一分钟脑筋急转弯 60-Second Adventures in Thought
双胞胎悖论 The Twin Paradox
阿尔伯特 爱因斯坦并没有一个双胞胎兄弟 Albert Einstein didn't have a twin brother
但对于双胞胎 他提出了一个有趣的观点 but he had some funny ideas of what you could do with one
他假设有一对双胞胎兄弟 He imagined two identical twins
一个叫阿尔 另一个叫伯特 let's call them Al and Bert
阿尔是个宅男 Now, Al is a couch potato
而伯特喜欢旅行 but Bert likes to travel
他乘坐太空飞船 so he hops into a spaceship
然后以接近光速的速度飞入了太空 and zooms off at close to the speed of light
当时爱因斯坦刚刚提出相对论 That's when Einstein's special theory of relativity kicks in
相对论认为你在太空中的飞行速度越快 It says that the faster you travel through space
你的时间就过得越慢 the slower you move through time
所以如果以阿尔的角度去看 So from Al's point of view
伯特的时间就比阿尔的时间过得慢 Bert's time would be moving slower than his own
换句话说 To put it another way
玩耍的时候 时间可能过得很快 time might fly when you're having fun
但如果时钟也在太空中飞行 but when clocks fly
那么它们可能走得相对较慢 they run more slowly in relativity
一段时间之后 伯特决定回来 After a while Bert decides to head back
仍然以接近光速的速度飞回来 still at close to the speed of light
回来时他的兄弟正在度假打盹 and returns to his brother with his holiday snaps
但当伯特回到家里时 But when Bert arrives home
阿尔现在比他的同胞兄弟老 Al will now be older than his twin
他们的双对约会会显得很尴尬 Which makes their double dates a lot more awkward
尽管这看上去不可思议 Although it seems implausible
但爱因斯坦根据相对论理论推出了这个结论 Einstein just followed his theory to its logical conclusion
而且有证据显示他是正确的 and it turns out he was right
"时间膨胀"概念 This concept of 'time dilation'
为我们的全球定位系统提供了理论依据 provides the basis for our Global Positioning System
你的导航仪因此知道 which is how your Sat Nav knows
你需要"前方200码的地方向左转" you need to 'turn left in two hundred yards'