Around the Lab: Diamagnetic Levitation and the levitating pan

What you're watching below is an example of diamagnetic levitation. The little bench that the coil is sitting on top of is solid aluminum. The coil is about three inches in diameter and contains a few hundred turns of magnet wire. A variac is used to drive the coil with AC current.

When the coil is energized, the alternating current creates an alternating magnetic flux. This flux sets up a counter-emf, (electromotive force) in the space occupied by the aluminum plate. This counter-emf creates a current in the aluminum plate that in turn creates a magnetic field opposing the one created by the coil. The two magnetic fields repel and the coil is levitated. Check out the videos and then check out the newspaper article from the '60s describing the levitational stove.

NEW YORK HERALD-TRIBUNE: Monday, November 21, 1951, pp. 1 & 6

PAN FLOATS IN AIR

In it seven coils of wire on laminated iron cores are contained inside a plywood cabinet of blond mahogany. The magnetic field from these coils induces 'eddy currents' in an aluminium cooking pan nineteen inches in diameter, which interact and lift the pan into space like a miniature 'flying saucer.'

The cooking pan floats about two inches in tha air above the stove in a stabalized condition; 'eddy currents' generate the heat that warms it while the stove top remains cold. The aluminium pan will hold additional pots and it can be used as a griddle. It is, of course, a variation of several other more familiar magnetic repulsion gadgets including the 'mysterious floating metal ball' of science hall exhibits.

Comments

The Valentine's Day Magnetic Monopole

There's an assymetry to the form of the two Maxwell's equations shown in picture 1. While the divergence of the electric field is proportional to the electric charge density at a given point, the divergence of the magnetic field is equal to zero. This is typically explained in the following way. While we know that electrons, the fundamental electric charge carriers exist, evidence seems to indicate that magnetic monopoles, the particles that would carry magnetic 'charge', either don't exist, or, the energies required to create them are so high that they are exceedingly rare. That doesn't stop us from looking for them though! Keeping with the theme of Fairbank[1] and his academic progeny over the semester break, today's post is about the discovery of a magnetic monopole candidate event by one of the Fairbank's graduate students, Blas Cabrera[2]. Cabrera was utilizing a loop type of magnetic monopole detector. Its operation is in...

Cool Math Tricks: Deriving the Divergence, (Del or Nabla) into New (Cylindrical) Coordinate Systems

Now available as a Kindle ebook for 99 cents ! Get a spiffy ebook, and fund more physics The following is a pretty lengthy procedure, but converting the divergence, (nabla, del) operator between coordinate systems comes up pretty often. While there are tables for converting between common coordinate systems , there seem to be fewer explanations of the procedure for deriving the conversion, so here goes! What do we actually want? To convert the Cartesian nabla to the nabla for another coordinate system, say… cylindrical coordinates. What we’ll need: 1. The Cartesian Nabla: 2. A set of equations relating the Cartesian coordinates to cylindrical coordinates: 3. A set of equations relating the Cartesian basis vectors to the basis vectors of the new coordinate system: How to do it: Use the chain rule for differentiation to convert the derivatives with respect to the Cartesian variables to derivatives with respect to the cylindrical variables. The chain ...

More Cowbell! Record Production using Google Forms and Charts

First, the what : This article shows how to embed a new Google Form into any web page. To demonstrate ths, a chart and form that allow blog readers to control the recording levels of each instrument in Blue Oyster Cult's "(Don't Fear) The Reaper" is used. HTML code from the Google version of the form included on this page is shown and the parts that need to be modified are highlighted. Next, the why : Google recently released an e-mail form feature that allows users of Google Documents to create an e-mail a form that automatically places each user's input into an associated spreadsheet. As it turns out, with a little bit of work, the forms that are created by Google Docs can be embedded into any web page. Now, The Goods: Click on the instrument you want turned up, click the submit button and then refresh the page. Through the magic of Google Forms as soon as you click on submit and refresh this web page, the data chart will update immediately. Turn up the:...

Copasetic Flow

Search This Blog