How Quarks Fixed the Mess That Was Particle Physics


Thanks to Skillshare for supporting SciShow. [ ♪ Input ] Physicists strive for simple explanations
for complicated phenomena. It’s kind of their thing. But sixty years ago, particle physics was
not simple. There were dozens of known subatomic particles
that all seemed to follow different rules at different times, and nobody knew what to
make of all of them. Then, a few physicists found the simplicity
hiding behind the chaos: quarks. And fifty years after their discovery, the
universe just doesn’t seem to make sense without them. Quarks originally helped explain a torrent
of particle physics discoveries that happened after World War II. But our knowledge of particles goes back further
than that. Before the war, physicists knew about familiar
subatomic building blocks like protons and electrons. And they knew that particles sometimes decayed: Some of those building blocks could transform into other particles, although the rules were
still being worked out. In general, though, it seemed like there weren’t
that many fundamental pieces of matter. The world was pretty simple. Then, experiments got better at crashing those
pieces into each other and seeing what happened. By 1950, the list of known particles included
pions and kaons and sigmas with new particles being found all the time. Soon, there were dozens of types of them. And no one knew why they were showing up or
how they might be related to more familiar particles. But throughout the fifties there were hints
at some sort of underlying order. Physicists quickly realized that the new particles
were much more like protons and neutrons than electrons or photons. They also noticed that the particles didn’t
come randomly. There were family relationships. For example, after the pion was discovered
they found a particle that acted a lot like the pion, but had the opposite electric charge. Then, there was a third particle that acted
like both of those, but had no charge at all. So eventually, physicists just grouped them
together as positive, negative, and neutral pions. Meanwhile, some particles, like the kaon,
took strange-looking paths through particle detectors. So scientists said that the kaon had — and
I’m not making this up — a quality called “strangeness”. And they grouped together particles with strangeness
and particles without it. There were lots of other groupings floating
around, too, with different people thinking different ones were more or less important. But in 1961, a physicist named Murray Gell-Mann
took a huge step forward. He found ways of grouping particles together
that naturally included lots of the other ways people had proposed over the previous decade. His groups came in a few different sizes,
but since they most commonly contained eight particles, Gell-Mann called his idea “The
Eightfold Way”, after the Buddhist path to enlightenment. Some of his groups were incomplete, though. For example, the Eightfold Way said that if
you grouped certain particles by strangeness, the group should have ten members. But physicists didn’t find the tenth member
until 1964 — a few years after Gell-Mann predicted it. Still, that was a good sign. Once they found that Omega-Minus Baryon, as
it’s now known, everyone knew Gell-Mann was on the right track. Then, around 1964, Gell-Mann and two other
physicists named George Zweig and André Petermann all independently came up with the same explanation
for the Eightfold Way’s success: Each of the particles was itself made of a few tiny,
indivisible pieces. Petermann wanted to call the pieces “spinors”
and Zweig wanted to call them “aces”. But Gell-Mann had a way with naming things,
and his name for them stuck: quarks. By combining just three types of quarks — called
“up”, “down”, and “strange” quarks — into collections of two or three, you could
produce all the particles physicists had seen over the previous few decades. Except for things in the same family as electrons. But those have their own models. And there were only a couple of those at the
time, anyway. Admittedly, though, the quark model did have
some weird features. It said that, unlike every particle ever observed, quarks didn’t have an electric charge that was a whole number times the charge of an electron. Instead, they had fractional charges: either
negative one-third or positive two-thirds. And that struck everyone as very weird. It was unlike every particle they’d ever
seen. But there was a reason they’d never seen
fractional charges: Over the next decade, physicists working with the model realized
that you could never see an isolated quark on its own. Quarks could only ever be in groups of two
or more, because there was just too much energy sitting in the space between groups to ever tear them fully apart. Again, it’s very weird. But just like the Eightfold Way, the quark
model caught on because it worked: It was a simple explanation for complex mysteries. It explained why neutrons — which are, like
the name says, electrically neutral — act like they have electric charges in them in
specific cases: They’re made up of two down quarks and an up quark, which each have charges. And it naturally explained strangeness, too: Particles with strangeness were particles with strange quarks in them. The real kickers came in 1968 and 1974, when
two different experiments showed conclusive evidence that the quark model was right. In 1968, experiments at the Stanford Linear
Accelerator fired electrons into protons. They found that they bounced off in ways that
only made sense if the protons were made of individual pieces like quarks, instead of
being solid balls of charge. Then in 1974, experiments at two different
labs revealed a new particle that couldn’t exist in the original three-quark model. Which would have been a disaster — if physicists
hadn’t already extended the original model to predict a fourth quark, called the “charm”. Today, we know of only two more quarks: The
bottom quark and the top quark. Which were originally called “truth” and
“beauty”, but apparently that was just too much. And there are good reasons to think that that’s
it: Our universe has six total types of quarks, and no more. With just those quarks, plus the forces between
them and a couple other particles that are cousins of the electron, we can figure out
a ton. We can understand the behavior of the hundreds
or even thousands of different types of particles that are created all the time in particle
accelerators. And that’s the kind of simplicity physicists
strive for. Ah, Physics. It’s so beautiful. Just like a good spreadsheet or really flexible
trello board. I co-host SciShow with Hank, Olivia, and Michael,
but I’m also the producer for the channel, so I spend a lot of my creative energy and
time organizing the workflow of the team. People always ask us how we put out more than
a video per day with such a small team. And it’s because we’re very organized. We have multiple spreadsheets, docs, calendars,
trello boards, and slack channels to manage it all. To know me is to know that I’m fascinated
by productivity and what works for different people and different groups of people. Which is why I appreciate that Skillshare
focuses so much on classes like this one called Productive Prioritization: Tools to Build
Your System. The teacher, Brian Cervino, works for Trello
— which is cool — but he doesn’t just focus on Trello. It’s more about the philosophies of productivity
and how to rethink how you’re utilizing your time. And right now Skillshare is offering SciShow
viewers two months of Skillshare for free, so join the millions of students on Skillshare
and check out this class or any of the more than 20,000 others, by following the link
in the description. And, if you want a trademark Stefan Chin productivity
tip, watch it at 2x speed. [ ♪ Output ]

