I have a question about artificial gravity in a spinning space station.

From astro.cornell.edu:

In space, it is possible to create "artificial gravity" by spinning your spacecraft or space station. When the station spins, centrifugal force acts to pull the inhabitants to the outside.

If a person in the space station is moving in a circle along with the space station, the centripetal force is towards the centre. So how will the person be "pulled to the outside"?

  • $\begingroup$ The person just keeps going straight, it's the station that's pulled towards the centre. $\endgroup$
    – M. Enns
    Commented Apr 20, 2017 at 22:39
  • $\begingroup$ Centripetal force is the inwards force needed to keep an object in circular motion; the force itself must have some physical origin, such as tension in the beams of the space station. Centrifugal force is the outwards force felt by an object in a rotating reference frame; the force itself is fictitious, and arises since the object's natural tendency is to travel in a straight line. $\endgroup$
    – gj255
    Commented Apr 20, 2017 at 22:50

1 Answer 1


The force of gravity we feel is really not gravity, but it is the bulk resistance from material we stand on. In elementary physics courses we call this the normal force. In more advanced physics such as general relativity we see the material of the Earth as deviating our path from a geodesic. With gravity there is no force to feel, except in the case of extreme tidal forces. So if you are on a rotating spacecraft the floor keeps pushing up on you just as the ground or floor does here on Earth. That is in fact what we feel. In the case of the rotating space station the material strength of the station maintains the centripetal force that keeps you on a circular path.


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