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The Museum of Unworkable Devices
Posted by
timothy
on Sat Mar 29, 2003 05:30 PM
from the more-fun-than-broken-packets dept.
from the more-fun-than-broken-packets dept.
Jippy_ writes "The quest for perpetual motion has been going on since at least the 11th century according to this site, and scientists have been getting it wrong ever since. Take a gander at some of the most valiant efforts (and ultimately the biggest failures) in trying to beat the laws of physics through the last 1000 years, along with other impossible inventions and devices."
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The newest item added to the exhibition... (Score:5, Funny)
Also known as the (Score:3, Funny)
(somebody had to say it)
Why didn't they just ask... (Score:3, Funny)
Re:Why didn't they just ask... (Score:5, Funny)
Parent
Goody! Lots of ideas... (Score:5, Funny)
I think that the problem with these devices isn't the laws of physics per se, I think its just that they were never properly marketed.
Scientists ? (Score:5, Insightful)
No. NON-scientists have been getting it wrong.
A solution? (Score:2, Interesting)
Re:A solution? (Score:2)
Now consider thousands of open source developers coding as one thousand monkeys typing on
Unworkable-DRM. (Score:5, Funny)
People will always try (Score:5, Insightful)
Re:People will always try (Score:5, Insightful)
For a typical steam power plant, (800K hot, 300K cold), the maximum theoretically possible efficiency is ~60% for a 100% reversible reaction (hint: these don't exist in power plants). I seriously doubt it is possible get anywhere near 98% efficient without some new ground-breaking physics in the same vein as Newton -> Einstein.
Simon.
Parent
Re:People will always try (Score:4, Informative)
Actually the Carnot cycle puts a limit on the conversion of heat energy into any other form of energy (kinetic, potential, electrical, magnetic, chemical, nuclear, etc). However, heat is the only form of energy so limited. Other conversions, say chemical => electrical are only limited by the second law of thermodynamics. For that matter, converting any other energy to heat can be very efficient. Electrical energy => heat, for example.
So, something like a microturbine [energy.gov] is limited to ~30% efficiency for electricity generation. Larger plants can get up to 35% efficiency. A fuel cell has no such limit and could potentially reach into the 90% range for efficiency of electricity generation. Hybrid fuel cell-turbine generation systems [doe.gov] are being tested which have efficiencies of over 50% and they speculate that they could hit 70% or more. The problem with such a system is that the upfront cost is very high and it does not get offset by the savings in fuel. Not yet, anyway.
Remember too that conversion of any energy to heat can be very efficient. Natural gas furnaces can be extremely efficient, as high as 97% [energy.gov]. That's because converting chemical energy => heat is not a Carnot limited process, and is only limited by the second law of thermodynamics.
Parent
Re:People will always try (Score:3, Interesting)
Take a "perfect" Carnot-cycle engine. submerge it in a vat of water. The waste heat will warm the water, which you can then use to generate electrical energy clearly in excess of the Carnot limit.
Additionally, the laws of thermodynamics have a serious flaw, which most folks who like to wag their finger and screech "The second! The second!" like so many autistic
The problem with your idea is thermodynamics (Score:5, Informative)
Parent
Buttered toast (Score:5, Funny)
Re:Buttered toast (Score:5, Funny)
Parent
Re:Buttered toast (Score:3, Funny)
The judges are still out on that one, it hasn't stopped moving yet.
problem with PM machines (Score:3, Interesting)
Re:problem with PM machines (Score:5, Insightful)
A body set spinning on a (somewhat miraculous) journey along an isopotential of gravitational force in the universe will continue spinning for eternity (or thereabouts. The universe might collapse...)
The spinning body's still not a perpertual motion machine because it doesn't interact, and should it ever interact, it'll be subject to the laws of motion and thermodynamics and still not be a perpetual motion machine.
Simon.
Parent
Re:problem with PM machines (Score:4, Insightful)
Parent
Do they have the ultimate 20th-c vaporware? (Score:5, Funny)
Surely they must be there, at least for another 10 years
Well, there's your perpetual motion, right there. (Score:5, Funny)
Without ever stopping!
Poll: How many of us have tried? (Score:4, Interesting)
I am a scientist now and after studying physics I guess I am completely cured from the idea that there could be a perpetuum mobile, a machine that produces energy out of vacuum.
