system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: what is negative g force and why does it make you feel so weird?
gpt
It's when you are being forced upward. For example, at the crest of a hill of a high-speed roller coaster where your momentum is going up from climbing the hill but the coaster's track curves downward faster than the parabolic trajectory you would otherwise travel. We're used to being held down by gravity, so when a situation occurs that makes up feel like we're being shot upward, it feels unusual to us. Particularly as we feel our organs being lifted inside our bodies.