Imagine a huge pair of scissors, with blades one light year long. The handle is only about two feet long, creating a huge lever arm, initially open by a few degrees. Then you suddenly close the scissors. This action takes about a tenth of a second. Doesn't the contact point where the two blades touch move toward the blades' tips much faster than the speed of light? After all, the scissors close in a tenth of a second, but the blades are a light year long. That seems to mean that the contact point has moved down the blades at the remarkable speed of 10 light years per second. This is more than 108 times the speed of light! But this seems to violate the most important rule of special relativity -- that no signal can travel faster than light. What's going on here?
2007-01-05 07:30:13 · 5 answers · asked by rajeevan 1 in Science & Mathematics ➔ Astronomy & Space
I would have to agree with Chang. Do you realize how big those scissors would be??? They would have to billions and billions of miles long depending on how big the angle is of the scissor opening. The mass of these scissors for one would be completely and entirely too great and impossible to close in 10 seconds and impossible to make. It only takes 8 minutes for light to reach the earth from the sun and that is 93 million miles away. So the length of these scissors would probably have to be trillions of miles long. There is no way to for an object to travel faster than the speed of light. Simple as that. You're thinking too hard on this one.
2007-01-05 07:46:25 · answer #1 · answered by C_Rock136 3 · 0⤊ 0⤋
The contact point is not matter. No matter is travelling faster than light. Just the visual intersection. Similarly, if I wave a flashlight into the sky, somplace way out there, the end of the beam can move faster than the speed of light, but not the light making up the beam. No physical laws are violated.
2007-01-05 08:20:40 · answer #2 · answered by Gene 7 · 0⤊ 0⤋
You're neglecting both the increase in mass, and compression of distance, as you approach the speed of light. In theory, you could not close the scissors. At least that's what I recall from my Physics courses a couple decades go
2007-01-05 07:43:24 · answer #3 · answered by Robert F 2 · 0⤊ 0⤋
You have not yet considered the energy required to allow for these "scissors" to be closed in a tenth of a second. It seems to me that this is the primary flaw in your proposal.
2007-01-05 07:44:22 · answer #4 · answered by Dendryte88 4 · 0⤊ 0⤋
What makes you so sure that you can close the scissors in 10 seconds?
2007-01-05 07:35:40 · answer #5 · answered by Cheng J 2 · 1⤊ 0⤋