Artificial Gravity

[Eudoxia]

So you have this ship heading to Mars, but, en route, someone vomits due to nausea in freefall, the vomit touchs the control panels, the system goes crazy, and the ship's antimatter drive blows up, turning billions of dollars into a continent-sized nova.

How do you fix this? Artificial Gravity.

[B]#1 - Rotation[/B]

Simply build a ring-shaped (Actually it's a torus) habitation module, and make it rotate. In space, with no air to create friction, inertia will cause it to rotate forever.

Artificial gravity is not generated, but simulated, thanks to centripetal force.

How fast does it have to spin?

[QUOTE=Atomic Rockets]Ca = 0.011 * Cr2 * Cl

Cl = Ca / (0.011 * Cr2)

Cr = sqrt( Ca / (0.011 * Cl))

where
Ca = centrifugal artificial gravity acceleration at point X (m/s2)
Cl = distance from point X to the center of rotation (m)
Cr = rotation rate at point X (rotations per minute)
Remember that 1.0 g is 9.81 m/s2
Notice that as point X is moved further from the center of rotation the artificial gravity increases.
Instead of doing the math yourself, you can cheat and use [URL=http://www.artificial-gravity.com/sw/SpinCalc/SpinCalc.htm]SpinCalc[/URL] or the Rotational Gravity Calculator.[/QUOTE]

(ed. note: Link on "Rotational Gravity Calculator" removed due to 404 error.)

However, there are problems: The Coriolis effect will cause nausea in a rotating torus. See:

[QUOTE=Atomic Rockets]As it turns out, there are limits on the rotation rate. The Coriolis effect can induce nausea. 1 RPM is safe, at 3 RPM most can acclimatize but some cannot (and it takes some time for those who can), at 5 RPM a few can acclimatize but most cannot, and nobody can acclimatize to 10 RPM and above. The only way to increase gravity without increasing the RPMs is to increase Cl.[/QUOTE]

Then again:

[QUOTE=Atomic Rockets]Or maybe not. Troy Campbell pointed out a [URL=http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=11020210&dopt=Abstract]recent study[/URL] with some hopeful conclusions:

However, the data on artificial gravity is a bit out of date. The original research into it had subjects sick at 3 RPM and incapacitated at 6 RPM+. However, more recent research suggests that, by using incremental increases in rotation and making a few limb movements, adaptation can occur with almost no feelings of nausea. The old research (done on about 30 subjects) simply went from zero to full rotation. Moreover, the adaptation can be simultaneous with non- rotational adaptation. So, moving in and out of the rotating habitat for maintenance or whatever is no problem. It's thought that rotation rates of up 7.5 to 10 RPM are possible. This makes Discovery's 5.5m radius centrifuge a real possibility. In fact, with 10 RPM, you could crank it up to a handsome 0.61 G, or 0.34G if you want to play it safe at 7.5RPM.
[/QUOTE]

[IMG]http://3.bp.blogspot.com/_RyWwFQN34dc/RgWZeIYbEDI/AAAAAAAAA8U/nTLmO-4TPvQ/s400/orbitalspacestation.jpg[/IMG]
[I]Station V from 2001: A Space Odyssey, uses rotation to produce artificial gravity.[/I]

[IMG]http://astroprofspage.com/wp-content/uploads/2006/12/AC75-1086-1q.jpeg[/IMG]
[I]A Stanford Torus. The torus rotates creating artificial gravity for people to live in.[/I]

[B]#2 - Acceleration[/B]

G-forces can provide gravity. Simply give the ship a constant acceleration of one gravity (1g = 9,8 m/s).

The problem with this is that ships in real life only burn fuel every now and then. If you are going to burn it constantly, you will need [B]a lot of fuel[/B]. As the amount of propellant in the tanks decreases, so does acceleration. You will need a computer to adjust it all and keep the acceleration constant.

Note that the structure has to be desgined to rotate. Otherwise some parts that were designed for freefall environments might just fall off.

[B]#3 - Mass[/B]

Put a massive object below the ship, and it generates gravity. Tada!

Oh, wait, you need extra fuel to carry said object. In the end the fuel would be more massive than the object.

[B]#4 - Magnetism[/B]

Put magnets below the decks and on shoes. It allows people to hold on to surfaces, but in general it's not very good.

[B]#5 - Actual Gravity Generators[/B]

(Thanks rosthouse for the heads up.)

