"Angela Collier is my favourite KZread science communicator" - Albert Einstein

@BrianFedirko

15 күн бұрын

this quiote, I trust is from Uncle Albert, because it's true. Gr8! Peace ☮💜Love

@andressigalat602

15 күн бұрын

"i was going to do that joke, but you got ahead of me." - Albert Einstein's first cousin once removed

@GSBarlev

15 күн бұрын

​@@andressigalat602in other words, "A Einstein?"

@dsracoon

15 күн бұрын

"Angela told me Feynman was a dumbass" Albert Einstein. Am I doing this right?

@pinocleen

15 күн бұрын

"QCD on the lettuce" - A.E.

The video really delivers on its promise, at the beginning of my shower I didn't understand QCD and at the end of my shower I still do not understand QCD.

@idontwantahandlethough

15 күн бұрын

SUCCESS!!

@thomasrivard9772

15 күн бұрын

You spend nearly 40 minutes in the shower?

@scolton

15 күн бұрын

@@thomasrivard9772 no, but I do spend about 25. shaving takes a while 🤷‍♂️

@mallninja9805

15 күн бұрын

@@thomasrivard9772 You don't??

@anguskeesbury7278

15 күн бұрын

Glad i am not the only one who watches these in the shower

"You can't explain it to a six year old because it takes 4 years of undergrad and 4 years of grad school-" Ok, so they must be at LEAST 8 years old. Got it.

@aidanwarren4980

15 күн бұрын

Being delivered from the womb straight into Physics 101

@DamienPalmer

15 күн бұрын

@@aidanwarren4980 Get that fetus into AP classes pronto!

@bartroberts1514

15 күн бұрын

Takes about sixteen hours to teach all of the coding needed for simulation, though. PDEs, if you cut out the timewasting geometry, accounting math, and trains leaving Chicago, another three months. The real issue is all of QM is just models, and what's behind the models is only vaguely represented by all of QED and QCD, so possibly a six year old, undistracted by all the noise adults have in their heads might be Mozart, and all of us Salieri.

@scarlettjoehandsome6130

15 күн бұрын

​@@aidanwarren4980I knew that guy

@shApYT

14 күн бұрын

@@bartroberts1514 8 years + 1 day

"Those are cartoons. They're not math." Angela shoving a category theorist into his locker.

@bohanxu6125

15 күн бұрын

shoving mathematicians into lockers? well... that's what physicists do on a daily basis because the mathematicians keeps bickering about rigorousness or something

@raum_dellamorte

14 күн бұрын

I laughed so hard a frictionless spherical cow shot out my nose, keeping in mind that I only say that to simplify the math.

@penttierareika4837

13 күн бұрын

Sad Oliver Lugg noices

@WhiteThunder121

13 күн бұрын

@@penttierareika4837 Oliver Lugg can define the set of all things that make you feel pain

@fariesz6786

13 күн бұрын

_•said monadic noises•_

“Albert Einstein catching strays from Dr. Collier is one of my favorite things about this channel.” - Mark Twain

@rudyj8948

15 күн бұрын

Damn, many illustrious thinkers on here watching A Collier, i had no idea

@savage5757

14 күн бұрын

1:10 you can't believe everything that is written on the Internet © Einstein, 1990 🤣

@andyk2181

13 күн бұрын

"Something about that smells so bad it's not even pong" - Wolfgang Pauli

@dannydetonator

10 күн бұрын

"I hear the voices of vegetables" - A. Jones

Watching at 2x speed so I can not understand QCD in less than 20 mins

@xponen

14 күн бұрын

By watching at higher speed, it actually enhances understanding because all points are presented temporally closely together, this mitigates issue like 1) low memory retention (memory fading before all points are presented) and 2) ADHD by focusing all attention at shorter time frame.

@thomasj.treder7971

14 күн бұрын

@@xponen Thanks! I'd been steadying myself to rip through at 4x -- *or more!* -- so I could not understand QCD even faster than my peers. Now that I know it won't work, I can get ignorant about something else instead. Saved my afternoon!

@TheDemethar

9 күн бұрын

you forgot to give it to the next person

@freddan6fly

9 күн бұрын

Take a big drink on next party and explain it to someone not nerding physics. They will really understand it.

I would like to propose that "Quantum Gastrodynamics" is a way better term for weak force flavor interactions.

@thenonsequitur

15 күн бұрын

That would legit be a better name.

@dashoc9430

13 күн бұрын

Oh, the flatulence jokes just waiting to be told… :P Just in case it satisfies anyone's curiosity, if we were to be strict with our Greek roots, I believe the topic would be called "quantum geumodynamics" - "gastro-" more precisely comes back to "stomach"!

@mal2ksc

13 күн бұрын

@@dashoc9430 But cooking is known as "gastronomy" when attempting to sound important. I say they're trying to incite chaos along the lines of cosmologist/cosmetologist. About the only thing those two professions have in common is that they both need proficiency in Photoshop.

@dashoc9430

12 күн бұрын

@@mal2ksc I don’t know exactly what the OP’s intentions were, but I took their comment to be humorous (and found it funny myself). My comment isn’t meant to negate it, but to complement it. Like the neutron to the OP’s proton, or the side to the their main :)

@GlennElert

10 күн бұрын

"Gastro" (γαστρο) is Greek for stomach, not flavor. Quantumstomachdynamics?

I don't know if you have ever tried to explain something to a 6 year old, but they will ask you why about a thousand times while you are explaining something. To me, this is the root of the quote. It is not about being able to get the 6 year old to understand or have them be able to explain in the future. It is about being able to answer all of their why questions. If you can accurately answer all of their questions then you fully understand the subject.

@freddy4603

15 күн бұрын

I wish this comment was the most liked one

@Michael-kp4bd

15 күн бұрын

And chances are that you do not _fully_ understand any topic, and this is one of the most effective ways to recognize the things you don’t.

