Time Travel Simulation Resolves “Grandfather Paradox”

A Year of Living Dangerously

驚險刺激的一年

 - Writing about science and society invites reactions, good and bad, from the middle to the fringe
 - 這個討論科學與社會的專欄獲得了各界的回應，好壞都有。

作者╱克勞斯 ( Lawrence M. Krauss ) 
譯者╱宋宜真

  　　Last September I wrote my first column for Scientific American, and this September marks my last one. In writing on science issues relevant to our culture and society, there is an inevitable tension between sticking just to science issues and commenting on potentially hot-button social issues. I have tried during the past 12 months to strike some balance, but without fail those issues that stir the greatest outrage also stir the greatest interest.

　　去年10月，我開始為這本雜誌撰寫專欄，而今年10月號，則是我最後一篇。撰寫和文化及社會相關的科學議題，難免會在純粹科學議題以及具有潛在爆點的社會議題之間造成緊張。過去12個月來，我已經努力在這兩個端點間取得平衡，而這些文章在成功創造出一些議題的同時，不但激起強烈眾怒，也引發了廣泛的興趣。

　　Nothing seems to stir more discussion than pieces about science and religion, an observation that reminds me of the comment that Henry Kissinger reputedly made about academic disputes: they are so vicious because the stakes are so small. After all, science will continue irrespective of religious opinions, and I expect organized religion will continue to be a part of the cultural landscape, too, largely unaffected by the ongoing march of human knowledge, as it has been for centuries.

　　最能引起討論的，莫過於在科學與宗教上做文章了。這個現象讓我想起季辛吉對學術爭論給予的知名評論：學術政治之所以如此險惡，是因為賭注太小了。畢竟，不論宗教上的意見為何，科學還是會繼續走下去，而我預期，有組織的宗教仍會繼續存在於我們的文化地景之中，一如過去數百年來，它在人類知識的演進史中如此屹立不搖。

　　Probably my greatest surprise came from the column on my favorite elementary particles, neutrinos. Several notes of thanks came from scientists who have devoted their lives to studying neutrinos' properties; perhaps they feel underappreciated, even by their colleagues, for studying such ephemeral objects.

　　讓我最驚喜的，或許是那篇談論微中子這個我最喜愛的基本粒子的文章。幾位致力於研究微中子特性的科學家捎來了一些謝意，或許他們覺得研究這些瞬息萬變的粒子，即使在同儕間也未得到應有的重視。

　　Among topics I didn't get a chance to write about, one stands out, so I will take advantage of this last opportunity to elicit hate mail (and to shamelessly plug my new book about the late physicist Richard Feynman, which is relevant because of its title, Quantum Man).

　　還有一些主題是我想寫卻還沒有機會寫出來的，因此我打算利用這最後一次機會，再招致一些攻擊信函，並且厚顏無恥地順道幫我的新書《量子人》（Quantum Man）打打廣告（這本書寫的是關於已故物理學家費曼的事蹟），因為書名跟今天要談的東西有關。

　　No area of physics stimulates more nonsense in the public arena than quantum mechanics—and with good reason. No one intuitively understands quantum mechanics because all of our experience involves a world of classical phenomena where, for example, a baseball thrown from pitcher to catcher seems to take just one path, the one described by Newton's laws of motion. Yet at a microscopic level, the universe behaves quite differently. Electrons traveling from one place to another do not take any single path but instead, as Feynman first demonstrated, take every possible path at the same time.

　　物理領域中最能引起大眾胡言亂語的，莫過於量子力學了，理由很簡單：沒有人能夠以直覺掌握量子力學的概念。這是因為我們的經驗都來自於古典物理學的世界，如果投手投出一顆棒球，它只會有一條行進軌跡，也就是牛頓力學所描述的路線。但在微觀尺度上，宇宙的行為表現卻有很大的差異。費曼首度證實，電子從一處移動到另一處時，並不會只有單一路徑，而是同時出現在所有可能的路徑上。

　　Moreover, although the underlying laws of quantum mechanics are completely deterministic—I need to repeat this, they are completely deterministic—the results of measurements can only be described probabilistically. This inherent uncertainty, enshrined most in the famous Heisenberg uncertainty principle, implies that various combinations of physical quantities can never be measured with absolute accuracy at the same time. Associated with that fact, but in no way equivalent to it, is the dilemma that when we measure a quantum system, we often change it in the process, so that the observer may not always be separated from that which is observed.

