1: 2019/03/15(金) 05:09:36.44 ID:+q+A4KO39
Physicists reverse time using quantum computer
MOSCOW INSTITUTE OF PHYSICS AND TECHNOLOGY
Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study comes out March 13 in Scientific Reports.
"This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time: from the past to the future," commented the study's lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.
"We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell's demon," Lesovik said. "The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time."
What makes the future different from the past
Most laws of physics make no distinction between the future and the past. For example, let an equation describe the collision and rebound of two identical billiard balls. If a close-up of that event is recorded with a camera and played in reverse, it can still be represented by the same equation. Moreover, one could not tell from the recording if it has been doctored. Both versions look plausible. It would appear that the billiard balls defy the intuitive sense of time.
However, imagine that someone has recorded a cue ball breaking the pyramid, the billiard balls scattering in all directions. One need not know the rules of the game to tell the real-life scenario from reverse playback. What makes the latter look so absurd is our intuitive understanding of the second law of thermodynamics: An isolated system either remains static or evolves toward a state of chaos rather than order.
Most other laws of physics do not prevent rolling billiard balls from assembling into a pyramid, infused tea from flowing back into the tea bag, or a volcano from "erupting" in reverse. But we do not see any of this happening, because that would require an isolated system to assume a more ordered state without any outside intervention, which runs contrary to the second law. The nature of that law has not been explained in full detail, but researchers have made great headway in understanding the basic principles behind it.
Spontaneous time reversal
Quantum physicists from MIPT decided to check if time could spontaneously reverse itself at least for an individual particle and for a tiny fraction of a second. That is, instead of colliding billiard balls, they examined a solitary electron in empty interstellar space.
"Suppose the electron is localized when we begin observing it. This means that we're pretty sure about its position in space. The laws of quantum mechanics prevent us from knowing it with absolute precision, but we can outline a small region where the electron is localized," says study co-author Andrey Lebedev from MIPT and ETH Zurich.
※続きは下記のソースでご覧ください
https://www.independent.co.uk/life-style/gadgets-and-tech/news/time-reverse-quantum-computer-science-study-moscow-a8820516.html
https://arxiv.org/pdf/1712.10057.pdf
MOSCOW INSTITUTE OF PHYSICS AND TECHNOLOGY
Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study comes out March 13 in Scientific Reports.
"This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time: from the past to the future," commented the study's lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.
"We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell's demon," Lesovik said. "The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time."
What makes the future different from the past
Most laws of physics make no distinction between the future and the past. For example, let an equation describe the collision and rebound of two identical billiard balls. If a close-up of that event is recorded with a camera and played in reverse, it can still be represented by the same equation. Moreover, one could not tell from the recording if it has been doctored. Both versions look plausible. It would appear that the billiard balls defy the intuitive sense of time.
However, imagine that someone has recorded a cue ball breaking the pyramid, the billiard balls scattering in all directions. One need not know the rules of the game to tell the real-life scenario from reverse playback. What makes the latter look so absurd is our intuitive understanding of the second law of thermodynamics: An isolated system either remains static or evolves toward a state of chaos rather than order.
