(Laughter)

おぉすごいな！ このすごい方程式を見て　いいねぇ

Check out those killer equations. Sweet.

今から18分 できる限り式を使わず

Actually, for the next 18 minutes I'm going to do the best I can

素粒子物理の美を説明します

to describe the beauty of particle physics without equations.

サンゴは 学ぶ所が多く

It turns out there's a lot we can learn from coral.

とても美しい 特異な生物です

A coral is a very beautiful and unusual animal.

サンゴの突起は 無数のポリプの集合体です

Each coral head consists of thousands of individual polyps.

ポリプは出芽と分岐を繰り返し

These polyps are continually budding and branching

同じ遺伝子をもつ複製を作ります

into genetically identical neighbors.

これを高知能なサンゴだとして

If we imagine this to be a hyperintelligent coral,

個体を一つ選んで 気になる質問をしましょう

we can single out an individual and ask him a reasonable question.

みんなと違って ちょうどその位置にいるのは

We can ask how exactly he got to be in this particular location

なぜ？

compared to his neighbors --

単なる偶然？ 運命か何か？

if it was just chance, or destiny, or what?

ポリプは 温暖化に苦言を呈してから

Now, after admonishing us for turning the temperature up too high,

ばかな質問だと言うでしょう

he would tell us that our question was completely stupid.

サンゴは意地悪になるんです

These corals can be kind of mean, you see,

私もサーフィンで傷を負いました

and I have surfing scars to prove that.

ポリプは続けます

But this polyp would continue and tell us

「隣のポリプは 私の完全な複製物だ 私は

that his neighbors were quite clearly identical copies of him.

すべての場所に

That he was in all these other locations as well,

同時に存在し それぞれを体験する」

but experiencing them as separate individuals.

サンゴにとって 多くの複製に分岐することは

For a coral, branching into different copies

当然なので

is the most natural thing in the world.

人類とは違い 高知能なサンゴらしく 量子力学を

Unlike us, a hyperintelligent coral

理解します

would be uniquely prepared to understand quantum mechanics.

量子力学の数学で 宇宙の仕組みが

The mathematics of quantum mechanics

正確に表現され

very accurately describes how our universe works.

現実が多くの可能性に分岐し続けることがわかります

And it tells us our reality is continually branching into different possibilities,

まさにサンゴのようです

just like a coral.

人類がこれを理解しがたいのは

It's a weird thing for us humans to wrap our minds around,

一つの可能性しか経験しないからです

since we only ever get to experience one possibility.

量子力学の奇妙さを示したのは

This quantum weirdness was first described

シュレーディンガーの猫が最初です

by Erwin Schrödinger and his cat.

猫なら

The cat likes this version better.

こっちのほうが好きでしょう（笑）

(Laughter)

放射性物質とシュレーディンガーが 箱に入っています

In this setup, Schrödinger is in a box with a radioactive sample

量子力学の法則によれば 試料から

that, by the laws of quantum mechanics, branches into a state

放射線が出る状態と

in which it is radiated and a state in which it is not.

出ない状態に分岐します（笑）

(Laughter)

放射した方では

In the branch in which the sample radiates,

毒が放出されて シュレーディンガーは死んでいますが

it sets off a trigger that releases poison and Schrödinger is dead.

他方の現実では生きたままです

But in the other branch of reality, he remains alive.

二つの現実は 各シュレーディンガーが別々に経験します

These realities are experienced separately by each individual.

各世界に 相手の世界は存在しません

As far as either can tell, the other one doesn't exist.

人は一つの現実しか経験できず

This seems weird to us,

別の現実を見られないので

because each of us only experiences an individual existence,

奇妙に感じます

and we don't get to see other branches.

シュレーディンガーと同様 私たちはサンゴのように

It's as if each of us, like Schrödinger here,

多くの可能性に分岐します

are a kind of coral branching into different possibilities.

量子力学の数学でわかるように

The mathematics of quantum mechanics tells us

これが微小世界の仕組みです

this is how the world works at tiny scales.

一言でいうと

It can be summed up in a single sentence:

「起こりうる全てが起こる」

Everything that can happen, does.

これが量子力学です

That's quantum mechanics.

でも 全て起こるわけではありません

But this does not mean everything happens.

ほかの物理学は 起こる事と起こらない事を

The rest of physics is about describing what can happen and what can't.

示します

What physics tells us is that everything comes down to geometry

物理学が示すのは 素粒子の相互作用と幾何学に

and the interactions of elementary particles.

