> we could already viably have multiple parallel civilizations scattered throughout the solar system

This is nonsense. A trip to Mars would take a minimum of 6 months and could only be resupplied every 2 years. Mars has a tiny amount of water, virtually no atmosphere, and receives 700x more radiation than Earth. Mars colonists would be forced to spend virtually all their time underground working hard to keep themselves alive, being bored senseless because there's nothing to do for fun (besides electronic entertainment, I suppose), or both.

Keep in mind that the Apollo program only gave us about two weeks of human time spent on the moon's surface total. In no way were we prepared to go to Mars after Apollo. We couldn't have managed a round trip around Mars, much less landing there and creating a permanent colony.

The idea that we would have "parallel civilizations" not just on Mars, the easiest other planet to inhabit, but "throughout the solar system" is delusional. Are we talking about also colonizing Venus, a planet where the surface temperature is hot enough to melt lead, the wind travels at hundreds of miles per hour, and the atmosphere is composed of sulfuric acid?

The sad (?) reality is that humans evolved to live on Earth and if we ever permanently live outside Earth, it will in all likelihood be in a form no longer recognizable as human, whether it's due to our physical bodies being engineered to withstand the rigors of life on a foreign planet or because our consciousnesses have been somehow uploaded to machines.

I cannot enough recommend the book A City on Mars. It's written by two giant space nerds who are nonetheless clear eyed on the many, many, many challenges to creating permanent space settlements of any kind.

https://www.goodreads.com/en/book/show/125084292-a-city-on-m...

https://www.reddit.com/r/space/comments/18xmkp0/a_city_on_ma...