No you can’t get free energy from magnets:
April 25th, 2008
|
| Share |
In response to the following comment which was left on another post recently:
i have one thing to say “PMM” Permanent magnet generator
google.it up if you must , there is no other way to reach my level of understanding ,
the e-mail is right, and if you wish to buy one or just need info on this and more please feel free to send me some mail
Well, I don’t know if the email which was given is right, but I figured this was worth addressing. There is indeed a type of motor sometimes called a “permanent magnet motor” which is simply a DC motor where there are permanent magnets around the motor’s armature. These are not as common as they once were because the magnets can sometimes loose their polarity over time and because having electromagnets provides generally better performance. However they are still used quite a bit for little toys and stuff.
That having been said, I believe what this commenter is talking about is a permanent magnet motor as a perpetual motion or free energy device.
Well I have some bad news. It seems on some level like it might be possible to make a motor which keeps on going forever by putting opposing magnets in a circle and then having a magnet rotate inside. The inner magnet is constantly pushed along by the repelling of the magnets around the outside, right? Well, unfortunately no. If you give the inner magnet a good push it might seem like it’s turning for longer than normal, but in reality there is no energy gained.
The problem is that the idea that the magnet will be pushed along is overly simplistic. Magnetic fields do not work quite like that, they don’t just push in one direction but rather a magnet will resist another magnet of like polarity entering its field, even if it is angled away or “shielded” because the state of the magnetic entering the field and leaving has equal energy. But as the rotor passes each magnet it may seem as if it gets pushed along, but it will eventually find a point to settle in, resulting in no energy gained.
There is an alternative kind of motor, which is very difficult to achieve, but it involves attempting to constantly move the magnet out of any equilibrium it may settle into by mechanically changing the layout or preventing any pocket it can settle into. However this presents another problem. The energy return is small and it’s not exactly free. As the magnet goes against the others, it is actually deriving a tiny amount of energy from the field difference. A magnet can do work, it simply can’t create excess energy. As the two fields are moved against each other they will actually depolarize the magnets. Permanent magnets are not really “permanent” and moving two in opposition to each other will actually wear down the fields and degauss the magnets. The energy required to repolarize them will always be greater than what is returned.
The idea is not new.
Yep. Thermodynamics will aways bite you in the butt! These have been built for a long time and it either doesn’t work or the inventor, after spending a lot of time getting the magnet to keep moving against each other will quickly find their magnets have been ruined.
I kinda feel bad for this guy… I wonder if I should tell him the problem..
This entry was posted on Friday, April 25th, 2008 at 8:19 pm and is filed under Bad Science, Good Science, History. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
View blog reactions
April 25th, 2008 at 8:28 pm
I see how he eventually realized he could not do the whole circle so he left a gap and then gives it a little push. I wonder if any more work is done than if no magnets? if so it would ruin them fast. It’s like how you polarize a nail by rubbing a magnet on it only it’s in reverse. You are rubbing in the opposite direction so it would ruin the magnet. I wonder how many times you could before it would be dead.
Quote Comment
April 25th, 2008 at 8:54 pm
“The energy required to depolarize them will always be greater than what is returned.”
I presume you mean the energy required to repolarise them.
But I get your point. No free lunches.
Quote Comment
April 25th, 2008 at 8:55 pm
Arrogance! Closed mindedness! How can we possible know such things wont work unless we find out about them? After all, we cannot really be sure they won’t work, can we?
Quote Comment
April 25th, 2008 at 9:03 pm
Finrod said:
OOps. I fixed that. Thanks
Quote Comment
April 25th, 2008 at 10:06 pm
Maybe someone can explain Steorn to me. See http://en.wikipedia.org/wiki/Steorn . It would seem to me that they would be smart enough not to really believe in perpetual motion.
Quote Comment
April 25th, 2008 at 10:21 pm
Here, I’ll explain Steorn to you… B.S.
There’s nothing more to say on that.
If we could get past the laws of thermodynamics, so many industries (and life as we know it) would be revolutionized. You simply can NEVER get more energy out than you put in to any device!
Quote Comment
April 25th, 2008 at 10:46 pm
Eric Berger, writing on the Houston Chronicle website, commented that:
“Recall that Steorn is a former e-business company that saw its market vanish during the dot.com bust. It stands to reason that Steorn has re-tooled as a Web marketing company, and is using the “free energy” promotion as a platform to show future clients how it can leverage print advertising and a slick Web site to promote their products and ideas. If so, it’s a pretty brilliant strategy.
