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More Einstein
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- Karthik Narasimhan
- @nkarthik
More about everyone's favorite physicist. From the New Yorker.
The Einstein exhibit at the Museum of Natural History. Wish I could go.
“…but it is strangely comforting to see that the man who created the modern world was so frequently befuddled by it. His relationships often failed. He fled one country and lived uneasily in another. He hated totalitarianism but was opposed to capitalism. He barely knew his sons.”
In the exhibit, the curator, Michael Shara, explains how light travels, why time warps, what makes stars shine. Walk in the door and you are immediately greeted with a view of yourself as seen through a black hole. (It is not a pretty sight.)
And then this : an almost apocryphal article about the relationship between Einstein and Gödel, that had (yet another) attempt to explain relativity to the layman. No matter how many times I read about what Einstein did in 1905, I can't help being astonished.
Suppose to make things vivid that the speed of light is a hundred miles an hour. Now suppose I am standing by the side of the road and I see a light beam pass by at this speed. Then I see you chasing after it in a car at sixty miles an hour. To me, it appears that the light beam is outpacing you by forty miles an hour. But you, from inside your car, must see the beam escaping you at a hundred miles an hour, just as you would if you were standing still: that is what the light principle demands. What if you gun your engine and speed up to ninety-nine miles an hour? Now I see the beam of light outpacing you by just one mile an hour. Yet to you, inside the car, the beam is still racing ahead at a hundred miles an hour, despite your increased speed. How can this be? Speed, of course, equals distance divided by time. Evidently, the faster you go in your car, the shorter your ruler must become and the slower your clock must tick relative to mine; that is the only way we can continue to agree on the speed of light. (If I were to pull out a pair of binoculars and look at your speeding car, I would actually see its length contracted and you moving in slow motion inside.) So Einstein set about recasting the laws of physics accordingly. To make these laws absolute, he made distance and time relative.