Loading...An intergalactic gravity mirror
Without leaving the planet it could be possible to see what was happening in the solar system billions of years ago – using a gravity lens type telescope that catches the light that travels around nearby black holes.
Not a new idea but an interesting one. Been discussed on stack exchange / physics for a while, here is a thread.
Its possible to use gravity as a lens, they should be possible to use it as a mirror also. Nice idea.