Quote Comment
April 25th, 2008 at 10:53 pm
Yeah this one has been around forever. It seems like it would kinda work if you don’t know much about magnets and have a simple view of how they work.
If you ever had one of those magnetic pendulum toys on a desk it’s kinda like that: It takes a little while to find a point of equilibrium and it seems to be moving on it’s own but it’s just the energy put in.
Of course, you could possibly build a mechanical method of extracting the energy that was put into the magnet to create it. Since energy is used to realign the domains and create the force you should theoretically be able to get that energy back by returning the magnet to a neutral position. That really would be a crap way to store energy though because it’s horrible return and if you work it out you don’t put much energy into the magnet to generate the field. I did see that too though a long time ago someone had made some wheels with magnets that would keep going because they wound a spring and that would move a gear to push them out of alignment every time they stopped. It was a fantastically complicated clockwork mechanism which managed to generate no real usable energy and ruined the magnets in the process.
Quote Comment
April 25th, 2008 at 11:03 pm
DV82XL said:
yea, you know they put so much damn effort into the “Orbo” thing I honestly was surprised that it turned out to be a complete let down. I wasn’t expecting it to be an actual overunity device, but I was kinda expecting it to turn out to be viral marketing or some kind of stunt.
Never really got a punchline on it.
Quote Comment
April 25th, 2008 at 11:27 pm
Actually that’s not true. It’s easy to make a magnetic motor and you use PERMANENT magnetics so that it never looses the force. People can make it but nobody will dare sell them or really go big with it because of the oil companies and nuclear companies and all the rest who would loose so much. Money.
here is proof:
http://peswiki.com/index.php/OS:Screw-Magnet_Motor
http://www.youtube.com/watch?v=kCr3lOhMJCg
http://video.google.com/videoplay?docid=3395707314986173705
There is actually a guy named Joseph Newman who built a free energy machine that is full scale and can power your whole house or a car and he was all ready to make it and sell it but he needed a patent to get investers to start the company and the government won’t give him a patent even if it works because they say it can’t be. And also someone offered him millions of dollars to give them the plans but he wouldn’t because he said he won’t let it be used for bad purposes and he wants to have it sold cheap enough that it will end the use of oil.
Quote Comment
April 25th, 2008 at 11:39 pm
A few clicks on a google search told me everything I needed to know about Joseph Newman. Why would anyone steal his own device from an independent panel right before they were about to test it? I’ll tell you the only reason I can imagine… B.S.
Quote Comment
April 25th, 2008 at 11:55 pm
Dusty Said:
“And also someone offered him millions of dollars to give them the plans but he wouldn’t because he said he won’t let it be used for bad purposes and he wants to have it sold cheap enough that it will end the use of oil.”
Ya know? If he was really so altruistic but afraid of intellectual theft… He could keep the rights to the technology and license the technology out to those he wanted to help… ya know, to end our dependence on oil and other such things.
No, I don’t suppose he would do that. That would allow independent investigation of his claims.
Quote Comment
April 26th, 2008 at 12:01 am
Dusty said:
The point here Dusty is that there is no such thing as an absolutely permanent magnet ALL magnets will lose flux if the dipoles are stressed.
Second Law always bats last.
Quote Comment
April 26th, 2008 at 12:07 am
Dusty said:
I suppose that if you capitalise PERMANENT, it should have the same status as those two mythical entities, an IRRESISTABLE force acting on an IMMOVABLE object. Does capitalisation imply the intrusion into our universe of some transcendent Platonic entity implied by the existence of some PERMANENT magnet? the world is what it is, and there are no free lunches.
Quote Comment
April 26th, 2008 at 12:09 am
Actually Joe Newman came up here a long long ways back: http://depletedcranium.com/?p=155
There’s some… really disturbing stuff about him… I think he’s genuinely mentally ill to the point of being dangerous and the whole thing with his “marriage” which was “commanded by god” to an eight year old is especially disturbing as an aside.
Quote Comment
April 26th, 2008 at 12:06 pm
Dusty: When we say a magnet is permanent it only means that it’s always magnetic and can’t be switched off like an electromagnet. It does not, however, mean you can’t demagnetize it. You certainly can do so by a number of ways like heating it or exposing it to a magnetic field that alternates or stresses the magnet.
