Horizontal running inside circular walls of Moon settlements
royalsocietypublishing.org
royalsocietypublishing.org
https://rs.figshare.com/articles/media/a_participant_running...
You'd probably want to switch directions often!
If you’ve ever been on a spinning wheel at a carnival where they move the whole thing 90 degrees it would be a bit like that.
The track would actually be straight, so you wouldn’t have to compensate for turning even.
I’m not saying you wouldn’t want to switch directions, but there shouldn’t be some imperative to do so often.
Another problem, as pointed out by someone else in the comments, is that the floor is not flat but points upward and the feet and ankles might feel that. Furthermore it's another possible source of motion sickess (flat but not flat.)
Not sure if runners that train by running in small circles are concerned about evenness and try to run the same amount clockwise and counter clockwise to even things out.
Indoor meets often had 200m tracks with tighter (frequently nonstandard!) radii. The good ones were banked, though it never seemed to be at the right angle, always too steep or too shallow.
Every race still goes counterclockwise, though.
Maybe it's my XC side talking, but I'd love to see a track in a figure 8 with an underpass. Left turn, over the bridge, right turn , under the bridge, and repeat! It would break up those monotonous 8 and 12 lap races nicely, and you could fit a longer track in a shorter rectangular building by using the hypotenuse. I'm sure people would hate the hilly incline, though...
But I would love to see it for medium distances, just to see what crazy stuff would happen!
The curves felt great for me though, I really liked the 200m better than the 100m. Can't imagine how shitty it'd have been for a left handed fencer to run track, because the big muscles would be on the inside leg.
A tapered cylinder "gravity gym" with adjustable angled walls, and variable speed spinning, could smoothly create much greater "gravity".
Spin gravity would also enable body weight exercises, core exercises, stationary or small area cardio like exercise bikes, VR games, yoga, etc. Even sleeping.
EDIT: I missed this:
> but Moon-based centrifuges allowing locomotion inside would pose technical challenges
Still think it will be inevitable. Far more useful physically and psychologically. "Spinning surface" is a simple challenge, compared to "low-g health deterioration" and "bored to death of running in circles".
Equipment like this might resolve issues with off-world childbearing. Time to "spin up" some space rabbits and see what we get! (Hopefully not tribbles.)
Spin areas will surely become ubiquitous in all low gravity colonies.
Startup anyone?
There's probably a reason it never caught on.
Reason two - Childbirth + vertigo? WTF!
Clearly they should have gone with a rudimentary linear accelerator such as a bungy drop or bouncing elevator type system!
Like a railgun.
https://science.howstuffworks.com/science-vs-myth/everyday-m...
A "gravity gym" is going to be basic healthcare. Wherever we go for the long term, we will ship and/or construct them.
Of course they could simply stop spinning it whenever they needed to open an airlock.
(Or just put it in orbit, where these problems are easier to deal with and you don’t need to deal with day/night radiation shielding/heating.)
Another issue is that you need a certain scale, otherwise the Coriolis force as well as differential gravity (the gravity at your feet being higher than that at your head) lead to disorientation and comfort issues. The lower limit seems to be about 40 feet, incidentally the size of a typical graviton on carnival on earth. That's quite a bit wider than the typical rocket, and for now we are much more comfortable with assembling stuff in a gravity well than in orbit.
You can have two habitats connected by a center tube, like an I. Rotate about the center of the I. Or a habitat and a cable connected to a counterweight.
It's not really necessary to build a wheel.
A big arena for playing professional sports could make a significant amount of money through televised sporting events.
Weighted suit wouldn't help with the weight of your organs. They are accustomed to hanging inside you at 1g. Running on wall would provide them with that.
Turns out there is research in this direction: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2379624/pdf/can...
It seems to say that there is a long term impact on connective tissue hardening… but it blames lack of stretching; not lack of downward force. Any regular movement would seem to fix that.
However, internally, organ tissue probably ‘bounces’ more due to gravity during movement… so less gravity means less flex of connective tissue.
TLDR: you seem to be right
And those people lose a lot of bone mass, muscle mass, and need physical therapy to get back to normal function in 1G. Two months of bed rest will absolutely ruin you. There's a good reason astronauts need to be fit to begin with!
6 months in space causes bone loss equivalent of 20 years of aging. Return to Earth, do physical therapy for 1 year, and you're still "10 years older" as far as bone loss goes. (https://www.sciencenews.org/article/space-bone-loss-density-...).
Generally, as far as I know, bone growth is triggered by impacts (think running etc), and is hard to stimulate with just muscle exercises.
Maybe they should do jumping while being pulled "down" by rubber bands.
