How viable is artificial gravity using centripetal force?

>>8578597
It's a gundam!

>>8578597
Once you get a big thing spinning, it will only take a little push sometimes to keep it that way, so it seems pretty viable

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>>8578700
This.

Anyone who has used something manual that has a massive flywheel knows this well. Like a pottery wheel for example. Hard to get going, but after that it is really easy.

assuming the thing is a few billion megatons it'll take approximately a lot of fucking energy to get it spinning in the first place

>>8578747
Except it's not a few billion megatons, the design for the stanford torus is around 10 megatons. In addition, the radiation shielding, which accounts for a large percentage of the mass, does not need to rotate with the habitat region

>>8578747
Anyone know what the delta v calculation for figuring that out is? W=1/2m(v2/2−v2/1) ? All my popsci math is for shit in the face of simple kinematics.

>>8578794
Wouldn't that be disorienting for the people inside, though? Seeing the shielding spinning relative to them I mean.

>>8578831
Who cares about that? They'll get used to it.

>>8578831
You'd just look outside and see something moving. I don't think it'd be a problem.

>>8578831
going outside and seeing a plane in the sky makes me vomit and fall over

Big problem would be heat i think. The whole thing would need to be spinning or friction would quickly friction weld whatever's standing still to whatever's moving. Pretty hard to cool shit off in space

>>8579014

>Pretty hard to cool shit off in space

how do you know this? Have you been to space? why do sci-tards always talk out of their ass when they clearly know nothing

>>8579020
Stop posting anytime

>>8579014
>The whole thing would need to be spinning or friction would quickly friction weld whatever's standing still to whatever's moving

The heat shield can simply float without touching the habitation zone.

>>8578719
That picture is akin to:
>I am Nostradamus, hear me roar!

>>8578747
All you'd need is ion thrusters to get it spinning, you brainlet. There isn't any friction up there.

>>8579093
oh good point, there's no friction, I didn't think of that
just add a couple thrusters and wait a few thousand years for it to accelerate, great thinking

>>8579101
For one, it wouldn't take that long, moron. For two, you're really impatient, aren't you?

>>8579020
He is completely correct. There is noting to convect or conduct to, which is the largest source of heat dissipation in the universe. It would have to radiate, and that means it has to cool by letting off tiny light particles, which takes a long time and is highly ineffective.

>>8578831
Inside - what relative motion are you then thinking of??

>>8579076
Yes it can, in free fall. As soon as you want to make a translational shift though, you're in for some chop.

>>8579101
More like a few thousand weeks. Probably less than that.

>>8579145
You can use large thin cooling fins, perpendicular to the sun. Problem solved.

>>8579093
>There isn't any friction up there.
> you brainlet
Yes there is. Just no air friction. The parts of the object itself certainly would experience friction.

>>8579157
That would be geometrically difficult for a torus. Also, it orbits a planet and hence is not always at the same position relative to the sun. They would have to move, and this would require them to be a certain size/strength. All adding to the weight of the craft.

>>8579159
>I don't know how friction works in relation to the craft spinning.
I love it, /sci/ is literally just all of popsci cunts, isn't it?

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>>8579101
Stop talking shit out your ass. Put in some numbers to back up your claim or get the fuck >>>/out/. I suggest using the density of iron or steel as basis for your calculations.

Here is my napkin calculation of the energy necessary to give it the desired acceleration a for a body with density rho and external radius r_e, that would depend, together with the thickness z, on the amount of people you want to shelter.

>>8579173
If there was a non-moving component like the radiation shield, it would experience friction with the spinning torus. Even though it is in free-fall, there are still micro-variations in the earth's gravity that would cause geodesic deviation and the parts would rub together. That good enough?

>>8579180
What about cold-welding, wouldn't that be an issue to:
>parts rubbing together.

>>8579191
Yeah, but I don't know too much about that. I understand the principle of it, but I don't really know how it adversely affects spacecraft.

>>8579197
Essentially, as the friction of the radiation shield rubbing against the craft removes the oxide layer it eventually welds together.

>>8579179
I messed up my formula but the mistake is quite obvious and left as an exercise to the reader.

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Guys I think this thread just gave me a brilliant idea how to solve the whole prolonged exposure to zero G issue.
Pic related. You'd just make the rocket longer and spin it along on the way. Not only will it generate gravity at the ends but the stars will look cool from the inside too.

>>8579214
That would be a real problem.

>>8579224
Yep, I just ruined my own 'no friction' argument, fuck my life.

>>8579222
This is actually a pretty good idea, anon, well done. - Someone should mail this to NASA.

