longer ships...

MuonNeutrino wrote:"It is not only not right, it is not even wrong."

Lord Skimper wrote:Was that a compliment?

Probably not...

Lord Skimper wrote:Was that a compliment?

No.

Vince wrote:

vovchara wrote:Here is a good explanation, why size matters: http://www.stardestroyer.net/Empire/Science/Size.html

That is a really, really informative link. (Humorous too.)

That particular argument only matters when strength of materials is a limit, though*. Given that when Honorverse ships' compensators fail, the crew is instantly squished but the ship structure survives, I don't think Honorverse ships are anywhere near their material limits.

The optimal impeller/compensator thing is more likely the correct answer.

(Also, I think the argument also is a bit too strong on the giant animals side. Yes, what is stated is literally true - you can't scale up a small animal to giant size and get it to function. Just a "chemical/radioactive mutation" wouldn't work. But evolution works around these problems by changing proportions. You can't just scale up a mouse to cow size, but there were cow-sized rodents in prehistoric South America. A giant spider [spiders don't rely on insect-style breathing] is probably possible, if it could evolve on a vertebrate-predator-free island for enough time. Even insects might be able to get around their breathing problems, given that not all insect breathing is entirely passive.)

That website has some good info, but it has a little bit too much "absolute dictum" to it IMO.

*EDIT: Which I think actually makes it not that strong an argument, given how common super-alloys and so on are in SF, and the sort of weapon attacks these ships tend to survive.

Wasn't meant to be taken literal, more like an attempt to provoke a critical thought towards a tendency to run with own imagination contemplating sizes of artificial objects in SF. People tend to forget, what no matter the "made up science" in a Sf work, they still should take into account things we already know about natural world. Things like inertia for example or structural stress, sure you could make up a lot new fantastic alloys and structural fields to compensate for it. But the realities of real world still apply. Specially realities of space combat, here is the question people tend to forget to ask: "When you could violate the physics laws by applying certain amount of energy or using materials with a higher ability to withstand structural stress, would you do it?"

We talking here about combat vessels, where a redundancy and safety margin aren't a secondary concerns. It's highly doubtful, what you will build ships which tend to collapse on itself or tear itself apart the moment you loose the energy source Not a very rare occurrence in space combat.

cralkhi wrote:That particular argument only matters when strength of materials is a limit, though*. Given that when Honorverse ships' compensators fail, the crew is instantly squished but the ship structure survives, I don't think Honorverse ships are anywhere near their material limits.

The optimal impeller/compensator thing is more likely the correct answer.

(Also, I think the argument also is a bit too strong on the giant animals side. Yes, what is stated is literally true - you can't scale up a small animal to giant size and get it to function. Just a "chemical/radioactive mutation" wouldn't work. But evolution works around these problems by changing proportions. You can't just scale up a mouse to cow size, but there were cow-sized rodents in prehistoric South America. A giant spider [spiders don't rely on insect-style breathing] is probably possible, if it could evolve on a vertebrate-predator-free island for enough time. Even insects might be able to get around their breathing problems, given that not all insect breathing is entirely passive.)

That website has some good info, but it has a little bit too much "absolute dictum" to it IMO.

*EDIT: Which I think actually makes it not that strong an argument, given how common super-alloys and so on are in SF, and the sort of weapon attacks these ships tend to survive.

cralkhi wrote:That particular argument only matters when strength of materials is a limit, though*. Given that when Honorverse ships' compensators fail, the crew is instantly squished but the ship structure survives, I don't think Honorverse ships are anywhere near their material limits.

If you need to design a ship deck to hold a 10,000 ton load in compression is there any logical reason to make it thousand times stronger in shear than this? Because this is what would be needed. Where might the material needed be better applied?

Not to mention that the shock loading of things like the fuel system would be roughly akin to setting off a large explosive charge inside the pipes when you instantly pressurize it to about the pressure at the bottom of the Atlantic ocean. How thick would these pipes be?

kzt wrote:

cralkhi wrote:That particular argument only matters when strength of materials is a limit, though*. Given that when Honorverse ships' compensators fail, the crew is instantly squished but the ship structure survives, I don't think Honorverse ships are anywhere near their material limits.

If you need to design a ship deck to hold a 10,000 ton load in compression is there any logical reason to make it thousand times stronger in shear than this? Because this is what would be needed. Where might the material needed be better applied?

Not to mention that the shock loading of things like the fuel system would be roughly akin to setting off a large explosive charge inside the pipes when you instantly pressurize it to about the pressure at the bottom of the Atlantic ocean. How thick would these pipes be?

To be fair a lot of the time other factors drive the size of components above the minimum size their raw strength would require. In the real world getting the desired stiffness can result in materials that are very lightly loaded compared to their ultimate compression strength.

Now I can't imagine getting the necessary stiffness for a warship would drive a thousand fold excess of strength. But in the real world many stone or masonry structures have compression loads thousands of times below the crush strength of their foundation stones or bricks. (But that's because those structures will fair for other reasons, like a thrust line going outside the structure, or displacement of blocks, long before the brick or masonry gets close to it's crush strength.


But it's possible that getting the desired level of damage absorption, or internal armoring, would drive up deck and bulkhead thickness sufficient to provide way more strength than their normal loads would require. (Probably still not enough to handle a compensator failure at full acceleration, but at least hundreds of times the minimum necessary strength for their normal loads)

(Just read an interesting book on structures, so some of this was fresh in my mind. Structures: Or Why Things Don't Fall Down by Gordon, J.E.)

kzt wrote:

cralkhi wrote:That particular argument only matters when strength of materials is a limit, though*. Given that when Honorverse ships' compensators fail, the crew is instantly squished but the ship structure survives, I don't think Honorverse ships are anywhere near their material limits.

If you need to design a ship deck to hold a 10,000 ton load in compression is there any logical reason to make it thousand times stronger in shear than this? Because this is what would be needed. Where might the material needed be better applied?

Not to mention that the shock loading of things like the fuel system would be roughly akin to setting off a large explosive charge inside the pipes when you instantly pressurize it to about the pressure at the bottom of the Atlantic ocean. How thick would these pipes be?

That does seem to be the effect though IIRC - we've seen ships lose their compensators, and they aren't described as exploding or crumpling or anything, but the crew gets squished.

Maybe the Honorverse construction technology is such that super-composites (or whatever battle steel actually is) are no more expensive than regular materials, and if compensator performance is volume limited rather than strictly mass maybe there's no disadvantage to massively overengineering everything?

cralkhi wrote:
That does seem to be the effect though IIRC - we've seen ships lose their compensators, and they aren't described as exploding or crumpling or anything, but the crew gets squished.

Maybe the Honorverse construction technology is such that super-composites (or whatever battle steel actually is) are no more expensive than regular materials, and if compensator performance is volume limited rather than strictly mass maybe there's no disadvantage to massively overengineering everything?

I'm arguing that this is dumb and absurd, not that it doesn't happen in the books.