Japanese researchers propose a concept for making artificial gravity on the moon

https://singularityhub.com/2022/07/11/japan-proposes-a-wild-concept-for-making-artificial-gravity-on-the-moon/

by cheinyeanlim • 4 years ago

33 60 4 years ago

dreen2• 4 years ago

Since were talking hundred-year timescales, wouldnt it be better to drill deep into the moon, set off a massive nuclear device inside the moons crust and build this thing in the resulting cavity? Then youre not only protected from muscle loss due to lack of gravity, but also from radiation (though probably not all).

At least we would have a good use for all these nukes

eterevsky3• 4 years ago

How would digging into the Moon help with gravity?

mkl2• 4 years ago

You could build the same spinning habitat in a hole in the ground, supported all around instead of balanced precariously on a stalk.

dreen2• 4 years ago

Its to help with radiation, and I guess meteorite strikes as well.

c048• 4 years ago

Why not simply build a space station instead with the same concepts? For argument's sake it would be a small O'Neil cylinder with a short shuttle or small space elevator to the moon.

I'd expect research or mining sites to be quite basic and not like this habitat anyway.

edit: I guess, if they build it in one of the moon's craters where the sun never shines, and where pockets of frozen water exist, it would make shielding from the sun a lot easier than a complex orbit.

eterevsky3• 4 years ago

In space you don't even need a full cylinder, you can spin several habitats on a tether.

yellowapple4• 4 years ago

Technically you could do that on the Moon, too. Kinda like one of those carnival rides with the seats on chains and a tower spinning everyone around.

In fact, maybe we should just cut to the chase and build amusement parks on the Moon. You know, for "physical and mental health" or something.

timbit42• 4 years ago

Tethered, wheel and tubes are all the same thing. The minimal setup is one habitat tethered to an equal weight. As you add habitats, you eventually end up with a wheel. If you stack these wheels, you end up with a tube.

underlines• 4 years ago

I have concerns.

- Everything falling down and the mess on the floor when this thing has a downtime

- The still existing gravity towards the moon, which would be a constant additional force pulling you sideways (down) with 1/6 g

SideburnsOfDoom2• 4 years ago

still existing gravity towards the moon, which would be a constant additional force pulling you sideways

That would be why it's a cone not a cylinder, to line up the "subjective down", the sum of forces including lunar 1/6 g; with the direction that the ground is in.

Stopping would be an issue. But it looks like there is some accommodation for that in the form of a big "bathtub" at the bottom that could hold the water. IDK why there's so much water in the first place though.

msk-lywenn• 4 years ago

You mean everything fall left* and do a big mess on the wall, right? Frames of reference are fun. We also have a force pulling us sideways on Earth since it's rotating but without doing the math, it's probably a lot lower than 1/6 g, indeed.

* or right, no idea if this is spinning clockwise or anti-clockwise.

Akronymus5• 4 years ago

And no matter which direction it spins, it depends on which direction you look. if you are looking "upwards" it falls "backwards", "downwards" = "forwards" and so on.

yellowapple4• 4 years ago

The Moon's "atmosphere" is (practically) frictionless, so if you build this thing with a similarly-frictionless bearing (e.g. really strong magnets) it could theoretically spin near-indefinitely.

Whether that's actually achievable (while still allowing people and supplies and water and oxygen and such to enter and exit) is of course another question.

unsupp0rted• 4 years ago

I wonder what it would do to human biology to have 1 g pulling us down as we evolved to handle, but also 1/6 g pulling us sideways. I guess it would cause all sorts of balance and medical issues.

SideburnsOfDoom2• 4 years ago

1 g pulling us down as we evolved to handle, but also 1/6 g pulling us sideways.

Look at the design, with the surface not vertical but at a steep angle inward. It's pretty clearly designed to produce a total perceived weight equivalent to 1g, composed of 1/6 g downwards caused by the moon, and I suppose 5/6 g sideways caused by rotation. The floor is at an angle that works with the sum of these forces.

Having said that, "spin gravity" isn't always comfortable, it depends on how large and how fast it is: https://space.stackexchange.com/questions/9575/mitigating-na...

This structure looks easily big enough to be out of danger, at 3rpm and 100m radius.

retube• 4 years ago

oh come on. this is the most transparent nonsense, doesn't make any sense. clearly a viral video marketing campaign.

mkl2• 4 years ago

I can't read Japanese and just watched the videos, but what they illustrate seems pretty strange. Why is it mostly water instead of human living space? If the water's meant to let in more light, that's more likely to end up boiling the water during the day and freezing it solid overnight. https://en.wikipedia.org/wiki/Moon#Surface_conditions

yellowapple4• 4 years ago

Water happens to be a rather effective radiation shield, so I suspect that might be at least part of the reason why there's so much of it in the design.

throw93232• 4 years ago

Better way is to make a scientific committee, that would declare all side effects (muscle loss, bone density loss...) as totally random and uncorrelated to moon environment. Worked before...

necovek2• 4 years ago

I always wonder why is nobody considering simply introducing "heavy" weights for every person to wear on planetary body like a moon? A sort of inverse-exoskeleton if you wish.

For an average 75kg person, you'd need to add roughly 5x (375kg) to their weight to reach parity between Moon and Earth, which if done with iron or steel would need less than 50l of volume spread around the body. Heavier metals could be used for an even lower volume, of course (though you'd want to avoid poisonous metals like lead, mercury or osmium), though you might hit other bottlenecks (gold and platinum are 2.5x denser, and iridium even more so, but price comes into play — perhaps locally sourcing them on other "rocky" planets is more feasible).

This does not resolve all of the issues mentioned in the article (like the effect on our internal organs, childbirth and such), but can definitely target a bunch of externally accessible muscles to keep them from getting atrophied.