100 thoughts on “How Quarks Fixed the Mess That Was Particle Physics”

  1. What I love about this channel is although the thumbnail only said quarks, it is not boring for people who know loads about quarks. It’s like a one way discussion and they talk things without running down a list. Sci show is what I would call a gentleman and a scholar

  2. I have some new names. Mnemonic and analogy. I think these two words contain most of modern physics. It starts with rules and laws. Then they have jumped onto mnemonic devices or analogies that feel like answers, and they refuse to second guess something established as a constant. Charge came before the atom, so the atom must include the established constant called charge rather than second guess charge. Why do positive charges clump together -oh, we need a Strong force. And then there's 'C'. Don't second guess the speed of light -transform everything BEFORE you look at it, and don't even think about second guessing relative time. Then see what you get. At best you have your favorite analogy, and no one is looking for non-transformed explanations. You may think relative time is more than demonstrated, but send a pendulum into space and you don't even have a clock anymore. No one truly explored better explanations, because peer review is not without its politics. They established constants and refused to second guess them. WE ARE SCREWED!

  3. up, down, strange, charm, truth, beauty, honey dew, chunky, thoughtful, Giorno, melloncholy, grunge, latina, 60% chance of rain, God's dice, brittish comedy, XOR, "homework folder", and latte.

  4. How you get protons or neutrons is actually pretty easy. A proton is a combination of two up quarks and one down quark. That is, 2/3 + 2/3 + -1/3. You can think of that as 2 + 2 – 1. That gives you 3/3 or +1 charge. A neutron is made of two down quarks and one up quark. That is, 2/3 + -1/3 + -1/3. You can think of that as 2 – 1 – 1. That gives you 0/3 which is no charge at all (and thus neutral).

    Another fascinating thing about quarks is that the energy required to separate a pair of quarks is sufficient to make a whole new quark in the process. That is, if you pump enough energy into the process of splitting up a quark pair, you WILL get them to separate, but the energy will then immediately collapse into two new quarks such that neither quark is left alone. E=Mc^2 after all. LOL

  5. "… And that's the kind of simplicity physicists strive for. Ah, physics. It's so beautiful."

    … And then you get to general relativity…

  6. I guess you could say the true beauty of this particle model is that it works …
    (•_•)
    ( •_•)>⌐■-■
    (⌐■_■)
    … like a Charm!

  7. Quarks are just another bizarre mythology of so-called "modern physics." For the true theory of the universe, go here: www.reciprocalsystem.guruh

  8. I have a Chemistry exam final tomorrow and I read on my book that protons and neutrons are made of quarks and I won't study quarks right now because it's hard to understand, so I decided to watch this and now I'm like I guess the book was telling the truth because I understood absolutely nothing and my brain will explode

  9. Until you can demonstrate real use and verifiable effects, this has to be lumped in the category of sophistry, if not fraud.

