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发表于 2016-7-13 00:07:57
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5. The Twin Paradox
5. 双胞胎悖论
Albert Einstein didn’t have a twin brother, but he had some funny ideas of what you could do with one. He imagined two identical twins. Let’s call them Al and Bert.
爱因斯坦当然没有双胞胎兄弟,但他有个有趣的关于双胞胎的假设。假设有对双胞胎兄弟——叫阿尔和伯特。
Now Al is a couch potato, but Bert likes to travel. So, he hopsinto a spaceship and zooms off at close to the speed of light. That’s when Einstein’s special theory of relativity kicks in.
阿尔是个电视迷,伯特却爱旅行。 于是伯特跳进一艘太空船,以接近光速离开。这时爱因斯坦的相对论就插进来了。
It says that the faster you travel through space, the slower you move through time. So from Al’s point of view, Bert’s time would be moving slower than his own. To put it another way, time might fly when you’re having fun, but when clocks fly, they run more slowly in relativity.
相对论认为,穿越太空的速度越快,你所经历的时间就越慢。从阿尔的角度看,伯特的时间比自己的要慢。换一个角度开看,快乐的时间总是过得飞快,但钟表却会走的相对较慢。
After a while, Bert decides to head back, still at close to the speed of light and return to his brother with his holiday snaps. But when Bert arrives home, Al will now be older than his twin, which makes their double dates a lot more awkward.
过了一段时间,伯特决定回头,仍然以近光速飞行,带着礼物回去看他的兄弟。但当伯特到家时,阿尔会变得比他要老,这就会使他们一起约会时变得很尴尬。
Although it seems implausible, Einstein just followed his theory to its logical conclusion, and it turns out he was right. This concept of time dilationprovides the basis for our Global Positioning System, which is how your SAT NAV knows you need to turn left in 200 yards.
尽管这个悖论很难以置信,爱因斯坦只是让他的理论符合逻辑,而最终证明他是正确的。“时间膨胀”的概念可以在我们的GPS系统中证明,这就是为什么你的卫星导航系统总是出错。
6. Schrodinger’s Cat
6. 薛定谔的猫
Erwin Schrodinger was a physicist, a theoretical biologist and probably more of a dog person. In the 1920s, scientists discovered quantum mechanics, which said that some particles are so tiny you can’t even measure them without changing them. But the theory only worked if before you measure them, the particle is in a superpositionof every possible state all at the same time.
埃尔温-薛定谔是物理学家、理论生物学家,同时可能是“爱狗不爱猫”派。19世纪末20世纪初,科学家创立了量子力学,认为一些粒子十分微小,以至于不可能在不影响的前提下测量。理论说明,在你测量粒子之前粒子处于“叠加状态”中,同一时刻可能呈现出不同状态。
To tackle that, Schrodinger imagined a cat in a box with a radioactiveparticle and a Geiger counter attach to a vialof poison. If the particle decays, it triggers the Geiger counter, releases the poison and bye-bye Tiddles.
为了进一步说明,薛定谔假设一只猫、一个放射性粒子同在一个盒子里,盒子里有一个连接着毒气罐的盖革计数器。如果粒子衰变,盖革计数器就会触发,释放毒气。所以再见了,猫咪……
But if the particle is in two states, both decayed and not decayed, the cat is also in two states, both dead and not dead until someone looks in the box. In practice, it’s impossible to put a cat into a superposition. You have the animal-rights lobby up in arms.
但是因为粒子同时处于两种状态,既可能衰变又可能不衰变,那么猫也可能同时处于两种状态。即是死的,又是活的。直到有人开始观察盒子里。现实中,猫是不可能被处于叠加状态的。因为动物保护主义者会阻止。
But you can isolate atoms, and they do seem to be in two states at once. Quantum mechanics challenges our whole perception of reality. So maybe it’s understandable that Schrodinger himself decided that he didn’t like it, and was sorry he ever started on about cats.
但是你可以分离原子,让粒子同时处于两种状态。量子力学挑战着我们对于现实的整体认知,这就是为什么薛定谔本人并不喜欢它,以及为那只可怜的猫感到抱歉的原因。
(编辑:何莹莹) |
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