@5naxalotl

14 күн бұрын

i want to give you half marks for this. i feel like the skill einstein is talking about is the ability to conceive of a useful model that can be built out of simple chunks in a recursive process where each step can be stamped as an image in a small mind. consider one of those dog dancing competitions, for example, where the trainer has trained the dog in an inordinate number of little elements, including the stitches that link them into sequences. dumb dog, complex result. however, i also know exactly what you're talking about and i think it's an admirable skill to be able to answer a child's but-why questions until the child is exhausted before the adult. this is a different but similar process of being able to package concepts for a small mind, and requires a really secure sense of philosophy to understand all things in terms of well defined components. the difference though is that in one process the adult is controlling the structure because they can see what the end point is and how to get there, and in the other process the child is allowed to drive. i realise it can be a fine distinction

@Michael-kp4bd

14 күн бұрын

@@5naxalotl great elaboration. Of note though is that Einstein did not say that quote. Is there a different one you’re referring to?

@meesalikeu

13 күн бұрын

@@5naxalotlyou never let a child start on that path without pressing them to tell you what they think or to give you a guess why first - that tends to slow the why why why’s down.

> sign up for a qcd lecture > Ask the professor if it's really about qcd or if it's just qed > They don't understand > Prepare a half hour KZread video about the difference between qcd and qed > They laugh "it's a qcd lecture" > Attend > It's all qed

@dominicellis1867

13 күн бұрын

The last 10 seconds is the professor saying QCD is beyond the scope of this QCD lecture.

"Doesn't that suck for Einstein?...People just make stuff up and they say Einstein said it." -Albert Einstein

@analoghabits9217

15 күн бұрын

always refer to yourself in the third person - AE

@Flesh_Wizard

14 күн бұрын

"my balls exploded" - Albert Einstein

The more I listen to Dr Collier, the more I realize I don't know shit about fuck but also the more I enjoy realizing this about myself. Dr Collier is a superhero. Her power is knowledge. Her secret weapon is an anti-crackpot-Dunning-Krueger-syndrome-theorists mischievous smile. Thank you so much.

@clvr51

15 күн бұрын

Dude this is pure gold. I agree with every single word and laughed my ass off from start to finish. Hats off to you my friend.

@werdnarotcorp8991

15 күн бұрын

@@clvr51 Me too.

@werdwerdus

14 күн бұрын

you were able to finally put into words how I've been thinking about her, perfection

@paavobergmann4920

9 күн бұрын

Yup. That.

My mental model of the relative complexity: QED: watching 2 or 3 billiard balls run into each other on a nice smooth pool table. QCD: watching a writhing ball of spaghetti the size of the solar system and oh yeah, the spaghetti is moving at nearly the speed of light and is made up of super-powerful magnets.

@Zeroisoneandeipi

20 сағат бұрын

I think I can summerize QCD. It is a game where a lot of 6 year old quarks spin on thier hands or feet or jump up and down. They wear red, green or blue T-Shirts, some of them are a bit strange but others are charming. Then there are other players which can use glue to catch the quark players. The rules who can catch whom are complicated, you have to consider the color of the shirts, how they are spinning, relativistic effects and the probability of sun shine during the game. The rules are so complicated that there is no way to calculate the exact outcome of the game you can only do some computer simulations. And I forgot to mention that the best players can play as bosons which makes everything more complicated.

“W boson?? More like L bozo”- my attempt at a joke

@MM-vs2et

15 күн бұрын

L elementary particle

@jaspershepherdsmith9047

14 күн бұрын

It's a good bit, congratulations.

@douggschmiddy9950

13 күн бұрын

Your attempt at a joke? more like your success at a joke. - my success at a joke

@user-en5vj6vr2u

Күн бұрын

“What the fuck is a W boson” -Albert Einstein

“ I’m saying words but math math math.” I think I need a T-shirt that says this.

@mallninja9805

15 күн бұрын

I'm procrastinating when I should be studying for my differential equations final exam tomorrow, and I saw this comment just as she said it. I feel this sentence in my soul...

@ypey1

15 күн бұрын

Einstein said that

@stephanieparker1250

15 күн бұрын

@@ypey1 I knew it!

@stephanieparker1250

15 күн бұрын

@@mallninja9805 good luck on the exam! 🙌

@werdwerdus

14 күн бұрын

please ❤ but a tank top haha

Einstein once said: "I have predicted many things in my life. My theory can predict Mercury's precession. My theory predicts black holes. But the prediction I am most proud off is that 12 year olds will incorrectly attribute quotes to me on the internet."

"wait, this video has nothing to do with war. why am i here?" - Sun Tzu

"you don't think the 5 year old understood machine learning, do you?" not even that far into the video and i'm already cracking up

@GSBarlev

15 күн бұрын

"Don't go around grabbing five year olds." -Angela Collier, science communicator

@amy_grace

15 күн бұрын

"Explain machine learning, CHILD!" 😂

@alphacat4927

15 күн бұрын

Yea she is really funny.

@kaiserruhsam

15 күн бұрын

I think that 5 year old understands it better than the fanboys and business morons

At CalTech in 1970 (and probably in his books later) Feynman described trying to tell his father, an intelligent layperson, about what he did. I remember Feynman telling how, when his father asked “when the neutron becomes an electron and a proton, was the electron always there ‘inside’ the neutron?” “And I couldn’t explain it to him.”

@idontknowwhatahandleisohwell

15 күн бұрын

Hell, if I could explain it to the average person, it wouldn't have been worth the Nobel Prize."-Richard Feynman.

@RicardoMarlowFlamenco

15 күн бұрын

But he did explain it to him. via his son talking about the “word bag” in his stomach that ran out of words. 😂. But maybe he got that analogy post 1970, yet it was a problem solved.

