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[G-Flex]

You're very confused.

Force is not energy. Gravity provides force, not energy.


Things orbiting each other due to gravity do not provide energy automatically. Nor do magnets pulling on each other. Those are forces.

Forces actually doing work? Now that's energy.


For instance, right now I'm standing on the floor. The gravitational force between myself and the planet is causing there to be a lot of force present and acting on a number on things. This doesn't mean energy is being dissipated from, or supplied to, anything at all.


There is no such thing as endless free energy from gravity or magnets. You cannot get the forces of magnetism or gravity to provide energy indefinitely.

Take gravity for instance. Say you have a vase high on a shelf. That vase has a certain amount of potential energy in the fact that it can, say, fall down (given that falling releases energy). Once it falls down and is in its stable state of no more potential energy due to gravitation, that's it. You can lift it up again, but THAT takes at least as much energy as you'll get out of it when it falls back down.


Also, things moving simply means that they CONTAIN energy. Specifically, they have kinetic energy (motion). That doesn't mean they're being supplied with energy or giving it off anywhere. Now, if something starts causing them to speed up or slow down, energy is obviously being supplied (if the things speed up) or dissipated (if they slow down) since they're either doing work on something or something else is doing work on them. Since you likely aren't familiar with the concept of "work", I'll say this: It's essentially interchangeable with energy in calculations (same units and so forth), and is equivalent to a force applied over a certain amount of distance. In other words, if I push on a cart with 40 newtons of force over a distance of 10 meters, that's 400 newton-meters of work, equivalent to 400 joules of energy that I needed to put into it (not counting friction or anything like that).


[edit]

For an example involving magnets:

It's basically the same deal. Magnets attract each other, so obviously that can result in interactions where energy is exchanged.

Say you have two magnets. They're attracted to each other, and are near each other on a desk. Given the right conditions, sure, they'll snap to each other, inducing motion and energy release. But then they'll just be stuck together doing nothing. They'll still exert force on each other, but no energy is released or introduced.


Fact of the matter is, no matter what crazy contrived system you come up with, you cannot make a closed system that releases energy indefinitely.

[Micro102]

it is possible, magnets and gravity do not require any input to have, and they create force, which can be transferred into energy. technically water wheel is free energy because the massive gravity from the moon and the earth and sun make rivers flow and all that stuff, so yeh gravity = flowing water = free energy. it is possible

[Neonivek]

so yeh gravity = flowing water = free energy. it is possible

That is no more a perpetual motion machine as a solar powered calculator. Your just finding external sources of power.

[Micro102]

i just want a free energy machine, get a good enough one to run an entire house or car and youve got one hell of a technological revolution

[RAM]

The example I find interesting is tidal power, an object orbiting provides an alternating gravitational force that can have energy extracted from it. Of course, all that means is that the moon is big and it is going to fall on your head...

To be fair, that is based off of the theory of conservation of energy and I haven't studied it, I am perfectly willing to respect someone who is willing to explore perpetual motion. Just because something seems impossible doesn't mean that people haven't missed something...

[Micro102]

perpetual motion is possible simply with the fact that there is a never ending steady flow of force called gravity, add that to magnetism and id say its 100% possible.

that propetual motion machine i linked to failed because glue kept failing, so why not get better lgue or just simply weld it?

[Sowelu]

This isn't a troll:

Micro, you're an idiot with respect to physics.  You need to get out of this thread, and into a physics class.

The fact that these people are also idiots doesn't change that.

The problem with waterwheels?  The water has to get up to the top of the mountain in order for it to flow back down.  That takes energy.  That energy comes from solar input.  When you move something from a low place to a high place, you expend energy and invest it in what we call "potential energy"...then you can convert that "potential energy" back to real energy when you move it down again.

You already know that what goes up, must come down.  But never forget:  For something to come DOWN, it MUST HAVE GONE UP TO START WITH.

The sun isn't free energy.  Sure, you can harness it and do great things, but it ISN'T FREE.  And you only get so much per square meter of material you expend...

[Neonivek]

This isn't a troll

Uhhhh... It takes a bit more then just saying it to make it true.

Saying "This isn't a Troll" and have it be true only happens in a few situations
1) You are writing in a joking tone that could be misinterpreted as insulting
2) You are writing in a harsh tone but you are simply being blunt.

The use of the word "Idiot" is what betrays your statement.

Though it really depends on how you interpret troll. While I am sure you don't mean to insult anyone... you are quite frankly insulting everyone. So your not a troll your just flaming. Unintentionally I'm sure.

[Sean Mirrsen]

To be fair, the water circulation system that exists on Earth is a very efficient one. Water goes down, the Sun evaporates it, water goes up, water condenses, water goes down, etc.

