Why perpetual motion free energy machines don't work

It still amazes me that with all our posts dedicated to trying to help homeowners save energy, our most popular posts are on free energy scams (mainly magniwork and hojo motor).  I've gone back and forth with the energy ignorant in the comment section of these posts, but I've never written a post dedicated to explaining why these products just won't work.  This post is speaking to those who are confused about perpetual motion devices that claim to create more energy than they consume.  If you notice in the title, I state they "don't" work, not that they "won't" work.  They don't work according to the existing laws of physics.  The future is unknowable. Perpetual motion devices have been attempted for as long as man started making complicated machinery. The goal of many unfortunate inventors  has been to create a machine that will produce useful work in a closed loop system, or in a system without any external forces.  Donald Simanek maintains an excellent history at attempts to create perpetual motion devices in his Museum of Unworkable Devices. In scientific terms, perpetual motion devices are impossible under the current laws of thermodynamics.   Being humans with tiny little brains, our understanding of the universe is limited, so there is always the possibility that the laws of physics will expand and/or change over time.  But as the laws currently exist, the two that are most frequently cited regarding perpetual motion devices are the first and second law of thermodynamics.  In summary (quotes attributed to C.P. Snow):

  1. First law of thermodynamics - Conservation of energy.  Energy can be transformed from one form to another, but it can't be created or destroyed.  "You cannot win (that is, you cannot get something for nothing, because matter and energy are conserved)."
  2. Second law of thermodynamics - Entropy. Systems always flow to a state of disorder.  "You cannot break even (you cannot return to the same energy state, because there is always an increase in disorder; entropy always increases)."{C}{C}{C}{C}{C}{C}

Wikipedia classifies the different categories of perpetual motion devices as follows: "One classification of perpetual motion machines refers to the particular law of thermodynamics the machines purport to violate:

  • A perpetual motion machine of the first kind produces work without the input of energy. It thus violates the first law of thermodynamics: the law of conservation of energy.
  • A perpetual motion machine of the second kind is a machine which spontaneously converts thermal energy into mechanical work. When the thermal energy is equivalent to the work done, this does not violate the law of conservation of energy. However it does violate the more subtle second law of thermodynamics (see also entropy). The signature of a perpetual motion machine of the second kind is that there is only one heat reservoir involved, which is being spontaneously cooled without involving a transfer of heat to a cooler reservoir. This conversion of heat into useful work, without any side effect, is impossible, according to the second law of thermodynamics.

A more obscure category is a perpetual motion machine of the third kind, usually (but not always)defined as one that completely eliminates friction and other dissipative forces, to maintain motion forever (due to its mass inertia). Third in this case refers solely to the position in the above classification scheme, not the third law of thermodynamics. Although it is impossible to make such a machine, as dissipation can never be 100% eliminated in a mechanical system, it is nevertheless possible to get very close to this ideal (see examples in the Low Friction section). Such a machine would not serve as a source of energy but would have utility as a perpetual energy storage device."

In summary, here are reasons why perpetual motion energy generation devices don't work:

Conservation of Energy - Say the law of conservation of energy wasn't a law.  You create a perpetual motion device that somehow overcomes all of the external forces mentioned above and you have a device that can operate itself perpetually (similar to the perpetual motion machine of the second kind listed above).  Now, your device can operate forever, but how can you extract any work from it?  If you take energy out of your machine, you will slow it down!  And no, magnets don't "create" energy, they just create a propulsion force.  To make magnets do work you have to add energy (i.e. spin them). I'm not sure I can spend too much time on this one point, because this is ultimately at the heart of perpetual motion energy generation machines.  If someone claims they can get energy out of a system, that energy has to come from SOMEWHERE!  It can come from the sun (nuclear), wind (which is created by the sun), gravity (one way trip), coal/natural gas/oil (dead organisms initially powered by sun), nuclear, humans (powered by food which is powered by sun), etc.  ENERGY HAS TO COME FROM SOMEWHERE. There is no free lunch. Now, there is this tiny little issue of dark energy (also mentioned at the end of this post), but it is outside the scope of this discussion because I don't know too many inventors claiming their perpetual motion device operates on dark energy.

Friction and external forces - This is really an expansion of the law of conservation of energy. Friction occurs when molecules of one thing come in contact with molecules of another thing.  Rub your hands together and feel heat generated.  That heat is energy leaving your body.  Anything operating on Earth will encounter external forces. Thought exercise time!  Think about driving your car down a flat highway.  Bring your car up to speed.  Go ahead, whatever speed you want, there is no speed limit here.  Now take your foot off the accelerator.  What happens?  You car is going to slow down and eventually stop because of air resistance (or friction between the air outside and the body of your car), rolling resistance between your tires and the road (or friction between asphalt and rubber) because gravity (external force) is pulling your car towards the earth, and the internal friction between all the working parts of your car (pistons, wheel bearings, crank shaft, etc.). Ok, we're done with the cute little thought exercise.  Now imagine that car is some perpetual motion machine.  Guess what, all those external forces are still there!