Perhaps this will be a cheap solution for those not living in the rotating megastructures. I should start collecting gold to be able to go sightseeing on the Moon.

noSyncCloud• 4 years ago

The additional mass will have tons of inertia, making ordinary activities like walking difficult, regardless of its current weight in the local gravity.

necovek2• 4 years ago

That's a great point. Perhaps it would have to be an actual mechanized exoskeleton that is passive only downwards.

No cheapo solutions for us plebs then. /me dumps all the platinum in the trash.

dghughes• 4 years ago

This does not resolve all of the issues mentioned in the article (like the effect on our internal organs, childbirth and such)

Yeah it would be like anchoring a balloon. Sure it's not going to float away but it's still a balloon. It's our internal jiggly bits that are important too.

kleene_op• 4 years ago

It's our internal jiggly bits that are important too.

For this I just have the right solution: extremely rich iron diet.

dTal• 4 years ago

Weights don't really accomplish much. The acceleration due to gravity is constant regardless of mass, so you would still have to bunny hop. And as a sibling comment pointed out, the inertia of all that extra mass would be huge, so actually moving would be 6x more difficult. You'd trip almost immediately, and the impact with the ground would hurt as much as on Earth, since you've calibrated your gravitational potential energy to be the same.

cardanome• 4 years ago

The already have a good solution for surviving in Zero-G: Exercise.

We had people on the ISS stay for a year.

I would also imagine the difference between zero gravity and little moon gravity to be quiet significant regarding keeping people healthy.

Will long extended stays be healthy? No but that is a problem for the far future. I think the focus now should be to get the basic logistics in order. I am sure there would be enough people that would be willing to participate in a mission to Moon even if it meant a shortening of their lifespan. Nothing about the first colonization attempts will be pretty but colonization has never been very pretty in human history to begin with.

deepdriver2• 4 years ago

Some long-term microgravity health risks are also short-term mission risks, like ocular problems and increased blood clotting. If a centrifugal habitat helps prevent these, so much the better.

throwaway290• 4 years ago

Does this address the Coriolis effect and other issues that make rotational "gravity" feel really weird compared to actual gravity (6:58 https://m.youtube.com/watch?v=nxeMoaxUpWk)?

smallerfish• 4 years ago

Somebody read and adapted Ringworld.

Also unless I missed it, they fudged the part where the trains transition from the static tracks to the rotating structure. If so, that speaks volumes to their level of attention to detail.

Did anybody pick up what the lit up pit in the middle was supposed to be?

idiocrat• 4 years ago

Again, there is a very practical reason why humans will never colonize the moon.

And that reason is the moon dust.

The moon dust is quite special as it is highly abrasive and sticks to anything because of the electrostatic charges.

It seeps though any gap and will wear down and render any mechanical machine useless in very short time.

Nothing soft (clothes, plastic) will survive on moon for more than few months.

The dust is a nightmare for anything non-moon and there is no help.

exitheone• 4 years ago

There is help and it's not looking quite so grim.

See one of the latest Real Engineering videos: https://www.youtube.com/watch?v=0k9wIsKKgqo

Dust buildup can be significantly decreased by weaving conductors throughout the outer shells and applying a current to it.

alanbernstein2• 4 years ago

What about... Being inside a building? You know, since humans need atmosphere anyway?

Akronymus5• 4 years ago

Any activity that requires going outside will inevitably get some amount of dust through the airlock. So, it is going to slow it down by a lot, but not stop it.

ekianjo3• 4 years ago

Unless the dust is completely electrically neutral you should be able to build powered repellents for it.

eesmith• 4 years ago

Yutu-2 is the robotic lunar rover which has been moving on the Moon's surface for over three years.

ken47• 4 years ago

I find the title a little bit strange. Japan, the country, did not propose anything. Specific entities within Japan did. Perhaps I'm too post-nationalistic for this article's title.

senttoschool• 4 years ago

Same for any news out of China in the western media.

It is as if people in the West thinks the entirety of China is united on every decision, invention that comes out of every entity in the country.

Fatnino• 4 years ago

More like, "comes through the country".

meany• 4 years ago

Doesn’t your remark make the same type of generalization about the West that you accuse the West of making about China.

deepdriver2• 4 years ago

YouTuber Scott Manley has a great video on artificial gravity in space, including concepts that resemble the article's proposal:

https://www.youtube.com/watch?v=nxeMoaxUpWk

Before I watched the video, I didn't know the Soviet Union tested a (small) centrifuge for artificial gravity in space back in the 70s:

https://en.wikipedia.org/wiki/Kosmos_782

yellowapple4• 4 years ago

I feel like building this as a spinning ring (possibly inside a crater) makes more sense from a structural integrity standpoint (and possibly also a radiation shielding standpoint). Granted, lunar gravity probably makes structural integrity about ¹/₆ᵗʰ as hard to achieve as on Earth, but the spinning tower still seems a bit precarious.

greedo• 4 years ago

Birds. They show birds flying in the cylinder...

TeamMCS• 4 years ago

They are carefully spun around using Carbon nanotubes

ekianjo3• 4 years ago

Kyoto University partnered with construction company, Kajima Corp,

So a university and a corp = Japan now. Wow.

So next time Facebook partners with some academics, we can say "The US proposes..." ?

ekianjo3• 4 years ago

Why does it have to be ON the moon though? An orbital station would rotate just the same, and if you are close enough to the moon you could still travel to the surface now and then for specific missions.

a5withtrrs• 4 years ago

Aren't there bigger issues...? Like no atmosphere protecting from radiation and things like space debris/projectiles?

Japanese researchers propose a concept for making artificial gravity on the moon

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