Seveneves: A Novel by Neal Stephenson (4.5 stars)

The Earth will very soon be unlivable. How could we survive? That's the thought experiment that occupies the first two thirds of this very lengthy novel. This is a exploration of an idea that progresses in a similar way to The Martian, i.e. with plenty of detailed technology discussion and little character development. It's a book about tech, and some macro-scale politics, but individual character study it is not.

 I loved this book, but it I can see why those less interested in pure technology "what if" imagination didn't like it at all. I was quite happy to read pages and pages of orbital mechanics discussion, but others may not be. Here's my somewhat random list of annoyances:

• Probability of pulling off space scenario seems far, far, lower than digging into the ground scenario at multiple sites. Many similar challenges except transport is way harder for space.
• Why morse code with the father? It was cute, but they could have sent voice just as easily and had higher bandwidth comms.
• Why did Earth stay functioning for so long? People are still driving trucks, working in factories, stocking shelves in the stores. Why?
• The third section probably should have been a completely new book, since it required completely new world building.

Annoyances with spoilers:

• I don't buy the submarine survivors at all. Was there a massive submarine building program started at the same time as the space one? How did they keep that quiet? How could they maintain equipment on the ocean floor for thousands of years?
• The the re-population from 7 eves seems equally implausible. Too much to go wrong in a very fragile space environment before population reached viability.
• In this future they have incredibly advanced micro robotics, but no basic cheap silicone storage? Having small robots like that requires advanced chip manufacture. Doesn't make any sense, and offered explanations aren't convincing.

But really, it's a great thought experiment and delves into many interesting areas of space exploration. How fast could we build in space, especially with a higher acceptance of risk? What would we need to mine an asteroid? How could we find water? Would society even survive when confined to such close quarters? If we rebuilt the entire human population would there still be racism?

4.5 stars.