Banned for making titular jokes... about tits.
MichaelD.965: Banned for trying to school me in Science and FAILING. Gravitational lensing is when light curves around a galaxy, which is only possible because light has the barest minimum of mass possible in any particle. More famously, light can't escape a black hole's event horizon for exactly the same reason, only theoretical calculations can suggest what goes on in there.
Did you really forget that lasers are also famously hot in most uses (especially in fiction) and heat is heavier than light? At any rate, Shin Godzilla's laser-breath is possible because the multiple flamethrowers in his mouth are flexible and can aim towards a common target in the same way as the Death Star's dish
And all the rest of you are banned for not correcting him on this.
Banned because my science teacher told me that light has no mass, so blame him. And as for it having heat, light isn't heat, but it can
convert to become heat while being absorbed.