Physics Help Forum magnetic levitation for artworks

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 Apr 20th 2016, 11:04 AM #1 Junior Member   Join Date: Apr 2016 Location: ipswich Posts: 1 magnetic levitation for artworks Hello everyone, I hope you can forgive a simple mechanic if this seems daft. I have read earnshaws theorem. First the idea and then the question. The idea concerns a large Oak Burl. It's approx 45 kilo in weight and loosely oblong in shape. I plan to carve an exact half globe bowl shape in the logical place in this burl and imbed a pattern of neodymium magnets just below the wood's surface, inside the bowl with all the magnets oriented "north pole facing inward" ie, into the bowl. I have just discovered the halback array so that may be way to go. Step 2 is a hollow wooden globe or ball that would sit inside the bowl with a suitable gap between the two and a pattern of magnets set all over the ball in the manner of latitude and longitude, also sunk into the wood just below the surface with there "south Poles" oriented outwards. If my thinking is correct I will have created a magnetic bowl repelling a magnetic ball. The bowl shape effectively providing the required mechanical support (pseudo levitation) . If the ball will float magnetically and stay in the bowl I can imagine it wobbling and/or spinning relatively freely. After the carving, sanding, varnishing story, a nice piece of organic art. In fact if the ball jinxes around, so much the better. Instability is my friend, aye. So, that's the idea. The question is simple. Will it work?. If not,why not. I hope there's a brain box out there who can help with this before I spend £200 on magnets. .
 Apr 20th 2016, 12:19 PM #2 Physics Team     Join Date: Jun 2010 Location: Morristown, NJ USA Posts: 2,352 Yes, it will work, if you have enough magnets to support the weight of the sphere. If there are N magnets evenly spaced around the sphere then half of them will be helping to provide lift at any instant (the half that are in the bowl). The magnets at the bottom of the sphere provide the most lift, as the repulsive force is directly vertical, whereas magnets closer to the rim of the bowl provide less lift because their forces are more horizontal. If there are N pairs of magnets evenly distributed on the surface of the sphere and bowl, and each pair provides F repulsive force, then the total lifting force is NF/4. You will need to do some experiments to see what the repulsive force is of a pair of magnets that are separated by distance caused by the magnets being inset into the surface of the wood. Others have done similar things: Last edited by ChipB; Apr 20th 2016 at 12:25 PM.

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