    Of course there may be some empirical demonstration which has been omitted. But that is doubtful because these are the same people that say:

    time stops at the black-hole… but its spinning.

    So likely its worse than medieval religion. Which at least provided us with 10 commandments of ethics.

    #9 and #2
    being violated in this video.

  10. Quarks, at say 0.43e-16m, are still e18 times larger than the Planck length e-34m.
    That allows the opportunity for a lot of subcomponents of quarks.
    Enter sub-quark physics. Must be at least 2 more levels of components. Must make the physicists (and accelerator builders) happy knowing this ;).

  11. …what total & utter narcissism
    get your face off the screen
    this is just self publicity
    just do voice overs
    stop being so
    insufferably
    vain

  12. I like how at 3:30 he acts like everybody (including general public) was into all of this and was super enlightened and were like ahh yes that is strange and unlike anything ive ever seen after all of these years ive been working at the gas station 😂

  13. The code to unlock the secrets of the universe is:
    Up, Up, Down, Down, Strange, Charm, Strange, Charm, Bottom, Top, [Start]😂🤣😅😊
    #Quarks #Contra30Lives #KonamiCode #QuantumPhysics

  14. They don't teach you about quarks in grade school, or most particles, because they don't want you to know the Truth about the universe. What we are all made out of, and what created us. I know the answer, it's both scientific and spiritual.

  15. MANDLEBROT and JULIA SETS hold all the truth in numbers. But then again, numbers are just details and I know where the devil resides.

  16. So theres 2 types of scientists. One is stuck in the 1980's, and the other one acts like they're in 2055. Hmm.

  17. Scientist:That's it our universe has six total types of quark.

    SOME NEW UNIDENTIFIES QUARKS:"Im gonna end this man whole career."

  18. How about you discover and use the fundamental particles called the full stop (or period) and the comma. They can break that continuous high velocity torrent of words into more easily absorbed chunks of information so your audience doesn’t get totally fatigued listening to you. And stop waving your hands about trying to emphasise each and every word. You’re speaking, not conducting an orchestra. Lastly, there’s nothing more futile than filling a screen with writing that you then read out. If we wanted to read so much, we would have bought a book, not clicked on a video.

  19. "Cousins of the electron", which are called… e.g. photons? "Electrons have their own models"… various models or one model for electrons known as…?

  20. The most expensive, overhyped, and least productive mess in the history of science – which is saying something !

  21. And atheists says there's no God and everything just came out of a big boom just wtf. The complexity of this universe is too much for you guys to concieve.

  22. 286th rule of acquisition: Quarks may hold the universe together, but latinum makes it worth living in.

  23. 5:15 – Wow, that gold x sulfur collision image from x CERN is beautiful.. 😵 I assume that it was "assembled" computationally, but still..

  24. 03:00 I like the name "spinors" for quarks, because you MAY think of them like each of the 3 dimensional vectors [aligned with an unreal, invisible, non-relative, "absolute frame of reference"] that define the "spining" of a proton or neutron in space (with time as the "binding" in between).
    -> This is why none of the 3 can exist independently [they are just "math numbers" in the Matrix].

  25. im alrdy master in productivity of skillshare n stuff.. i can make those videos on my own just need time n teach ppl.. infact hats what ma future videos gna be like in another chanel

  26. The next atomic bomb is gonna split quarks instead of atoms and it's gonna be devastating lol

    I don't actually know if this is possible but imagine the destruction though if we've come so far and still can't split them. If there's as much energy as he makes it sounds like it'd be crazy.

  27. 4:54 thank science, I wondered what had happened to Truth and Beauty

    (… I also wonder if an Emo physicist decided there was no more truth and beauty in the world lol)

  28. The bottom quark and the top quark which were originally called truth and beauty, but apparently that was just too much. Hahahahaha

  29. The problem with quarks is that the math involved is absolute nonsense. The theorists take the matrix representation of a Lie algebra and multiply the matrices together. This is not well defined. If the math is nonsense, so is the theory.

  30. Standard model of particles zoo is wrong. Prove it? There is no association between quarks and leptons as per standard model. During beta emission, a neutron within an unstable nucleus will emit out "some" energetic electrons before it itself is turning into  a proton. This clearly implies that a neutron has some elements of electrons within itself. Without any doubt that standard model is wrong. If you are interested in real discoveries, I would recommend you to read my book, The Unification Theory – Volume One and you will be amazed with lots of new, interesting discoveries. In God I trust.

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