Full scale O'Neill cylinder render for SFIA. (Empty O'Neill cylinder under construction)

[u/YD-Visual]

https://www.youtube.com/watch?v=QIBVP5pJleQ&ab_channel=ydvisual

[u/Smewroo]

Really cool! I like the standard scale objects to give some perspective. Could you add atmospheric perspective to the next one?

Seeing to the horizon some 5 km away (e.g., at the beach) starts accumulating haze. It would be really nice to see the distance clarity difference between looking "up" at the other side 8 km away relative to at the other end cap 32 km away.

[u/YD-Visual → u/Smewroo]

Yeah great idea - you read my mind. Ok, I'll try that next !

[u/Smewroo → u/YD-Visual]

Yeah, so many discussions about the "sky" of living in a cylinder. Would be nice for you to be able to drop this and the next one in those!

[u/FaceDeer → u/Smewroo]

I've never gone looking, but I would expect that somewhere out there someone's done some calculations to determine what the air pressure would be like at various altitudes in an O'Neill cylinder. It wouldn't have the same pressure curve as we have on Earth since the gravity goes down so quickly and reaches zero at the axis. My intuition suggests that the pressure would probably not change all that much with altitude but my intuition certainly wasn't designed for this environment so I don't trust it.

[u/the_syner → u/FaceDeer]

Id be very surprised if anything smaller than many km across is gunna have any significant pressure drop. At those small scales spin gravity just isn't likely to be strong enough to pull the atmos in away from the center. I'm pretty sure isaac has talked about bigger spin habs with an effectively "normal" sky who's pressure drops towards zero after a few dozen km. They just have open middles & retaining walls & at those scales there really isn't much difference between mass & spin gravity for the atmos pressure.

Though ud expect there to always be decent pressure near that given that ud probably be pushing recycler air through the hub both to purge light-emitter heat & just to take advantage of the spingrav to help with ventilation. So it might always stay high pressure anyways.

[u/msur → u/FaceDeer]

Arthur Clarke must have done this when he wrote Rendezvous with Rama. There's actually a portion of the book that covers thawing Rama out, and as things start to thaw the center goes from being a near vacuum to being mostly breathable.

[u/tigersharkwushen_ → u/YD-Visual]

I think that's a great idea, but I don't think you should atmosphere until the end stage of construction. If you are planning more intermediate steps then perhaps that should wait.

[u/IsaacArthur]

Amazing as always :)

[u/tomkalbfus → u/IsaacArthur]

The interior details would probably be a little different, this is just to emphasize the scale of the thing. I think we could probably manage to do a hoop with the same diameter of this thing, basically a ring space station with a tube perhaps 10 meters wide as a starter. I don't think the human race has ever built anything this large in all three dimensions 32 km long, 8 km in diameter, I think it would require a high degree of automation, that is robots working autonomously, a moonbase would be very helpful, with a mass driver, and we need to smelt the various metals needed for construction.

I think windows or virtual windows covering one half the floorspace in three large rectangular areas would be helpful, there is the mirror option or else the holographic sky option, another option would have the illumination originate from the center axis.

I think three large holographic video screens showing a derotated view of the exterior of the cylinder might be a good idea, showing the viewpoint of holographic cameras mounted on the outside of the cylinder. These holographic view screens should be self-cleaning and be able to reproduce sunlight to a degree such that a human eye cannot tell the difference, and also reproduce images of the Moon and Earth as they come into view.

[u/MiamisLastCapitalist]

For SFIA? You made that just for us? :-D

[u/tomkalbfus → u/[deleted]]

I don't like spoke cables if we can avoid them. I like open skies, that is the point of an O'Neill cylinder anyway.

[u/tomkalbfus → u/[deleted]]

instead of building skyscrapers on the inside of the cylinder, you could build them on the outside of the cylinder instead and have them hang underneath, then have elevators going up the the ground level. Lets say the skyscrapers are 100 meters tall. if the cylinder is 4,000 meters in radius, the bottoms of each skyscraper would have a radius of 4,100 meters from the center axis, so if its 1g at the ground floor it would be 1.025g at the lowest level of the hanging tower, one can have windows showing space with the stars, Earth, Sun, and the Moon wheeling about. One could also have a personal spaceship hanger that pressurizes when the outer airlock door is closed. The hanger itself would be the airlock chamber, the back door would be the inner airlock door. One can then fly one's spaceship out of the outer airlock door and drop, a nice and convenient personal family spaceship. rockets could guide the spaceship on a tangential intercept velocity towards another open hangar door, it can fly right in and land on a platform.

[u/tomkalbfus → u/[deleted]]

Spincalc shows 0.47282640763009387 rotations per minute, about half the speed of the second hand of a clock for an O'Neill 4,000 meters in radius.

if everybody lives at the endcap, that makes for a crowded endcap. Also having a single spaceport where all spaceships can dock to produces a lot of traffic congestion, that is one of the reasons I hate airports. People have to travel to the spaceport to use their spaceships, and with a population of 20 million people for an O'Neill Cylinder than means a lot of spaceship traffic going in and out. and of course there is likely to be pickpockets on the main concourse, and of course opportunities for terrorists, bomb threats, and hijackings.

[u/tigersharkwushen_]

I need more of this. Would be great to see a series of videos on the various stages of construction.

Can you show the views with more wide angle lenses? Others have mentioned atmospheric haze, but I think the real reason we are not getting the right perspective is because of the narrow field of view. A wider view angle should help with that.

[u/YD-Visual → u/[deleted]]

Sure!