Title: Perpetual Motion
1Perpetual Motion
- by
- Robert Nemiroff
- Michigan Technological University
2Physics X About This Course
- Officially "Extraordinary Concepts in Physics"
- Being taught for credit at Michigan Tech
- Light on math, heavy on concepts
- Anyone anywhere is welcome
- No textbook required
- Wikipedia, web links, and lectures only
- Find all the lectures with Google at
- "Starship Asterisk" then "Physics X"
- http//bb.nightskylive.net/asterisk/viewforum.php?
f39
3Perpetual Motion
- is ...
- technically, something that is always in motion.
- practically, a machine that generates energy from
nothing. - However,
- Newton's law indicates that anything that starts
in motion, remains in motion, so in this sense
perpetual motion is expected. - Machines that generate energy from nothing have
never been found and are now considered a waste
of time.
4Perpetual Motion Machine First Kind
- Perpetual motion machines of the first kind
generate energy from nothing. - This violates the local conservation of energy,
and since this energy can be used to generate
heat or work, it also violates the first law of
thermodynamics - 1st Law "The change in the internal energy of a
system is equal to the amount of energy added by
heating the system minus the amount lost as a
result of the work done by the system on its
surroundings."
5Perpetual Motion Machine Second Kind
- This type of perpetual motion machine uses heat
as a power source directly and continuously,
without the flow of heat to a sink. This violates
the second law of thermodynamics. - 2nd Law "Heat (macroscopically) cannot flow
spontaneously from a material at lower
temperature to a material at higher temperature."
6Perpetual Motion Machine Third Kind
- This type of perpetual motion machine relies on
eliminating friction. Technically, this is not
so much an energy generating machine so much as
an energy storage device. - It is not possible to move with zero friction, so
although low friction devices are real, zero
friction devices are not.
7Perpetual Motion Machine Useful Thought
Experiments
- At least two classic though experiments seem to
create perpetual motion machines. - Maxwell's Demon (analyzed in another lecture)
- Brownian Rachet Wheel
8Perpetual Motion Brownian Ratchet Wheel
9Perpetual Motion Brownian Ratchet Wheel
- A ratchet wheel with cogs has a paw that allows
it only to rotate in one direction. Random
brownian motion of the air molecules strike the
wheel, sometimes causing enough motion so that it
clicks forward one cog. The paw prevents it from
even clicking back. Is the slow rotation of the
wheel perpetual motion? - 1. Yes, you've done it!
- 2. No.
- 3. It depends in how many dimensions the paw can
move.
10Perpetual Motion Brownian Ratchet Wheel
- No. The wheel will only rotate as expected when
the the ratchet and paw are significantly colder
than the surrounding air or the heat bath. Then
the device works by tapping into the heat flowing
from the heat bath to the wheel. - When everything is the same temperature, the paw
may have its own Brownian motion and will allow
the wheel to go in either direction.
11Perpetual Motion Magnetic Tower
- Balls are pulled up a ramp by a powerful
permanent magnet but then drop through a hole at
the top, returning them to their original
position.
12Perpetual Motion Magnetic Tower
- Why doesn't this work?
- 1. Any magnet powerful enough to pull the balls
up the ramp would be powerful enough to keep them
from dropping through the hole. - 2. The rolling ball would at first be attracted
to the magnet, but after it rolled its polarity
would reverse and it would then be repelled from
the magnet. - 3. The system works, but there is no way to
extract power. - 4. The electric companies kill anyone who gets
too close to making this work to protect the
profit of their investors.
13Perpetual Motion Magnetic Tower
- Why it doesn't work
- 1. Any magnet powerful enough to pull the balls
up the ramp would be powerful enough to keep them
from dropping through the hole.
14Perpetual Motion Float Belt
- Hollow balls float up through water, only to be
pulled back down as they descend in air.
15Perpetual Motion Float Belt
- Why doesn't this work?
- 1. There is no way to push the balls in at the
bottom without losing water. - 2. Pushing the balls in at the bottom will take
at least as much energy as gained from the balls
floating up and the falling down. - 3. This will work only so long as the water is
cooler than the ping pong balls. - 4. A team at Brookhaven is now nearing
break-even energy for device that works on the
same principle.
16Perpetual Motion Float Belt
- Why it doesn't work
- 2. Pushing the balls in at the bottom will take
at least as much energy as gained from the balls
floating up and the falling down.
17Perpetual MotionConservative Forces
- A conservative force creates work on a particle
that is independent of the path taken.
Therefore, paths that return to their starting
point can gain no work -- no energy. Therefore,
a conservative force field cannot be used to
create a perpetual motion machine that generates
energy. - Examples of conservative force field include
Newtonian gravitational force and Coulomb
electric force.
18Perpetual Motion MachinesThe US Patent Office
- Many people try to patent their own perpetual
motion machines. The US Patent office will no
longer grant patents to machines that it feels
are perpetual motion power generators, without a
working model. - Some people try to create machines so complex
that no one could determine their efficiency
without such a model.
19Perpetual Motion Machines Complex Hoaxes
- Examples Machines that are powered by a
cleverly hidden person. - http//www.museumofhoaxes.com/hoax/Hoaxipedia/Perp
etual_Motion_Machine_of_Charles_Redheffer/
20Perpetual Motion Machines RJN Advice
-
- If you have created a true perpetual motion
machine from which you create free energy, please
do not hold press conferences and tell everyone.
Please start creating power from your machine
and selling it. The electric company MUST buy
it, and you can make a fortune.