Most other laws of physics do not prevent rolling billiard balls from assembling into a pyramid, infused tea from flowing back into the tea bag, or a volcano from "erupting" in reverse. But we do not see any of this happening, because that would require an isolated system to assume a more ordered state without any outside intervention, which runs contrary to the second law. The nature of that law has not been explained in full detail, but researchers have made great headway in understanding the basic principles behind it.
Spontaneous time reversal
Quantum physicists from MIPT decided to check if time could spontaneously reverse itself at least for an individual particle and for a tiny fraction of a second. That is, instead of colliding billiard balls, they examined a solitary electron in empty interstellar space.
"Suppose the electron is localized when we begin observing it. This means that we're pretty sure about its position in space. The laws of quantum mechanics prevent us from knowing it with absolute precision, but we can outline a small region where the electron is localized," says study co-author Andrey Lebedev from MIPT and ETH Zurich.
※続きは下記のソースでご覧ください
https://www.independent.co.uk/life-style/gadgets-and-tech/news/time-reverse-quantum-computer-science-study-moscow-a8820516.html
https://arxiv.org/pdf/1712.10057.pdf
- 24: 2019/03/15(金) 05:26:40.01 ID:HUOwrLc+0
- モスクワ物理学研究所の研究者は、米国とスイスの同僚と協力して、量子コンピュータの状態を1秒の何分の1か過去に戻しました。
彼らはまた、星間空間にある電子が自発的に短い過去に戻る確率を計算しました。
この研究は3月13日にScientific Reportsに掲載されました。
中略
チームは、短い過去に、自発的に局在化するほんの一瞬のうちに電子が「にじむ」ことを観測する確率を計算することに着手しました。
毎秒100億個の新しく局在化した電子を観測して宇宙の全寿命（137億年）を過ごしたとしても、粒子の状態の逆進化は1回しか発生しないことがわかりました。
中略
研究者らは、85％のケースで、2量子ビット量子コンピューターが実際に初期状態に戻ったことを発見しました。3つのキュビットが関係していたとき、より多くのエラーが起こりました。結果としておよそ50パーセントの成功率をもたらしました。
著者によると、これらのエラーは実際の量子コンピュータの不完全性によるものです。より高度な装置が設計されるにつれて、誤り率は低下すると予想されます。 - 2: 2019/03/15(金) 05:10:27.59 ID:CiC696WL0
- なるほどねー
- 3: 2019/03/15(金) 05:10:35.88 ID:mxLaX1w50
- 日本語で頼む
- 4: 2019/03/15(金) 05:11:03.90 ID:8WOUsB1q0
- 英語で読むのしんどいよ
日本語にしてよ - 7: 2019/03/15(金) 05:13:16.16 ID:TRFKol9b0
- ちょっと何言ってるかわかりません
- 8: 2019/03/15(金) 05:13:34.88 ID:3PTLNCJX0
- タイムマシーンができるのはもうすぐだよ
よだぐすうもはのるきでがンーシムイマ - 11: 2019/03/15(金) 05:16:58.71 ID:RjOsGLwM0
- >>1
これは逆転とは言わんだろ - 12: 2019/03/15(金) 05:17:12.28 ID:Ho715Yru0
- 完成したのか魔空空間
- 13: 2019/03/15(金) 05:19:27.50 ID:pS4/m9WW0
- 英語が読めないので記事の内容はさっぱりわからんが、時間というのは概念に過ぎないので進めたり巻き戻したりすることは出来ないよ
- 14: 2019/03/15(金) 05:20:28.90 ID:bZlyEvg/0
- >>1
なるほど見た瞬間全部理解した - 18: 2019/03/15(金) 05:22:48.66 ID:KfWXe4Tp0
- 地球を逆回転させれば時間は戻るよ
- 20: 2019/03/15(金) 05:23:39.58 ID:J/HuNL7E0
- つまりネプチューンマンとブドーが使ったあの技のこと？
- 21: 2019/03/15(金) 05:24:34.65 ID:t1gQaBQQ0
- >>20
その通り（適当） - 22: 2019/03/15(金) 05:25:21.43 ID:TRFKol9b0
- さて、３０億年前のリュウグウに降り立ってみよう
おや、全く同じ世界だ
そりゃ、そうだ岩石に寿命は無いからね
「現在」だの「過去」だの「未来」だのっていうのは限りある命をもった
生命体の妄想だよ
巨大な装置を使って地球の自転を止めて、地球の公転を止めたら
事実上「時」は動かない
でも実際には、地球は太陽に向かって落ちていってしまい
そこで完全に「時」は止まるんだよ
生命体の話だから - 23: 2019/03/15(金) 05:26:34.37 ID:d1AiXcNt0
- エイプリルフールにはまだ早い
- 27: 2019/03/15(金) 05:28:14.45 ID:yE7Bn0qI0
- タイムパトロールがくるぞ
- 30: 2019/03/15(金) 05:33:47.49 ID:TRFKol9b0
- 地球の自転を加速し、地球の公転を加速させても未来には行けない
地球の自転を逆回転させても、地球の公転を逆回転させても過去には戻らない
物理学者は妄想に落ち込んでいる - 33: 2019/03/15(金) 05:46:33.00 ID:D4slPPsU0
- 銀河の速度を遥かに上回る移動手段がないとタイムマシーンができても意味がない
- 34: 2019/03/15(金) 05:47:47.94 ID:NGPSCSMz0
- たまげたなあ
全宇宙をモニタリングできる可能性があるってこと？ - 35: 2019/03/15(金) 05:48:00.48 ID:7YAJIeV80
- この手の実験って辻褄合わせに過ぎないんだよね
タイムマシンって無理だなぁと思い知らされるだけ - 36: 2019/03/15(金) 05:49:03.36 ID:nc/9coRR0
- ついにこの日が来たか。
いわゆる量子テレポーテーションの地平線の向こう側に到達したということ。
平行世界理論では、今この瞬間から未来人がやってくる可能性のある世界にシフトしたということだ。 - 37: 2019/03/15(金) 05:51:02.79 ID:3vPrYja90
- 量子力学で無重力を達成しようとする映画おバカすぎてくっそつまらんかったなあ
インターステラーだったっけ - 38: 2019/03/15(金) 05:51:04.05 ID:1/PpR5sv0
- 量子の世界では不可解な事はいろいろ起きるしたとえそれを人類が解明したとしても
一度地面に落ちたリンゴが木に上に飛び上がってまた枝にくっ付く事は未来永劫に起きえないだろうな - 39: 2019/03/15(金) 05:51:14.74 ID:2nIf5zTC0
- 原子崩壊してても観測しない限り崩壊してるかどうかはわからない
- 42: 2019/03/15(金) 05:53:25.38 ID:pyO5LUG00
- ムーンウォーク的なもんと思っていいんだよな
ダメだって言われてもそう思うことにするけど - 47: 2019/03/15(金) 06:03:12.10 ID:7tIfI2th0
- 相対性理論の概要知ってればわかることだけど、
老化現象の若返り的なことと、過去に戻ることは全然別だからな
過去に戻ってやり直すとかそういうのは理論からして全く影も形もない
想像の範疇を超えていないし、まあ不可能だろう - 48: 2019/03/15(金) 06:03:35.32 ID:/YlqdxX90
- >>1
要約すると、量子コンピュータ上の量子情報を上書きした後に元に戻す事(量子情報の巻き戻し)が50%の確率で成功した。なお、確率は量子コンピュータがまだ不完全であるためで技術が進み完成度が高まればもっと高確率で量子情報の巻き戻しが出来ると見ている
って感じか？
普通にバソコンのコマンドキャンセルからのロールバックの話にしか見えないな - 50: 2019/03/15(金) 06:10:22.51 ID:+6IwXcTh0
- そもそも時間の逆転の定義が・・・・
- 51: 2019/03/15(金) 06:12:33.36 ID:qpKv5tXj0
- 日本で時間を逆転すると英語になることがわかった
- 55: 2019/03/15(金) 06:13:54.05 ID:4QNRq6Va0
- おもったとおりだわ
- 43: 2019/03/15(金) 05:53:41.94 ID:L4HxmDGu0
- 物が元の状態に戻ったからって、時間が逆戻りしたわけではないだろう。
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