But I think that the assumption that all the collisions are elastic is too unrealistic. I expect that adding the inelastic collisions, where two fragments can merge in a bigger fragment, would produce a very different result, where a big chunk (50%?) of the moon is reconstructed and get to a stable almost circular orbit.
This was my first beef with the book. It seems to me that
1) the forces involved in smashing the big chunks into smaller pieces make the inelastic-ness of this significant, and because of this
2) there would not be the accelerating self-destruction that eventually turns into the white rain.
Physics aside, the idea that multiple non-communicating groups, separated for 5000 years, would be able to communicate, is unrealistic. Two friends who are linguistic professors tell me that the idea is preposterous.
But I think that the assumption that all the collisions are elastic is too unrealistic. I expect that adding the inelastic collisions, where two fragments can merge in a bigger fragment, would produce a very different result, where a big chunk (50%?) of the moon is reconstructed and get to a stable almost circular orbit.
For comparison: "What Made the Moon? New Ideas Try to Rescue a Troubled Theory" https://www.quantamagazine.org/what-made-the-moon-new-ideas-... HN discussion: https://news.ycombinator.com/item?id=15094302 (59 points, 27 days ago, 18 comments)