[Space/Spaceships] Getting the velocity/Delta V I want with the tech I want

[scc]

flyingwombat, the problem is more that an Ion Drive only provides 3 MPS per fuel tank, and a 4 year trip, one way, needs 300 MPS

[flyingwombat]

Originally Posted by Flyndaran

Suspended animation has never been proven to work. That would push the TL to 9 or 10. If that's allowed, then all sorts of THS type engines become possible.

OK, hibernation chamber, then. Age at 1/10th of the normal rate.
How about a mass driver for propulsion?

[scc]

Originally Posted by flyingwombat

OK, hibernation chamber, then. Age at 1/10th of the normal rate.
How about a mass driver for propulsion?

Mass Drivers provide something like 20 times the acceleration of Ion Drives but a 10th of the Delta Vee, not workable. Given the distances that is is occurring across, even if I keep the reduced ones, Delta Vee is more important then acceleration.

[Flyndaran]

Originally Posted by flyingwombat

OK, hibernation chamber, then. Age at 1/10th of the normal rate.
How about a mass driver for propulsion?

Real mass drivers are far worse than even the mediocre ones from THS. If you have a large comet or asteroid to move, where mass and acceleration is of no consequence, it makes some sense.

Hibernation chambers are just as pie in the sky dreams as cryogenics. The slowed aging aspect is simply super science as hibernating animals don't age any slower.

[scc]

I wasn't thinking of staple crops, but rather cash ones. In particular the sorts of ones where people buy it SOLELY because it's expensive

[Fred Brackin]

Originally Posted by Flyndaran

Hibernation chambers are just as pie in the sky dreams as cryogenics. The slowed aging aspect is simply super science as hibernating animals don't age any slower.

How can you know that? Aging is poorly understood and only irregularly studied in humans. Anumal aging is even less studied partly because animals live so much shorter lives that they don't make good models for humans.

Nevertheless there are studies that claim that slowing your metabolism down by eating less will extend your lifespan. By everything I understand slowing your metabolism to 10% should slow all your metabolic processes proportionately and aging I a metabolic process.

[johndallman]

Originally Posted by flyingwombat

Four years isn't all that long. I believe that is how long it took for ships to go from Spain to the Philippines and back.

Those were carrying goods (such as spices) that were both lightweight and extremely valuable, rather than more general trade. Also, sailing ships were a technology that was quite economical to run, didn't have to carry their propulsive energy with them and provided a very low standard of living for their crews. Spaceships don't usually meet those criteria.

[malloyd]

Originally Posted by johndallman

Those were carrying goods (such as spices) that were both lightweight and extremely valuable, rather than more general trade. Also, sailing ships were a technology that was quite economical to run, didn't have to carry their propulsive energy with them and provided a very low standard of living for their crews. Spaceships don't usually meet those criteria.

Actually spaceships on a freight run 4 years long probably should meet the second of those, since there's no good reason to have any crew at all.

And the freight *better* be high value for its weight. Even at perfect efficiency, getting your ship up to 300 mps and back down uses energy thtn has never been cheaper than on the order of $1000 per pound. So if you can't charge $1000 per pound for it, your freight run is a money loser even if the other operating costs are zero and cargo (and ships!) are free at the point of origin.

It's next to impossible to make interstellar trade make sense in a realistic setting, since any civilization that can actually build a starship is going to be able to make anything at home more cheaply than they could ship it back. Even if they have to assemble it atom by atom. And you can send the atomic scale blueprint without a starship.

[Johnny1A.2]

Originally Posted by malloyd

Actually spaceships on a freight run 4 years long probably should meet the second of those, since there's no good reason to have any crew at all.

And the freight *better* be high value for its weight. Even at perfect efficiency, getting your ship up to 300 mps and back down uses energy thtn has never been cheaper than on the order of $1000 per pound. So if you can't charge $1000 per pound for it, your freight run is a money loser even if the other operating costs are zero and cargo (and ships!) are free at the point of origin.

It's next to impossible to make interstellar trade make sense in a realistic setting, since any civilization that can actually build a starship is going to be able to make anything at home more cheaply than they could ship it back. Even if they have to assemble it atom by atom. And you can send the atomic scale blueprint without a starship.

That's a bit of a non sequiter, because the ability to build fast STL starships doesn't automatically imply the ability to assemble anything you want atom by atom. Just because you have the energy doesn't mean you have the means to apply it to whatever you want. It's a bit like saying that the ability to build an Apollo moonship implies the ability to synthesize a steak from scratch.

It's true that shipping bulk ore or the like doesn't make sense over interstellar distances, but that doesn't mean that nothing could possibly be worth shipping.

[malloyd]

Originally Posted by Johnny1A.2

That's a bit of a non sequiter, because the ability to build fast STL starships doesn't automatically imply the ability to assemble anything you want atom by atom. Just because you have the energy doesn't mean you have the means to apply it to whatever you want. It's a bit like saying that the ability to build an Apollo moonship implies the ability to synthesize a steak from scratch.

We may have had the ability to assemble things atom by atom before we launched Apollo. We certainly have it now well before we could launch a starship. Yes it would cost a completely insane amount to attempt to assemble a steak an atom at a time with the probe of an atomic force microscope, but it would cost an equally insane amount to ship it from Alpha Centauri.