Placeholder Image

字幕表 動画を再生する

審査済み この字幕は審査済みです
  • It's hard to get to space

    宇宙への旅

  • As much as we all wish there were an easy,

    それが簡単になれば

  • and affordable way to see our planet floating in the dark

    どれほど楽しいだろう

  • Right now, the only way is to become an astronaut or a billionaire

    今行けるのは宇宙飛行士か 金持ちだ

  • But there is a concept that might make it possible

    でも宇宙旅行の夢を叶える

  • -while serving as the starting point for the exploration of the universe-

    ある概念が考案されている

  • The space elevator

    宇宙エレベーターだ

  • How exactly does it work?

    どんなものだろう?

  • To understand how a space elevator will get us into space

    宇宙エレベーターとは何か

  • We must first understand what an orbit is

    まずは軌道から説明しよう

  • Being in orbit basically means falling towards something,

    軌道に入るとは つまり

  • but moving fast enough to miss

    落ち続けるということだ

  • If you throw a ball on earth it makes an arch through the air,

    物を投げると 弧を描いて地面に付く

  • and then hits the ground

    宇宙でも同じことが起きるが

  • In space, gravity makes you move much the same way,

    横に速く進むことで 地面に付かず

  • but if you move sideways fast enough

    地球を回り続けることができる

  • the curvature of the earth makes the ground fall away beneath you

    軌道に入るには

  • as fast as gravity pulls you towards it

    ロケットは速く飛ぶ必要がある

  • So, to enter Earth's orbit rockets have to go up

    一方 高い位置から飛べば

  • and sideways fast

    速度を稼ぐことができる

  • By contrast, a space elevator taps into energy from Earth's rotation

    おもちゃを回す子どもと

  • to get the cargo going fast

    アリを考えてほしい

  • Imagine a child spinning a toy on a rope with an ant on the child's hand

    先の方にいるアリは

  • As the ant climbs out along the rope

    それだけ速く飛べる

  • it starts to move faster and faster as it ascends

    高い所からロケットを飛ばせば

  • Compared to rockets, with cargo launched on an elevator

    燃料が少なくて済む

  • you only need to provide the energy to go up

    地球の遠心力を利用できるのだ

  • Fast sideways movement comes free with the Earth's rotation

    だが宇宙エレベーターは

  • But the space elevator would without a doubt

    史上最も高価な建築物になりそうだ

  • be the single largest and most expensive structure ever built by humans

    作る価値はあるのか?

  • So, is it worth it?

    計算してみよう

  • It all comes down to costs

    ロケットは少しの輸送でも

  • Rockets burn a huge amount of rocket fuel

    大量の燃料を使う

  • just to get a small amount of cargo into space

    今は1kg送るのに

  • At current prices, it costs about $20,000 to put one kilogram of payload into space

    2万ドルの費用がかかる

  • that's $1.3 million dollars for the average human

    人を送れば130万ドル

  • $40 million dollars for your car

    車なら4000万ドル

  • billions for an international space station

    宇宙ステーションは億単位だ

  • This immense cost is one of the major limitations of human spaceflight

    これが宇宙進出の障壁になっている

  • Even with advancing technology,

    技術が進んでも

  • this cost isn't likely to be comparable with the price of an airline ticket anytime soon

    まだ飛行機程度にはなりそうにない

  • A space elevator would solve this problem

    宇宙エレベーターなら大丈夫

  • After construction,

    一度作れば 費用は大幅に減って

  • a space elevator is projected to reduce the cost one hundredfold to $200 per kilogram

    1kg200ドルになる

  • If an inexpensive space elevator costs 20 billion dollars,

    エレベーターが200億ドルなら

  • then we'll recoup our losses after launching only one million tons

    100万トン分運ぶことで元が取れる

  • Close to the weight of two international space stations

    宇宙ステーション2機分だ

  • So what would a space elevator look like in real life?

