776. Could you see a laser beam in outer space since it can't reflect off of anything? — RM, Rochester, NY
No. The reason that you can see a very intense laser beam as it passes through the air is that light can scatter off of dust particles and air molecules. When it does, some of the laser light is sent toward your eyes and you see the light coming toward you from the laser beam's path. But if there is no air in the path of the laser beam, the light will travel without scattering and you won't see the path at all.