80 years? 90?

80歳? 90歳?

120?

120歳?

Longer?

もっと?

And do you think you'll change your mind once you reach that age?

実際にその年齢になったら気が変わると思う?

Fifty thousand years ago most humans died very young.

5万年前、ヒトはとても若くして死んでいたが、

As we learned how to use the resources around us to treat ourselves, this got better and better.

以来、環境資源の使い方を学ぶにつれ、寿命はどんどん改善した

Today, humans are living longer and healthier lives than ever before.

今日ヒトは、かつてないほど健康で長生きになった

But this has an unforeseen consequence.

でも、このことが予期せぬ結果も生む

We spend an ever-increasing part of our lives being sick and in need of care.

老後は病気と介護の必要が増すばかりだ

Most of us will die in a hospital bed, which is depressing enough by itself.

ほとんどの人は病院で亡くなるが、それ自体とても深刻なことだ

But we also have to witness the same happening to our loved ones.

そして愛する人にも同じことが起こる

Except, maybe we can stop this forever.

でも、たぶんこれは解決できる

The most effective way to treat a disease is to prevent it.

予防にまさる治療はない

It saves many more lives if you stop a million people from smoking, than coming up with better chemo therapies.

化学療法を改良するより、タバコをやめさせる方が、ずっと多くの人を救える

So why not put a halt to the cause of all disease: the process of aging.

なら全ての病気の根源を撲滅しよう、それはつまり老化のプロセス

In a nutshell, aging is caused by physics, and not biology.

ようするに、老化の原因は生物学的なものじゃなく、物理的なものだ

Think of cars: Parts wear down from rubbing and grinding, metal rusts, filters get plugged, rubber cracks.

自動車だってすり減ってゆく、金属はこすれ、フィルターは錆付き、ゴムにはひびが入り

Our bodies are worn down by trillions of tiny physical processes.

我々の身体も、数兆の小さな物理的原因ですり減ってゆくのだ

Oxygen, radiation from the sun, our metabolism.

活性酸素や太陽の放射線、代謝など

Our bodies have many mechanisms to repair this damage, but over time they become less effective.

それらを修復するしくみはたくさんあるが時とともに働きが落ちる

So our bones and muscles weaken, our skin wrinkles, our immune system gets weaker.

骨や筋肉は弱くなり、皮膚にはしわが増え免疫も弱くなる

We lose our memory and our senses diminish.

記憶は失われ、感覚も衰える

There's no such thing as dying of old age.

高齢が原因で死ぬことはない

We all die because one of our important parts breaks.

私たちは皆体の重要なパーツが壊れて死ぬ

The older we get, the more damaged and fragile we become until one or multiple diseases take over and kill us.

歳をとるほど傷つき、もろくなり、ついに病気によって死ぬ

Unnoticed by most of us, longevity research has made some unprecedented advances in the last few years.

ここ数年、長寿研究はいつの間にか空前の進歩をとげた

For the first time, we're starting to understand the mechanisms behind aging and how to manipulate them.

初めて老化の背後にひそむメカニズムと、それを操作する方法が解明されつつある

Aging is neither mystical nor inevitable, and we might be able to stop or delay it during your lifetime.

老化は神秘でも不可避でもなく、止めたり遅らせたりできる可能性がある

We'll discuss the science behind it and how scientists are trying to stop it in another video.

科学者が試みているその方法については別の動画で取り上げる予定だが

But first, if we could, should we end aging?

それが可能だとして、老化を止めるべきなのか？

Is this a good idea?

老化を止めるのは良いことなのか

The end of aging or life extension makes many people uncomfortable.

老化の停止、もしくは寿命の延長は多くの人を不快にさせる

We're born, are young, become older, and then we die.

我々は生まれ、若者は歳を取り、そして死ぬ

This has been the natural order for literally all of human history, and getting old is a good thing, right?

これはヒトの全歴史を通して自然の摂理であり、歳を取ることは良いことだった

We celebrate the idea of living long enough to experience old age.

私たちは長生きして老年に達することを祝う

We even call them the golden years.

また、黄金の年代とまで言う

But the reality is that everybody wants to become old, but nobody wants to be old.

でも実際のところ、みんな長生きはしたいけど老人になりたいわけじゃない

Think of the Greek myth of Tithonus for example.

たとえばギリシャ神話のティファヌス

Tithonus was the lover of the goddess Eos and probably an amazing dude.

ティファヌスは女神イオスの恋人で、とてもいいヤツだったのだろう

Because she begged Zeus to grant him immortality, so they could spend eternity together.

彼女はゼウスに彼の不死を願い許されたため、二人は永遠に一緒に過ごせた

But she forgot to specifically ask for eternal youth.

ところが彼女は永遠の若さを頼むのを忘れた

Tithonus was granted eternal life, but he kept aging, unable to die.

ティファヌスは永遠の命を授けられたが、彼は歳をとり続けた、それも死ぬことができずに

After a few hundred years, he was reduced to the size of a grape, babbling on senselessly forever.

彼は数百年、死ぬこともできず老い続けブドウ粒のサイズまで縮み、無意味に永遠に生き続けた

Thousands of years ago, humans already feared never-ending old age.

数千年前ですら、人は終わりのない老年期を恐れていた

But ending aging does not mean getting weaker and weaker.

老化を止めることは、体が日に日に貧弱になる心配はいらない

If you become too old, it's too late.

