We're talking about hundreds and thousands of years though. A few hundred years ago, the mere thought of airplanes and cell phones would be considered witchcraft. I don't think it's a long shot to be reasonably optimistic about where humanity can get in terms of technology.

Imagination is unlimited. I don't mean to harsh anyone's dreams. But technological development isn't a predictable march forward.

There is less low hanging fruit as things progress. I'd guess we're very close to the peak of attainable technology.

Once sustainability comes into the picture then, IMO, we're beyond the limit.

It's not supposed to be all easy. A big part of advancement is creating technology that enables us to reach higher with less effort. Sustainability is a big issue now that a lot of people are working towards. Once we unlock more efficient techniques of capturing solar energy, energy becomes almost a non issue until we reach another barrier that's orders of magnitude away. Space travel will reduce resource limitations too.

>I'd guess we're very close to the peak of attainable technology.

Not many people, and pretty much no research scientist, would agree with that statement. I can personally think of several technologies I'm 100% certain will exist in < 40 years that will drastically alter everything about day to day life.

I’m very curious what are the technologies you’re tracking?

European global expansion also had hard physics limits. The age of sail grew the global GDP tremendously. I wouldn't discount multi-year asteroid mining trips/etc. from having the same impact in 50-100 years.

Really? What do you imagine to be receiving from an asteroid that cannot more easily be obtained from the earth?

Large volumes of minerals that are already in space (don't need to expend energy putting them in orbit) to build settlements, ships, etc...

"settling Mars will require more sustainable lifestyles than most first world citizens now enjoy."

Not if they decide to use nuclear power. Humanity has at least one more dramatic jump in power-use/person that has been ready since the 1960's.