But I remember say 20 years ago I spent a long time trying to invent such machines. I kept trying to design it and kept asking people why it wouldnt work. It took a long (frustrating) time before I could sortof acknowledge that it didnt seem to work.
So honestly... who has undergone the same process?
Re:Poll: How many of us have tried? (Score:3, Interesting)
Tapping the Zero-Point Energy (Score:3, Interesting)
If I remember right, the circumstances were that the system had t
and the timecube? (Score:5, Funny)
I have requested that the UCS, or
Union of Concerned Scientists, act
to evaluate Nature's Harmonic Time
Cube Principle of Creation - for the
welfare of children, nature and the
future of all humanity. The dumb,
stupid and evil bastards have ignored
their obligation to their humanity
fellowship to research Time Cube,
and deserve to be spit upon publicly.
It is their moral duty to test Time
Cube, and a curse of evil if they ignore
the greatest discovery of humanity.
I have offered $10,000.00 to the evil
bastards if they disprove Time Cube.
They can't disprove it, so they hide
like yellow-belly bastards they are.
Re:and the timecube? (Score:3, Funny)
I guess I'm out of luck.
Perpetual motion *IS* possible (Score:2, Insightful)
Of course, you need to keep your superconductor cold, so put it in outer space, or keep the liquid helium flowing.
And for you nitpickers: yes, there are superconducters that work at liquid nitrogen temperatures, but you can't make wire out of them yet.
Re:Perpetual motion *IS* possible (Score:3)
Re:Perpetual motion *IS* possible (Score:3, Interesting)
Well not quit, now yes if you spin a wheel in space it will probably spin for a hella long time. But forever is no garentee, or even possible. Space is not perfect. It's not absolute zero and it's not a perfect vacuum. It runs slightly above abs zero and has plently of trace hydro
I've got it!!! (Score:5, Funny)
Send $1,000 to P.O. box 324, NY, NY 20002 to get in on the ground floor!!
Re:I've got it!!! (Score:5, Funny)
Send $1,000 to P.O. box 324, NY, NY 20002 to get in on the ground floor!!
I'm guessing that with the intelligence of some of the /. crowd, you should be recieving approximately $20,000 in unmarked bills within the next week...
;)
neurostarParent
Excellent museum (Score:3, Funny)
I have a source of unlimited power (Score:5, Funny)
what it does is post a comment extoling the virtues of Windows 95 over Linux. It then uses the heat generated by the ensuing flamewar to power a small town.
First hand experience (Score:5, Interesting)
Re:First hand experience (Score:3, Informative)
http://www.lhup.edu/~dsimanek/museum/unwork.htm#w
almost (Score:5, Funny)
Weather and other perpetual motion (Score:3, Interesting)
I feel like (as a non-scientist, non-physicist) that I have an intuitive understanding that all self-contained devices relying only on their own mechanics would never attain perpetual motion due to the dragging forces of gravity, friction, and other forms of external resistance.
But I don't have such an intuitive understanding that a machine that takes advantage of outside consistent forces as a source of energy (like gravity) could not attain perpetual motion. Especially if we loosen the definition of "outside consistent forces" from the scientific definition (those natural forces that always balance themselves) to the practical definition, like those forces that aren't naturally occuring but happen all the time anyway, like the directional airflow in a building's exit corridor, or the vibration of a dance floor, or all the other places in the world where energy is being expended and not captured. If we made machines that were built to rely on those forces always happening, and capturing them to convert them to energy, wouldn't that be generating more energy than is expended to run it, considering that the expended energy it depends on would be happening anyway? I know it's mathematically lazy but there's no reason why we can't double-count that stuff.
Yes, no, and maybe. (Score:5, Informative)
As for weather, the problem is you're relying on an external power source - the sun. Turn that off, and boom, no weather (well, eventually anyway). You are correct though, we can use this energy that's just sitting around and gain more than we put into something. In fact, this is how our entire planet survives - both its organisms and our modern society. Think hydroelectric damns and wind turbines - they're just using something that's there anyway. And plants take advantage of the ever-present sun to store chemical energy within themselves, which other organisms then use when they eat said plants, etc.
