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My old toy train is a perfect way of illustrating Einstein's profound question.
我以前的玩具火車 最適合用來解釋愛因斯坦的深奧問題
of what the fixed speed of light meant for the universe.
光速恒定對宇宙的意義
Einstein started with a simple question:
愛因斯坦先從一個簡單的問題開始
How fast is something like this little train moving?
這列小火車的行進(jìn)速度有多快
Well,this is the 1950s and toy trains weren't all that good.
當(dāng)時是1950年代 玩具火車的品質(zhì)并不怎么理想
So let's say it's traveling at about one mile per hour.
就假設(shè)行進(jìn)速度大約每小時1600米吧
But change way you look at it from. You get a different answer.
但若改變觀察點 就會有不同的答案
The earth spins on its axes at around 1,000 miles per hour.
地球以大約1600公里的時速繞著地軸旋轉(zhuǎn)
So,seen from up here,my train is actually traveling much faster.
所以若從這里看 這列火車的速度就快得很多
Of course,the earth as a whole is orbiting the sun at 67,000 miles per hour.
當(dāng)然整體而言 地球繞著太陽旋轉(zhuǎn) 且時速為108000公里
And even the sun isn't stationary. It is orbiting the center of the milky way.
就連太陽也并非靜止 而是繞著銀河系的中心旋轉(zhuǎn)
And the Milky Way is moving through space,too.
而銀河系也在太空中旋轉(zhuǎn)
So how fast is the train really moving?
那么火車的行進(jìn)速度究竟有多快？
Well,it all depends on way you see it from.
答案完全取決于從哪里觀察
It could be 1 mile per hour,1,000 miles per hour,60,000 miles per hour.Or many times faster.
可能是每小時16公里 每小時16000米 每小時10800公里 甚至快好幾倍
