quite possibly a cat wrote:First, I swear I remember contra-grav rings that you could just put around something.
I think you may be thinking of the 'counter-grav collars' from 'Ms. Midshipwoman Harrington', the scene with Honor sorting things out after the collision in the passageway:
Changer of Worlds wrote:"And you," she wheeled on the missile tech who had just begun to gloat at his rivals' stunned expressions, "get that push-pull back under control, tighten the grav-collars on those missile drives before they fall right out of them, and see to it that you stay in the right heavy tow lane the rest of the way to wherever you're going!"
"Uh, yes, Ma'am!" The missile tech recognized command voice when he heard it, even if it did come from a midshipwoman who looked like someone's preteen kid sister, and he knew better than to irritate the person who had produced it. He actually braced to attention before he scurried back over to the bundle of drive units and began adjusting the offending counter-grav collars...
I certainly admit that there's not much detail, but to me the line about tightening the collars suggests that they need to be secured to whatever they're lifting. Anyway...
quite possibly a cat wrote:However a Grayson type city is already sealed so you could probably haul that into space. Obviously a vacuum ready city would be a bit tougher than one that's just sealed against heavy metals.
The problem here is that, as the description of the construction of the Mueller school dome illustrates, the dome stuff seals *above* ground, but underground it's still anchored into bedrock like any other major construction. Grayson domed cities are just that - cities with domes over them. If you need to bring along layers of bedrock for a normal city, you'll need to bring along layers of bedrock for a Grayson city, and it's the stupendous weight of that bedrock that's the real problem.
For the rest of it, it's not a question of simply sustaining large populations in space. I completely agree with you that the honorverse is perfectly capable of that. If it were constructed in advance, the honorverse is indeed 100% capable of taking the population of a planet and sustaining it in space habitats instead. The problem is that we're not asking simply 'can the honorverse support planetary populations in space', for which the answer is manifestly yes, but rather we're asking 'can the honorverse evacuate a planetary population in the face of catastrophe', which is a lot harder. By definition, we're talking about a population that is currently living on a planet, which means they probably don't have a billion people's worth of space habitats or hibernation ships ready to go (I don't think that *every planet* is going to have a fleet of these ships waiting, and if not then you have massive travel time lag to get them all there), and as Jonathan_S's post shows, transporting that many people even over short distances (even just from surface to orbit to board the colony ships) is an extremely non-trivial task. It's *moving* the people that's the real problem, more than just housing them.
Weird Harold wrote:You're thinking far too small. NYC is far bigger than a measly 10km in diameter. It would be neither wise nor necessary to cut a hemisphere of bedrock/substrate, but both wise and necessary to include as much atmosphere as possible. A spherical bubble of 10-15 miles radius would probably work about right. with the center of the bubble about half the radius above ground level.
As for placement and powering of the bubble generator, that's an engineering problem and I refer you to the Will Rogers quote above your last post. :p
I know 10km radius (not diameter) is a bit small. I was intentionally being conservative - that was a *best* case scenario, practically speaking you'd need an even bigger size. You are correct that the center of the sphere doesn't necessarily have to be at ground level, but you still need enough bedrock for the whole thing to not just fall apart - with the tower sizes they have in the honorverse, I don't care how much countergrav you have they'll still need some massive foundations just for wind resistance. Even if the average depth of the rock under the city you cut out is only 1 or 2 km (and it'll likely have to be at least that much just to get enough area), that's still an enormous amount of rock.
To use your example of new york city, you'd need a slab at least 60km across. If you approximate it as a 1km thick cylinder (it'll be thicker at the center and thinner at the edges, but this is an estimate), that's now ~7.6e15 kg. So even if you use a more efficient bubble-cutting scheme, if you want realistic sizes you still end up with over seven quadrillion kg of rock - even more than last time. Even if you try to cut it in half and shave it to a half-km depth (which strikes me as probably the absolute minimum plausible depth given the km-scale height of honorverse towers), that's still almost four quadrillion tons of rock. I refer you to my previous post for how hard that'll be to lift.
And I'm pretty sure that quote is intended as a cautionary tale, not an exemplar.
Seriously, though, ideas are well and good, but we still have to ensure they're at least vaguely plausible. While I certainly am not trying to accuse you of anything even *remotely* on his level of insanity, that's how you get skimpers. It shouldn't stop anyone from proposing ideas, but we don't get to dismiss difficulties as simply 'engineering problems' if we actually care about getting solutions.
