>>10954550>you're not propagating a sound through the stickThe speed of sound is, more generally, the speed of vibrations in the material. By tapping one end you are sending vibrations to the other. You cannot think of an object this size as perfectly rigid.
>like if you shine a laser pointer at the moon No, it's not like that. Unlike the point of laser light, a perfectly rigid stick could be used in faster-than-light communication. You could tap out a message in morse code instantaneously to someone a lightyear away, for example.
