Copasetic Flow

Lab Book 2014_05_14     Hamilton Carter This lab notebook entry documents testing a YBCO superconductor for magnetic levitation, troubleshooting a jammed glass Dewar stopcock, and exploring mathematical parallels between relativistic projectile trajectories and classical drag models.

This one of the more interesting magnet levitating over a superconductor pictures I've seen in a while.  The sequence shows a magnet on the end of a non-ferromagnetic chain being lowered into a superconducting dish.  The chain becomes a graphically impressive part of the demo in the last frame.  You might have heard that magnets won't levitate stably over a flat type I superconductor, and the won't.  The sides of the dish are adding lateral repulsive forces that keep the magnet in place! The picture is from "Cryophysics" by K. Mendelssohn.  It's volume 7 of the excellent and completely out of print "Interscience Tracts on Physics and Astronomy"

+Bruce Elliott  asked an excellent superconductor levitation question, so, no lab stuff, journal articles, or homework problems today, just superconductors.  A few days ago, I posted the following video of eddy current levitation to Google + with this explanation... Staying with the eddy current theme, what if you played the game a different way?  The video below shows a coil of wire driven by wall current, (60 Hz here in the USA).  The alternating current creates a rapidly changing magnetic field.  The eddy currents in the aluminum plate, (aluminum like copper is not magnetic), oppose the original magnetic field created by the coil and cause it to levitate.  The coil gets very, very hot in the process because of all the energy from the wall current being turned into heat by the electrical resistance of the coil, (video 1). http://youtu.be/5HnihTg1rso What the post and video are demonstrating is a combination of Faraday's Law of In...

March 3rd, 2008 -- A weekly look at science, engineering, and fringe science happenings from the week before! Levitation: Fact or Fiction? Pravda.run ran an interesting article on levitation. It presented a chronological history of accounts of levitation. The initial accounts were more mystically slanted including various swamis, nuns, and saints. As time progressed, the coverage moved towards anecdotal and scientific accounts. These included accounts of levitation by Daniel Douglas Hewm that were verified by people such as Mark Twain and William M. Thackeray . Finally, the article discussed modern 'scientific' example of levitation such as the Meissner effect . Another physical phenomenon that can result in levitation and was not covered in the article is diamagnetism . It was used most spectacularly to levitate a frog in the Netherlands. This experiment was carried out at the Nijmegen High Field Magnet Laboratory. The moon-bound art museum: greg.org reported on ...