すべて行き着くということです

And things can happen only if these interactions are perfectly balanced.

何かが起こるのは 相互作用が完全に平衡な場合

Now I'll go ahead and describe how we know about these particles,

だけです

what they are and how this balance works.

その粒子を知る方法 その実体

In this machine, a beam of protons and antiprotons

平衡がどう作用するのか説明します

are accelerated to near the speed of light

この装置では 陽子と反陽子のビームが

and brought together in a collision, producing a burst of pure energy.

光速近くまで加速して衝突し

This energy is immediately converted into a spray of subatomic particles,

一体化して 混じりけのないエネルギーが放射されて

with detectors and computers used to figure out their properties.

原子より小さな粒子の放射に

This enormous machine --

変換され

the Large Hadron Collider at CERN in Geneva --

検出器とコンピュータで解析されます

has a circumference of 17 miles and, when it's operating,

この巨大な加速器LHCは

draws five times as much power as the city of Monterey.

ジュネーブのCERNにあり

We can't predict specifically

一周27km

what particles will be produced in any individual collision.

稼働時にはモントレー市の

Quantum mechanics tells us all possibilities are realized.

５倍の電力を消費します

But physics does tell us what particles can be produced.

衝突ごとに どの粒子が生まれるかは

These particles must have just as much mass and energy

予測できません

as is carried in by the proton and antiproton.

量子力学は すべての可能性が

Any particles more massive than this energy limit aren't produced,

実在するといい 物理学は生成可能な粒子を示します

and remain invisible to us.

生成された粒子のエネルギーは必ず

This is why this new particle accelerator is so exciting.

陽子と反陽子が運ぶエネルギーに等しく

It's going to push this energy limit seven times

このエネルギー限界を超える粒子は

beyond what's ever been done before,

生まれず 目にできません

so we're going to get to see some new particles very soon.

この新型加速器がすごいのは そこです

But before talking about what we might see,

エネルギー限界が従来より７倍

let me describe the particles we already know of.

高いのです

There's a whole zoo of subatomic particles.

新しい素粒子はすぐ見つかります

Most of us are familiar with electrons.

予測する前に

A lot of people in this room make a good living pushing them around.

既知の素粒子について説明します

(Laughter)

いわゆる「素粒子動物園」です

But the electron also has a neutral partner called the neutrino,

電子は身近ですね

with no electric charge and a very tiny mass.

みなさんは

In contrast, the up and down quarks have very large masses,

これを使って

and combine in threes to make the protons and neutrons inside atoms.

いい暮らしをしています（笑）

All of these matter particles come in left- and right-handed varieties,

電子には中性の仲間がいます

and have antiparticle partners that carry opposite charges.

無電荷で質量がとても小さいニュートリノです

These familiar particles

アップクォークとダウンクォークは 質量が膨大で

also have less familiar second and third generations,

三つで 陽子と中性子を作ります

which have the same charges as the first but have much higher masses.

物質の素粒子には

These matter particles all interact with the various force particles.

右回りと左回りがあり

The electromagnetic force interacts with electrically charged matter

逆の電荷をもった反粒子が相棒です

via particles called photons.

身近な素粒子には

There is also a very weak force

聞き慣れない第２ 第３世代があります　第１世代と電荷は同じですが

called, rather unimaginatively, the weak force ...

質量ははるかに大きいものです

(Laughter)

物質の素粒子は 力の素粒子と相互作用します

that interacts only with left-handed matter.

「電磁力」は 電荷をもつ物質と相互作用します

The strong force acts between quarks

光子という素粒子が媒介します

which carry a different kind of charge, called color charge,

非常に弱い力もあります

and come in three different varieties: red, green and blue.

安直に「弱い力」と呼ばれていて

You can blame Murray Gell-Mann for these names -- they're his fault.

左回りの物質とだけ相互作用します

Finally, there's the force of gravity,

「強い力」は クォークに働きます

which interacts with matter via its mass and spin.

クオークは 色荷というチャージをもち

The most important thing to understand here

色荷には 赤 緑 青の３種があります

is that there's a different kind of charge associated with each of these forces.

この命名はマリー・ゲルマンの

These four different forces interact with matter

あやまちです

according to the corresponding charges that each particle has.

最後は「重力」です　質量とスピンを介して

A particle that hasn't been seen yet, but we're pretty sure exists,

物質と相互作用します

is the Higgs particle, which gives masses to all these other particles.

