Here we see the classic Newtonian rocket in action. Fire spews out the back end, the action, which then causes the equal and exactly opposite reaction of the rocket going forward.
It is a simple concept. This makes me wonder why I have spent fruitless months of mind numbing effort in my attempt to make sense out of that really screwy looking device. You see, the part that was giving me the problem was trying to make some sense out of the idea that somehow sending a flame, fires, toxic sludge and light rays out into space was somehow going to result in my ‘conserved momentum'. Let's assume that this Newtonian rocket sent one infra red heat ray out of the back of that device and then after some hours had passed you checked up on that infra red heat ray and found that it was zipping out past the orbit of Pluto, well on its way out of the solar system. Just how some vagrant light ray on a tour of the universe was somehow supposed to contribute to my ‘conserved momentum' was a mystery to me. I spent months trying to figure out just how such an equal and opposite action like that one was going to result in an equally opposite reaction like the one I was looking for.
It was then that I realized that this Newton law was just some matter based anthropocentric projection on the energy field of the universe, and like all supposedly ‘physical explanations' that explain matter based upon other matter, it involves a person's mind in some knotty matter based tautology that doesn't really explain anything.
Well having cleared my mind of that obfustication caused by matter based thinking, it was then that I realized that for every ‘action' there was an equal and same ‘reaction' Not an ‘opposite reaction'. A same reaction.
When you look inside such a device, what you will find is that as the pressure builds up, some small proportion of the force generated is polarized in the correct direction of desired travel, and results in the build up of a relatively small amount of momentum in the equal and same direction as a result. The rest of that momentum, the majority of the momentum in this system, goes into the steady stream of wasted energy that has its momentum polarized in the unequally opposite direction.