I think that's just what the cylindrical room is often called when it's used for motorcycles. The paper repeatedly references it, abbreviated "WoD." I don't think there's any death involved. :)
A train or roller coaster on a slightly tilted circular track would probably do the job. A slight tilt would just move the gravity vector orthogonal to the floor.
It would have to be big enough to avoid people getting dizzy, and even then it would still be a factor I think. That said, size/scale is less of a concern on the moon I would argue.
Maybe that doesn't matter.
Running on reliable constant nuclear power, from a safe distance.
Maximum gravity at the tilted edges. Only natural gravity at the center. Enter & exit from a tunnel that connects under the center.
Aside from the challenges of location & distance from Earth, if we can build small mobile cities on water (mega cruise lines) on the untamed ocean in Earth gravity, surely a small stationary spinning platter city in low gravity is possible.
I think humans are going to find out that one g has many uses besides health. Good for a lot of manufacturing too. Gravity is a stabilizer, vertical organizer, anchor. Just as low gravity will have many advantages. Being able to quickly “adjust” gravity, by moving location, will be significant.
Who is doing the adjusting and the moving?
I don't think you'd want to move anything large. You'd build eg your factory in the environment where it's best; and build a second factory in a different environment, instead of moving them around.
However, if you eg making computer chips, you might move those around between different environments, depending on the processing step.
If entire factories needed to "move" up and down in g-forces, they should be in their own variable spin bowls! Not sure what kind of factory that would be.
[0] https://vimeo.com/869858712 also available as https://www.youtube.com/watch?v=iiPmgW21rwY
Or align the axis with the major light source if that is different, like the sun for inner solar system locations, and at least the lighting won't keep moving around.
Not much different from watching scenery go by in a vehicle then.
I imagine some texturing on the inside of the enclosure could create small scale surface turbulence that even reduces the minimal friction there.
If that combined that with earth’s gravity has to give you 1.1g, that has to be (via the Pythagorean theorem) about 0.2g or 2m/s². Let’s pick r = 100m. Then, v² has to be 20, giving as a velocity of about 16 km/hour. r = 1km would require about 50km/hour.
Sounds doable, until you consider your “put gyms, hotels, swimming pool, living quarters, etc. in it”. That’s a lot of mass and space.
Centrifuges that we put potential astronauts and fighter pilots in are a lot smaller.
On the other hand, there’s the idea of “a massive floating railway, Maglev-style, which will travel along a track with a radius of 2.5 kilometers within an underground vacuum tunnel. The machine will run on excess energy generated from wind and solar, and it can reach speeds up to 2,000 km/h. When the renewable energy production is insufficient, the kinetic energy from the train movement will be reconverted and sent to the grid.” that engineers claim can be built (https://www.greenoptimistic.com/energy-train-mph/). That would hit over 10g and weigh a lot more than that hotel. I can’t find updates, though.
That’s a lot cheaper and for many sports likely would bring the same benefits.
Is that any better than ankle weights? Or wrist, I suppose.
Comments:
> would pose technical challenges
That's a very funny disadvantage to call out! "Technical challenges" are how you know you are on the moon.
A stable rotating system would seem to be one of the simplest possible lunar challenges. If it is implemented within an existing environment shell, it could be quite low tech.
> demand substantial electrical energy.
Maintaining rotation in low Earth gravity should be a very low energy process. The only energy loss would be friction at the point of rotation, which should be minimal, and some position controlled weights, for maintaining balancing in the context of human movement.
But the proposed no-tech solution has a great return on investment, and is realistic for early days, or infrequently inhabited outposts.
It was a fun and unique experience to run on for a short amount of time, but most people would get dizzy after a few minutes of jogging on it. The curved platform also turned out to be a bit of a tripping hazard. It was more often used as a sort of swing (could this work on the moon?).
I'm skeptical that the experience on the moon will be much better, especially since the diameter they're proposing is even smaller.
1. https://sdusd-newsfeed.blogspot.com/2012/09/pt-loma-high-sen...
Because even if your claim is correct, and the conflicting visual input is disorienting, the Moon-dweller on a similar contraception could just close their eyes.
Blind people only have 2 out of the three signals so they might be less prone to motion sickness.
Rowing is pretty full body and doesn’t seem that reliant on gravity.
In theory exercises like the major compound lifts should go a long way because they stimulate almost every muscle in the body. You get a lot of sustained muscle growth out of doing big lifts even just 2-3 times of week.
Of course you're not going to be literally lifting weights in space because they're weightless! But resistance can be produced with bands, pneumatics etc.
Rowing is a really good one because you get resistance training and cardio at the same time.
But the Moon does have gravity, just less of it. Is no one considering just squatting and deadlifting huge-ass boulders? Fill a big basket with moon rocks and eventually it's gonna be heavy...
That's why it's recommended for osteoporosis.
For super-fit astronauts, that's pathetic.
