🚀 go-pugleaf

In article <1992Dec11.061927.170448@zeus.calpoly.edu> mhorning@zeus.calpoly.edu (Mark E. Horning (Captain Neutrino)) writes:
>crb7q@kelvin.seas.Virginia.EDU (Cameron Randale Bass) states
>>In article <BCR.92Dec8002924@hfl3sn02.cern.ch> bcr@cernapo.cern.ch (Bill Riemers) writes:
>>>
>>>I used to have a ball suspended above my office desks with magnets.
>>>
>>...
>>>
>>>The other problem you will have is that your car will feel a tremendous force
>>>trying to flip it over.  However, a really simple solution is simply to use
>>>strings to keep the car stable.  If you connect it to the ceiling, it will
>>>look like the strings are holding the car up, so hook the string up to the
>>>floor!  Then if anyone asks you can tell them the strings are to keep the car
>>>from floating away!  (With my ball I only need one string, but in this case
>>>you'll probably need at least three.)
>>
>>     No offense intended, but this is the kind of horrible idea that
>>     gives the free energy nuts fodder for their insanity.
>>
>>     Since you cannot with ordinary permanent magnets produce a 
>>     stable six degree-of-freedom levitating system, you are misleading
>>     at least the audience, and probably the kid by saying the strings
>>     are being used to 'keep the car from floating away'.  Actually, you
>>     are taking away at least one degree of freedom, so you can have
>>     a stable system.  If it weren't there, it would flop over or
>>     fly pretty quickly away (depending on configuration).
>>
>>     The interesting and scientific part is that six DOF levitating
>>     permanent (nonsuperconducting) magnetic systems are not possible,
>>     and that you must restrict the degrees of freedom to allow stability,
>>     or use superconducting magnets, or actively control the magnets.
>>     Please don't advise someone hide the physics for the sake of
>>     a trick.
>>
>	Can't you use gravity to remove one of the degrees of freedom?
>Put lead weights in the bottom of the train for ballast. Or am i missing
>something obvious?

     I'm game.  Can you use gravity to remove one of the degrees of freedom?
     If so, how?

     Think about it this way, if you can use weights to 'balance' it,
     why can't you simply do it in appropriate circumstances with the 
     innate original weight?

                                dale bass
-- 
C. R. Bass                                          crb7q@virginia.edu        
Department of Mechanical, 
     Aerospace and Nuclear Engineering
University of Virginia                              (804) 924-7926