しかし歳を取りすぎたら、老化を止めることに意味がなくなる

A 90 year old who stopped aging would die anyway after a few years.

90歳では数年先には死んでしまうので、老化を止めるのには遅すぎる

Too much damage has been done to his internal machinery.

内部にダメージが蓄積しすぎて、

There are already too many surfaces for disease to attack.

病気に対して弱点だらけなのだ

Instead, the concept of life extension promises to end diseases, and with them, the end of a fixed maximum age.

寿命の延長とは病気をなくし、寿命の限界を打破することだが、

We don't know how much we could prolong our lives.

どれほど寿命を延長できるかはまだ分からないでも、

We might make every human healthy to the currently accepted maximum age of around 120, or we might stop biological aging and disease indefinitely.

健康寿命の限界は現在の最長寿命である120歳程度なのか、あるいは無期限に伸ばせるのか

Nobody knows at this point what's possible.

現時点では誰にも分からない

Okay, but even if we could achieve that, should we?

仮にそれが可能だとして、ではそうすべきなのか?

Well, life extension is really just another phrase for medicine.

まあ、寿命の延長とは医療の別名に過ぎない

All the doctors are doing is trying to prolong life, and minimize suffering.

すべての医師がしているのは、生命を延長し、苦痛を最小にすることだ

The vast majority of healthcare resources are spent on the consequences of aging.

医療資源のほとんどは加齢の影響についやされる

Nearly half of your lifetime healthcare costs will be spent during your senior years, and another third during middle age.

あなたの生涯医療費のほぼ半分は老年期に費やされ、別の3分の1は中年の間に費やされる

We are actually already trying to prolong life with our current medicine.

寿命延長なら現在の医薬はすでにやっているのだが、

We're just doing it very inefficiently.

ただ効率はとても悪い

Trying to stop aging from happening is not less natural than transplanting a heart, treating cancer with chemotherapy, using antibiotics or vaccines.

老化が起こらないように試みることは、心臓移植、がんの化学療法、抗生物質の使用、ワクチンなどと較べても不自然というわけではない

Nothing humans do nowadays is purely natural anymore, and we enjoy the highest standard of living ever as a consequence of that.

今日ヒトのすることはどれも自然とは言えないが、その結果、我々は最高水準の生活を楽しんでいる

What we're doing right now is waiting until it's too late and the machine is failing.

私たちが今やっていることは、機械が壊れて手遅れになるまで待ち、

And then we use the vast majority of our resources trying to fix it as well as we can, while it breaks down even further.

そしていずれダメになるにしても、できるだけ修理することに資源の大部分を費やしている

But life extension still feels hubristic.

しかし、寿命の延長は依然として思い上がった感じを与える　

Most people assume that they will want to die once they reach a certain age, and this might still be true.

ほとんどの人は一定の年齢に達したら死ぬべきだと思っているが、それは依然として本当かもしれない

The idea of avoiding death entirely is off-putting for many.

死を回避するという考えは多くの人にとって不快である

The end of biological aging would not be in the end of death in any way.

生物学的老化の撲滅は、いずれにせよ死の撲滅とは違う　

It's more like a summer evening when you were a kid, and your mom called you inside.

それはむしろ、子供の頃すごした夏の夕暮れにお母さんに呼ばれた時のことに似ている　

You just wanted to keep playing, have a little more fun during sunset before you went to sleep.

お母さんに呼ばれても寝る前にもう少しだけ夕暮れに遊んでいたかった

It's not about playing outside forever, just a little longer, until we feel tired.

永遠に外で遊びたかったわけではなく飽きるまでほんの少しでよかったのだ　

If you imagine a world without disease where you and your loved ones could live in good health for another 100 or 200 years, how would this change us?

あなたや愛する人達がさらに100年か200、健康で暮らせる世界が来たら、私たちはどう変わるのだろう

Would we take better care of our planet if we knew we would be around longer?

今より長く生きるとわかったら、地球のことももっと大事にするだろうか

If we could work for 150 years, how much time would we spend figuring out what we're good at?

もし150年間働けるとしたら、自分の得意分野を見つけるためにどれくらいかけ、　

How much more time would we spend learning?

どれくらいの時間を学ぶことに費やすだろう　

Would the intense feeling of pressure and stress many of us are feeling right now, go away or get worse?

多くの人が感じているプレッシャーやストレスは良くなるのか悪くなるのか

So asking again, if you could choose how long to live right now, in good health and with your friends and family, what's your personal answer?

みなさんにもう一度聞こう、今もし健康で友達や家族に囲まれる人生をどのくらい長く生きたいか決めることができるとすれば、どう答えるだろうか

What would you like your future to look like?

どういった未来を望むだろうか　

But maybe you're still unconvinced.

でもまだ納得がいってないかもしれない　

Some nagging feeling remains.

何かしつこい感じがつきまとっている　

That is the Reaper whispering into your brain.

死神があなたに囁いている　

Watch my video to hear what he says, and why you shouldn't listen.

死神について、そしてなぜ死神のいうことを聞いてはいけないかの動画を見てみてください　

Your eternal future may depend on it.

あなたの不朽の人生がかかっているもしれません　

Go watch the other part over at CGP Grey's channel, and if you're not already subscribed, subscribe.

残りは CGP Grey のチャンネルから見てください、登録してない人は、ぜひ登録を