　　尤有甚者，即便支配量子力學的是決定性的定律（我再次強調，它們是完全決定性的），但測量的結果只能以或然率來表示。這種內在的不確定性主要根源於知名的海森堡測不準原理，而這意味著我們無法同時絕對精準測量出各種物理量。與這相關（但絕對不是等同）的是，在我們測量量子系統的過程中，我們通常會改變它，因此觀察者永遠無法與被觀察物分開考量。

　　When science becomes this strange, it inevitably generates possibilities for confusion, and with confusion comes the opportunity for profit. I hereby wish to bestow my Worst Abusers of Quantum Mechanics for Fun and Profit (but Mostly Profit) award on the following:

　　科學走到這怪異的地步，難免會引發困惑，而困惑便是獲益的良機。接下來我要頒佈「最會濫用量子力學以獲得樂趣和利益」（其實主要是利益）的獎項給下列人事物：

　　DEEPAK CHOPRA: I have read numerous pieces by him on why quantum mechanics provides rationales for everything from the existence of God to the possibility of changing the past. Nothing I have ever read, however, suggests he has enough understanding of quantum mechanics to pass an undergraduate course I might teach on the subject.

　　喬普拉（Deepak Chopra）：我拜讀了這位仁兄的許多大作，從而得知如何由量子力學證明上帝的存在以及改變過去的可能性。然而，就我來看，這位仁兄對量子力學的知識程度，恐怕還不足以通過我在大學開授的相關課程。

　　THE SECRET: This best-selling book, which spawned a self-help industry, seems to be built in part on the claim that quantum physics implies a “law of attraction” that suggests good thoughts will make good things happen. It doesn't.

　　《祕密》（The Secret）：這是一本暢銷書，也帶動了「自我幫助」的相關產業。此書似乎立論於「量子物理的吸引力法則」這個不實陳述，進而宣稱正面思考會帶來美好的事物。最好是。

　　TRANSCENDENTAL MEDITATION: TMers argue that they can fly by achieving a “lower quantum-mechanical ground state” and that the more people who practice TM, the less violent the world will become. This last idea at least is in accord with quantum mechanics, to the extent that if everyone on the planet did nothing but meditate there wouldn't be time for violence (or acts of kindness, either).

　　超覺靜坐：超覺靜坐者認為，一旦他們達到「量子力學的低能量基態」便得以飛翔，而只要有更多人參與超覺靜坐，暴力事件便會減少。後面這個觀念勉強符合量子力學：如果地球上所有人都放下手邊的事情專心靜坐，他們就沒有時間從事暴力活動（以及慈善活動）了。

　　For the record: Quantum mechanics does not deny the existence of objective reality. Nor does it imply that mere thoughts can change external events. Effects still require causes, so if you want to change the universe, you need to act on it.

　　備註：量子力學並未否認客觀真實的存在，也不表示光靠思想便可改變外在事物。事情依舊需要原因才會發生變化，因此倘若你想要改變世界，你還是得實際行動。

　　Feynman once said, “Science is imagination in a straitjacket.” It is ironic that in the case of quantum mechanics, the people without the straitjackets are generally the nuts.

　　費曼曾說：「科學是穿著約束衣進行想像。」諷刺的是，在量子力學的例子中，那些不穿約束衣的通常都是瘋子。

Could time travel soon become a reality? Physicists simulate sending quantum light particles into the past.

發現最大古老黑洞 是太陽100億倍

這個宇宙巨人位於遙遠的星系中央(示意圖)

德國科學家模擬旋轉宇宙中的「時間旅行」

時間旅行不是夢 — 哥德爾的旋轉宇宙

自然科學的邊緣與本質

不可承受之重

飄飛的雪花，從事科學研究真正的壓力究竟從何而來？

千萬別選錯座標

日心說最重要的意義就是「一切都恰到好處地兜在一起」。

沉淪

高涌泉

Research Into Ghostly Particles Wins Nobel

兩名物理學家憑控制量子粒子獲諾貝爾物理學獎

Toppling the Giant

推倒巨人

比光速還快的粒子略過愛因斯坦？
Will faster-than-light particles bypass Einstein? Lightspeed particles 'may break laws of physics'.

日本輻射外洩，會影響我們嗎？

日本福島第一核電廠發生了史上第二嚴重的核子災變，距離福島2500公里的台灣是否可能受到輻射外洩的波及？

台灣會不會發生大海嘯？

探索天文的利器──光學望遠鏡

令人著迷的「平行」宇宙