Originally posted by woadman
yes, but hasn't it been proven that light "bends" around objects with great amt. of gravity ? Is that some form of friction or energy working against light while it tries to move thru space in a straight line ?
Not friction. Light simply follows the curvature of space. Gravity IS a curve in space so light just follows like a ball rolling down a hill that has bumps and holes in it, the ball just follows the path it encounters on its journey downhill.
Of course, the ball stops when it gets to the bottom of the hill but light just keeps going on its new course.
You can think of gravity as bending a spandex sheet, which is a decent approximation in a 2 dimensional way.
Of course the real bending is 3 and 4 dimensional. 4 dimensional because it also changes the flow of time. Close to a mass, time slows down, away from the object, time speeds back up closer to what it would be flowing, in a totally mass free system. Of course there can never be any place in the entire universe that is totally free of the effects of mass.
You get into near space, go away from Earth and you are now dealing with the gravity bending space effect from the sun.
You keep going and say you head due north out of the plane of the galaxy, even if you are a million light years away from the milky way, you are still on a curve created by the accumulation of all the stars in our milky way galaxy. You can see that by the fact Andromeda galaxy and the milky way are crunching to a crash in a billion or so years, space is bent in such a way as to be attracting entire galaxies and their attendant dwarf satellite galaxies like the large magellanic cloud and the small magellenic, they are captured by the gravity of the milky way. Space is bent around those objects in such a way as they fell into our galaxy and now the original galaxy is shattered and spread out in a million pieces, a shadow of their former selves, not even close to the more or less flatness of our own galaxy. So even if you got out of the milky way a million light years away there would still be the gentle bending of space from the mass of the entire galaxy added up together.