Specifically, I have often wondered whether gravitational lensing might be able to (theoretically) be used in order to see light reflecting off the Earth that has zoomed off into space and been bent by one object after another until it comes full circle back to Earth again. Given the distance the light would have travelled, could we not use this technique to peer back through time at our own planet?
- Is it reasonable that this could happen given the size of the universe and the mass and distribution of objects within it?
- Given the restraints above, would be be able to estimate how far back in time we are looking?
- Given the above, how bright would something have to be in order for its light to travel this distance and still be detectable?