
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):
- 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).”
- 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).“
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 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:
- 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.
- 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.
- 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.
- 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.