I remember reading this as a teenager, and despite being already so steeped in transhumanist ideas that I should have found it very ordinary, I was so excited by it, having never read something like it before, I raved about it to my mother. "... and then they go to another star and find aliens but the aliens are not like us they're uploaded minds in Dyson spheres, which is like if you surround a star with solar collectors and..."