You have to make the ship large though. If it's too small, you'll get weird Coriolis effects. Still, that's probably better than losing muscle mass like crazy.

>>8578597
Centripital force is not a viable alternative to gravity

>>8578747
If it wasa few billion megatons, it would already have natural gravity.

>>8579288
t. know it all Jesus

>>8579288
Gravity and acceleration are the same thing in GR. It is viable.

>>8579288
>>8579323
What about cold-welding as a mentioned above faggots? Wouldn't your torus just end up welded to the radiation shield?

>>8579288

>spin some around in one of NASA's centrifuges
>they pass out from the G-force

If it works when its killing it will work when its keeping them alive god damn it.

>>8579353
>If it works when its killing it will work when its keeping them alive god damn it.
You'd make a great mission commander. :')

>>8578747
Assuming we can build these things energy looks like a trivial matter

>>8579352
Put the fucking thing in the hull itself and let it rotate.

>>8579214
Except there is no friction, because the radiation shield is separated from the spinning colony by several feet:

" There will be a clearance of several feet to keep the hull and shell from touching or scraping. The shell will be tied by cables to the central hub to ensure that no such scraping can occur and the cable lengths will be maintained tight like bicycle spokes. Inevitably, there will be concern that the hull and shell may scrape despite these precautions. The solution will be simple: add more clearance. An extra 4 feet of clearance will only increase the shell mass from 10,000,000 tons to 10,100,000."

http://www.nss.org/settlement/ColoniesInSpace/colonies_chap12.html

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As I was autistically scribbling in the middle of a birthday party I didn't notice the error, not that anybody cares.

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>>8579089
But, Nostradamus was right.....

>>8579153
They can both change in tandem. It wouldn't be any more difficult than any of the other instant death things involved with such a habitat.

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>>8579179
>or get the fuck >>>/out/.

God fucking damn it! Stop sending shitheads to our board. It isn't a trash heap. There is literally a board for that shit and it is >>>/trash/ Because /out/ is a great board when faggots like you don't dump your orange peels into it.

>>8579430
Completely wrong. Embarrassing.

>>8579461
Yes... I know it is not right to do physics in parties, but the cake was bad!

It's probably the most viable element of the entire fantasy.

Logically, it's smashed assholes on a skewer

>>8578970
You would probably fail as a candidate for space colonization. Fortunately for the effort, there are millions of viable candidates to take your sorry place.

>>8579093
The design calls for transfer of energy between the outer passive shielding and inner torus. The end product would be a more slowly rotating out shield and the full speed habitat.

>>8578831
There would be no need for windows facing the shielding, would there?

>>8579180
Roller bearings.

Do you folks realize this has already been studied?

http://www.space.com/22228-space-station-colony-concepts-explained-infographic.html

>>8579164
That's why you put it at the Earth-Sun L3 or L5. Relative position for PV panels and cooling panels would always be fixed.

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what would happen if you threw something straight up in a place with centripetal gravity?
my intuition tells me that from the point of the observer, the thrown object would appear to move against the direction of rotation

what would this mean for things like helicopters?
i feel like it wouldn't work
can somebody throw together a force diagram and check it

PBS Spacetime
https://www.youtube.com/watch?v=EHKQIC5p8MU

>>8579916
the thrown object would move in a perfectly normal way afaik - just as if you were on a planet.

>>8579014

What are the alternatives to a really really really big ball bearing and what could be done to save momentum if the bearing were to break?

>>8578719
this is dumb

The real purpose of our civilization should be the production of AGI that will be able to spread throughout the galaxy using von neumann probes. One day all usable material reachable at fractions of C will be converted into computing substrate.

>>8579222

Is the "no gravity here" section a really long rod with bearings at each end?

>>8580034
Almost.
If you were a tennis player you would feel something different in the ball trajectory, because it's not perfectly straight and parabolic.
Here is a good explanation of the coriolis effect in a space station:
http://www.bogan.ca/physics/coriolis.html
But that is a small station, if the radius is in the km range, angular velocity is going to be quite smaller and the effect less evident.
Probably invisible for normal human activity.

>>8579020
>how do you know this? Have you been to space?
Top god damn kek

if you just had an empty torus full of air, when you begin spinning it, the air will remain stationary, and relative to someone who is on the surface of the torus, the wind will appear to be blowing

after you start spinning it, how long would it take for the air to "stabilize"?

>>8579191
like dicks lol

What radius of the ring is necessary to achieve a somewhat 1G uniform pull along the height of a simple two storey building?

>>8578597
>How viable is artificial gravity using centripetal force?

The physics behind it are sound, but long term biological effects have never been researched.