一番重要なのは 力ごとに

The main purpose of the Large Hadron Collider

別のチャージが対応する

is to see this Higgs particle, and we're almost certain it will.

ということです

But the greatest mystery is what else we might see.

４種の力は その力に対応した

And I'm going to show you one beautiful possibility

各素粒子のチャージに応じて 物質と作用します

towards the end of this talk.

未発見ながら確実に存在するのが

Now, if we count up all these different particles

ヒッグス粒子です　他の素粒子に質量を与えます

using their various spins and charges,

LHCの主目的は

there are 226.

ヒッグス粒子の発見です　ほぼ確実ですが

That's a lot of particles to keep track of.

ほかに何を発見できるかが 最大の神秘です

And it seems strange

ここからは すごい可能性を一つ

that nature would have so many elementary particles.

お話しします

But if we plot them out according to their charges,

素粒子を

some beautiful patterns emerge.

スピンやチャージを考慮して数え上げると226個です

The most familiar charge is electric charge.

多いのです

Electrons have an electric charge,

自然界にそれほど多種の素粒子が

a negative one,

あるのは奇妙にも思えますが

and quarks have electric charges in thirds.

チャージに基づいて描画すると

So when two up quarks and a down quark are combined to make a proton,

美しいパターンが現れます

it has a total electric charge of plus one.

一番身近なのは電荷ですね

These particles also have antiparticles, which have opposite charges.

電子の電荷はマイナス１

Now, it turns out the electric charge

クォークの電荷は1/3の倍数

is actually a combination of two other charges:

アップクォーク二つと ダウンクォーク一つで

hypercharge and weak charge.

陽子を作ります　電荷の合計はプラス１です

If we spread out the hypercharge and weak charge

素粒子には 逆の電荷をもつ反粒子が存在します

and plot the charges of particles in this two-dimensional charge space,

電荷は

the electric charge is where these particles sit

別の二つのチャージの組み合わせです

along the vertical direction.

ハイパーチャージとウィークチャージです

The electromagnetic and weak forces interact with matter

２次元チャージ空間に

according to their hypercharge and weak charge,

ハイパーチャージとウィークチャージを展開して 各粒子のチャージをプロットすると

which make this pattern.

電荷は

This is called the unified electroweak model,

縦方向に示されます

and it was put together back in 1967.

ハイパーチャージとウィークチャージに基づいて

The reason most of us are only familiar with electric charge

電磁力と弱い力が物質と

and not both of these is because of the Higgs particle.

相互作用します

The Higgs, over here on the left, has a large mass

これは

and breaks the symmetry of this electroweak pattern.

1967年に統一された電弱統一モデルです

It makes the weak force very weak by giving the weak particles a large mass.

身近なのは電荷だけで

Since this massive Higgs sits along the horizontal direction in this diagram,

両方ではないのは ヒッグス粒子が原因です

the photons of electromagnetism remain massless

左側にあるヒッグスは質量が大きくて

and interact with electric charge along the vertical direction

電弱パターンの対称性を破ります

in this charge space.

弱い素粒子の

So the electromagnetic and weak forces

質量を大きくし 弱い力を弱めます

are described by this pattern of particle charges

大質量のヒッグスが図の横方向に位置しているので

in two-dimensional space.

電磁力を担う光子は質量をもたずに チャージ空間の縦方向で

We can include the strong force by spreading out its two charge directions

電荷と相互作用を

and plotting the charges of the force particles in quarks

します

along these directions.

電磁力と弱い力は ２次元空間で

The charges of all known particles

素粒子のチャージのパターンとして示されます

can be plotted in a four-dimensional charge space,

強い力を２チャージ方向に展開して

and projected down to two dimensions like this so we can see them.

クォークに働く力の素粒子のチャージを描くと

Whenever particles interact, nature keeps things in a perfect balance

強い力を導入することができます

along all four of these charge directions.

既知のすべての素粒子の

If a particle and an antiparticle collide,

チャージを ４次元チャージ空間に描画して

it creates a burst of energy and a total charge of zero

２次元に投影できます

in all four charge directions.

素粒子が相互作用するとき ４チャージ方向で

At this point, anything can be created

完全に平衡が保たれます

as long as it has the same energy and maintains a total charge of zero.

粒子と反粒子が衝突すると エネルギーが放出されて

For example, this weak force particle and its antiparticle

全４チャージ方向でチャージの和がゼロになります

can be created in a collision.