A gravity generator thing would work if it were possible to create a material that reduces the effect of gravity between two objects on either side of it. Coat half of a weight with it, and it'll weigh less when turned coated side down. Make two such weights attached to a pivot, and you'll have a system that generates power from gravity. Still not perpetual, like any physical machinery, but will work as long as it doesn't rust, or until the anti-grav material reaches its saturation limit (presuming it works by absorbing gravitons or somesuch).

It should be slightly easier with magnets - whereas the gravity field is uniformly distributed in all directions, magnetic fields have polarity and shape, leaving more wiggle room for creative applications.

[Micro102]

actually the moon pulls and pushes the water, water does not need to be moved up to flow through a river. but that is how most rivers are formed.

thing is i am in a physics class, college physics, and i am awsome at it.

[G-Flex]

it is possible, magnets and gravity do not require any input to have, and they create force, which can be transferred into energy. technically water wheel is free energy because the massive gravity from the moon and the earth and sun make rivers flow and all that stuff, so yeh gravity = flowing water = free energy. it is possible

Did you not read what I posted?

Gravitational and magnetic forces can only result in a certain amount of energy (the potential energy of a system) being dissipated from a system without any external inputs going on. It does NOT provide limitless energy, and if you want to get MORE energy out of it, you have to put at least as much energy INTO it. I've said this before, but: constant force does not mean constant energy output or input.

For example, tidal energy, which you're mentioning, is NOT a source of free energy. The fact is that things don't orbit each other forever like that; eventually the orbit will, theoretically, decay. The energy only seems infinite because of how massive and long-term it is.

actually the moon pulls and pushes the water, water does not need to be moved up to flow through a river. but that is how most rivers are formed.

thing is i am in a physics class, college physics, and i am awsome at it.

To be honest, nobody cares what class you're in. The fact is that you are betraying a severe misunderstanding of very, very basic physical principles.


[edit]

Here's another, very basic gravity example, since you don't seem to be understanding the general principle:

Imagine a uniform sphere just floating in space, held in shape by its own gravity. There is gravitational force involved, of course; that's what is holding it together. However, that force is never going to actually do any mechanical work or otherwise release energy, because it's already in its most stable condition; there is no gravitational potential energy within the system, it is inert, and no energy will come of it despite the fact that there will always be forces acting upon the sphere holding it in shape. Now, if something HAPPENS to it, then the gravity might start doing something that releases energy, but that would only be because energy is being PUT into the system by whatever happened to it.

Compare that to, say, a planet-sized cube in space. A cube is very far from the most stable form of something of that size; planets tend to become circular for a reason. The way gravity works on the shape, it reforms, gradually becoming more and more circular. This acceleration and movement of the parts of the body will, in fact, cause energy to be released, since they're being accelerated and decelerated. Just  like my vase example earlier, the amount of energy that would be released between the initial state and the end stable condition (the sphere) is the gravitational potential energy, and a system only has so much (of any kind of potential or other energy, really, at all).

Your Sun example was wrong, too. The Sun's going to burn out eventually.

[andrea]

yes, tidal energy isn't endless. gravity does it, but it also draws energy from the moon (i think). tidal forces are what made always the same half of the moon face earth (note: this doesn't happen only with water.). probably moon is slowly slowing down.

probably. what i said is based on what i read somewhere some time ago. i can't remember much.

but for all human purposes, tidal forces can be thought as unlimited. still far from perpetual motion though.

[G-Flex]

The energy is more from the moon-Earth system than from the moon itself, really.

The thing is that, in addition to orbital decay, and what you mentioned about the rotation of the moon having probably slowed down over time, the Earth's rotation is also probably getting slowed down as well.

[andrea]

yes, true. i forgot about that, thanks.

and i even read that recently! and still can't remember where...

[Sean Mirrsen]

That would imply that the Earth started at a higher orbital speed, which would imply being closer to the Sun to keep in orbit. However, since it would be impossible for Earth to move away from the Sun, even taking solar wind into account, the Earth couldn't have slowed down. Same applies to the Moon - if it slows down, it must have been moving faster originally. If it was moving faster at any point in time, it must have had an orbit that is closer to the Earth than it is now. If the gravitational motion decreases orbital speed, the Moon should have fallen on the Earth eons ago.

Also, can't agree on the gravity causing the Moon to remain facing the Earth. Last time I checked, Mercury isn't doing anything of the sort, and it should be subject to much more stress than the Moon is. Rotation of mass should be of little matter to gravity, since it influences all mass around it equally, therefore a sphere or planetoid that has its center of mass in its geometric center would not be affected. Instead, my hypothesis on the matter was that there are noticeable amounts of metal dispersed throughout the Moon's volume, perhaps some lighter metals that won't form a metal core. Since it's not magnetized itself, the Moon wouldn't be subject to the repel/attract iteration as it passes through the Earth's magnetic field, but it would experience a form of magnetic "friction" or resistance, that would eventually sync its rotation to its orbital cycle.