I've seeen those, but I was never really certain how they worked.
So you're claiming light has weight?
Yes,....
well, sort of.
Light has momentum. The photons have no rest mass, but since they move at the speed of light and from all relative observers, always move at that speed, the photos have a measurable mass associated with it's high velocity. Do a Google search on "light, momentum, photon, mass" and you'll turn up a ton of good explanations.