They would transmit light at some rediculously low speed and the light emergeing would be a record of anchient scenes on the other side.
Holy crap!
The reason I was asking about the speed of light is because I had this fantastical idea about sending cameras out into space to capture events that happened in earth's history and, of course, the camera would have to go faster than the speed of light or use some kind of warping.
For instance, sunlight bounced off Earth from Dealey Plaza on November 22nd, 1963 and is now somewhere out in space. Someone on another planet 43 light years away has just missed the opportunity to know if there was a second gunman on the grassy knoll.
In order to see that spot, you'd have to have the camera out in space in the direction that Earth was facing wherever it was in its orbit. That would be the easy part with computer models, I mean, figuring out where the camera would have to be, of course.
Naturally, the seemingly impossible part of it would be getting a camera out light years ahead of the light that left Earth in 1963. Also, the camera would have to be capable of seeing extremely small detail from light years away but we can pretty much do that already, right?