Here is a physics question Emily and I were debating recently: Imagine you are floating in deep space, a few metres from your space ship. All you have are a space suit – from which nothing can be vented – and a bowling ball in your hands. The obvious way to shift yourself towards your ship is to throw the ball in the opposite direction. If you are very patient, you could also (a) wait for your ship’s gravitational field to draw you in or (b) release the bowling ball, letting it hit you and push you back.
Is there any way to generate movement towards the ship without releasing the ball? My contention is that any way you can move it without letting go will only put you in some kind of spin, it will not actually move you towards your ship. Basically, this is because Newton’s third law ensures that any collection of actions will be self-compensating. Am I right to believe so?
Note: One major reason for confusion about this is because we are used to situations in which it is possible to push off something. When you stand on the ground and hurl a ball on earth, both your mass and that of the earth absorb the equal and opposite force. Those floating helplessly in space have no such luxuries.