Overview Effect – Spin Gravity Compared
An evening pause: A fun look at the physics and scale of the many spinning space stations proposed by science fiction writers over the decades. None of this is real, since sadly we have done only a few very inconclusive efforts in space to test this engineering.
Hat tip John Hunt.
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This comparison reinforces my sense, ever since my first watch of Interstellar, that having an O’Neill Cylinder operational around Saturn in just 57 years (the time between when Murphy Cooper “solves the problem of gravity” and when her father is recovered from outside the wormhole) is a real stretch of plausibility. But then, Space Station V and Clavius Moon Base being in place within three decades in 2001 was a real stretch of plausibility, too.
But that doesn’t detract from the sense that these are both great science fiction films.
Thank you for posting. I’ve always wondered how the depictions of artificial gravity were derived. As far as I could tell, Star Trek never addresses the issue. The gravity is just there, unless they are outside the Enterprise.
Gary–
In Star Trek they use “artificial gravity,” which is vaguely explained away as utilizing “graviton particle generators.” (Which are apparently very robust, they only “lose gravity” when it drives the Plot. But ya’ know, it’s not a Documentary…)
Gary,
In Stark Trek, if you dig deep enough into show canon — and admittedly, you have to dig — it seems that the Federation has discovered exotic particles called ‘gravitons’ which they manipulate to produce gravity on board ships and starbases. There’s nothing to explain how this works, nothing even on the level of the efforts made to explain how warp drive works. I think it’s best to just understand that for most sci-fi movie or TV show mostly or entirely set in space, it is a species of handwavium needed to make filming the production affordable.
This is one of the things I really appreciated about The Expanse (beyond the fact that it’s well written and not terribly woke), which features in the video Bob links. They actually aim for some realism where gravity is concerned. There are no gravitons or handwavium. Spin and thrust gravity are the only types of artificial gravity allowed: Ships under constant acceleration produce the artificial gravity most commonly seen; if you’re travelling to Mars, you spend the first part of the trip accelerating toward it; then you flip your ship and decelerate (a “flip-and-burn”). As a result, ships are effectively designed like tall buildings, with decks perpendicular to the vector of thrust. Without acceleration, the only other recourse is magnetically plated shoes or boots that you use to keep contact with the floor — and it is depicted as being quite awkward. In short, gravity is earned the hard way, and they take the trouble to show it.
There are a few exceptions depicting centripetal gravity, like the Behemoth shown in the video — originally a gigantic O’Neill-form ship commissioned by a group of Mormons (The Expanse also tries to take religion seriously) as a generational ship to a nearby star system, but subsequently hijacked for use by an armed separatist force based in the Asteroid Belt.
For years (“somewhat as a voice in the wilderness”, ha) I’ve been noting that centrifugal habitats would be useful on the Moon, Mars, Ceres etc. And probably easier to construct than in-space habitats., due to resources instantly to hand and the fact that humans are awfully familiar with engineering large fixed and moving structures in a gravity field, while far less so in microgravity.So far no one is much interested… c’mon people! Recognize my genius! :)
Seriously, imagine that Lunar g or Mars g isn’t sufficient for long term human health. What then? Perhaps a biotechnological solution can be found… eventually. Meanwhile, a relatively simple, practically 19th century solution is just sitting there waiting for someone to pay attention.
To those who have mentioned “The Expanse”., I would recommend the books.
My favorite characters were Amos and Detective Milller.
Patrick,
In The Expanse, this idea is taken up to the maximum possible level: Tycho Manufacturing literally spins Ceres – the entire planet – up to the point where it has 0.3G via centripetal gravity. Ceres is wholly settled in underground settlements, and is described as being honeycombed with many levels. Obviously, not the kind of engineering challenge that’s within reach within our lifetimes….
Gary,
I like the books better, too.
The series is not without points to admire. (Both Amos and the Detective are both cast well. Naomi, on the other hand…) But it is uneven after the first two seasons.
The idea of “Gravitons” goes way back, and if you’re a Particle Physicist, everything’s a particle and it fits the standard model. And for the string-theory people, the Math works, but still no “gravitons.”
Richard M–
I enjoyed the Expanse but had trouble following the plot.
They do make an excellent effort to follow the laws of physics during spaceship maneuvering but, in my opinion, it comes across as too acrobatic. I just want them to fly the ship sorta like an airplane…. I’ve already suspended my disbelief for the sake of the Story.
The whole Gravity thing on Star Trek, as you noted is sparse. It comes up mostly in Next Gen & Enterprise.
Cool stuff !
Thanks all,
A,
Biotechnology comes up in The expanse as well.
“Belters” take them in their youth to help bone development.
I was always a Ringworld fan.
I will have to read the novel Ring World. I am surprised the Dyson Sphere was not mentioned and credit given to the O’Neill cylinders by name.
Good video none the less, especially about the studies on the rate of rotation.
Dyson spheres aren’t mentioned because they don’t have spin gravity. It’s not a megastructure compendium, but a look at fictional spin gravity.
A Dyson sphere is likely to break under its own weight even if you don’t spin it, and if you did spin it, most of the interior would still be uninhabitable unless you add even more weight to add walls to keep all the air from collecting around the equator. At that point, why not just save a lot of effort and build a ringworld (with an optional Dyson swarm) instead?
My favorite characters also. The best was the colorful language of earths leader. Shocking, yet refreshing. Never failed to to make her rivals (and readers) off balance. Didn’t know it was made into a movie. I will borrow it from the video place. (Library)
For those who follow whistleblowers concerning the shots, here is an influential brain surgeon that has the ear of Kennedy, May have helped write the book on Fauci. Warns his audience about SV 40 in the vaccines. (Simeon virus 40 which always causes cancer) Jack Kruse, 45min. Extensive historical information and why they’re doing this to us.
https://www.youtube.com/watch?v=TcbuqQd57rY&pp=QAFIAQ%3D%3D
The Ringworld is unstable!