Eli5: If a laser is shined into space will it continue to infinity (if it doesn’t hit a solid object)?

Question

Seems like a gargantuan, if not infinite amount of energy would be required for this to occur

In: 10

Answer 1

It doesn’t take more energy to go further because it doesn’t use any up traveling. It’s just a clump of energy that happens to be moving in the same direction.

Same as how you can see stars for a super long distance, but it requires less energy because it’s only moving in a specific direction instead of everywhere.