I think the big thing is that all those original achievement don't defy physics to achieve them. It was a case of ignorance and the belief that we just were not

I think the big thing is that all those original achievement don't defy physics to achieve them. It was a case of ignorance and the belief that we just were not that smart. And while there was a big period of exponential growth - there is an upper limit. We aren't going to Galaxies in a few hundred years - the time to Andromeda is 2.5 Million Light Years. Unless we fundamentally have physics wrong, we aren't doing that any quicker no matter how hard we try.