@dv9051

15 күн бұрын

I remember someone asking if there was an electron inside the nucleus during beta decay. This derailed the lecture, and the question never was really answered.

@vegapunkrecords

15 күн бұрын

Does anyone have a source for this? Would really like to read/watch the full speech/lecture.

@MattMcIrvin

15 күн бұрын

I can explain that! I'd just say "no". (that's close enough to being the right answer)

I'm really glad that this professional science communicator was able to ensure I understood that I do not understand QCD.

I like Feynman's opposite quote: "If I could explain it simply, it wouldn't be worth a Nobel Prize."

"I never said half the things I said." - Yogi Berra

@smoceany9478

15 күн бұрын

"i never said half the things i said" - babe ruth

@GSBarlev

15 күн бұрын

"First time?" -Mark Twain

@misterjaxon2559

15 күн бұрын

I wonder if he really said that.

@Sam_on_YouTube

15 күн бұрын

Berra actually said a LOT of really funny things that are well documented. There's a bunch he didn't say, but I think that one is real.

@ad3larde

15 күн бұрын

I think that quote was mine - Ghandi

When I was 6 years old I would get into trouble for mixing the colors of my Play-Doh. Imagine my horror if someone had tried to teach me that it was ok for quarks.

@GSBarlev

15 күн бұрын

Physics parents: "No! You don't have the same quantity of red, green and blue! That's illegal!"

@AdrianBoyko

15 күн бұрын

You should read about how your brain perceives colors. You’ll probably be so traumatized that you’ll gouge your eyes out.

@DamienPalmer

15 күн бұрын

@@AdrianBoyko So... you *shouldn't*.

@AdrianBoyko

15 күн бұрын

@@DamienPalmer I already did 😵

@raum_dellamorte

14 күн бұрын

Hold on... I really think we need to go back to the maths here so you can more fully grasp how everything you know about Play-Doh is wrong.

One of the problems is that the approach that makes the leap from QED to QCD seem simple and natural is a really mathematically abstract one, where you take *gauge symmetry* as the most important thing that determines the whole theory. Usually when you study electromagnetism in a quantum mechanics class, gauge symmetry comes in kind of late as an advanced topic. If you express electromagnetism as potentials, you can do things to the potentials and simultaneously do something to the phases of the matter wave functions, and it's unchanged even if you do it differently at every point in space-time. And then you turn it on its head and say that gauge symmetry is what *determines* electromagnetism--you start with the relativistic QM of matter particles, then add gauge symmetry and the potentials have to come in, then you somehow breathe life into those and treat them as aspects of a physical field and you've got QED. Then you say, well, the gauge symmetry involved a mathematical object called a Lie group, and for QED the group is the simplest nontrivial one you can use, "U(1)", which is actually the same as a circle (messing with phases of the wave function, which go in a circle). Then you go from "messing with the phase" to "messing with some multidimensional space of color charges", which is a different Lie group, and QCD falls out, and then you mess with other quantities (the "flavordynamics" stuff Angela was talking about) and a big chunk of the Standard Model falls out. And whether the force carrying field has charge has to do with whether the group operations are commutative. But the class has this big mountain climb to even get to that point and it's very abstract. How do you even do that in an elementary context? I haven't quite figured it out. I recall Heinz Pagels trying in his book "The Cosmic Code", but it was a stretch.

@Lolleka

15 күн бұрын

You don't. You just don't ask anyone that hasn't already climbed lots of mountains to follow you on a tour of the Seven Summits.

@MattMcIrvin

14 күн бұрын

@@Lolleka oh yeah, and then Heinz Pagels died falling off a mountain

@sfitzsi

14 күн бұрын

Great explanation of the complexities of communicating QCD!

@DavidvanDeijk

13 күн бұрын

Thanks, hope this is true because then i learned something

@MattMcIrvin

13 күн бұрын

@@DavidvanDeijk This is how all the forces in the Standard Model are constructed--it's all gauge theory. The part I left out is that if you do this you get force-carrying particles that have no mass, but the W and Z particles that carry the weak force are very massive, and that's where the Higgs field comes in. Even general relativity is a different kind of gauge theory, where the gauge transformations are on space-time.

I'm extremely grateful to this video for showing me that a Saturn V plushy not only exists but is now also in my online shopping cart.

@mk1st

12 күн бұрын

Plushy? I thought it was one of those wobbly AI generated things.

QCD is the most complex, sciency sounding name I've ever heard. Even more than the mathematics of quantum neutrino fields --Albert Einstein

@AstarionGrle000

15 күн бұрын

😂

@Rockyzach88

15 күн бұрын

Now start mixing different cool sounding sciency professions together. How about Quantum Computational linguistic Chromo Dynamics.

@Zappbrannigan83

15 күн бұрын

@@Rockyzach88 you've embiggened science with your cromulent vocabulary. 🫵🫡🍻

@ohno5559

15 күн бұрын

Mathematics of wonton burrito meals. Got it.

@Zappbrannigan83

15 күн бұрын

@@ohno5559 in ur proposal, are u going to dynamically cram wontons into the burrito? With a glueon layer of cheese? Or will the burritos be inside the wontons?

One could make a great debate between Lincoln and Einstein with all the things they never said.

@KitagumaIgen

15 күн бұрын

You're quoting Socrates, right?

@FPSIreland2

15 күн бұрын

@@KitagumaIgennah that’s Plato

@GSBarlev

15 күн бұрын

What frustrates me about comments like this is that quotes wrongly attributed to Lincoln and Einstein are, in fact, wrongly attributed to Mark Twain! 😉

@zamplify

15 күн бұрын

Lincoln had a secretary named Einstein. Einstein had a secretary named Lincoln.

