This wiki page states the following about solar sailing, "a form of spacecraft propulsion using a combination of light and high speed ejected gasses from a star to push large ultra-thin mirrors to high speeds."
I understand the part where ejected gasses bump into the sail pushing the spacecraft.
But I dont understand how light can do this since light has no mass.
How does that work?
Does this mean that if I have a mirror balancing on a needle I would be able to push it over with my flashlight?