Im studying general relativity right now and I dont understand the equivalence principle. I understand it when relating to objects with mass. When in a sufficiently small space you cannot tell whether your are being accelerated in space far away from any gravitational force, or if you are in a gravitational field. How ever it states that there is no experiment you can do to tell the difference between the two, including a light experiment. This doesnt make any SENSE!!! I was under the impression light has no mass, which means when it bends, it is due to the curvature of space time or if you like a gravitational potential. Which means sitting on the earth light would bend downwards towards the earth. But why would it bend in a spacecraft accelerating through space? Why is acceleration bending light? please help me
