symbio Posted January 5, 2005 Posted January 5, 2005 Hello everyone (a formality for my first post only) So, I built two objects out of neodymium magnets and ball bearings, and then hung one from the bottom of the other. When I spin the bottom object it remains spinning for an impressive amount of time, but it does stop. It's momentum appears to be sustained (it seems to spin longer than the mechanical force applied would provide momentum for) by the force of alternating magnetic fields as they (the magnets on both top and bottom objects) pass by oneanother. My question is simple. Would it keep spinning forever in the vacuum of space or under some set of unknown (to me) circumstances. I'm not a scientist, just a curious mind. So please try to keep your answers simple. also, since this is my first posting, I would also like to thank the people in this community for remaining true to their curiosity and their willingness to share the fruits which were plucked in it's name. I look forward to eating them up like the voracious animal I am, and promise to serve them up as the man I will become. Jeremy
swansont Posted January 5, 2005 Posted January 5, 2005 No. There will always be friction. You can't get around the second law of thermodynamics, not even with a good lawyer.
5614 Posted January 5, 2005 Posted January 5, 2005 nice one swansont (answer and the joke at the end)... thats a line for one of your cartoons (or is that where ya got it from?) can i just ask, you say you had a neodymium magnet, was it an NIB (neodymium iron boron) or just a plain neodymium magnet? if it was an NIB how big and where did you get it from?
Severian Posted January 5, 2005 Posted January 5, 2005 No. There will always be friction. You can't get around the second law of thermodynamics, not even with a good lawyer. Give me any definition of 'forever' and I can give you a value of the frictional force which is small enough to allow the thing to spin 'forever'.
5614 Posted January 5, 2005 Posted January 5, 2005 forever is a time span which is everylasting or infinite... i dont know how you could put that into a mathematical equation other than 9 recurring.
jordan Posted January 5, 2005 Posted January 5, 2005 Severian, I think the definition of "forever" in this case is an infinite time span. Even the most minute co-efficient of friction will cause it to stop spinning eventualy (even if that is theoreticly longer than the universe itself will survive). By the definition of infinite time span, the cannot be any friction acting on it. 5614, you seemed to have missed his point.
ydoaPs Posted January 5, 2005 Posted January 5, 2005 there is no such thing as a perfect vacuum. there will always be friction.
ecoli Posted January 5, 2005 Posted January 5, 2005 there is no such thing as a perfect vacuum. there will always be friction. What about in space???
ydoaPs Posted January 5, 2005 Posted January 5, 2005 http://en.wikipedia.org/wiki/Vacuum_fluctuation http://math.ucr.edu/home/baez/physics/Quantum/virtual_particles.html http://zebu.uoregon.edu/~imamura/209/apr14/virtual.html http://www.google.com/search?hl=en&q=virtual+particles
5614 Posted January 5, 2005 Posted January 5, 2005 What about in space??? space is a good vacum, ever considered the planets, gases and photons travelling around in it... plus what yourdad said.
ecoli Posted January 6, 2005 Posted January 6, 2005 Correct me if I'm wrong, but won't an object thrown in space keep moving for ever (Newtons Laws), as long as no force is applied. So shouldn't Symbio's pendulum keep spinning? I guess I don't know enough about how virtual particles work to make this sort of assumption.
Rasori Posted January 6, 2005 Posted January 6, 2005 Space isn't a perfect vaccuum (as I'm told time and again). If it were, where would the gases that made the sun have come from? There are still pockets of hydrogen floating around (and probably other stuff, too). What if you were to use a vaccuum created by man, though? Is it not theoretically possible to pump the air out of a building (that's completely airtight) completely? Granted, you'll have to make a support structure capable of withstanding the atmospheric pressure, but I'm pretty sure that wouldn't be too hard...
symbio Posted January 6, 2005 Author Posted January 6, 2005 Sorry for the delayed reaction, I wasn't plugged in till late last night and had to reharge all day. OK, let's forget the vaccum and infinity for a moment. Is the pendulam spinning or a longer time than the mechanical input provided force to spin, or not. In other words, are the overlapping magnetic fields providing motive power, or does it just appear that way? Just curious and hoping to find some answers here. P.S. I buy my grade 50 neodymium magnets from http://www.leevalleytools.com and I am using both 1/8" and 1/4" magnets in the mechanism which wasn't described above Thanks again for your thoughts in this matter. Jeremy
swansont Posted January 6, 2005 Posted January 6, 2005 Sorry for the delayed reaction' date=' I wasn't plugged in till late last night and had to reharge all day. OK, let's forget the vaccum and infinity for a moment. Is the pendulam spinning or a longer time than the mechanical input provided force to spin, or not. In other words, are the overlapping magnetic fields providing motive power, or does it just appear that way? Just curious and hoping to find some answers here. P.S. I buy my grade 50 neodymium magnets from http://www.leevalleytools.com and I am using both 1/8" and 1/4" magnets in the mechanism which wasn't described above Thanks again for your thoughts in this matter. Jeremy[/quote'] No. You aren't tapping in to magnetic stored energy - all of it is provided by the spinning.
ydoaPs Posted January 7, 2005 Posted January 7, 2005 Correct me if I'm wrong' date=' but won't an object thrown in space keep moving for ever (Newtons Laws), as long as no force is applied. So shouldn't Symbio's pendulum keep spinning? I guess I don't know enough about how virtual particles work to make this sort of assumption.[/quote'] Space isn't a perfect vaccuum (as I'm told time and again). If it were' date=' where would the gases that made the sun have come from? There are still pockets of hydrogen floating around (and probably other stuff, too).What if you were to use a vaccuum created by man, though? Is it not theoretically possible to pump the air out of a building (that's completely airtight) completely? Granted, you'll have to make a support structure capable of withstanding the atmospheric pressure, but I'm pretty sure that wouldn't be too hard...[/quote'] vacuums are impossible. since there are particles, there will be a froce applied to the object(friction). also, gravity will accelerate/deccelerate the object.
symbio Posted January 7, 2005 Author Posted January 7, 2005 No. You aren't tapping in to magnetic stored energy - all of it is provided by the spinning. Is it possible to tap into that energy?
swansont Posted January 7, 2005 Posted January 7, 2005 Is it possible to tap into that energy? In general, yes, you can tap into stored energy of a magnetic field. But in a permanent magnet I don't think it's so easy, because you'd have to be able to re-orient the domains to do so.
symbio Posted January 8, 2005 Author Posted January 8, 2005 In general, yes, you can tap into stored energy of a magnetic field. But in a permanent magnet I don't think it's so easy, because you'd have to be able to re-orient the domains to do so. Could you explain that for me? I was also wondering if there was anyway to overlap the stationary magnetic fields so that there is no where the magnets in motion have to rest? Thanks again, Jeremy
[Tycho?] Posted January 8, 2005 Posted January 8, 2005 In general, yes, you can tap into stored energy of a magnetic field. But in a permanent magnet I don't think it's so easy, because you'd have to be able to re-orient the domains to do so. And even if you did, so called "permanent" magnets do eventually lose their magnetism. Perpetual motion remains and impossibility I'm afraid.
symbio Posted January 9, 2005 Author Posted January 9, 2005 I think getting stuck on the word perpetual is a mistake. Would it not be useful, if all we could do is extend the productive output of an existing power source? So, any ideas on tapping the magnetic forces within neodymium magnets?
ydoaPs Posted January 13, 2005 Posted January 13, 2005 i just noticed that this thread is in quantum mechanics. why is it here?
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