system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5 Is being weightless in orbit exactly like the sensation of endlessly falling?

Is falling in orbit the same as vertical falling, and do astronauts constantly have that sinking feeling and simply get used to it?  Is space sickness a thing like sea sickness, and are there cases of astronauts in training that just cannot overcome it?  When they get back to earth, does falling lose its thrill and roller-coasters etc just become mundane?
gpt
Well, all an orbit is is just falling but moving sideways fast enough that you miss. The feeling is what physicists call "freefall" and it's the first few seconds of falling before wind resistance really takes hold.