Why do astronauts float and people on the surface of Earth do not?
The only difference is the ISST is 4220 my and the surface of Earth is 4000 my from CM. Centripetal force holds a body to the surface and centrifugal force allows man to stand up. Why does the same mechanism not work in orbit as on Earth? People on Earth and astronauts are orbiting the same CM. At first I thought it might be the weight of the atmosphere; but then I remembered the Moon: it has no atmosphere. Then I thought of the outward pressure due to the heat at the Earth CM; I'm not sure about the Moon.