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>>8580147
>after you start spinning it, how long would it take for the air to "stabilize"?

https://en.wikipedia.org/wiki/Turbulence
https://en.wikipedia.org/wiki/Drag_%28physics%29
https://en.wikipedia.org/wiki/Momentum

>>8580151
>What radius of the ring is necessary to achieve a somewhat 1G uniform pull along the height of a simple two storey building?

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>>8580287
i was asking because i'm not smart enough for fluid mechanics

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>>8579916
>>8580034
>>8580124

>>8580295
>i was asking because i'm not smart enough for fluid mechanics

it depends on a whole lot of factors, like what is the surface area of the ring that is actually touching the air, how fast the ring is spinning, and how much mass of air is inside the ring.

It would be something like maybe an hour or less, with smaller/slower rings coming up to speed quicker, and larger/faster ones taking more time.

Basically the answer really depends upon the size of the ring.

>>8578597
It's ok for labrats that we will become.
Humanity has taken the flame of science as far as it could. Space is not ment for humans.

>>8578747
>a few billion megatonnes
That is called a planet, desu.

>>8579020
are you the kind of retard who thinks space is cold or something

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>>8579222
I get that you're trying to make a joke, but people have proposed concepts very close to this, using a tether rather than a "longer rocket".

For instance, if someone were going to go to Mars in a small capsule, for argument's sake, let's say it's a Dragon 2 launched by a Falcon Heavy.

Pic related: you use the upper stage as a counterweight, connected by a tether to the capsule, and use the thrusters to spin it up so you have light gravity (somewhere in the lunar to martian range). You stick a BEAM on top for living space during the coast, now there's a tolerable two rooms for two people or a comfortable amount of space for one person. You sleep and shelter from radiation in the middle of your containers of supplies and waste.

This could also be launched on a Falcon 9 to LEO, or by a Falcon Heavy to a lagrange point where real deep space conditions can be observed, and would be about a thousand times more interesting and useful than the ISS.

>>8578970
but the plane would take up half your fov

>>8579780

[eqn] \frac{the \; joke}{your \; head} [/eqn]

>>8580323
what the h*ck is this

>>8580323
Remember the Cant.

>>8580869
scene from "The Expanse" tv series. he's on a somewhat "small" space station that rotates for artificial g

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>>8578597
Your pic reminded me of this pic.

>>8578597
>How viable is artificial gravity using centripetal force?
TRL = 6 or 7. 9 if you count human centrifuges on Earth. Totally viable, but there are drawbacks to having a spinning vessel (i.e. docking and EVA become more complicated).
>>8578747
>few billion megatons
You don't have to have a full Stanford Torus to achieve artificial gravity via centrifugal action. Most human centrifuges on Earth are boom/truss and counterweight types, which could just as well be implemented in space at similarly small scales. One version of Transhab was planned to use a tether and counterweight (in the form of a spent rocket stage) to similar effect, for a transit to Mars.
>>8578803
Well it's rotational velocity, not linear, so it'd be delta-omega instead of delta-v. And to figure out how much propellant it'd take (assuming you use propellant instead of reaction wheels or the like), you'd have to look at the moment of inertia of the assembly, the moment arm of the thrusters used to spin it up, the ISP of those thrusters, and of course the initial and final angular velocities. Technically you'd need to look at the change in inertia due to expended propellant too but I doubt it'd be significant to matter much.

>>8578719
That screen save is stupid.
You really think we aren't going to start engineering our genome?

>>8579916
>what would happen if you threw something straight up in a place with centripetal gravity?
It would fallow a curved path, and land in front of you.

>what would this mean for things like helicopters?
Surprisingly little. In a ring large enough to fit a helicopter, the centrifugal and coriolis effects are going to be small enough to be managed by the pilot.

>>8580147
You don't just begin to spin it, way too much energy is required.
Realistically it would be a very slow process that takes months, air would just accelerate gradually with it.
So there would be a breeze during the speed up, but very gentle and difficult even to notice.

>>8581166
How do they get the water to flow?

>>8582104
They could use pumps. Especially if you're talking about fountains or plumbing. If you really need the central waterway to flow, you could raise part of it and let it flow downhill like an aqueduct.

how do you detect air leaks on something like this?
how do you fix it before it becomes problematic?

i know we have a way to detect leaks with some kind of radiation magic, but iirc it's for small scale, and we can't afford to irradiate a whole space station full of people

>>8579806

I can't imagine the fuel costs of stationkeeping for a multi-million ton vehicle in L3.

>>8583675
The hull could be compartmentalized double layered with pressure sensors inside it. This way if a debris did cause hull fracture the sensor would know exactly where.