Hypotheticly yes, but you would need something very big to block the light or reduce it. Planet sized for example, this is one way we detect planets around other stars, by measuring how much the light dims.

Another potential problem is that (at leas according to this wikipedia article https://en.wikipedia.org/wiki/List_of_nearest_galaxies) the closest galaxy is around 33000 light years away. So any signal we send will take 33000 years to get there and any potential return would take the same amount of time, so 66000 years in total. That is far longer than any human civilization exists

Or if the conservatives didn’t kill our solar industry in the eraly 2010s we could have had a lot more renewables

No we didn’t. At least in all charts I could find (here for example) the usage of coal and gas did not change in the worst case and went down in the last few years because renewables increased

I assume you are talking about fission. We (Germany) somewhat famously don’t have nuclear power anymore and I think that is a good thing. IMO the risks overweigh the benefits, and I don’t only mean the risk of a nuclear power plant blowing up. Aside from that there are two mayor downsides.

First they are fucking expensive to build at least any recent projects I have heard of are billions over cost.

Second is the waste problem which specifically is a hot topic in germany, there just doesn’t seem to be a good way to get rid of it. I have read some comments saying that there are ways to deplete them even more but never heard of such a system being actually used.

A minor point for me is also that I think, that less centralised infrastructure using wind and solar energy is a better way to go.

Some proponents (especially online) love to talk about “small” reactors, but I’ve never heard of one actually being in use, at most there were tests of it is actually feasible (as far as I know at least, and I am not an expert)