A review by robotswithpersonality
The High Frontier: Human Colonies in Space by Gerard K. O'Neill, Freeman Dyson

Way more approachable than I thought it would be. A balance of feasibility from a technical standpoint as well as economic. Appreciate the emphasis on environmental, humanitarian considerations and justifications for developing space habitats. 
I particularly enjoyed the the sci fi moments, where the author writes letters from the perspective of fictional people inhabiting these new habitats, we life a little sci fi in the middle of the science! If you like the nitty gritty of the Red, Green, Blue Mars series, I think you'll like this.

I have to admit, it's the first time I remember encountering engineered space stations/habitats, versus terraforming a planet, as the FIRST choice for carrying human civilizations into space. You see them in sci fi films, but the idea of it being actually more feasible, more beneficial is not one I'd considered before.

The emphasis on staging so that the required investment makes sense, see a return early enough to keep people supporting the project, go from manufacturing to larger habitats, supplying the Earth with solar power while the Earth supplies the habitats with things it can't get until it's set up with asteroid belt harvesting/homesteading to get what they need...and possibly go further from Earth...seems doable! 

The digression into what ifs about the search for intelligent extraterrestrial life, was amusing, if a bit flimsily connected to the main purpose of the work. 

I figure the need to keep meat and dairy sources as sources of protein, 'for the children' would be deemphasized in an age with tastier vegan options, and the recognition of widespread lactose intolerance, especially since the author acknowledges the infeasibility of cattle for early habitats, to paraphrase, not a good enough exchange of plant matter required to feed for end product. 😬

The whole New World analogy reaallly aged badly:
No nuance to the multiple mentions of 'hostile Indians' as an obstacle space settlers won't have to face. YIKES. 
There's definitely bleed through from a time when the frontiersman, the 'settling of America', colonialism were ideas that held only romance for White westerners. 'Our pilgrim ancestors', again YIKES. 

All of which is to say...I think if this book was written today, it would probably phrase a few things differently, add in whatever technical knowledge has been gained in the intervening fifty years, and as a result calculate the time table differently. But so much of what O'Neill describes, even to someone whose eyes tend to glaze over when financial or technical details are discussed, feels reasonable and in the eventuality that Earth becomes unliveable, (because otherwise I'm staying on solid ground!) and desirable. He had me as soon as he described the size dimensions and the amount of greenery, and animals, really. 🤷🏼‍♂️
I can't judge him too harshly for being hands off when it comes to speculating about how human society and government will develop in their new habitats, because we've definitely proven ourselves unpredictable as a species. I remain hopeful that if we all had a bit more space, and a bit more hope, things could work out better for all.