@chrisl6546

15 күн бұрын

With Yogi Berra as moderator

I love relearning all this stuff. When I studied it 40+ years ago unitary symmetry was the model and quarks were still somewhat controversial. Now everything's changed and I'm learning from people half my age.

In this video, I learned that without gluons my Elmer's glue wouldn't work.

@AdrianColley

14 күн бұрын

I mean yes.

@xponen

14 күн бұрын

Elmer's glue using photon (QED), while atomic nucleus using gluon (QCD).

@yarondavidson6434

14 күн бұрын

Quite the opposite. Without gluons there won't be even a single material that your Elmer's glue (in the theoretical case you could get any) would fail to work on.

My explanation of why QCD is hard (for physicists to do, which is kind of a different matter from why it's difficult to explain) is to show Feynman diagrams and explain roughly what they mean, then say: "you can always draw more and more complicated diagrams. With QED, these diagrams get less and less important, so you can often get away with ignoring them past a point, and get a pretty good answer by only computing the simple ones. With QCD, the complicated diagrams get *more* important, so you can't get away with that kind of trick."

@r3lativ

15 күн бұрын

That's a great point.

@dinobotpwnz

15 күн бұрын

Exactly. The main reason is the sign of the beta function and that was missing from the video.

@modolief

15 күн бұрын

Very informative, thanks!

@pierrecurie

15 күн бұрын

Even ignoring the Landau pole, the # of diagrams grows too fast. It's an asymptotic series. The QED coupling constant is small enough that a reasonable # of diagrams leads to a "good enough" answer.

@frederf3227

15 күн бұрын

QCD is the 1+2+3+4+... = -1/12 of physics?

I used to have an abstract algebra professor who told us that you don't understand a proof until you can explain it to your teddy bear.

@birdbrainiac

15 күн бұрын

If the teddy bear understands your explanation, you have an entirely different problem on your hands.

@xantiom

15 күн бұрын

This is valid. In programming it is known as "rubber duck debugging" which is used for solving problems, at which you get into an answer while you are trying to describing the problem to someone else. To exploit this phenomenon, instead of bothering a friend to listen to you, they place a rubber duck and explain their hurdles and where they are stuck until you get an insight while you are bitcjing about it.

@Michael-kp4bd

15 күн бұрын

@@xantiommy work just had an outing and we ended the night at Dave & Busters, where one of my coworkers used all her credits on the rubber duck claw machine (honestly best value, cuz your credit doesn’t get used until you get a duck). Anyway, she gave them out and now I have an actual rubber duck to rubber-duck with as I develop. My coworkers didn’t know the term, and I showed them the wiki article, and the article’s main picture shows the same lil’ guy I got! Anyway, my troubleshooting ability is about to skyrocket

@AntsanParcher

11 күн бұрын

This makes way more sense than the saying it's a spoof on.

I take notes on your videos. Let's start a podcast.

@marko1395

13 күн бұрын

10/10 would watch.

@billyalarie929

2 күн бұрын

PLEASE I NEED THIS

If your average 5yo child is already familiar with advanced linear algebra, complex matrix calculus, Lagrangian mechanics, Dirac's quantum field equations, non-abelian Lie groups and the Yang-Mills gauge theory, yes, I think you can explain QCD to them.

@Wick9876

15 күн бұрын

Think of how stupid the average 5yo is, and realize half of them are stupider than that. They may not have even mastered their Dirac.

"you really think someone would do that, go on the internet and tell lies?" -Aberham Lincoln

@jocabulous

15 күн бұрын

Aberham Linkin

@lbgstzockt8493

15 күн бұрын

@@jocabulous Aberham Linkin Park

@quarkonium3795

15 күн бұрын

@@lbgstzockt8493Abracadabrahamilton LinkedIn

@conscientunit1157

14 күн бұрын

-shinzo abe lincoln

@loveless-savage

13 күн бұрын

I think this is misattributed, didn't Einstein say this?

“Quantum Flavor Dynamics” sounds like the motto of a New Age Guy Fieri

@dekumarademosater2762

15 күн бұрын

"Quantum Flavour Dynamics" needs a t shirt. A lickable t shirt.

@clvr51

15 күн бұрын

I instantly thought it'd be a sick name for a math rock band lol

Hi Angela! First of all, I loved the video! But I wanted to add on to what you said at the end -- that QCD can only be evaluated numerically (via lattice QCD). I just wanted to say that absolutely not! Most experimentally-relevant calculations of QCD are done completely analytically. It's literally what I did for my PhD and the ATLAS collaboration was even able to measure and compare to our analytical predictions. I know this isn't well-known in the community, so here's a bit of background: The idea that QCD can't be computed perturbatively ("knowing which Feynman diagrams matter") is because the strong coupling alpha_s is very large (0.118 at 91.2GeV, compared to 0.007 of QED). However, since alpha_s runs, it gets smaller as you go to higher energies (asymptotic freedom, as you mentioned in the outro). By the time that you get to experimentally-relevant energies (i.e. 13.6 TeV at the LHC), alpha_s is again small enough to be able to treat the theory as being perturbative. In fact, at experimental energies QCD is basically just fancy QED. So, recap: At small energies you need lattice QCD to say anything tangible, but at high energies QCD is just a regular perturbative theory. There is one additional complication however: The fact that colliders collide protons, which are low-energy QCD objects, and not quarks, which can be treated perturbatively. It turns out that this wrinkle gets handled by something called a "parton distribution function", which essentially connects quark/gluon cross-sections with proton cross-sections. In fact, because of this, your typical QCD experimental prediction pipeline looks as follows: 1) Experimentalists measure these parton distribution functions at other experiments, 2) A theorist computed the cross-section for some QCD process completely perturbatively/analytically, 3) They multiply their result with a parton distribution function. And voila, you've got yourself a phenomenological prediction for a proton-proton QCD experiment!

