Weird idea but I wonder if there are ways to take this from "crazy tech" to "hard tech".
Weird idea but I wonder if there are ways to take this from "crazy tech" to "hard tech".
The Sun. Literally.
Satellites have to be that far for the Einstein ring to be bigger than the apparent size of the solar disk.
Edit: to make it a bit more clear, the gravitational lens does not quite behave like a normal lens. Instead, you see the light from _behind_ the object. So if you're too close to the lensing object so that the Einstein ring is not larger than it, you'll just see a part of the object to be a bit more bright.
Also, the gravitational lens does not actually _focus_ the image, it distorts it into a band around the lensing object.
Or to put it another way: A gravity lens bends space so that the light from behind an object curves around it while travelling straight.