If gravity holds the space station in orbit then why is it 0g inside?
If gravity can hold the space station in orbit, than why does the supposedly from space tele- visit always shown as 0g. Wouldn't gravity be present in an orbiting body? Even minutely! the why don't the interviewed bodies fall towards the gravity holding the spacecraft in orbit?
Science humourist Dave Zobel had a go at answering Terry's question:
Dave - Why do the astronauts float about? If they just put on heavy boots, wouldnít they be able to stomp around like the rest of us? The brief answer Terry, is the same reason that when you jump off of a very high building with your keys in your hand Ė which I donít recommend Ė as you are descending to the Earth, your keys sort of float up from your hand. They donít stay anchored in your hand and the things that are in your pockets donít stay anchored there. and the reason for that is because you and your keys, and everything else are all falling at the same time and at the same rate, well thatís what's going on with the International Space Station and really, anything else in orbit. You are falling not to the Earth but around the Earth, but itís the same idea. And everything is falling. So, itís all falling at the same rate. Thatís also the reason that when astronauts train in the airplane known colloquially as the vomit comet where they go up and then come crashing down towards the Earth and then at the last moment, pull out and go up again and do that over and over, and over until everybody has had the chance to see what everybody else had for breakfast. There's that same weightless period and that gives them 20 or 30 seconds to be able to float around and feel what itís like to be in the International Space Station.
The space station in orbit is in "Free Fall" so everything in it experiences the same gravitational force and acceleration. The space station and everything in it is falling together, so there is no relative acceleration--no relative force. This is the same reason you feel weightless at the very top of the arc on a swing, or when the roller-coaster plunges, or if you ever happen to go sky diving.