Now, is it possible to generate gravity like in sci-fi? Well, there is a relationship between magnetism and gravity. In the early 90's an Russian engineer, [URL=http://en.wikipedia.org/wiki/Eugene_Podkletnov]Eugene Podkletnov[/URL] made a device (A spinning superconductor) that generated a [URL=http://en.wikipedia.org/wiki/Gravitomagnetism]gravitomagnetic field[/URL] (What is that I don't even). The European Space Agency claims to have also done a similar thing [URL=http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html] here[/URL], but the result was only 100 millionths of a gravity.

[scientist]

What the ..

Do you work at Nasa or something?

[Adbor]

Another thread I don't understand by Eudoxia.

[LUHG!]

[QUOTE=scientist;21547579]What the ..

Do you work at Nasa or something?[/QUOTE]

He probably nicked it from somewhere and is trying to look smart.

[Simples]

Interesting!

[CheeseMan]

[QUOTE=LUHG!;21547613]He probably nicked it from somewhere and is trying to look smart.[/QUOTE]

He probably nicked it from his workstation at NASA.

[Yuluthu]

If you have magnets on your shoes, how do you walk

[LUHG!]

I'm just looking at his past threads and it's full of smartass stuff then theres this one thread about trouble with a router...

Just made me laugh.

[TacoFamine]

So confusing...must go back to threads about sperm in eye.

[CheeseMan]

[QUOTE=LUHG!;21547654]I'm just looking at his past threads and it's full of smartass stuff then theres this one thread about trouble with a router...

Just made me laugh.[/QUOTE]

some people who work at NASA have trouble with computers OK

[rosthouse]

You may want to include something about the posibility to "generate" gravity, as it has been experienced in an experiment by ESA.

[url]http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html[/url]

Even though the effect is very small, it could be the key to generate gravity in the future :buddy:

[LUHG!]

[QUOTE=CheeseMan;21547676]some people who work at NASA have trouble with computers OK[/QUOTE]

OK.

[jlj1]

#1 I don't understand why it works, but it does

[CheeseMan]

[QUOTE=LUHG!;21547698]OK.[/QUOTE]

Thank you.

[greasyjamici]

I didn't understand much of this, but very smart of you.

[Useful Dave]

Haven't you forgotten the tumbling pigeon?

[angelangel]

Using magnets to stay onto the ground isn't artificial gravity.

Your bones and muscle will still degenerate.

[NoDachi]

Pretty standard Atomic Rockets paste.

[Number-41]

Didn't magnets also attract non-magnetic substances, but only if they were ridiculously strong?

[TamTamJam]

Magnets in your boots wouldn't stop nausea. You get nausea because of a fluid somewhere near your ear, which is used in your body to feel whether your standing right or your hanging upside down and balance yourself, goes all over the place, making your body think YOU are going all over the place. So magnets wouldn't help with nausea.

[editline]08:04AM[/editline]

Not to mention magnets would interfere with their computers.

[CNiall]

[QUOTE=jlj1;21547700]#1 I don't understand why it works, but it does[/QUOTE]

It's the same principle that those fairground rides which spin around quickly and cause you to be stuck to the walls use.

[sltungle]

[QUOTE=CNiall;21548105]It's the same principle that those fairground rides which spin around quickly and cause you to be stuck to the walls use.[/QUOTE]

But in reality you're not actually being 'pushed out', you're just trying to travel in a tangent to the circle, but you can't because there's a physical barrier blocking you.

[Eudoxia]

[QUOTE=LUHG!;21547613]He probably nicked it from somewhere and is trying to look smart.[/QUOTE]

Oh no, I have been discovered.

Seriously now: I edited the OP to add the part about using superconductors to generate gravity, also added some pictures I couldn't add before. I had to leave for a sec and someone was going to use the computer so I decided to post the thread and update it later.

[Bubbus]

[QUOTE=Eudoxia;21547546]As the amount of propellant in the tanks decreases, acceleration will increase. (F=ma)[/QUOTE]

Fixd, assuming you're using propulsion with constant force output regardless of how much fuel you've got left. If not then who knows

I'm a big fan of the rotational method of generating gravity, it seems the most possible to achieve right now and the most energy efficient because of the lack of friction in space

[Strongbad]

[QUOTE=Eudoxia;21547546]So you have this ship heading to Mars, but, en route, someone vomits due to nausea in freefall, the vomit touchs the control panels, the system goes crazy, and the ship's antimatter drive blows up, turning billions of dollars into a continent-sized nova.

