in einstein's famous gravity model - gravity is caused by a disruption of some fabric by an object with mass (i.e. the ball on the fabric causes the fabric to "expand" creating an inward force toward the ball for other objects). i was thinking about this and wondering the following: 1) if gravity is indeed this - i.e. a disruption or interference of something with the space-time fabric - could "mass" be described in the same way. i.e. - the mass of the object is defined by the way it interferes with the space-time fabric. 2) the speed of light could also be related then as such ... the light particles/waves - don't interact with the space-time fabric in the same way that "massive" objects do. light perhaps passes through the fabric as if it were a vacuum of space-time. in other words - imagine that a ball that falls down a tube - the ball's velocity is restricted by the friction of the tube. the tighter the tube (or the bigger the ball) - the slower it falls. but - if the tube is big enough, or the ball small enough - the friction of the tube becomes irrelevant - and the ball's velocity has a maximum potential. to tie this back to the previous concept- imagine that light is the ball - and space-time the tube - and in this case, the light particles/wave is not restricted by/influenced by the space-time fabric - and so reaches a maximum velocity. 3) a follow-on concept is that light particles/waves are only two-dimensional - i.e. they exist in only two dimensions instead of three (or three instead of four if you include time). thus - mass, or interference of the space-time field is defined by three space dimensions. i.e. in the same way that a box has an area but no volume - light has velocity - but no "real" mass. if that is the case - then perhaps, mass-energy equivalance is only true for certain dimensions. i.e. energy could exist in 1d and 2d particles/objects - even though they may have no mass. any thoughts?