system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If I have a 1 light year long stick and push it, why does that information not travel instantly?
gpt
Information travels through materials in a wave at roughly the speed of sound in the material, not light. When you push on the end of a stick, you are pushing on atoms that then have to push on adjacent atoms, which push on adjacent atoms, etc.etc. until the far end of the stick moves. There is no such thing as a perfectly rigid object.