# See earth history

Hi friends,

There is a thought process that intrigues me.

If light reflected from earth reaches a blackhole farther that formation of eath lightyear distance. Slingshot the ray back to earth, and on earth we somehow capture those radiation.
Assuming signal lost is very low somehow.
Any comment explain question more clearly or any answers are most welcomed.

#### MANISPACERING

if light is reflected from earth passing throught he thick atmosphere with refraction and reaches the nearest black hole at centre of our Galaxy -A-S*its not slingshotted , its just consumed by it and changes its frequency and radiate at at the other end with laser flares and spikes ...and you lost your light !!

Catastrophe

i mean if Light passes in the accretion disk and surrounds the blackhole and eventually get enough centrifugal force to escape its orbit in direction of earth again

#### MANISPACERING

i mean if Light passes in the accretion disk and surrounds the blackhole and eventually get enough centrifugal force to escape its orbit in direction of earth again
its not there in light , massless energy particles never could circle around the accretion disk and to surround it "black holes "are not actually a sphere ! there is under estimation in this part !

#### billslugg

Yes, some light could be slung around a black hole and returned to Earth. The nearest black hole is 5,000 light years away. We would be looking at the Earth over a distance of 10,000 light years. If we used an optical telescope of say 100 meters in diameter, at the green wavelength, 650 nanometers, the resolution of the sytem, in degrees, would be 70 times the wavelength divided by the mirror diameter. Result is 5e-7 degrees. At 10,000 light years the smallest detail that could be resolved is 700 million kilometers which is bigger than the orbit of Mars.

#### Catastrophe

##### "There never was a good war, or a bad peace."
There you have a good technical reply to a question that I, personally, found quite difficult.
Light is reflected from Earth (normal) and passes close to (but not trapped) by a black hole, and happens to be returned to Earth. What do you see - is that the question? Well, you see what the light was last reflected by. If it is just bent, and not reflected by anything else, that would be Earth, with some modification of wavelength along the way.

It would be interesting to know what OP had in mind when asking this question.

Cat

#### billslugg

I suspect the OP was intended to explore the feasibility of looking at the edges of a black hole to see the Earth as it was many years ago.

#### Catastrophe

##### "There never was a good war, or a bad peace."
billslugg
The light would already have taken years since reflecting from Earth, so you mean additional effects from the black hole, other than slingshotting?

Cat

#### billslugg

The black hole would warp the space around it to such an extent that an impinging photon could "do a 180" and be returned on a path back to Earth. The image made by all those returned photons would be extremely distorted. If the black hole was moving radially relative to Earth then the photons would become red shifted or blue shifted.

Catastrophe

#### Catastrophe

##### "There never was a good war, or a bad peace."
OK. Thank you for that clarification.

Cat