Thanks,
Not for a moment would I suggest the force described is not in total accordance with Newton's laws.
The question was/is does this force push, the good Professor suggests that Newtons 3rd law does not require a push force to exist. It is simply a mass transfer equation and that a rocket in space has nothing to push on, ie. absence of an atmosphere. Explaining the push force acts throught the combustor/nozzle does not sit with him.
I can think of a limitless list of examples to visualise the effects.
Shouldering a shotgun and firing it in space, I have no doubt the bruise on my shoulder would be just the same on earth as in space, and I don't bruise easy.
Explaining holding a fire hose while pointed at a wall (on earth) as opposed to pointing the stream into the open. In the first case the stream has a lot more to push on, ie. the wall as opposed to just air. The fireman of course will not notice any difference in hanging onto the hose in either case. For good reason there is none, it is not what it is pushing on but the mass ejection of the fluid. This example does not work for him either.
Frustration led me to question myself, so I sort other explanations here, just to be sure to be sure.
Last edited by Obidiah; 9th April 2013 at 11:12.