Placeholder Image

字幕表 動画を再生する

  • So two guys walk into a bar.

  • Really?

  • No, seriously.

  • Two guys walk into a bar,

  • an ice cream bar:

  • Dave, a physicist working on the Large Hadron Collider at CERN,

  • the European laboratory for particle physics,

  • and Steve, a blues singer.

  • "Dave, how's it going?"

  • "Steve, good to see you!"

  • "Two scoops of chocolate almond for me."

  • "Vanilla shake."

  • "Hey, I just saw something about the LHC on TV.

  • You guys found bozo in your detector?"

  • "Well, not exactly.

  • We found a boson,

  • probably the Higgs boson."

  • "What's that?"

  • "It's a particle."

  • "Don't you find particles all the time?"

  • "Yes, but this one means

  • that the Higgs field might really exist."

  • "Field? What field?"

  • "The Higgs field.

  • It's named after Peter Higgs,

  • although many others contributed to the idea.

  • It isn't a field, like where you grow corn,

  • but a hypothetical, invisible kind of force field

  • that pervades the whole universe."

  • "Hmmmm, okay.

  • If it pervades the whole universe,

  • how come I've never seen it?

  • That's a bit strange."

  • "Well, actually, it's not that strange.

  • Think of the air around us.

  • We can't see it or smell it.

  • Well, perhaps in some places we can.

  • But we can detect its presence with sophisticated equipment,

  • like our own bodies.

  • So the fact that we can't see something

  • just makes it a bit harder to determine

  • whether its really there or not."

  • "Alright, go on."

  • "So, we believe this Higgs field is all around us,

  • everywhere in the universe.

  • And what it does is rather special -

  • it gives mass to elementary particles."

  • "What's an elementary particle?"

  • "An elementary particle is what we call

  • particles that have no structure,

  • they can't be divided,

  • they're the basic building blocks of the universe."

  • "I thought those were atoms."

  • "Well, atoms are actually made of smaller components,

  • protons, neutrons, and electrons.

  • While electrons are fundamental particles,

  • neutrons and protons are not.

  • They are made up of other fundamental particles called quarks."

  • "Sounds like Russian dolls.

  • Does it ever end?"

  • "Actually, we don't really know.

  • But our current understanding

  • is called the Standard Model.

  • In it, there are two types of fundamental particles:

  • the fermions, that make up matter,

  • and the bosons, that carry forces.

  • We often order these particles

  • according to their properties, such as mass.

  • We can measure the masses of the particles,

  • but we never really knew where this mass came from

  • or why they have the masses they do."

  • "So how does this Higgs field thing explain mass?"

  • "Well, when a particle passes through the Higgs field,

  • it interacts and gets mass.

  • The more it interacts, the more mass it has."

  • "OK, I kind of get that, but is it really that important?

  • I mean, what if there were no Higgs field?"

  • "If there were no Higgs field,

  • the world wouldn't exist at all.

  • There would be no stars, no planets, no air, no anything,

  • not even that spoon or the ice cream you're eating."

  • "Oh, that would be bad.

  • Okay, but where does this Higgs boson fit into things?"

  • "Alright, now, you see the cherry in my shake?"

  • "Can I have it?"

  • "No, not yet. We have to use it as an analogy first."

  • "Oh, right, the cherry's the Higgs boson."

  • "No, not quite.

  • The cherry is a particle moving through the Higgs field, the shake.

  • The shake gives the cherry its mass."

  • "I get it. Okay, so the molecules of the shake are the Higgs bosons!"

  • "Well, you're getting closer.

  • It takes an excitation of the Higgs field

  • to produce the Higgs boson.

  • So, for example, if I were to add energy

  • by, say, dropping this cherry in the shake,"

  • "Ah, then the drops that spill on the bar

  • are the Higgs bosons."

  • "Almost! The splash itself is the Higgs boson."

  • "Are you serious?"

  • "Well, that's what quantum mechanics teaches us.

  • In fact, all particles are excitations of fields."

  • "Okay, right. Well, I kind of see why you like particle physics,

  • it's quite cool,

  • strange, but cool."

  • "Yeah, you could call it a bit strange,

  • it's not like everyday life.

  • The Higgs boson is an excitation of the Higgs field.

  • By finding the Higgs boson,

  • we know that the Higgs field exists."

  • "Right. So now you found it,

  • we know this Higgs field exists.

  • You must be done.

  • Is there anything left of particle physics?"

  • "Actually, we've just begun.

  • It's a bit like, you know, when Columbus thought

  • he had found a new route to India.

  • He'd, indeed, found something new,

  • but not quite what he was expecting.

  • So, first, we need to make sure that the boson we found

  • is actually the Higgs boson.

  • It seems to fit, but we need to measure

  • its properties to be sure."

  • "How'd you do that?"

  • "Take a lot more data.

  • This new boson lives for only a very short time

  • before it breaks down or decays

  • into lighter, more stable particles.

  • By measuring these particles,

  • you learn about the properties of the boson."

  • "And what exactly are you looking for?"

  • "Well, the Standard Model predicts how often

  • and in what ways the Higgs boson would decay

  • to the various, lighter particles.

  • So we want to see if the particle we have found

  • is the one predicted by the Standard Model

  • or if it fits into other possible theoretical models."

  • "And if it fits a different model?"

  • "That would be even more exciting!

  • In fact, that's how science advances.

  • We replace old models with new ones

  • if they better explain our observations."

  • "Right, so it seems like finding this Higgs boson

  • gives a direction for exploration,

  • a bit like that Columbus guy heading west."

  • "Exactly! And this is really just the beginning."

So two guys walk into a bar.

字幕と単語

動画の操作 ここで「動画」の調整と「字幕」の表示を設定することができます

B1 中級

TED-ED】ヒッグス粒子の基礎 - デイブ・バーニーとスティーブ・ゴールドファーブ (【TED-Ed】The basics of the Higgs boson - Dave Barney and Steve Goldfarb)

  • 471 65
    emkulu に公開 2021 年 01 月 14 日
動画の中の単語