There is no “permanent” magnet that never looses it’s field. When a magnet is manufactured the actual material is not inherently polarized, not even those powerful neodymium iron boron magnets. They have no field until they are either stroked or in more cases placed in a special soloniod which imparts the magnetic field and uses energy. You actually do this all the time without even knowing when you use a harddrive or a video tape. Those are just magnetic material and a little electromagnet is able to change the polarity of them in different places to store data. As it runs by the write head the head changes from north to south and back again and in doing so it can change the field of the surface of the tape or disk.
I can relate a story on this. A long long while back there was a claim of overunity from a little ramp someone built which had angled magnets pointed up it and small tracks with a little cart which had an opposing facing magnet. The tracks were necessary to keep it from being turned sideways or something because in general you can’t get magnets to work by just pushing one direction (which is why the simple spinning mechanisms fail) Now what would happen is the cart was given a small push at the bottom of the ramp and it would be accelerated to the top and then fall off by gravity. It was clear that there was an energy gain because the push would not be sufficient to make it ascend a ramp of similar height and it was accelerated. It was clearly greater than the energy to force it to enter the magnetic field.
So where did this energy come from? Well, the magnets were being forced to oppose eachother by the track system and thereby push the magnet against the others and move it in opposition without turning or making it go out of the magnetic field by any lower energy means. What was happening is that the fields were being degraded rapidly. Actually the inventor found that small magnets didn’t seem to work after the first few demos so he added bigger ones, which worked for a short while but clearly were slower after a few takes. Think of the following: If you take a steel screw driver and rub a bar magnet in one direction on it then you impart a small magnetic field, and it will pick up screws. Now imagine you rubbed it in the opposite direction or in the same direction but with the opposite pole. It would oppose this but if you pushed it anyway it would degrade both magnets – the energy which I had expended by imparting a polarity to the screw driver is not used to remove the polarity from the other magnet and it will actually create a force which pushes back and therefore there will a loss as heat, but very small.
So when I make the magnet by stroking it, I’m using mechanical energy to do this, right? I have to move the other magnet and my arm to do this because it won’t work if it just stays still as it needs to drag the domains to a new alignment. Now having expend this energy I have a new magnet and it will stay that way unless I force it to be opposed in a manner opposite to this. The magnet can exert a force, and as long as there is only the force, it’s fine because it’s static and it is not expending energy. But if I force it to do work, as with a force against it then that energy I put into it must be dissipated, and as long as there is equilibrium of the system where, for example, it picks something up and then I pull it off with equal force, then the field will in theory not be degraded. But in the above circumstance the force changes so work is being done. ~~Force does not need to be conserved but energy does.~~
Magnets do not actually have much energy at all. It does not take very much to bring the domains into alignment and begin exerting the force. In reality when you make a magnet, most of the energy used is lost in the solonoid or in the stroking of the magnet. So when the inventor of the ramp started to run the car up the ramp he found that the magnets were being destroyed. This was a long while back so he was lucky that there were only ceramic magnets avaliable and that made it less of a financial loss than had he used the newer rare earth ones.
It turns out that this is a terribly inefficient and poor system and you get very little before you will find the magnets are very badly degaussed!
Quote Comment
April 26th, 2008 at 3:39 pm
How much energy can be put into creating a magnet, per mass of material? And how efficiently can it be tapped by one of
these gizmos which run by depolarizing the magnet? Probably the energy storage density *and* the power to weight ratio
would suck. But maye it’s worth asking anyway.
Quote Comment
April 26th, 2008 at 4:11 pm
Burya Rubenstein said:
You got it in one: it would suck
Quote Comment
April 26th, 2008 at 4:39 pm
Burya Rubenstein said:
Well I looked up the magnetic potential for the best neodymium magnets and it turns out to be around 50 megaGauss Oersteds, which is the unit you usually see it measured in but the SI unit is Kj/M^3. If I convert that then it comes out to 397.9 kiloljoules per cubic meter, which would actually be an enormous magnet if you had a whole cubic meter of it.
So if I round it it comes to about .4 joules per cubic centimeter. So if you wanted one joul of energy you’d assume a size of a little more than two centimeters by one centimeter by one centimeter – or figure about the size of maybe a sugar cube.