@sillygoofygoofball

15 күн бұрын

thank you for saying this, that really bothered me

@sfitzsi

15 күн бұрын

Fantastic comment!

Thank you. Fun explanation. When I got my Ph.D in physics, we were searching for quarks. I heard Feynman, Gell-Mann and others speak on Unified Field Theory at an APS meeting in D.C. I gave my first paper as a grad student and went down stairs after the talk. There was a standing room only crowd in the Ball Room. I wiggled in and found a place to stand and not block others. After the intro, Feynman spoke. Feynman had long hair light brown hair down to his shoulders. He was young and spoke with the accent of a Brooklyn truck driver. He opened with a pretty bold statement that was close to "I don't know what you know because I never read the literature". Someone gave his talk (Gell-Mann?) writing on an opaque projector with a black marker blocking 50% of the image (equations) on the screen with his head. We have still trying to do Unified Field Theory. Fun video.

I mean, which 6-Years old cannot understand irreducible representations of SU(3)?

@3zdayz

15 күн бұрын

Still prefer R3. A simple sphere and no tangrnts

@steffenbendel6031

15 күн бұрын

A 6 year old in a woke school.

@bridgetown1966

15 күн бұрын

this gotdamn american school system... when i was a kid, it was the three R's: readin', ritin', irreducibl' representations of SU(3)

@rynabuns

15 күн бұрын

@@steffenbendel6031Can you explain "irreducible representations of SU(3)" to a 6 year old or are you "woke" as well?

@edwinrollins142

15 күн бұрын

​@@steffenbendel6031what is a woke school and why is that a bad thing?

"Don't go around grabbing five year olds" - Angela Collier (but I'm pretty sure Albert Einstein said it first)

I think you did a great job of explaining most of the stuff and got close to describing what's hard about QCD, but didn't quite get to the punchline. The hardest part about QCD isn't that the Feynman diagrams are more complicated, or that there's so many gluons and flavors - that's an annoying thing for sure, but people can still compute diagrams up to a couple of loops (especially using Mathematica packages). The hard and beautiful thing about QCD is that if you wanna describe the inside of a proton, it just doesn't make sense to compute Feynman diagrams because what's going on inside is nonperturbative. Feynman diagrams wouldn't give a meaningful answer in any way to the problem, even if you could compute and sum all of them! That's why we need to do the path integrals with lattice QCD. You got close to mentioning this when you talked about perturbing QED, but I think it's worth pointing out as another pitfall of Feynman diagrams. Not only are they a cartoon for the math, they are sometimes cartoons for math that we shouldn't be doing in the first place for certain physical questions. (I know that the main point of the video wasn't to explain why QCD is hard, just hard to explain. But I guess my point is that it's hard to explain if you start from Feynman diagrams, precisely because they don't work in the theory. But explaining it with just path integrals might be "easier"?) Cheers and thanks for all the fun the content!

I think the important thing is you successfully taught me that I don't need to know any more about QCD. I've tried before, but now I am happy to stop worrying about it. Thanks for the video Angela!

As someone who doesn't have a physics degree and sucks at advanced math, this video taught me basically everything I'd actually want to know about qcd.

Thanks! I now have a full understanding of QCD from this 30m KZread video

@mikechmielewski386

15 күн бұрын

That’s exactly what Einstein said!

There is a reason for QCD : the subnuclear zoo. In the late 60s the number of particles discovered using particles accelerators numbered in the hundreds. QCD brought that mess down to a handful.

@billyalarie929

2 күн бұрын

“Subnuclear zoo” is one of the wildest phrases I’ve ever heard

Perhaps it's my background as a programmer, but I really don't see the problem here. For me it's kinda backward, most of the time I don't have an elegant mathematical model, or even an algorithm for a particular problem, so for me "let's just brute force (if feasible) or simulate" is the first kind of solution I go for. Finding or creating a neat algorithm that runs fast and produces the exact solution is a nice cherry on top, you use it if you already know it or if your code *must* run fast. Having a closed-form mathematical solution, a formula that just spits out an answer is like having a surprise birthday present. For me, the thought that reality doesn't fit into a math model is just a base assumption. I'm very happy to be proven wrong, but the closer you get to reality, the more factors your program must consider - the rearer such happy accidents occur. Like, generating _the_ optimal schedule for a school that considers a basic set of restrictions (no double-booking of instructors, classrooms, and students, balanced loads on students and faculty, no excessive movement across the building, etc.) is already computationally intractable. And that's all in the macroscopic world, so no wonder that we can't have exact probabilistic models for the QCD. It's kinda amazing that we can solve a hydrogen atom!

@trolleymanV

15 күн бұрын

Love this comment, I completely agree (probably also because I'm a programmer)

@jell0goeswiggle

15 күн бұрын

In addition to the NP problems, simulating natural phenomena is messy on its own. The two tests are: "is it fast (enough)" and "does it look plausible (enough)". Obviously how those are weighted varies on what you're trying to do (1 second of simulation per day is acceptable for like, Pixar, but certainly not for Nintendo). Even in the macroscopic here, there are tons of things that get commonly ignored because they play so small a part in the classical physics. (E.g. approximating friction as a simple coefficient, ignoring aerodynamics, etc. intra-molecular interactions in liquids, etc. depending on the ~~field~~ domain.)

They obviously meant explaining it to a 6 yr old Einstein.

I left school when I was 14 and even then I wasn’t great at math or science. I didn’t understand almost any of this. I still watch all your videos the whole way - there’s something so enjoyable about someone talking about a very specific topic they have mastery over.

