics I’m not 100% sure how to answer your question. We refer to color kind of like how we talk about angular momentum or other quantum properties, so I would argue we treat it as a quantity. But (at least in my mostly conceptual particle physics class) we usually talked about it more as a quantity. Maybe people who specialize in the field or simply know than I do could argue why it’s definitely one or the other.

[@iam6424]

@@infpail7232 thnks... quantity seems abt ryt...Quality is more of a subjective thing....!👍🏼

[@infpail7232]

@@iam6424 yeah that’s the way I think of it but I wanna make sure I don’t give wrong advice so I wanted to leave it a little open in case someone more qualified can give more insight

[@user-dz3rd6zw4o]

Good explanation!

[@BritishBeachcomber]

Thank you *Arvin,* for another great explanation.

[@user-rx4li3bq8d]

Wonderful explanation 👍🏻

[@BrianSu]

this is very clear and easy to understand. Well done!

[@ArvinAsh]

Great to hear!

[@bigmackdombles6348]

incredible job! This is the first time I've understood any of this.

[@wakkowarner7391]

Explained simply and I'm still going to have to watch this several times.

[@MitzvosGolem1]

Excellent 👍 I send this to others.

[@kartikeypatel7426]

Well information. Good show.

[@basheerkadhim7213]

Incredible explanation and animation! , thank you Arvin Ash

[@memoi6308]

Awesome video. Thank you!

[@robertschlesinger1342]

Excellent video. Very interesting, informative and worthwhile video.

[@johnfox9169]

A tremendous presentation. Very well done!!