Some people that don’t understand Newton’s Third Law of Motion: For every action, there is an equal and opposite reaction.” They use this misunderstanding in an attempt to claim that rockets couldn’t work in space because there’s no air for the rocket to push against. Misunderstanding basic science does not disprove anything.
Several people have kindly demonstrated how rockets can work in a vacuum*:
The Action Lab
*I use the common vernacular for vacuum to mean very low air pressure. There is no known perfect vacuum anywhere in the universe.