This feels like, in molecular biology, going from understanding how certain proteins interact with other proteins or genes to developmental biology where you suddenly have 20,000-25,000 (ish for a eukaryote) points that all can be modified in many ways and exist in specific places at specific times. You can't really have an analytical explanation of multicellular development for now and im glad other stem people have similar struggles lol

"I am not a professional science communicator" says PhD with 150k+ subscribers on a KZread channel where she mostly communicates science. Jokes aside, love your content. Looking forward to finding out why my understanding of QCD is wrong. It's the one I thought I knew pretty well! Although I'm sitting here now wondering if anti-red and cyan are the same thing, so maybe not. Update: I'm not sure what I understand anymore, except this: to the chagrin of pure mathematians everywhere, Monte Carlo wins again.

This video reminds me of that time I brought a proton and a gluon to my favorite bar. We had a strong bonding experience. What a positive interaction it was.

@DJRonnieG

15 күн бұрын

😆

@ChristopherSadlowski

15 күн бұрын

Go to bed. 👉 Go to bed right now and think about what you said... 😊

@TheNeonParadox

14 күн бұрын

@@ChristopherSadlowski 🤣🤣

@dominicellis1867

13 күн бұрын

Why did the quark fall off my school project? Because I forgot to put the glue on.

There may be a lot of made up quotes of Einstein, but he is a very good frame of reference a range of things. Like how it took Einstein 4 years after getting his PhD to finally get a professorship gig. And what’s even more crazy is that it took him four years after his miracle year, after producing four seminal pieces of research that also includes his Nobel-winning work, to get a job as a professor. If it took a Nobel laureate 4 years after he did his Nobel-winning work to get the job he wanted…

@capnmnemo

15 күн бұрын

Well, maybe Mileva was busy and couldn't do the work or him.

@DanGRV

13 күн бұрын

"There may be a lot of made up quotes of Einstein, but he is a very good frame of reference a range of things." -Albert Einstein

My best understanding of that "Einstein" quote is that giving a satisfying simplified explanation of something requires a much better understanding than what you need to just feel satisfied by your own understanding.

Let's crack open the proton. (Insert gif where Donald Glover walks into the apartment and everything is on fire.)

Float like a butterfly, sting like a bee. -Allen Einstein

@MrAzulmagia

15 күн бұрын

"I don't fear the man that solved a thousand different equations, I fear the man that solved the same equation a thousand times." - Albert Eistein

@Frahamen

12 күн бұрын

Sexy, almost evil, talkin' bout butterflies in my head -Shifty Shellshock

13:26 "Behold! The field in which I grow my equations. Lay thine eyes upon it and thou shalt see that it is -incredibly complicated- barren.

@GSBarlev

15 күн бұрын

I wanted to know where this quote originated (expecting some 19th century romantic) and was wildly disappointed that the original is attributed to *Hank Green.* But then I dug further and found that, in keeping with the theme of the opener, it's a misattribution (he _popularized_ it but didn't originate it)!

Wow, you really give me hope! I’m a 66 year old retired woman and that you understand all this so well makes me happy. Thank goodness there is someone who understands this so well. Thank you.

You definitely can explain QCD to a six year old, it's just the explanation takes usually about two decades.

@roger5059

6 күн бұрын

Then you explained QCD to a 26 year old

This channel is a gift to the world. I have more than once thought about transcribing these videos, adding visual explainers to the pages, and printing them out as accessible pamphlets! (I haven't, though... copyright's a bitch!)

@DJRonnieG

15 күн бұрын

The main obstacles to these sorts of ideas are our procrastination and the excuses we make for ourselves. Copyright, shmopyright! Jokes aside, I can see how copyright is a genuine obstacle, but if you're really determined, try something short and simple. You can fit a lot of info in a tri-fold brochure (double-sided).

@tomasroque3338

15 күн бұрын

@@DJRonnieG I did make an A3 horizontal scientific poster for the "Why aliens won't be made of Silicon" video! And I mostly 'scripted' one other pamphlet of this sort too. I just wouldn't actually distribute/sell these. They're more like pet projects for myself.

@DJRonnieG

15 күн бұрын

@tomasroque3338 I hear you, I've done my own fair share of pet projects in various forms of printed material. There's something rewarding about creating something nice in print that you can hold in your hand. It's long overdue for me to make a "turtle care pamphlet". So many people adopt Red-eared sliders with precious little information about their needs. 🐢 In any case good luck and if you ever want to share any finished project, feel free to drop me a comment.

@tomasroque3338

15 күн бұрын

@@DJRonnieG Wow, I love that! I've laid out plans for a custom chess board where each piece is a different type of turtle (the movements and playstyle being analogous to each turtle's behavior and traits). But it would cost some to built it, and that's the kind of thing I'd have to pay someone else to do.

23:31 I think you make a really good point about the Feynman diagrams giving people a false sense of understanding, and especially about the whole “antimatter does not go backwards in time” thing

@GSBarlev

15 күн бұрын

She covered this in depth in another video, and while I was initially pretty... defensive? about the interpretation, because-hey, the math works-her larger point about "unphysical" solutions to equations (like Dirac Holes) has ultimately won me over and disabused me of much of my juvenile Feynman Fanboism.

@3X3NTR1K

15 күн бұрын

We should describe it differently wrong ways instead. Like: "Matter and antimatter both go forward in time, but antimatter does it walking backwards."

@Sturzfaktor2

14 күн бұрын

@@3X3NTR1K I now imagine a little positron constantly looking over its shoulder in order not to stumble into a nearby electron while walking backwards.

The pain on your face as you got out the "they're called gluons because... they stick... things together... like glue" xD

I have been trawling various wikipedia articles every so often for years trying to understand the "but why" of QCD, so this is great for me

I'm so embarrassed. I used to think I understood some of this stuff. Frank Wilczeck wrote a book titled "Longing for the Harmonies" and I read it over and over and over until I was able to grasp his explanations. Now I realize he was explaining only the most basic notions of his field. He's a really good explainer. I'm just not a very good understander. Love the video!