Entropy - This is the hardest to explain but it is also the most obvious.  Basically, everything in the universe wants to go to a state of disorder. Buildings don't build themselves, and when they're built, they eventualy fall down.  Heat always flows from hot to cold. Everything dies.  Everything falls apart.  Maybe one day the universe will start collapsing in on itself, time will reverse itself, and this won't be the case.  But in the known lifespan of the universe (13.75 billion years) entropy has always (100% of the time) increased.   A perpetual motion machine would result in no net disorder, which has never happened in 13.75 billion years.  Not a fan of history dictating future, that's fine, how are you going to get past conservation of energy? Michio Kaku (who graduated first in his Harvard physics class, received his doctorate from Berkeley, and taught at Princeton) addresses perpetual motion machines in chapter 14 of his excellent book Physics of the Impossible.  In his book, Kaku breaks down "impossible" into three classes (summarized below):

  • Class 1 impossibility - impossible today but do not violate known laws of physics
  • Class 2 impossibility - technologies that sit at the edge of our understanding.  If possible, they may be realized thousands or millions of years in the future
  • Class 3 impossibility - technologies that violate the known laws of physics.  If possible, these technologies would represent a shift in our understanding of physics

Kaku labels perpetual motion a Class 3 impossibility (teleportation and telepathy are Class 1, time machines are a Class 2).  He states in the closing of chapter 14 on perpetual motion:

Because creating a true perpetual motion machine may require us to reevaluate the fundamental laws of physics on a cosmological scale, I would rank perpetual motion machines as a Class III impossibility; that is, either they are truly impossible, or we would need to fundamentally change our understanding of fundamental physics on a cosmological scale in order to make such a machine possible.  Dark energy remains one of the greatest unfinished chapters in modern science

Do you understand why I'm referencing this?  An expert in theoretical physics labels perpetual motion as 1 of only 2 class 3 impossibilities in all of theoretical physics (the other being precognition). Finally, I must address a claim that I see all the time regarding free energy devices.  Conspiracy theorists claim that the big bad energy companies are suppressing free energy devices because it will destroy their profits.  This is complete and utter rubbish. Let me tell you how I would get around this issue if I had stumbled on the greatest discovery in all of history:

  1. Chronicle my discovery in exhausting detail.  Paper, electronic, pictures, videos, etc.  Create hard copies and store them with trusted love ones.  Email electronic copies to email addresses I make up on multiple different hosts.  Take out multiple safety deposit boxes in many different states/countries and store identical copies of my research in each one.
  2. Create a company whose purpose is to build and sell my device or power from my device.  Make sure to find a good attorney to ensure all legal work is in proper order.  Getting a good attorney is critical.
  3. Go to investors/universities/press and demonstrate my findings.  Sell shares of my company if capital is needed.  Venture capital guys are pretty good at making money on any kind of idea, there is no need to go to the energy companies.
  4. Become the richest and most famous person in the world while alleviating many of the world's problems.

How could the big bad energy companies hurt my plan?  They couldn't.  Nobody can stop someone else who has a powerful idea.  Sure, the person who created the idea could be murdered, but if step 1 is followed properly, the idea still lives on. Would you really fear death if you had the idea to change the lives of 7 billion people?  Blaming large energy corporations is the cowards excuse for why his/her favorite perpetual motion device won't work.  Of interesting note is Andrea Rossi and his cold fusion energy generator.  Rossi seems to be following the steps above, and is in the middle of step 3.  We'll see if the device (which is not perpetual motion, but is cheap, clean energy) works or not.  Hopefully he reaches step 4. Hopefully you now understand why perpetual motions machines won't work according to the existing laws of thermodynamics.  Could the future change and could dark energy provide unlimited power?  Sure it can, but until then, machines will never operate perpetually, much less create free energy. End of story.


