How does everyone see life onboard an O'Neill cylinder?

[Swank]

This may have been covered, but wouldn't you need a heat sink?

Lighting the interior with (say) a half kilowatt per square metre means a lot of energy input. I suppose it depends how it enters and is distributed. I don't imagine you would lose it to space very quickly, not on this scale and at room temperature or less?

Getting even more handwavy, if your habitat tracks the sun, the cap at the far end will be in permanent shadow, so I'm guessing an axial tail radiator would work, mechanically configured to modify its area — it may be very long. That would give you a manageable temperature gradient along the cylinder, so maybe snow on the 'shadow cap' wall and a moderate climate on the lower slopes?

I seem to recall everyone would live in accomodation stacked in the end caps, which would be shielded, maybe with water reservoirs or an ice shield?

The cylinder might be a lightweight 'stage' for whatever landscape you want. Can't imagine any traditional farming — vertical farms would seem sensible, maybe tethers supporting them across the diameter...

People wouldn't live in the end caps where there is no gravity but a lot of spin. They would live in the straight sections.

The amount of heat can always be controlled by shortening the daylight hours, as well as controlling the albedo of the 'land'. But heat can also be tapped off to produce electricity using the refrigeration cycle and radiators.

I agree that traditional farming would be misplaced - but edible gardens would be nice. The end caps may be great vertical farms since plants are unlikely to be bothered by the spin.

 

[THX1138]

One thing I found out is that the atmospheric pressure inside the cylinder is much less than that at sea level. So, less chance of a pressure cooker scenario it looks like. And when you look at the lay out, the strops of land are separated by equal sized strips of clear panels, to me are similar to the black and white stripes on a zebra. These strips are known to cause a micro air flow around the zebra in order to cool it down in the hot Savana sun. So, I think this may be the same in the cylinder also.

Plus, the atmospheric conditions and temp can be controlled also by the amount of water vapor in the air. this can be gone at the hubs.

Just some thoughts.

 

[Wayne Mack]

Considering that the center of the tube is at low pressure, it seems like the place the pressure could go is up.

Centripetal force provides "gravity" starting a little way from the hub, however the seeding system could use water pressure to create downward velocity.

Plants grow in deserts. Clearly there are ways of maintaining life at lower humidity levels - such as irrigation.

At best, the pressure at the center would equalize with that at the outer edges. Given the addition of centripetal force, it seems that the edges will always have greater air pressure. With a rotation speed of 28 revolutions per hour, at 100 feet or 30 meters from center, the effective gravity is 0.007 g. Together, these imply to me that there will be no outward pressure at the hub, which results in particles being collected there. This would include both water and dust and result in a muddy cloud or perhaps river.

Doing a little more reading, the design calls for a separate farming ring of larger dimensions (20 mile diameter vs 5 mile). Temperature control is purely radiant heat transfer.

One of the biggest challenges, though, would be the central axis. The design consists of two counter rotating cylinders joined by a central axis. Furthermore, the two cylinders constantly move together and apart to maintain direction. I wonder about the stresses placed on the axial rod and ball bearings supporting it. A single bearing failure could endanger the whole system and replacing a bearing while active would be a challenge.

Ref: O'Neill cylinder - Wikipedia

 

[Swank]

A single bearing failure could endanger the whole system and replacing a bearing while active would be a challenge.

Mag lev bearings?

 

[Daysman]

People wouldn't live in the end caps where there is no gravity but a lot of spin. They would live in the straight sections.

The amount of heat can always be controlled by shortening the daylight hours, as well as controlling the albedo of the 'land'. But heat can also be tapped off to produce electricity using the refrigeration cycle and radiators.

I agree that traditional farming would be misplaced - but edible gardens would be nice. The end caps may be great vertical farms since plants are unlikely to be bothered by the spin.

Eek!

No, not that high up — though the axis might be an interesting place to visit.

If the end caps are hemispheres, at 45 degrees incline the downforce is ~70% of that experienced in the cylinder valley, and the sloping area below is ~70% of the whole cap.

Might be a great place to build homes, with the view n'all.

Can't imagine farming there, but vertical farms maybe, except light would be way better in the valley, though (as mentioned in a recent post) it may be relegated entirely from the main habitat and, as you say, the whole valley given over to homes, swimming pools, restraunts...

But aren't these the early designs? Isn't radiation an issue?

 

[Swank]

Isn't radiation an issue?

Water is excellent shielding, as are a variety of compounds with lots of hydrogen in them. If the forward hub was full of water or a lot of rock that would shelter the occupants from the radiation coming from the sun. I assume the reflectors could be built to only reflect useful light.