'understanding' something is perhaps the biggest myth of physics.

@brianarodriguez2090

15 күн бұрын

This comment goes so hard

@drmathochist06

15 күн бұрын

You can understand a model just fine. But the map is not the territory; THAT'S the myth.

@zyansheep

15 күн бұрын

The word "understanding" is kinda just a disguised query for a bunch of different things that are expected of people who "understand" a concept to be able to do with the concept, i.e. explain it, apply it, draw parallels to other concepts... like for many (most) words the true underlying reality is messy and complicated, the word just represents a pattern our brains abstract that reality into for convenience. Now _thats_ the real myth!

@conodigrom

14 күн бұрын

Except Feynman spent most of his time warning us that if understand something on paper because you're not smart enough or you've not spend enough time on it or you're not seeing it in the proper way and end up thinking like "come on, it is really complex, who can REALLY understand this? but i can manage the equations and say the right words, therefore it's ok" akin to a philosophical zombie, you're only fooling yourself.

@kindlin

12 күн бұрын

Understanding buoyancy is easy, do you sink or float? Do you weight more or less than the water you can displace? It's a problem any child has asked and anybody after a couple years of school should be able to solve, assuming the boat is a rectangle or you just know the displacement. But there is so much more you could know: how the forces balance, hydrostatics, what is the force of the water made of, what is the force of gravity, what if you vary any or all of these in either space or time? Once you start asking these questions, you are now beginning to truly understand that topic.

If Feynman could have watched Angela's videos, he would have had the biggest grin from start to finish.

I think we over-emphasize the empirical aspect of particle theory, where we can't find when beta decay will happen, etc. and not that it's a probability distribution. Yes those mean the same thing, but it's a nitpick. I feel its more sufficient to my brain to say "we know that there's a 10% chance of an electron being 30 angstroms away from a point" than "we cannot actually find this electron"

@cattnipps

14 күн бұрын

I like that clarification, thank you :)

"if you hold a proton in your hand it will just chill” proton beer cozy

@user-ys3ev5sh3w

15 күн бұрын

Proton, unlike magnet, has degree of freedom in 4d, therefore repulsion between 2 protons changes in attraction. like with magnets: if to hold 2 magnets in 2 hands (dof=1) then repulsion wins, but if drop them (dof>1) then attraction wins.

@michaelprozonic

15 күн бұрын

@@user-ys3ev5sh3w but how does that keep my beer cold on a hot summer day?

@user-ys3ev5sh3w

15 күн бұрын

​@@michaelprozonicit's easy. protons starts to attract each other and make 1d lines (like with magnets if throw them on table) so one degree of freedom disappears. in that 1d line they became motionless (temperature=0)

@NullHand

15 күн бұрын

Dang, you Fizzicists are so much more laid back. Whenever I went around with too many protons in my hand I was usually told "Get that $*':$@ back in the fume hood you idiot!"

@michaelprozonic

15 күн бұрын

@@user-ys3ev5sh3w ok, working on that now. how do i fit my beer can into a 1d line though and how many protons do I need for each 12oz can? Can you tell me which aisle at Home Depot has the protons?

If a 6-year old can't explain something to me, can I understand it?

@GrantWaller.-hf6jn

15 күн бұрын

A good way to find out what they know.

@n20games52

15 күн бұрын

@@GrantWaller.-hf6jn Ha! Yes!

the steady pace and enthusiasm with which you present a really cool topic (at the pointy end of science) makes for a great video

36:22 This went very well. I now understand why I don't understand QCD. That said, I feel I have a better understanding of what is in the forest, and why I should stay out of the forest. Thanks for taking the time to make this.

Why do we fall down, Master Bruce? To learn to pick ourselves back up. -Albert Eyestine

You know we're the worst when we all come down here immediately to make up a bullshit quote only to see a million people have beat us to it.

@tylerm.8684

13 күн бұрын

-Albert Einstein

Really loved this video. One of those occasions where KZread throws up a spot on recommendation as weirdly I'd just spent my Saturday lunch time reading an article about QCD in Scientific American, possibly to the bemusement of the staff at Wagamamas but certainly to my own bemusement. Whilst I definitely didn't understand it, I did get the impression it is an exciting time for QCD theorists who seem to have solved long standing problems evaluating the strength of the strong force against distance in the limit and at low energies. Then to have this video pop up within a few hours was perfect. I'm never going to understand QCD but I feel I don't understand it on a deeper level now 🙂 - You have a new subscriber.

You definitely did reminded me of the book called «Thinking physics». It's not for 6 yo, it's for middle schoolers, but it starts with integrals and ends with quantum theory, and all of that with actual physics problems explained in a way middle schooler would be able to do them. The book is wonderful introduction to physics for younger teens, you could learn it in your 5th year of school.

1. cool glasses 2. great video yo 3. "Be the change you wish to see in the world" -- 50 Cent

@Asdayasman

14 күн бұрын

Huh I actually didn't like the glasses, but neglected to mention because I thought it was irrelevant. I guess I was wrong, glasses appraisal in the comments section is approved behaviour.

@ictogon

12 күн бұрын

Thank you 50 Cent

16:37 "Every single thing you know and touch and love can be described with qed" Put that on a T-Shirt and sell it please.

@steffenbendel6031

15 күн бұрын

But I love gravity - that keeps me grounded.

@kingduckfilms

15 күн бұрын

Yes! Also "it's all electrons babe"

@hedgehog3180

15 күн бұрын

I'm going to show up with my “The cool stuff is actually all organic chemistry” t-shirt and start an argument.

@AdrianColley

14 күн бұрын

There's also caesium-133 but it doesn't meet the "love" criterion.