To put that in context, that would a cell phone for between one and four seconds – in theory – if you somehow extracted it all and with 100% conversion effeciency. Alternatively it would be enough to move a couple hundred grams (like the weight of a few US quarters) up to one meter of elevation.
Otherwise, it’s enough to move
Of course, there are a couple things to consider. The first being that you can’t get all the energy out anyway because once it gets bellow a certain strength it won’t be able to move anything. Secondly I used the most favorable figure for the most high energy density magnets avaliable.
It’s tiny.
Quote Comment
April 26th, 2008 at 7:26 pm
Yeah, the actual potential energy avaliable from the magnetic field of a conventional magnet is small but it can be really large in a superconductor which is why they have been proposed as an energy storage mechanism by means of both the magnetic and electrical potential you can put into a superconducting coil.
Also it would be a horrible way to store energy (in a permanent magnet) that is because when they make magnets they usually use a coil to create the magnetic field and it can take a lot of power (not energy but huge amounts of power in pulses) but a lot of the energy is lost because when you start pulsing a big induction coil you will loose a lot of the energy to the resistance of the coil and some to reactance too.
Sorry guys. Your magnet pushers are not going to get you squat for energy. Plus those rare earth magnets are expensive.
Quote Comment
April 27th, 2008 at 9:55 am
For some, TANSTAAFL and the Second Law of Thermodynamics are mysteries more profoundly incomprehensible than the abyss which lies between the stars.
Quote Comment
April 27th, 2008 at 1:37 pm
Finrod said:
Bah. TANSTAAFL is a myth. For one thing, there’s a diner which I go to frequently near my home and I’ve gotten to know a lot of the wait staff, one of whom is a good friend and I know the owner. Two years ago the owner was there and when my bill came up he told me it was on the house because it was my birthday, which it was and apparently the waitress I know told him.
Then there was a time I was in the mall a long while back and there was a radio station there doing some kind of promotion and they had free bagels and ice tea and they had sandwiches but they were all out of those at the time.
Oh and then there’s local congressional campaigns. My congressman has had a free barbecue with free hot dogs and hamburgers in the past.
If you look hard enough, you can sometimes find a free lunch.
Quote Comment
April 27th, 2008 at 2:00 pm
The “Free Lunch” thing is not really meant literally. I mean, if I really wanted a free lunch I could get one by going over to my local relatives house on some excuse to see them and then raiding the fridge.
It’s a metaphor.
Quote Comment
April 27th, 2008 at 2:29 pm
Chuckles said:
He knows Chuckles, he’s making a funny.
Quote Comment
April 27th, 2008 at 3:13 pm
The calculations on the energy potential of rare earth magnets appears to be correct, but off the top of my head I would have guessed they had a bit more energy than that. I knew it was low, but that is extremely low. Permanent magnets were once used in accelerators and that kind of thing in the very early days, but they simply degrade too quickly for any use in modern systems. They were used to guide ion beams in the very early days of research on much smaller scales but any stress on the magnetic field will degrade the polarity very quickly. The larger systems use superconducting magnets.
I’ve had a free lunch before. I had one a couple of years ago from the ‘Summer Sale-A-Bration’ at car dealership. If you consider ‘free’ to not include having some high pressure sales to buy a truck which was more expensive than I was in the market for. It was my fault for thinking that the big advertised event would actually have some lower prices. There was not much of a “Sale” to it but I got a free hotdog and soda.
Quote Comment
April 28th, 2008 at 1:11 pm
An Actual Scientist said:
That’s how they get you! Now bare in mind that you could probably get a free lunch, a free dinner and a free air ticket if you are willing to sit through a weekend of a very intensive time-share marketing session. I don’t think it’s worth it even if it’s “free” in terms of money, you end up selling your soul.
Quote Comment
October 7th, 2009 at 11:39 am
Just a question here. Besides going off theory, readings, (un)common sense, etc etc, has any of you ever tried this out? I mean, man once said, and wrote, that a piece of metal would never fly, or float… So the magnets would cancel themselves, in theory and law and whatnot, but what if they wouldn’t?
Try it, use your intellectual brains to build a disproval then comment that it will not work.
BTW, I built a very small one, and it ran for about a month non stop until the earthquake knocked it off balance. Received a continuous 7w of power for the entire period. Yeah, 7 watts is nothing, but it is a start.
