[MonroeDNA]

Exactly right.

If you throw a bseball backeards, you get moved forwards. Conservation of mommentum.

If the baseball hits a trampoline, and comes back and hits you, you move forward sitll, though the trampoline moves backwards.

Rockets fly in space (vacuum) because they throw things backwards (hot particles). Nothing to push against, but nothing needs to.

"For every reaction, there is an equal, but opposite reaction." Jet engines, rocket engines, and propellers work, giving a nod to this statement.

[MonroeDNA]

The trampoline bounce-back thing is analogous to blasting of from a concrete pad, or,"pushing" against water, or anything.