    どうやって作るのだろうか

  • A space elevator has four major components:

    主な構成要素が4つある

  • the tether, anchor, counterweight and climber

    テザー 錨 おもり 上昇機だ

  • The elevator part of the space elevator is the tether and the climber

    紐状のテザーが地球と終点を繋ぎ

  • It extends from the surface of the Earth to space

    上昇機がそれを昇る

  • The climber is like a conventional elevator carriage

    普通のエレベーターのように

  • A chamber that works its way up and down the tether

    これで昇り降りをする

  • At the base would be an anchor

    地下には錨を置き

  • pinning the tether to the Earth along with a port for climbers

    これでテザーを地球に固定して

  • At the top is the counterweight which holds up the tether

    上からはおもりが引っ張る

  • The tether is held tight like a rope

    これによりテザーは

  • and supported from above by the tension from the counterweight

    伸びた状態で安定する

  • Located higher than 36,000 kilometers above the Earth's surface

    その長さは3万6000キロ以上になる

  • At the counterweight could be a space station,

    おもりとして使えるなら

  • a launching point for all missions from the spaceport elevator

    発射台などを置くことも可能だ

  • But can we actually build one?

    しかし実際 作るのは難しい

  • It's hard to say

    特にテザーは

  • The biggest challenge is the tether

    軽くて 安くて

  • It needs to be light, affordable

    今ある物質より強いものが必要だ

  • and more stable than any material we can produce right now

    グラフェンやダイアモンドナノ糸は

  • There are promising materials like graphene and diamond nanothreads,

    強さが不十分だ

  • but even they may not be strong enough

    強さ以外にも

  • And aside from being incredibly strong,

    雨による腐食や宇宙の放射線

  • the tether would also have to withstand atmospheric corrosion, radiation

    デブリに耐える必要がある

  • and micrometeorite and debris impacts

    さらに 上昇には数日かかるが

  • Additionally, it takes several days to climb the elevator

    その動力は何なのか

  • How do we power the climber?

    莫大なエネルギーだ

  • It requires a lot of energy to go up

    原子炉でも乗せるのだろうか

  • Do we need a nuclear reactor on our elevator carriage?

    レーザーで何とかできるのか

  • Or do we beam it power from the ground with a super powered laser?

    テザー3万6000キロ分の材料は?

  • And where do we get the raw materials for a 36,000-kilometer-long tether?

    地球から伸ばすのか

  • Do we make it on Earth and launch it into space?

    宇宙から地球に伸ばすのか

  • Or do we make it in space and lower it down to the Earth?

    小惑星から調達できるか

  • Could asteroid mining be the answer?

    技術的障壁はまだ山のようにある

  • Put simply, there are still some major technological hurdles to overcome

    事故の危険性もある

  • And a space elevator is not without risk

    テザーが切れたら大惨事だ

  • Should the tether break, it would collapse in spectacular style

    もし地表近くで切れたら

  • If it breaks near the anchor

    上昇機が落ち テザーは宇宙に逃げる

  • the force exerted by the counterweight will cause the entire elevator to rise up

    宇宙で切れたら

  • ascending into space

    テザーが地球に落ちてくる

  • Should it break near the counterweight

    デブリは将来 大問題になるだろう

  • the tether will fall,

    もし作るのなら 失敗は許されない

  • wrapping around the world and whipping the end off

    だからまずは月に作る

  • The resulting debris in orbit could pose serious problems to future spaceflight

    という案もある

  • If we build a space elevator on Earth, we have to do it right the first time

    重力が地球より弱いので

  • For these reasons some experts have proposed first building

    ケブラー等の物質がテザーに使える

  • a space elevator on the Moon

    困難な挑戦でも

  • The Moon's gravity is much weaker than the Earth's

    宇宙エレベーターの価値は大きい

  • so a flimsier but existing material like kevlar

    宇宙進出の真の一歩となるだろう

  • could serve as a tether

    実現できなくても

  • Even with all these challenges,

    その過程で多くを学べるはずだ

  • the payoff of having a working space elevator would be immense

    宇宙の時代が来れば

  • It might be the first step to truly becoming a space-faring civilization

    輝く未来は夢ではなくなる

  • Maybe we will never build a space elevator,

    Subtitles by the Amara.org community

  • but in trying to do so we might learn an awful lot

  • And when it comes to the exploration of the universe,

  • there can't be too many dreams of a glorious future

  • Subtitles by the Amara.org community

It's hard to get to space

宇宙への旅

字幕と単語
審査済み この字幕は審査済みです

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

B2 中上級 日本語 宇宙 エレベーター 地球 上昇 ロケット 軌道

宇宙エレベータ―空想科学か人類の未来か(Space Elevator – Science Fiction or the Future of Mankind?)

  • 755 101
    mommy に公開 2016 年 05 月 12 日
動画の中の単語