Originally Posted by

**Gingervytes**
They ASSUMED incorrectly (on purpose), that there is an equal and opposite force from gas movement due to pressure gradient force. Escaping gas needs something to push off of

Mathematical proof that the thrust equation is false

Attachment 39978
Nope, rockets send material in one direction, if they are in space they still send that material in one direction.

Newton's law for every action there is an equal and opposite reaction then says that as the gases in the combustion vessel are moved in one direction the vessel is moved in the other.

No atmosphere needed