Could Earnshaw be only thinking inside the box


by Mack7963
Tags: earnshaw, inside
Mack7963
Mack7963 is offline
#1
Dec18-13, 01:01 PM
P: 3
Hello PF people
i just joined the forum after many many months of being driven insane concerning Earnshaw's Theorem, i myself am not a scientist or physicist so i am limited in the amount of knowledge that i have, but my curiosity wont let me accept what everyone else seems to be in agreement with.
As far as i can understand it is stated that a permanent magnet cannot achieve stable equilibrium, which is why they always attract, as i have discovered on many occasions, my own sense of logic tells me that this is due to each magnet having a single axis, so after thinking about this for a while, i had one of those archimedes moments, although i wasn't in the bath at the time, what if the the single axis became a shared axis, between two permanent magnet, lets say one magnet at point east and one at point west, joined via a rigid connection, my logic tells me that each magnet would cancel the other out, which as far as i can see would create a third state, stability, the problem i foresaw was that the magnets would try and flip the other way, using the north south axis, so using the same process and adding two more magnets to cancel out the potential north south flip, and connecting them with a rigid body would mean the magnets have no where to go, so all they can do is sit there above a surface made of permanent magnets, possibly using a halbach array for the surface, i honestly believe that with a four magnet rig connected to a cross shape, stable levitation of permanent magnets can be achieved. i have already built a platform form for the magnets to be mounted to, but sadly i built it to big, not taking into account that magnetic fields are curved, i did manage to hold the whole thing in one place but its tendency to slide off the field was the only issue, the usual flipping characteristic was not present, the next one i build will be a lot smaller so i can build a surface that it wont slide off. i would seriously love some feedback on this concept. i don't know if youtube links are allowed on here but i put a video on there of me doing this experiment, as i said at the beginning i am not a physicist so please dont be too harsh in your replies.
Thank you
Michael
Phys.Org News Partner Physics news on Phys.org
Physicists design quantum switches which can be activated by single photons
'Dressed' laser aimed at clouds may be key to inducing rain, lightning
Higher-order nonlinear optical processes observed using the SACLA X-ray free-electron laser
AlephZero
AlephZero is online now
#2
Dec18-13, 02:05 PM
Engineering
Sci Advisor
HW Helper
Thanks
P: 6,344
Trying to argue against math is usually a waste of time, so good luck with your experiment!

But stable magnetic levitation is possible using diamagnetic materials like water, or even frogs. All you need is a frog, and a VERY strong magnet ... http://www.ru.nl/hfml/research/levitation/diamagnetic/
DaleSpam
DaleSpam is offline
#3
Dec18-13, 02:35 PM
Mentor
P: 16,476
Quote Quote by Mack7963 View Post
its tendency to slide off the field was the only issue
This is exactly the type of instability predicted by the theorem.

Mack7963
Mack7963 is offline
#4
Dec18-13, 02:38 PM
P: 3

Could Earnshaw be only thinking inside the box


i get the arguing against math point, trouble is that wont satisfy my sense of logic until i actually see it not working, i believe the other term for this condition is stubbornness, thank you though for the good luck sentiment, i have seen the frog levitation experiment, all i need to do now is acquire a frog and a very very expensive 10 tesla magnetic coil, anyone have next weeks winning lottery numbers per chance?.
Mack7963
Mack7963 is offline
#5
Dec18-13, 02:55 PM
P: 3
Dale
so if the sliding off the field is one of the issues, do you think that if the east west magnets where angled outwards then they would centralize themselves, again going back to each one canceling the other out, if one magnet is pushing against the other both with equal force, then the two magnets should stay in one place, as long as the curvature of the field is large enough, I'm also wondering if having a 5th magnet opposite to all the rest and central would not anchor the whole thing somehow.
DaleSpam
DaleSpam is offline
#6
Dec18-13, 04:52 PM
Mentor
P: 16,476
Quote Quote by Mack7963 View Post
Dale
so if the sliding off the field is one of the issues, do you think that if the east west magnets where angled outwards then they would centralize themselves, again going back to each one canceling the other out, if one magnet is pushing against the other both with equal force, then the two magnets should stay in one place, as long as the curvature of the field is large enough, I'm also wondering if having a 5th magnet opposite to all the rest and central would not anchor the whole thing somehow.
The point of the theorem is that under the assumptions of the theorem there will always be some direction of slipping. All you can do is design things which violate the assumptions of the theorem.
Bobbywhy
Bobbywhy is offline
#7
Dec18-13, 07:28 PM
PF Gold
P: 1,852
Here are at least eight different magnetic levitation devices you can purchase:
http://www.scientificsonline.com/cat...tic+levitation


Register to reply

Related Discussions
Earnshaw's Theorem Introductory Physics Homework 2
Thinking Inside The Box Brain Teasers 17
Earnshaw's Theorem General Physics 6
Earnshaw's Theorem Classical Physics 9
about earnshaw's theorem Classical Physics 1