Quote Comment
October 7th, 2009 at 12:15 pm
gm said:
You are a bald-faced liar.
It is that simple.
You know it, and everyone here knows it.
You are not fooling anyone.
Quote Comment
October 7th, 2009 at 8:14 pm
gm said:
That does not make any sense. If you look at the force lines of a magnetic setup you’ll realize it’s impossible for it to be repelled indefinitely in a standard setup. The magnet simply will land in a point of low opposition. If the system is low friction, it can give the illusion that it is moving due to some energy, but really it’s just that it has low enough friction for the momentum to keep it in motion for a while.
All the classic designs suffer from this. The moving magnet just eventually finds a one of the areas of low opposition and settles there.
There has been some effort made to try to avoid this problem by using a system of movable magnetic wheels where any time that the central magnet gets close to settling in an area, some kind of ratcheting mechanism or a secondary magnet moves to stop it from settling.
A lot of design effort has gone into overcoming the problem of the thing just settling into equilibrium, and in some designs this problem has been solved. When it is, a larger problem arises. If you can build a mechanical system where the magnets are always in opposition and moving against each-other, guess what happens? You can get a small amount of energy but you degauss your magnets. It’s like the classic example of creating a magnet by stroking a nail with a magnet, except in this case the magnet is being stroked in reverse, thus the field is degraded by each rotation.
Many have found this to be the Achilles heal of the attempts. They spend a long time trying to build a motor that will not settle down and stop. Finally they have one that seems to be generating its own energy (which it kind of is – for a short time). They get excited. Then they notice it is slowing down. Then comes the final rude awakening: All their effort to extract energy from magnets has extracted a small amount of energy and in the process their expensive rare-earth high gauss magnets have been destroyed.
You can’t win here. Magnets can do work, but it must be in equilibrium when it comes to energy or the magnetic field is degraded.
Quote Comment
October 8th, 2009 at 12:07 am
gm said:
Bull.
“knocked off balance” my ass. They will cancel themselves because it’s simple: energy can’t come from nothing. If you draw energy out of anything it will be limited. Magnets seem magic but they’re not. 7watts for a month? I really doubt it.
Quote Comment
October 8th, 2009 at 12:11 am
gm said:
I’m not going to build a disapproval, because I don’t want to spend a lot of money on magnets that will either prove I was right or possibly get damaged.
I’m schooled in electrical engineering so I know ALLL about how electric motors work. I know the theory and how they’re built and I can design them. If you think putting magnets in a circle is going to make a magic motor that goes forever and gives you energy then you have no idea how a motor really works or how physics works for that matter.
Quote Comment
October 8th, 2009 at 3:10 am
Drbuzz was the only one worth reading. You others just proved my point. You are all (maybe) educated theorists with no hands on. I have dealt way too many times with the lot of you, and not just in forums. Rather than trying something, you take what you have learned in school,in a book, at a seminar, on Discovery channel, or just heard someone smarter than you speak, and go from there. So you are an electrical engineer, who isn’t? I used to be you. Thought I knew it all UNTIL an uneducated person proved me, and all written documentation, wrong.
I am not looking for infinity, I am not looking for decades. I am looking for a simple, non solar, non wind solution for a home in the middle of nowhere. Do I have to replace it in a year, no problem. In a week, nah, not good. I know I will not get 220v 10kW from the motor directly, righht now at least. But if I can get enough to transform into my needs and power my oven, I am good.
There is an old saying, ya gotta crawl before ya can walk.
Yes, it was knocked off balance. That is what happens when you perfectly balance something and some other force shifts it off ever so slightly.
Quote Comment
October 8th, 2009 at 3:22 am
Well I am certainly not a theorist, but you are certainly a liar: you did not build and run an overunity device.
Claiming that you have is a lie. It doesn’t matter how often you assert otherwise it will still be a lie.
Quote Comment
October 8th, 2009 at 3:35 am
I calculated the energy in a magnet once. Even if you could get it to somehow stay in motion, the energy in a powerful neodymium magnet is very small. I’m talking about a few dozen joules per cubic centimeter at the absolute most. As noted above, the most powerful magnets on the market are only 397.9 kiloljoules per cubic meter. That’s nothing.
It would be a very expensive way of getting very little useful energy. Worse than wind and solar even!
Getting kilowatts out of it is impossible. The laws of physics preclude it.
Quote Comment