When a magnetic field moves through a conductor a current called an Eddy current is induced in the conductor due to the magnetic field’s movement. The flow of electrons in the conductor creates an opposing magnetic field to the magnet which results in damping of the magnet and causes heating inside of the conductor similar to heat buildup inside of power cords. The loss of energy used to heat up the conductor is equal to the loss of kinetic energy by the magnet.
And a note of caution if you decide to try this, these magnets are not for unsupervised children. In fact, everyone should be careful:
Neodymium magnets larger than a half inch are very strong and should be handled with extreme care since they can be dangerous. It is best to stick with neodymium magnets of quarter inch diameter or less.
This breathtaking video of the Aurora Borealis is not a time-lapse video — this is what it looks like in real time. It was filmed in Yellowknife, Northwest Territories, Canada by astro-photographer Kwon O Chul, and not only displays the bright northern lights and these rather magical looking glowing teepees, but also sets them to the awed, ambient sounds of tourists in the cold night air.
From the Ri Channel's View the Tales from the Prep Room series, this is how you make a fluidized bed of sand: Making Sand Swim. Watch how these solids suddenly behave a lot like a fluid as air escapes between the sand particles, causing them to float. It’s definitely one of the more strange and fascinating demonstrations that we’ve seen.
Seen at science museums, maker faires, and all over the internet, Singing Tesla Coils combine science and music in the most fantastical and memorable of ways. But how do they work? From Physics Buzz:
Sound waves are vibrations of the air around us, which you can make just by clapping your hands or talking. Pitch is just the number of times the air vibrates per second. Higher frequency, higher pitch. Tesla coils are a combination of circuits that output thousands to millions of volts. That high electric field arcs up and out of the coil, filling the air with sparks and making it possible to light up fluorescent lights wirelessly. Certain types of Tesla coils, like the one used here, are putting out hundreds of sparks per second, with a rest between each spark. That’s already a lot like a sound wave. Each spark is pushing on the air and can create a sound. Change the frequency of the sparks and you get an equal frequency wave, hitting your ears like a note of music. The creators had to find a way to move seamlessly between frequencies to make the notes sound distinct, instead of just playing the whole scale.