If I were to take a really really really (light years) long stick and push something on the end of it, would it happen “instantly”?

1.08K viewsOtherPlanetary Science

Obviously theoretical but if I took a light year long stick and say pushed a button at the other end would that button be pushed at the same time for me as say someone standing at the button? How does the frame of reference work when physically moving something? And could that “work” as a method of instant communication?

In: Planetary Science

34 Answers

Anonymous 0 Comments

Basically, you’re talking about rudimentary FTL communication.

In theory, yes, but the rod would need a few additional properties: infinitely rigid and massless. The rigid requirement is to remove any possibility of compression which would normally happen internal to the material. The massless requirement is to overcome internal inertia and gravitational influences.

In practice, no, because ideal material properties don’t exist – hence, theoretical.

Instantaneous communication would also break causality rules as we know them – that is, the person at the receiving end would read the message before light could arrive showing the sender transmitting the message.

You are viewing 1 out of 34 answers, click here to view all answers.