Shielding against the Sun with a large sheet of aluminum foil in Earth orbit?

[hmmm27]

A new glass for greenhouses, perhaps. The holy grail for food production.

Perhaps, but in opposition to the pop-sci vision of "solar glass" building windows, a discrete assemblage including prismatic/mirror elements might be longer-lasting, allow for PV upgrades when available, and disallow the need for opaque PV elements.

 

[Algr]

- on Earth, the mirrors could be rigidly mounted and track the sun

For dissipating heat, this wouldn't be necessary. The mirrors could be permanently mounted facing up.

 

[Tiger Blood]

There is a new paper about shielding the sun. It proposes that 99% of shield material comes from the moon.

Here is the abstract:

This paper presents an approach to Solar Radiation Management (SRM) using a tethered solar shield at the modified gravitational L1 Lagrange point. Unlike previous proposals, which were constrained by the McInnes bound on shield surface density, our proposed configuration with a counterweight toward the Sun circumvents this limitation and potentially reduces the total mass by orders of magnitude. Furthermore, only 1% of the total weight must come from Earth, with ballast from lunar dust or asteroids serving as the remainder. This approach could lead to a significant cost reduction and potentially be more effective than previous space-based SRM strategies.

https://www.pnas.org/doi/10.1073/pnas.2307434120

 

[DaveC426913]

There is a new paper about shielding the sun. It proposes that 99% of shield material comes from the moon.

https://www.pnas.org/doi/10.1073/pnas.2307434120

What? No pics?

 

[hmmm27]

Does UV do anything useful ?

 

[DaveC426913]

Essential to creation of vitamin D..
Bacterial sterilizer...

 

[Tiger Blood]

What? No pics?
View attachment 330065

 

[Nik_2213]

I'm reminded of the picturesque Mediterranean islands etc whose towns & villages are widely white-washed / pink-washed to mitigate Summer sunshine. White is okay if you stay in shade, pink is probably better on the eyes, but photo-chromic polarised snow-glare goggles would seem advised...

Melting 'black-top' roads may become more of a problem, finding a non-glare binder that reflects infra-red problematic.

FWIW, we need some UV for our health: Trick is to acquire it in correct mix, strength and moderation...

 

[Strato Incendus]

Just out of curiosity and for context, what would happen to such a giant solar shield in the event of a solar flare?

I’ve also heard of concepts that act more like a rim with a lid that can be gradually opened, depending on how much sun you want to let through. Such a construction (again placed at the first Lagrange point) would probably be built out of a more robust material than a thin shield of aluminium. Nevertheless, the question remains of what a solar flare would do to such a construction.