The problem still lies in self-contained systems. A friend of mine took years to believe me that you couldn't run a ship (assuming no wind outside) with windmills powering a motor that actually powers the ship. Friction is a bitch
Parent
Perpetual Motion Machines of the First Kind (Score:5, Interesting)
Perpetual motion machines of the second kind don't violate conservation of energy, but they rely on a decrease in entropy. With a machine like that a ship could run an engine that extracts energy from the ambient water temperature to do work, leaving a trail of colder seawater behind the ship. That doesn't violate conservation of energy, but it does cause a global reduction of entropy.
It takes more cleverness to come up with a machine of the second kind, and it's usually less obvious why they don't work.
Here's a machine like that. Assume we have a propellor made of some heat resistant material like ceramic, inside a larger ceramic housing in which it is free to rotate. Stick a big permanent magnet around it so that there is a magnetic field running through it, parallel to the propellor axis. Now inject a hot plasma of some sort into the device. Electrons in the plasma move in tight little counterclockwise circles because of the field. Protons move in much wider clockwise circles (they're heavier), so they hit the propellor blades preferentially in one direction and make it rotate.
Of course the plasma is going to cool down quickly if the protons in it are imparting kinetic energy to the propellor. So as a perpetual motion machine of the first kind, it's obviously going to run down and stop. But take the whole machine and drop it on a planet where the ambient temperature is high enough to keep the plasma hot. As the propellor extracts energy, more heat flows into the machine. What's wrong with it now?
Re:Perpetual Motion Machines of the First Kind (Score:5, Informative)
Parent
Re:Perpetual Motion Machines of the First Kind (Score:3, Informative)
Re:Perpetual Motion Machines of the First Kind (Score:3, Informative)
If this could work, we could have cars and airplanes that ran off the heat of the air surrounding them.
Nobody ever spoke much of harnessing the power of the heat in the ocean, until those thermal gradients were discovered between surface waters and deep water. With two heat reservoirs you can transfer heat from one to the other, extracting some of the energy as a tax as it moves from warm to cold regions, generating nice things like fresh water and electric [slashdot.org]
Magnets and PM (Score:3, Interesting)
One cannot expect to use permanent magnetism as a source of perpetual motion because when a permenant magnet does work, it loses a certain amount of its magnetism in the process. This phenomenon can be seen directly with the following simple home-science experement: Place two magnets side by side, such that like poles are adjacent to eachother. Let go of one and note how far it gets pushed away. Now in a PM device, the magnets will obviously have to be brought back together at regular intervals -- so tape them together so that you effectively create an environment where the repulsion action is perpetual (which is what you are trying to achieve). Leave it alone for a few weeks. Come back after that time and remove the tape. Repeat the experiment that you did at the beginning and you will notice that the free magnet gets pushed quite a bit less than before -- sometimes not even at all! What is of particular interest is the stronger the magnets were originally, the more pronounced this loss of magnetism is, so powerful magnets quickly become weak magnets, which are capable of doing less work, and therefore require more time to lose a measurable amount of their magnetism.
tanstaafl
Here's the Real problem... (Score:3, Insightful)
Weird News [xnewswire.com]
atoms (Score:3, Interesting)
Re:Ideas (Score:3, Insightful)
The rock spinning isn't really energy as such since it is just obeying Newton's first law of motion - anything moving will continue moving unless acted upon by an external force.
And unfortunately the only way to harness the "energy" is to apply an external force.
Re:Go Forever? (Score:3, Informative)
A machine must do Work (definition: The transfer of energy from one physical system to another).
Perpetual motion is easy. A perpetual motion machine is impossible.
Simon.
(Getting tired of pointing out that machines have to DO something)
Re:A serious question (Score:3, Informative)
What proof of perpetual motion would physicists accept? The answer to that question is this: none.
Not true. You build a machine that operates forever, and it works, and it can be reproduced...well, then, you would've rewritten physics. Rewriting physics, you see, happens every once in awhile. Newton, Gauss, Einstein -- someone comes along and provides a better way things work. And, here's the thing: if they can show that
Re:A serious question (Score:3, Informative)
As to Scientific American: Who the hell cares? If you have a perpetual motion machine, and you can demonstrate it, and it's replicable, then all the naysayers will come around, or be laughed at themselves. Same thing with every other physical 'law' that's been overturned. But...until you get that proof, expect to be laughed at and called a fraud, since you're filling the same shoes as the last ten thou