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Dearest JooWee, The link you provided was an invaluable aid to my further comprehension, in particular, the following notation: "You would certainly become tired! The solution is simple. Physicists have taken over the common word “work” and given it a new technical meaning, which is the transfer of energy. The energy of the bag of cement is not changing, and that is what the physicist means by saying no work is done on the bag." The previous common definition being: Activity involving mental or physical effort done in order to achieve a purpose or result. My confusion was wholly based that I assumed I was familiar with the nature of work. "Please don’t think I’m being condescending when I say this is basic high school physics, because it really is." Ohhhh ..... you noticed that, too! (I am smiling) It would be difficult for me to take offense at that, for you see, as I have admitted in a previous posting, I am uneducated. "I have taken the time to explain it again here because I think it is important that we learn to differentiate the real thing from the pseudoscience of Perpetual Motion Machines." That choice was yours to make and I, for one, am very pleased that you have taken the time. I fear I will have trouble with some of these concepts as I venture to delve deeper into the subject, if only because the some words and phrases may no longer convey the same meaning as in common usage. i.e. Perpetual = lasting an indefinitely long time Motion = the action or process of moving Machine = an apparatus consisting of interrelated parts My interpretation would be: An apparatus consisting of interrelated parts performing action or process of moving that would last an indefinitely long period of time. I think a waterwheel would satisfy this criteria. In this case, I realize that the intent is to add an additional requirement that this machine be Self-Running. That it provides the power to propell itself in a closed system, without the addition of fuel. Even this requirement does not seem insurmountable to me; because, I think the universe is a closed system that powers itself. I do not think that the universe relies on a thermo-nuclear model that must eventually exhaust itself of a fuel supply. That is why I plan to continue to investigate the possibilites of an electric model. Thank you again, JooWee, for sending the link above. I came across a section on "electricity and circuits" that may lead me closer to my goal.
ericsongs, thanks for the transcript of the inspirational opening of the Thunderbolts of the Gods video. There are countless more examples of the classic "truth is a truth until proven otherwise" adage. I agree wholeheartedly with that and have absolutely no contention there. The second law of thermodynamics is not just true because we say so. It is true until proven otherwise. We are all waiting eagerly for some visionary such as yourself to prove the second law of thermodynamics wrong, as that would change life as we know it. My only advice to you is to understand it thoroughly before you embark on this journey to prove it wrong. One good place to start is to study how this law came about in the first place. With all due respect, I feel your "100 joules = 100 joules except when it doesn’t?" question (rhetorical or otherwise) demonstrates a less than complete understanding of the concepts of both the first and second laws of thermodynamics. I'm afraid that I have to back out of this debate for it would take much more than this comment thread for anyone to properly explain these concepts, and others have done a far better job of it than I could. Cheers! Recommended reading: Fundamentals of Physics, by David Halliday, Robert Resnick, and Jearl Walker.
Dear Chris, I did. And it seems logical. That is why we needed to narrow the definition of "work" to fit the model. Otherwise, the math just won't work. (no pun intended) That makes me wonder how many times we have observed a phenomena, calculated a formula to describe the function, found new information, chose to either ignore it or remold the parameters to maintain the initial statement. BTW - Thank you for providing this space to us, and allowing me to participate. I know it must grow tiresome, at times.
Dearest JooWee, Your candor and grace are very much appreciated. You have demonstrated the following principal without fail. "As far as possible without surrender be on good terms with all persons. Speak your truth quietly and clearly; and listen to others, even to the dull and the ignorant, they too have their story." (Desiderata - Max Ehrmann, 1927) You have been very kind and I feel like I have lost a friend. (I intend to heed your advice)
ckmapawatt's picture
ericonngs, I get tired of people who aren't trying to understand anything and are stuck their ignorant ways. You were trying to understand something, so it's a great discussion. Don't get me wrong, perpetual motion is harder to understand than most people think.
such technalities on the WORK definition and then you call gravity a force? check gravity units plz
ckmapawatt's picture
From how stuff works, "The force of gravity acting on an object is also that object's weight. When you step on a scale, the scale reads how much gravity is acting on your body. The formula to determine weight is [source: Kurtus]: weight = m * g where m is an object's mass, and g is the acceleration due to gravity. Acceleration due to gravity on Earth, is 9.8 m/s² -- it never changes, regardless of an object's mass. " Gravity is an acceleration force.
Well.....the magnet HO-JO electric generator DOES work....BUT they claim the magnets EVENTUALLY loose their magnetism when used to generate energy; which makes perfect sense to me...ONLY how long does that take? I would like an answer to that if anyone knows it. And magnetism IS STORED ENERGY in a sense; really is. Howard Johnson did say he left his magnets spinning on their own untouched for like a year; I think eventually they slowed down and stopped, but after a long long time...Then he gave them a push and they spun another year or so BUT those were unattached to a generator....Had they been attached to a generator, I wonder how long it'd take for them to loose their magnetic charge???That is the only known drawback of the magnetic generator. If anyone knows the figures on the magnets' loss of charge; posting it here would be MOST APPRECIATED !! Thanks -Balagooon
I forgot one thing.....To Chris who wrote the article: I may have overlooked this , but Have you Chris ever built and tested one of these HO-JO Magnet Generators your own self? Cause if you never did, then your entire point is defenseless and MOOT. But if you did, then you would know; if you built it correctly. Thanks very much for a reply to this too ! --Balagooon
ckmapawatt's picture
I have addressed that point many times. You are the type of person that these people prey on (if you're not one of them yourself). You're either extremely ignorant of your part of the fraud. I hate to be blunt, but I'm getting sick and tired of those who come on here and write ignorant comments that are totally devoid of fact or scientific reasoning.


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