(August 24, 2018 at 8:10 am)polymath257 Wrote: What happens when you 'use the stick to turn off the sun'? You push on it. That produces a compression wave that travels down the stick at the speed of sound in that stick. This is much, much slower than the speed of light. So, in fact, it would take much longer than 8 minutes for the compression wave from your push to get to the sun. Once it does, and the sun goes out, the effects of that move outward at the speed of light.
The point is that in relativity, there are no 'solids' that instantaneously transmit information from one end to the other. Such transmission happens as a compression wave along the solid which travels at much less than the speed of light.
Wow. Thanks for the info. But still it seems paradoxical to me for this reason: Let's say that the side of the stick that is near the switch is only 3cm away from it, but on earth, when I thrust the stick I thrust it 10 cm forward. If it takes it so long for my thrust to "register" on the other side of the stick, will I not feel the resistance of the other end striking the switch on my end?
I suppose, for sake of this second example, we could replace the lightswitch with a brick wall. Obviously, I can't push the stick with enough force to push through a brick wall. But how does that work if the stick is only 3 cm away from the wall and I thrust the stick 10 cm?
