>>18505295Their video assumes a total eclipse which means a mirror would need to withstand 5,000-10,000 degrees F, meaning it would have to be miles wide of solid Tungsten. If it took 1000x all the resources we have ever launched into space we still could not do that. It's not exactly practical. A mirror far enough away to be made of a thin heat shield is much more practical, but even with multiple heavy lifters it would be too close to the planet to block all the solar radiation.
Not to mention, you cannot just put anything in space wherever you want. It's a symphony of moving parts. There are actually only a few null spots where gravity between one entity and another is neutral. These are called Lagrange points, and the L1 is in front of a planet, it's the only place a space mirror could go. For Venus this point is only about 1M KM away, so the mirror would have to be tens of thousands of miles wide to totally eclipse Venus. No total eclipse version is possible without wasting too much of our resources on it. A partial is all we can do. It is going to take a while. The surface is also volcanically active, so we really have no idea how long it could take to cool enough to operate on.
Moreover, the Lagrange points are filled with asteroids at L1, L4, and L5, so an extremely significant effort must be carried out to track every nearby stellar object so that we can predict safe places to put shields or solar panels or even satellites. We would have to monitor the surface temp all the time.
I'm being generous to say potentially thousands, Venus is possibly so volcanic it could be millions of years away from usable.
Kurzgesagt is hopelessly optimistic and naive. We can make solar satellites right now and it would be green, but politicians aren't even talking about a treaty to make it possible. It would beam power all over the planet as we spin so we need to be buddies with everybody here first. We won't even accomplish that in 60 years.
