> If photons are massless, than how can black holes suck in light?
Galileo showed that all objects fall in the same way, whatever their
mass. It seems reasonable to me that this would include objects with
zero (or negative) mass, if such objects existed.
Einstein showed firstly that mass and energy are pretty much the same,
and secondly that gravity can be thought of as due to curvature in
spacetime, emphasising that the mass of the falling object is