The reason a rocket works in space and why you cannot pull yourself up by your own arms is simple. You are not causing newtons 3rd and conservation of momentum to take effect. You are not releasing mass. Now take away gravity, air. Then cut off your own arm and throw it away. Will you move?[/b]
You are pushing your own arm away just like a rocket pushes a part of its own mass away.
Not hard to understand is it?
Looks like (many of) you are incredibly confused about how things are able to move. I will educate you.
Newtons First LawAn object will remain at rest, or continue in motion, unless acted upon by an external force. Let's say we have a football, at rest, on a table. How can we move it? We could poke it with a finger. We could blow on it. We could lift one side of the table.
Q: What do all of these methods for moving the football have in common?
A: They apply an unbalanced force on the football.
Now imagine that someone swaps the football for one made of lead and covers it to look like the football we moved previously. They ask us to blow on it again, which we do. This time, our breath is not sufficient to overcome the normal force of the lead ball. We blow and blow and it goes nowhere. We poke it with our finger which
will move it, but it takes much more force on our part. The same with lifting the table to allow gravity to accelerate it toward the floor. More force required to overcome the normal force of the lead ball.
All of these examples are able to cause something to accelerate
without hurling mass which the space cultists are obsessed with.
They work by applying an
unbalanced force on an object.
That is all you need to understand Newtons first law.
No need to imagine two molecules in a chamber, or a grenade exploding in space. When you have digested (and squabbled over) that, I'll move on to the second law.