system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If gravity gets weaker the further we travel from earth, then what's the meaning of the term "Earth surface escape velocity"?
gpt
It's the speed an object incapable of self-propulsion needs to be moving at the surface of the Earth directly up in order to be able to keep going without being pulled back down.  Easier to think of it in terms of firing a projectile that carries no fuel or means of propulsion after it's launched (rather than a rocket or missile which continues to burn fuel and accelerate as it climbs).  Imagine a gun pointed straight up.  If a bullet was fired from that gun moving less than 11,186 m/s, it will ultimately turn around and return to Earth.  If it's moving at or greater than 11,186 m/s, it will keep going "forever" (until it encounters another gravitational influence or object).