Neeger Kirvega:
This could make me look stupid but... i got thinking.. and just cant figure it out.
Imagine a rocket, in space. So the rocket turns on engines and fire starts bursting out and the rocket should move forward because the engine is pushing the rocket that way.. but now think: what is it pushing itself against? shouldnt vacuum rather suck the rocket in the other direction?
No, not stupid at all -- because that is exactly what it SEEMS would have to happen. Lemme see if I can explain how rocket propulsion works in a vacuum. Ummm.........the engine causes the spacecraft to move by throwing mass one way (in this case high pressure gas) to get an opposite reaction. In other words it isn't pushing against anything. It is propelling itself with opposite force. A good example is a fire hose. With full pressure it takes two people to keep the hose from flying through the air, away from the flow of water. The water isn't pushing against anything, yet a very strong opposite force is created. Multiply the pressure of that water (moving mass) by 10,000 or whatever it is in the case of a rocket engine, and you have an uber powerful moving force, regardless of the atmosphere that it is used in. Hope that makes sense. I am tired.
F~