@kindlin

12 күн бұрын

Also... _is mostly described with_

I want to thank you from the bottom of my heart for what you have told me in your previous videos. I am very interested in physics and I am able to learn things pretty well. I have been reading books and for the most part I felt like I understood the English explanation of what happens in physics. I knew that I would have to understand the math in order to add to the knowledge of humanity in this field. I taught myself calculus 20 years after taking it in college and getting an A- but not really getting it. I understand what I taught myself. Thinking I could get a little into the math I was hit with reality quickly. So I procrastinated and I kept using words to learn physics. THEN YOU SAID THAT IF A PERSON DOESN'T DO THE MATH THEY ARE NOT DOING PHYSICS. I hate being patronized and people worrying about my feelings instead of being blunt So thank you for being your kinda snarky self. Oh I found free MIT classes or at least the lectures online linear algebra differential integral calculus more linear algebra matrices introduction to quantum physics weave and electric physics etc. I am still in the beginning but understanding and have an opportunity to actually succeed thank you

My favorite quote about quantum mechanics is from CGPGrey: “look, ‘spin’ and ‘whirl around’ don’t mean what you think they mean. In the quantum world, words mean NOTHING, there is only MATH.”

Nice play with the spooky color balance in the video. Echoes the daunting weirdness of QCD.

Angela: definitely a professional science communicator!

The deadpan humour is awesome. Thank you for your contribution of good content on KZread :D

It is possible to know what something is at one level without understanding how it works. We don't understand how most things work, so this is very common.

One of the most enjoyable videos.ever. I read Feynmann's QED lectures given to the public, and he said that no one in the audience would understand QED, and that was okay because neither did anyone else. You captured that beautifully.

"I was too stupid to come upon such a brilliant idea as the string theory" -- Albert Einstein according to string theorists

I am studying chemistry. The moment you said "field theory" i was like: "Nope. I have no clue what those are, and if i find out i'll be stuck modeling molecules for the rest of my life. Byeeeee!!"

@gwensmosh5532

13 күн бұрын

that really is a feeling when learning about stuff in your field of study. You don't want to learn too much about something or you'll get hired to work with/study it! In urban planning, I've ignored some friends warnings against studying GIS.

Thank you for explaining why I don't understand QCD except in a vague, limited, fragmented, intuitive way. I appreciate the jargon tossed in at the end. All in all I've learned something, had a few laughs, and at least have enough information to keep asking questions.

Why is it that we’re always taught that Feynman diagrams should have time going upwards but when we actually use Feynman diagrams time is always going across?

@hayuseen6683

14 күн бұрын

Maybe because we don't read or write bottom to top, so we turn it to the side to make a linear sense of progression of the statements

One thing that bothers me just a bit, Feynman diagrams are not only used in the path integral formulation - like, you use Feynman rules all the time even if you are exclusively doing canonical quantization

First video of yours that I'm watching. I actually really appreciate the style of this video, and look forward to moving on to your other content.

As an undergrad physics student, I thought this explanation was great for me. It gives a very good window into what I might be learning eventually. As usual, amazing video!

i've been a carer for schizophrenia for around ten years, i don't have any formal qualification other than a certificate that says i've done a carers course, but one thing i learned even before the course is that when someone is hallucinating saying "you're imagining things" results in a very bad day. anyway. i treat all people as if they are mentally ill, i find that most people have hard time understanding how to tie shoelaces, never mind einstein. so in order to get your point across and have it actually register in someone else's brain, you have to put things in the simplest terms - that, say, a six year old can grasp. cos most people are six year olds, mentally. including me.

@mateostenberg

12 күн бұрын

"I treat all people as if they are mentally ill" if most people had a hard time trying their shoes, maybe your point of reference for mental illness is skewed? I get hyperbole but it's just kind of a weird thing to say

@sfitzsi

11 күн бұрын

Excellent point, you can’t effectively communicate unless you can empathetically imagine their reality and respond with good will and respect their desire for agency. Anasognosia is a very difficult feature of schizophrenia. When the way you reason is distorted you cannot reason your way out of it. It can alienate loved ones, that they can’t just snap out of it and adopt the caregivers reality, but it’s not their fault. Thanks for the work you do and for sharing your insights!

Hey I don't know how often you hear this, but thank you

"She right, I withdraw my statement and offer my congratulations." - Einstein

There is a very good quote from peter watt’s echopraxia “But people have an unfortunate habit of assuming they understand the reality just because they understood the analogy. You dumb down brain surgery enough for a preschooler to think he understands it, the little tyke's liable to grab a microwave scalpel and start cutting when no one's looking.”

Quark star superconductivity is not boring - pulsars with mass up around 2 solar masses are likely to be quark stars, and those are likely to be quark stars, and those are likely to be _color_ superconductors. If that's not wild, and exciting QCD, I don't know what is.

@Cotonetefilmmaker

13 күн бұрын

QCD is the one true QFT manifest in the world.

As an electrical(electro-magnetic?) engineer I 100% agree with the superiority of the electron over the proton. Hopefuly we can someday agree about the usefulness of the right hand rule and the passive sign convention haha

Appreciate the space between "8" and your exclamation mark when counting the number of gluon types in your table. Not leaving any ammunition for these factorial jokers 😆

Actually the channel «All Angles» gives quite good introduction of QCD with algebra and group theory, and the group theory is so simple, kindergartener would be able to understand it. Simple symmetries and basic counting and arithmetics under 10.

Can’t wait for this video to age like a proton

I have a good understanding of QVC now.

I love being taught enough to know how much I don't know

I think it's so cool that there are some types of expertise it's impossible to "dabble" in. You have to devote yourself to it, to even take the first steps. I suspect that's always been true, even in prehistory.

@hedgehog3180

15 күн бұрын

Grug likes to dabble in Clovis points but Grug cannot do that newfangled bronze smithing.