Rodrigo Istalindir said:
I'd think anything that got captured would have to have a hell of a lot of momentum to fall into orbit instead of making a dash down the gravity well. Excape velocity of .5c is hard to get away from. Consider, too, that neutron stars are pretty darn small (1/50,000th the size of the sun), so even if something managed to orbit it, they'd have to be be so far away...
I think you're reading a few things about gravity incorrectly here. Yes, the neutron star has a very high
surface gravity. But planets aren't worried about that.
Take a star twice as massive as our sun, and assume it has planets. Replace that star with a neutron star (or even Foldger's crystals) of the same mass, and the planets will keep going around as they did before. The orbits depend on distance from the center, and the total mass of the body you're orbiting. Exactly how dense the central body is doesn't matter much.
Given this - the nature of the bodies (black hole, neutron star, normal star) isn't relevant for discussion of planetary orbits in a binary system. We only have to consider masses and distances.
You can have reasonable stable orbits in a binary system in several different ways:
1) The radius of the planet's orbit is very large compared to the distance between the binary pair. In this case, as far as the planet is concerned, the pair is basically one object.
2) The radius of the planet's orbit around one of the stars is very small compared to the distance between the binary pair - in which case, the second star is pretty much like a large, distant planet.
3) One of the binary pair is much less massive than the other.
In most other cases, the setup isn't very stable for the planet.
If you are talking real physics, it is going to be darned hard to get a habitable planet to survive a supernova of it's star. New planet formation is not terribly likely - it is expected that it happens when a nebula collapses during formation of a star. But when supernovae go, they go big, and everything nearby is getting pushed outwards very hard, so the resulting nebulae are light-years across and moving outwards, getting thinner as time goes on. Not the coalescing theme you want to see, there.
Not that it can't happen. And not that one cannot construct systems with habitable planets around neutron stars. But it probably isn't a normal thing.
Forward has a number of interesting books with rather exotic worlds and forms of life. And his science is extremely plausible (the man knows his stuff). Unfortunately, his characterization is kind of weak.
