system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If in the vacuum of space there are no exterior forces acing on a spacecraft, why can't we continuously speed up the craft to light speed with constant thrust?
gpt
It takes more and more energy to constantly accelerate a spacecraft. This means that as you approach C the amount of energy that you need to go faster approaches infinity. Sadly humans do not have access to infinite energy so we can never actually reach C.