A graphene solar shield is not obviously intractable.
#Graphene is increadibly lightweight, at 0.763 mg/m^2, or 0.763 kg/km^2. A shield capable of blocking 1% of solar flux (1% * 2 * pi * (8000 km)^2) would weigh about 3 million kg, or 3,000 tonne, if comprised of a single graphene layer.
The actual mass budget would be far larger, but based off this minimum with addition of more structure, guidance/station-keeping, and possibly some form of visibility enhancements.
And clarifying: I'm not saying this _will_ work or _is_ a good idea.
I'm only saying that it won't obviously _not_ work.
It's also a very impressive demonstration of just how _immaterial_ graphene is.
The questions of what a practical structure of such effect _might_ look like, and if or how graphene might be treated for reflectivity, or how that would affect the behaviour of any such shield, would be interesting.
The social network of the future: No ads, no corporate surveillance, ethical design, and decentralization! Own your data with Mastodon!