If I have solid rod several light year long and I push one of the ends. How long will it take for the other end to be pushed?

Question

Will it take years for the “movement” to be felt from the other end?

In: 19

Answer 1

It would probably take decades. Kinetic energy moves through a substance at that substance’s speed of sound. Kind of like how sound travels faster through water than air. Even in an incredibly hard substance like diamond the speed of sound is only 12000 m/s. That’s 5 digits to light’s 9.