How do you fix this? Artificial Gravity.

[B]#1 - Rotation[/B]

Simply build a ring-shaped (Actually it's a torus) habitation module, and make it rotate. In space, with no air to create friction, inertia will cause it to rotate forever.

Artificial gravity is not generated, but simulated, thanks to centripetal force.

How fast does it have to spin?

(ed. note: Link on "Rotational Gravity Calculator" removed due to 404 error.)

However, there are problems: The Coriolis effect will cause nausea in a rotating torus. See:

Then again:

[IMG]http://3.bp.blogspot.com/_RyWwFQN34dc/RgWZeIYbEDI/AAAAAAAAA8U/nTLmO-4TPvQ/s400/orbitalspacestation.jpg[/IMG]
[I]Station V from 2001: A Space Odyssey, uses rotation to produce artificial gravity.[/I]

[IMG]http://astroprofspage.com/wp-content/uploads/2006/12/AC75-1086-1q.jpeg[/IMG]
[I]A Stanford Torus. The torus rotates creating artificial gravity for people to live in.[/I]

[B]#2 - Acceleration[/B]

G-forces can provide gravity. Simply give the ship a constant acceleration of one gravity (1g = 9,8 m/s).

The problem with this is that ships in real life only burn fuel every now and then. If you are going to burn it constantly, you will need [B]a lot of fuel[/B]. As the amount of propellant in the tanks decreases, so does acceleration. You will need a computer to adjust it all and keep the acceleration constant.

Note that the structure has to be desgined to rotate. Otherwise some parts that were designed for freefall environments might just fall off.

[B]#3 - Mass[/B]

Put a massive object below the ship, and it generates gravity. Tada!

Oh, wait, you need extra fuel to carry said object. In the end the fuel would be more massive than the object.

[B]#4 - Magnetism[/B]

Put magnets below the decks and on shoes. It allows people to hold on to surfaces, but in general it's not very good.

[B]#5 - Actual Gravity Generators[/B]

(Thanks rosthouse for the heads up.)

Now, is it possible to generate gravity like in sci-fi? Well, there is a relationship between magnetism and gravity. In the early 90's an Russian engineer, [URL="http://en.wikipedia.org/wiki/Eugene_Podkletnov"]Eugene Podkletnov[/URL] made a device (A spinning superconductor) that generated a [URL="http://en.wikipedia.org/wiki/Gravitomagnetism"]gravitomagnetic field[/URL] (What is that I don't even). The European Space Agency claims to have also done a similar thing [URL="http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html"] here[/URL], but the result was only 100 millionths of a gravity.[/QUOTE]

This has certainly lifted my spirits.

[Price_]

I don't know what I just read.

[Peluri]

[QUOTE=Price_;21548319]I don't know what I just read.[/QUOTE]

it's okay you don't probably even need it in your life unless you're space scientist or something like that

[Awesomecaek]

[quote]
[B]#5 - Actual Gravity Generators[/B]

(Thanks rosthouse for the heads up.)

Now, is it possible to generate gravity like in sci-fi? Well, there is a relationship between magnetism and gravity. In the early 90's an Russian engineer, [URL=http://en.wikipedia.org/wiki/Eugene_Podkletnov]Eugene Podkletnov[/URL] made a device (A spinning superconductor) that generated a [URL=http://en.wikipedia.org/wiki/Gravitomagnetism]gravitomagnetic field[/URL] (What is that I don't even). The European Space Agency claims to have also done a similar thing [URL=http://www.esa.int/SPECIALS/GSP/SEM0L6OVGJE_0.html] here[/URL], but the result was only 100 millionths of a gravity.[/QUOTE]

We need to know about Higgs boson. If those guys in CERN actually prove it's existence, this shit could get interesting.

[mike]

[QUOTE=Awesomecaek;21548797]We need to know about Higgs boson. If those guys in CERN actually prove it's existence, this shit could get interesting.[/QUOTE]

that's not really how it works

[MachiniOs]

[quote]#4 - Magnetism

Put magnets below the decks and on shoes. It allows people to hold on to surfaces, but in general it's not very good.[/quote]
Dount that would stop the vomit.