Slashdot Mirror

← Back to Stories (view on slashdot.org)

The Museum of Unworkable Devices

Posted by timothy on 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."

10 of 306 comments (clear)

  1. Scientists ? by Anonymous Coward · · Score: 5, Insightful

    > scientists have been getting it wrong ever since.

    No. NON-scientists have been getting it wrong.

  2. People will always try by Blaine+Hilton · · Score: 4, Insightful

    I for one have always been interested in perpertal motion machines and the related laws of physics. I believe so that if we could just improve effeciency we will achieve very near pertual machine like effects. I meen if we are using engines that are only 40% effiencent and we can improve that to 98% then that is still very possible. IMHO

    1. Re:People will always try by Space+cowboy · · Score: 5, Insightful

      I wonder which way (physics or perpetual motion) your interest swings. The Carnot cycle places a limit on even ideal circumstances for the thermodynamic production of Work from Energy.

      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.

      --
      Physicists get Hadrons!
  3. Re:The newest item added to the exhibition... by Anonymous Coward · · Score: 0, Insightful

    The site is still working fine moron.

  4. Perpetual motion *IS* possible by Anonymous Coward · · Score: 2, Insightful

    In a superconductor, electrical resistance is ZERO. Electric current will move forever.

    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.

  5. Re:Ideas by russx2 · · Score: 2, Insightful

    Regarding the rock, yeah, in theory it will spin forever. But, asides from the initial energy to get it into space and give it momentum... how do you harness the "energy" from the spinning? The short answer is, you can't.

    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.

  6. Re:problem with PM machines by Space+cowboy · · Score: 4, Insightful

    You're defining a PM machine by excluding the 'machine' bit. Part of the definition of a machine is that it has to do Work (technical definition - The transfer of energy from one physical system to another).

    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.

    --
    Physicists get Hadrons!
  7. Here's the Real problem... by core+plexus · · Score: 2, Insightful
    "The trouble with most folks isn't so much their ignorance. It's know'n so many things that ain't so." -- A favorite quote of Richard A. Muller, by 19th century humorist Josh Billings.

    Weird News

  8. Re:problem with PM machines by EngMedic · · Score: 3, Insightful

    physics is a very terse discipline - most words have only one meaning. to be completely technical, Work is one of several things : the dot product of Force and Distance vectors, or the integration of Force with respect to distance. Defining it as the transfer of energy isn't wrong, per se... but it's definetly hazy, and that kind of sloppy definition has a nasty habit of leading to trouble.

    --
    filter: +3. Hey, look! all the trolls went away!
  9. Re:The problem with your idea is thermodynamics by slamb · · Score: 2, Insightful
    True, heat engines will never get better than 60%. However motors already get the high 90 percent efficiencies. This is yet another reason why cars should move away from engines.

    I don't buy that argument. Motors convert electrical energy to kinetic energy. Where does the electrical energy come from? Typically a heat engine and generator. 60% * x% * 90% is less than 60%.