Really though when they get to the moon I just want to see them bring a barbell and two big buckets which they fill up with moon rocks. In general free weights are better for hitting a variety of muscles at once vs machines being better for isolation exercises, if you're trying to prevent muscle wastage across your entire body, a barbell may very well be superior!
Lunar Roving Vehicle curb is only 76lb/34kg. That's would be a fun OHP set.
The Descent Stage of Lunar Landing Module is 358kg/789lb. Probably strong man car squat with one of the legs for reps.
Many landed probes/landers between the 1-5 plate territory territory.
>if you're trying to prevent muscle wastage
I actually like all the new light weight resistence cable machines that perfroms like IRED released in the last few years. But a 24 ft barbell with 10 ft of mooncrete bumper plates on each side to replicate a 5plate pull would be neat.
I think the NASA goal is to build up muscle base on earth and do least impact/injury risk routine to preserve muscle mass and bone density. I'm assuming it's not bro science, and they have injury table for astronauts who are genpop fit but not lifter strong, and optimizing for that. I wonder what their policy on steriods is.
Keep in mind that you are doing your 3 squat sessions a week on top of a whole week of lugging your own body around in 1g.
> Low-intensity steady-state exercise or high-intensity interval training on ergometers may serve to preserve cardiorespiratory fitness [12,25–27] but have little impact on muscle and bone mass.
The main protagonist was trying to train for earth gravity so he cycled around it very fast until he felt 1G
I don't get why whole body locomotion would be the best way to combat muscle hypotrophy and bone demineralisation when that is not the best method on earth.
A better approach would be using bands or even moon rocks to lift weights etc.
Just set new lunar records for the deadlift, squat etc.
Whole body locomotion is approximately the only way we have ever tried on earth to combat muscle hypotrophy. So we don't know whether that's the best method or not: we just haven't tried anything else.
To be more precise, any method we have tried on earth, be that bands or weight lifting etc _also_ included a hefty dose of whole body locomotion inside a strong gravity field.
(You can get great results from hitting the gym for squats and deadlifts three times a week for an hour. But that regime also includes 24/7 exposure to 1g of gravity.)
It would seem like the obvious thing to try though as it is the best method in regular gravity.
The only thing we know for sure is that moving around in 1g is generally enough for our bodies. Especially once you throw in a bit of deliberate exercise. We also already know from our space stations that 0g is bad for you, and even exercise can only mitigate some of the damage.
But that's already the limit of our definite knowledge.
But we don't know where the boundaries are, and whether the transition is smooth. Eg I would suspect 0.01g to be still pretty bad, and 0.99g to be indistinguishable from earth for our bodies. But would 0.9g be enough? Probably yes, but who knows? What about 0.5g? Is it bad? Is it 50% as bad as 0g?
Would 0.2g give you 80% of the benefits of 1g? We don't know.
Perhaps your liver works best in 1g? We can make some educated guesses, but honestly we don't know! No one has run experiments.
I'm not sure how realistic the muscle-powered flight is, but a different form has been done on Earth.
When I would ride behind a motorbike, at 40+ mph, it was effort to just keep my body from being pushed down into the handlebars. At 50+, my tires would start to skip upwards/outwards.
This article seems like a good survey of the general impact low-g has on the inner ear changes, but I've barely skimmed it: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8595211/
On earth the fluids quickly settle and the dizziness fades. I wonder if maybe it would take considerably longer on the moon. It is probably something they can adjust to, but I was wondering.
And even that aside, I'm not sure the lack of gravity would change how quickly cochlear fluid settles. I think that settling is due to resistance from the fluid turbulence of the cochlear canals, not due to gravity.
(23 second mark)
Theoretically you could achieve the same result in zero-g, but getting started is much more difficult, as are microadjustments in speed and balance.
I guess that makes sense too, since a few reps of weightlifting every couple days is enough to trigger muscle growth and bone densification.
The amount of exercise you would have to do to even begin to remotely keep up with earth's gravity is insane.
Separately, how does aging fair with zero g? can really old people live longer up there or is it actually worse?
This does not bode well for expanding out into the solar system. It might only work if we do some genetic engineering to make off-world habitats more habitable.
Regular engineering, of robots, will probably work first.
Running in small (10m) diameter cylinder increase gravity significantly without need to spin the cylinder.
Anyway to minimize effects of Coriolis force in spinning cylinder, I think that the size of the cylinder would be significantly larger than the size in the movie.
(It's still very expensive in absolute terms, and you can have a discussion about whether it's really the best use of tax payer funds.)
Or perhaps a bowl shape that you climb up the sides of as you speed up.
A carnival show where a motorcycle rides inside a conical well.
In lunar gravity you can probably do (some of) it without the motorcycle.