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Apr26-11, 03:48 PM
P: 778
A thought experiment for surpassing the speed of light

Quote Quote by k4ff3 View Post
You have a straight, light, hard, inelastic rod at hand. It's pretty long, long enough so that you can hold it out of your window and into your friends window at the other side of the street.

The way you and your friend communicate is through morse code. You move the rod a distance x so that it hits your friend's wall and makes a sound. *Bump--BumpBump-Bump* The morse code is easily heard and interpreted.


Make your rod reach from your house to another galaxy, and place your friend there. Continue communicating as usual. Will the information now travel faster than the speed of light?
No, because there is no such thing as a perfectly inelastic material. The force of pushing one end will propagate at the speed of sound through the material to the other end.