I think building a assemble in space, space telescope would be the best use for a mega project in science. I admit I don't know enough about colliders to evalua

I think building a assemble in space, space telescope would be the best use for a mega project in science. I admit I don't know enough about colliders to evaluate the scientific impact. But I think once we figure out how to assemble gigantic telescopes in space, the options for astronomy and maybe physics are huge. With the ability to launch cheaply now, and with Starship maybe even cheaper in the future. You can build something truly gigantic in space. What I think is more practically pressing is a commercial competition for next generation of fission reactors, but that was pressing since the 1970s and politics has ignore it. So that's not gone happen.