エネルギーが同じで チャージの和がゼロであれば

In further interactions, the charges must always balance.

何でも作れます

One of the weak particles could decay into an electron and an antineutrino,

例えば この弱い力の粒子と反粒子は

and these three still add to zero total charge.

衝突で生まれます

Nature always keeps a perfect balance.

さらに相互作用しても チャージは常に平衡します

So these patterns of charges are not just pretty.

弱い力は 電子と反電子ニュートリノに

They tell us what interactions are allowed to happen.

崩壊しますが

And we can rotate this charge space in four dimensions

三つのチャージの和はゼロのままです

to get a better look at the strong interaction,

いつも完全に平衡が保たれます

which has this nice hexagonal symmetry.

チャージパターンは綺麗なだけでなく

In a strong interaction, a strong force particle,

どんな相互作用が発生し得るかを読み取れます

such as this one,

４次元でこのチャージ空間を回転させれば

interacts with a colored quark, such as this green one,

強い相互作用を見られます

to give a quark with a different color charge -- this red one.

六角形状に対称です

And strong interactions are happening millions of times

強い相互作用では 例えばこの強い力の素粒子が

each second in every atom of our bodies,

例えばこの緑のカラークォークと相互作用して

holding the atomic nuclei together.

別の色荷をもつ この赤いクォークとなります

But these four charges corresponding to three forces

体中の原子では 毎秒

are not the end of the story.

強い相互作用が 無数に発生して

We can also include two more charges corresponding to the gravitational force.

原子核を一体に保っています

When we include these,

３種の力に対応した４種のチャージだけでは

each matter particle has two different spin charges,

終わりません

spin-up and spin-down.

重力に対応した

So they all split and give a nice pattern in six-dimensional charge space.

２チャージも導入できます

We can rotate this pattern in six dimensions

このとき 物質の素粒子は それぞれ

and see that it's quite pretty.

上下二つのスピンチャージをもちます

Right now, this pattern matches our best current knowledge

６次元チャージ空間にすべて分かれて

of how nature is built at the tiny scales of these elementary particles.

きれいなパターンを描きます

This is what we know for certain.

６次元でパターンを回転させると

Some of these particles are at the very limit

かなり綺麗になります

of what we've been able to reach with experiments.

素粒子レベルの微小スケールで自然の仕組みを示す最有力の思想と

From this pattern

これが一致

we already know the particle physics of these tiny scales --

しています

the way the universe works at these tiny scales is very beautiful.

確かに一致しています

But now I'm going to discuss some new and old ideas

いくつかの素粒子で

about things we don't know yet.

すでに装置限界に達しています

We want to expand this pattern using mathematics alone,

微小スケールでの素粒子物理は

and see if we can get our hands on the whole enchilada.

このパターンから明らかとなりました

We want to find all the particles and forces

微小スケールの宇宙の仕組みは とても美しいのです

that make a complete picture of our universe.

未知の世界について 新旧交えて

And we want to use this picture to predict new particles

お話しします

that we'll see when experiments reach higher energies.

数学だけを使い パターンを拡張して

So there's an old idea in particle physics

全体像をつかめるか試します

that this known pattern of charges,

宇宙を完璧に描く 素粒子と力を

which is not very symmetric,

すべて見つけたいのです

could emerge from a more perfect pattern that gets broken --

もっと高エネルギーの実験で見つかる

similar to how the Higgs particle breaks the electroweak pattern

新しい素粒子を予測したいのです

to give electromagnetism.

素粒子物理学には昔から

In order to do this, we need to introduce new forces

対称性に欠ける この既知のチャージパターンは

with new charge directions.

完璧なパターンが崩壊して生まれたという考えがあります

When we introduce a new direction,

ヒッグス粒子が電弱パターンを破って

we get to guess what charges the particles have along this direction,

電磁力を生むのと

and then we can rotate it in with the others.

似ています　そのためには 新しい力とチャージ方向を

If we guess wisely, we can construct the standard charges

導入する必要があります

in six charge dimensions as a broken symmetry

新しいチャージ方向を導入すれば

of this more perfect pattern in seven charge dimensions.

素粒子のチャージが明らかになり ほかと一緒に

This particular choice corresponds to a grand unified theory

回転可能になります

introduced by Pati and Salam in 1973.

上手くやれば６チャージ次元の標準的なチャージが

When we look at this new unified pattern,

もっと綺麗な７チャージ次元パターンの対称性を