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[C4lv1n]

So I've been thinking about the possiblities of artificial gravity. No spinning spaceships or stuff like that, just some sort of contraption or material that, when powered creates earth normal gravity. As I thought of this I figured that something like this would either require an almost infinte amount of power, or else violate the law of conseravtion of energy.

Think about it, you put in so much power, and now you have a gravity. What can you do with that? Hydro-electric power comes from the water falling because of gravity. If you set up a similar type of generating station over this new field then now it's not unreasonable to assume that we could get more power out than we put in. Unless of course it would require an infinite amount of electricity to power such a device/material.

Mabye I'm rambling and have no clue with my Grade 10/11 education, but it seems like this to me.

[Levi]

If you set up a similar type of generating station over this new field then now it's not unreasonable to assume that we could get more power out than we put in.

Yes it is unreasonable a person more knowledgeable than I in physics will claim!  Probably due to something like "The law of conservation of energy" or some other physics mumbo jumbo. 

Here is some stuff on artificial gravity though:  http://en.wikipedia.org/wiki/Artificial_gravity

[C4lv1n]

If you set up a similar type of generating station over this new field then now it's not unreasonable to assume that we could get more power out than we put in.

Yes it is unreasonable a person more knowledgeable than I in physics will claim!  Probably due to something like "The law of conservation of energy" or some other physics mumbo jumbo. 

Here is some stuff on artificial gravity though:  http://en.wikipedia.org/wiki/Artificial_gravity

That's kinda the whole point, it should be impossible, so either artificial gravity is entirely impossible, or it draws a crazy amount of power, more than you could possibly create.

[Virex]

The problem is that gravity is fundamentally a different force then electromagnetism. So far we've only been able to generate electromagnetic energy effectively. To generate gravity one would need a fundamentally different way to generate energy. And I mean fundamental as in the difference between a gerbil and the LHC.


Also there is no reason to assume that it would break the laws of physics. If it were really possible to generate gravity, then the generation of the gravitational field itself would cost just as much energy as could be recovered by letting the water within that field "fall". this is because you have to add the potential energy to the water first, while making the field, before you can exploit it to generate energy. It's the same reason you can't use a capacitance, AC current, a table spoon of electrons and a magnet to generate electricity. Accelerating the electrons would cost far more energy then you can recover by tapping the generated electric field.

[Cthulhu]

So I've been thinking about the possiblities of artificial gravity. No spinning spaceships or stuff like that, just some sort of contraption or material that, when powered creates earth normal gravity. As I thought of this I figured that something like this would either require an almost infinte amount of power, or else violate the law of conseravtion of energy.

Think about it, you put in so much power, and now you have a gravity. What can you do with that? Hydro-electric power comes from the water falling because of gravity. If you set up a similar type of generating station over this new field then now it's not unreasonable to assume that we could get more power out than we put in. Unless of course it would require an infinite amount of electricity to power such a device/material.

Mabye I'm rambling and have no clue with my Grade 10/11 education, but it seems like this to me.

The big hole here is "some sort of contraption or material."  We can all think of a thousand different ways artificial gravity could make semiperpetual motion devices and etc but you have to have something that can do that.

[Virex]

Well, actually it requires the assumption that you can get gravity at a fixed rate, instead of a price dependent on what will be influenced by the extra gravity.

[MonkeyHead]

Acctually, gravity is real easy to make. Just get a lot of stuff together - the rest takes care of itself, eventually. Its the amplification of gravity's weakness thats the problem...

[SniHjen]

If you are simulating Earth's gravity, then the force is 9.8 meters / second^2

That means you are constantly accelerating,("down") and is being blocked by the ground.
But on a spaceship, the spaceship would have to accelerate at 9.8 meters/second the opposite way. ("up"*)

not just temporarily, but EVERY SINGLE SECOND.

*no such thing as "up" in space.

The only way to have something that behaves as gravity, is centrifugal force. (something spinning with you on the inside. (and don't tell me that isn't a real force (just because it's only real in rotating frame of reference)))

[MonkeyHead]

tweaked that slightly for you

If you are simulating Earth's gravity, then the force acceleration is 9.8 meters / second^2

The force is 9.81 N/kg as an average over the globe - more at the poles, less at the equtor (Earth deviates from spherical)

That means you are constantly accelerating experiencing a gravitational force downwards cancelled out by a reaction force from whatever surface you are in contact with,("down") and is being blocked by the ground.
But on a spaceship, the spaceship would have to accelerate at 9.8 meters/second the opposite way. ("up"*) yes, if you wanted to remain at rest with reference to the spacecraft at 1G

not just temporarily, but EVERY SINGLE SECOND.

*no such thing as "up" in space.

The only way to have something that behaves as gravity, is centrifugal force. (something spinning with you on the inside. (and don't tell me that isn't a real force (just because it's only real in rotating frame of reference)))

[SniHjen]

the "force" thing in the first WAS stupid, but the .81 bullshit is just being pedantic and isn't necessary.

the 3rd one... gravity IS acceleration FYI.

[Virex]

the "force" thing in the first WAS stupid, but the .81 bullshit is just being pedantic and isn't necessary.

And inaccurate to boot, because it may vary by 0.05 J/m

[Darvi]

the "force" thing in the first WAS stupid, but the .81 bullshit is just being pedantic and isn't necessary.

And inaccurate to boot, because it may vary by 0.05 J/m

Uh, he did say it would vary.

[Kardos]

As I thought of this I figured that something like this would either require an almost infinite amount of power, or else violate the law of conservation of energy.

Think about it,

[G-Flex]

The problem is that gravity is fundamentally a different force then electromagnetism. So far we've only been able to generate electromagnetic energy effectively.

Forces are not energy.

Electrical energy and gravitational energy do in fact exist, and we can generate both. Want to generate gravitational energy? Pick something up off the ground and drop it. Turning electrical energy into gravitational energy is about as easy as turning gravitational energy into electricity.

If you are simulating Earth's gravity, then the force is 9.8 meters / second^2

That means you are constantly accelerating,("down") and is being blocked by the ground.

That is not how physics works.

A force is not an acceleration. A net force results in acceleration, but when you're being pushed against the ground there is no net force.

Gravity results in acceleration of 9.8 meters per second squared of an unimpeded object, approximately.

[Fayrik]

*tears hair out in a physics rage*
Come on man.
I'm no freakin' genius, but I know that large amount do not equal infinity.

If you had say, a metal plate that could generate artificial gravity, then you attempted to create an infinite hydro-electric dam through this... Yeah, it's work.
Except, the power output will be less than the power input.

There are so many obvious factors that tell us that we can't get this to work. First of all, we have the fact that, unless in a vaccum, your water will be slowed by air pressure. This will loose precious energy.
Secondly, the mechanisms that drive the generator will still have friction, no matter how much you lubricate them. More energy loss.
And, finally, gravity is really weak. The energy output of water falling would most likely never break even.

Sorry for that, I have to get this stuff off my chest.

The real issue of artificial gravity, however, isn't how it can be applied, but it's peripheral effects. If you tried implementing aforementioned slabs in a spaceship, you'd soon find the outer hull buckling in on itself, because it's effectively containing half of earth's gravity inside it. Sure, this example is in space, but I'm certain the same effects would happen anywhere you put such a device. Gravity effects everything, and, as such, will mess even the smallest things up.

(Yeah, I've performed far too many thought experiments on this stuff. And I'm only off to go and do more. ¬.¬)