What will happen -- Mirrors on the Moon to illunimate the Earth....

[mrspeedybob]

Should we do it? IMHO, no. At least, not yet.
And since it's purpose is food production, I think we can rule out painting the moon.

Re-directing enough light for enough time for food production seems a bit impractical. Especially since so much un-used land is available to increase food production at a fraction of the cost. What might be practical though would be a large scale emergency lighting system. You could rotate the mirrors and illuminate remote areas for night time disaster relief, search and rescue, or military operations much more quickly then transporting and setting up large earth-bound generator / flood light systems.

 

[lightarrow]

if we fix huge amount of mirrors on surfface of moon...can we obtain light on Earth during night ?

In case, it could theorically be useful to concentrate those mirrors' light on collectors on Earth to get electric energy. Clearly those mirrors should be perfectly adjustable via Earth control. Not possible with actual technology, anyway.

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lightarrow

 

[Neon]

If we did build mirrors on the moon, it must be rotated as the moon is not only at different points of view but also like like up and down from the earth.​

And that is why we don't get the beautiful lunar eclipse every month.:(

 

[lightarrow]

If we did build mirrors on the moon, it must be rotated as the moon is not only at different points of view but also like like up and down from the earth.​

And that is why we don't get the beautiful lunar eclipse every month.:(

Certainly I didn't mean to rotate the Moon too :-) We should be satisfied to have light for half of the time (= it's better than nothing).
But probably it would cost less (for every kW of energy collected) to put many mirrors in orbit around Earth, I really don't know this.

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[OmCheeto]

...
Anyway, it's still a far better option to put em in Earth orbit. Their location above the night side as well as their orientation to the Sun is built right in.

I just learned this morning, that the Russians actually did this.
For a few hours anyways.

The Man Who Turned Night Into Day
WRITTEN BY BRIAN MERCHANT
January 20, 2016 // 10:00 AM EST
...
After years of development, in 1992, Syromyatnikov and his team launched the 88-pound Znamya-2 into space aboard a vessel called Progress M15, bound for the Mir space station as a secondary payload.
...
As planned, on February 4, Znamya left Mir. When it found its orbit a safe distance away, the mirror successfully deployed. And, sure enough, it sent a five kilometer-wide beam of light back down to Earth. The beam swept through Europe, moving from the south of France to western Russia at a reported speed of eight kilometers per second. “Several” turned out to be an overstatement—its luminosity was equivalent to a single full moon’s. Unfortunately, excessive cloud cover prevented the effect from being seen much on land; as the BBC reported, some Europeans reported noticing a flash of light as it glanced by, but that was about it.

Still, the theory had proved correct, and the design was sound. Znamya was de-orbited after a few hours and burned up in the atmosphere above Canada upon reentry.
...

 

[sophiecentaur]

It wouldn't increase the greenhouse gas effect as such

Why not? It could, if engineered perfectly, send all the sunlight arriving at the Moon, onto the Earth's surface. That could increase the energy arriving around the full Moon condition by about 1/16. The mirrors would need to focus and to track, perfectly. But that amount of extra energy would be more than any other source that has added to the Sun's energy input to the Earth.
But one needs to ask why we'd do that. It could well be more in our interest to use mirrors on the Earth's surface to get rid of a lot of the Sun's battering.

 

[Keith_McClary]

Rjukan sun: the Norwegian town that does it with mirrors

Last week for the first time ever, the winter sun shone on the Norwegian town of Rjukan. ... High on the mountain opposite, 450 metres above the town, three large, solar-powered, computer-controlled mirrors steadily track the movement of the sun across the sky, reflecting its rays down on to the square and bathing it in bright sunlight.​