34
votes
What is the most efficient crop for converting kilowatts of UV light into calories people can eat?
UV is a poor energy source for agriculture, with enough energy per photon to easily damage living organisms. If you have a source of kilowatts of UV and want to grow crops, you need to convert it to ...
- 6,492
33
votes
What is the most efficient crop for converting kilowatts of UV light into calories people can eat?
It's going to be hard to get more efficient than algae. We're happy (some of us, at least) to put spirulina powder in smoothies, and so forth, so we already eat it.
Algae will be probably the simplest ...
- 5,937
19
votes
Where do forge-worms live outside of forges?
They are surface-adapted bugs originally of cthonic origin
These critters are the descendants of organisms that live in molten lava. The dwarves were friendly to the originals, who kept returning ...
- 1,624
19
votes
Where do forge-worms live outside of forges?
Forest fires
Forge-worms metamorphose through a complex life cycle. Only the adult stage requires extreme temperatures.
Adult forge-worms emerge from their pupae in the inferno of a forest fire. They ...
- 8,735
15
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Convenience, due to multiple and maybe concurring factors, for example:
the cylinder can be brought closer to the rescue place, easing logistic on the evacuation. One thing is moving a lot of people ...
- 301k
13
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
You need an artificial habitat no matter what.
The nearest suitable planet for this species is many light years away. Some delicate aspect of this species' biology makes cryogenic preservation or ...
- 14.8k
11
votes
Accepted
Where do forge-worms live outside of forges?
Perhaps they evolved in a continuously burning natural gas field such as the Darvaza gas crater in Turkmenistan (image from linked Wikipedia page).
Then when gas was piped to nearby ovens they ...
- 1,159
10
votes
What is the most efficient crop for converting kilowatts of UV light into calories people can eat?
Microbial electrosynthesis is more energy-efficient than photosynthesis. Engineer microbes to produce nutrients and use electricity from your reactor to power the process.
- 927
9
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Biologically incompatible species
There is an incompatibility between available planets and the biology of some/all of the species required for the primitive civ to survive. A constructed habitat is a ...
- 91
9
votes
Can I spin 3753 Cruithne and keep it spinning?
Having Earth like gravity inside the tunnel means that also the asteroid is experiencing a centrifugal force equivalent to that intensity.
Whether the asteroid is able to withstand it, it depends on ...
- 301k
8
votes
Where do forge-worms live outside of forges?
A volcano is the obvious option, but a cool fantasy answer could be that they evolved around an incredibly long-burning coal-seam fire. It's not particularly realistic as they don't burn long enough ...
- 2,962
8
votes
Where do forge-worms live outside of forges?
Natural nuclear reactors
Your planet has a much higher rate of meteor impacts and a lot of these have a lot of uranium in them. As such, it's quite common for high temperature natural nuclear reactors ...
- 41.6k
7
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Why rescue them?
The aliens value the diversity of civilizations in the galaxy. They want to preserve as many as possible, not as dry databases but as actual, thriving, developing cultures.
Just ...
- 120k
7
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Entertainment value
Let's take another point of view on this situation : a primitive civilization will be relocated in order to keep them from extinction. Sure, you could bring them to some planet ...
- 840
7
votes
Would a rotating habitat work on the surface of a moon?
It depends on what you want to achieve
A centrifuge in a not-zero gravity environment would be a bit hard to use.
Since you are supposed to stay on the cilindrical wall of the centrifuge, the walls ...
- 7,469
6
votes
Best materials to build a worldhouse roof
Unless you are going to invent some magical material (Plasteel, Ceramite, Ferrocrete, Transparent Aluminium etc.) that has the properties you require, I don't think there is something that can even ...
- 35k
6
votes
Would a rotating habitat work on the surface of a moon?
Ever seen a photo of a high-banked race track? The kind where you don't need to steer at all to make a corner, just very slightly manipulate the throttle? Or one of those "barrel of death" ...
- 47.3k
5
votes
Accepted
Best materials to build a worldhouse roof
Air
This glass-weight calculator tells us that glass has a specific gravity in the range of 2 to3 grams per cubic centimeter. This means that 1 inch thick glass has a weight of about 0.11 pounds per ...
- 2,555
5
votes
Breathable air on large space habitat with no water?
Yup you can have oxygen/breathable air, without water
Meet Perchlorates
You can simply get oxygen by heating up perchlorates at high temperatures, which causes them to heat up and release oxygen. ...
- 3,422
4
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
It's on the way
Due to speed limits, the nearest suitable planet is thousands of years away. So whatever vessel you use to transport the civilization, it needs to be a self-sustaining ecosystem in its ...
- 66.3k
4
votes
Accepted
Breathable air on large space habitat with no water?
It is possible.
The mechanisms for loosing hydrogen and oxygen are very different. So conditions need to be as such to prefer loss of the former and not the latter.
Earth looses hydrogen at about 3 kg/...
4
votes
Where do forge-worms live outside of forges?
Erratic geysers
Their ancestors evolved to thrive in geysers, a wet environment that is subject to high pressures and temperatures. As volcanic activity slowed down in their region, they also became ...
- 3,409
4
votes
Can I spin 3753 Cruithne and keep it spinning?
Working on the assumption the asteroid is solid enough to withstand the spin, or you provide some way to strengthen or fix the rock, you could spin it up using various propulsion units. Perhaps the ...
- 1,517
3
votes
Accepted
Spaceship habitat size
Let's start with food requirements. Based on this article in Primal Survivor, it takes roughly 5 acres of crops for food self-sufficience. Multiply that by a million, and you get 8,000 square miles. ...
- 17.8k
3
votes
Accepted
Critical animal species for temperate rainforest climate
Foxes, Rabbits, and Grass
This is a classic simulation to introduce people to the idea of population modeling using the most paired-down elements. There is an important balance between these groups: ...
- 32.3k
3
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Practicality & Simplicity.
The following assumptions are made in this answer:
The advanced race has time to construct at least one cylinder before the extinction event occurs and the science/...
- 18.8k
2
votes
Best materials to build a worldhouse roof
It needs to be able to withstand a variety of gravitational strengths
Use what seems appropriate for each situation. You want very different architectures for high and low gravity, the atmospheric ...
- 78.5k
2
votes
Is there any practical reason to keep a primitive civilization on an artificial habitat
Ethics
Humans won't see reason about environmental destruction. They won't stop competing to dig up resources to kill each other. The aliens can't kill them - it would be unethical - and they can't ...
- 23.7k
Only top scored, non community-wiki answers of a minimum length are eligible