system
Given the following post, respond as if you're commenting on Reddit:
human
Why does a photon move non-stop in space and where does it get "energy" to do so?

Why does a photon move non-stop in space and what is giving the photon energy to move? Does this energy come from the photon itself, from space, or from something found in space?
gpt
Motion does not require a continuous supply of energy to keep moving. The reason a car must always be powered to retain its speed is that friction from the air and road and internal frictions of the car "steal" energy away from motion (which heats the tires, moves the air etc...), so your engine provides power to replace that energy.

In vacuum however, nothing stops you once you're moving, both photons and baseballs travel forever in space never having to replenish their kinetic energy. This is Newton's 1st law. They retain the energy they are given and do not change their energy unless they interact with something. In this way, Newton's 1st law is a consequence of the conservation of energy.