萬物簡史 第21期:如何營造一個宇宙(13)

The analogy that is usually given for explaining thecurvature of space is to try to imagine someone froma universe of flat surfaces, who had never seen asphere, being brought to Earth. No matter how farhe roamed across the planet's surface, he wouldnever find an edge. He might eventually return tothe spot where he had started, and would of coursebe utterly confounded to explain how that hadhappened. Well, we are in the same position in spaceas our puzzled flatlander, only we are flummoxed bya higher dimension.

為了解釋空間是彎曲的，人們經(jīng)常提出一個類比，他們試圖想像，有個來自平面宇宙、從來沒有見過球體的人來到了地球。不管他在這顆行星的表面上走得多遠，他永遠也走不到邊。他很可能最終回到始發(fā)地點。他當然會稀里糊涂，說不清這是怎么一回事。哎呀，我們在空間的處境，跟那位先生的處境完全相同。我們只是糊涂得更厲害罷了。

Just as there is no place where you can find the edge of the universe, so there is no placewhere you can stand at the center and say: "This is where it all began. This is the centermostpoint of it all." We are all at the center of it all. Actually, we don't know that for sure; we can'tprove it mathematically. Scientists just assume that we can't really be the center of theuniverse—think what that would imply—but that the phenomenon must be the same for allobservers in all places. Still, we don't actually know.

如同你找不著宇宙的邊緣一樣，你也不可能站在宇宙的中心，說："宇宙就是從這兒開始。這是一切的最中央。"我們大家都在一切的最中央。實際上，我們對此缺少把握。我們無法用數(shù)學來加以證實?？茖W家們只是推測，我們確實是在宇宙的中央--想一想，這會意味著什么--但是，這種現(xiàn)象對所有地方的所有觀察者來說都是一樣的。不過，我們真的沒有把握。

For us, the universe goes only as far as light has traveled in the billions of years since theuniverse was formed. This visible universe—the universe we know and can talk about—is amillion million million million (that's 1,000,000,000,000,000,000,000,000) miles across. Butaccording to most theories the universe at large—the meta-universe, as it is sometimes called—is vastly roomier still. According to Rees, the number of light-years to the edge of this larger,unseen universe would be written not "with ten zeroes, not even with a hundred, but withmillions." In short, there's more space than you can imagine already without going to thetrouble of trying to envision some additional beyond.

據(jù)我們所知，自形成以來，宇宙只發(fā)展到光走了幾十億年那么遠的距離。這個可見的宇宙--這個我們知道而且在談論的宇宙--的直徑是1.5億億億(即1 500 000 000 000 000 000 000 000)公里。但是，根據(jù)大多數(shù)理論，整個宇宙--有時候稱之為超宇宙--還要寬敞得多。根據(jù)里斯的說法，到這個更大的、看不見的宇宙邊緣的光年數(shù)，不是"用10個0，也不是用100個0，而是用幾百萬個0"來表示。簡而言之，現(xiàn)有的空間比你想像的還要大，你不必再去想像空間外面還有空間。