demonstration

Showing 10 posts tagged demonstration

Generate your own electricity with some wire, a magnetic field, and the relative movement between the two of them: Alom Shaha explains electromagnetic induction using this hand-powered – or perhaps more accurately, bacon-sandwich-powered – generator.

Related watching: magnetic fields, probably one of the more awe-inducing subjects on this blog.

via Science Demo.

Gravitational acceleration + optical illusions + how to! In this Get Set… Demonstrate, science teacher Alom Shaha shows step by step how to create Pearls of Water, a physics-defying demonstration that must look even more unbelievable in person than it does on video.

And if you want to see this in person, the instructions, equipment list, and safety notes for setting it up are here (pdf).

Want to see similar versions of this illusion? Check out artist Matt Kenyon’s Supermajor and Brusspup’s Amazing Water and Sound Experiment.

via Science Demo.

There are quite a few neodymium magnets falling through copper pipes on the internet, but we can still understand why this demonstration video is making the rounds: it’s just so cool looking! We’ve covered the phenomenon of magnetic damping before:

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.

Want to know more? Look up Lenz’s Law and watch Veritasium’s Derek Muller demonstrate how this phenomenon is related to English scientist Michael Faraday and the first electric generator, created with a magnet and a coil of wire in 1831:

Physics! Another must-watch magnet-doing-magic-like-things-video comes from the Ri Channel: Levitating Superconductor on a Möbius strip

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. 

Related watching: ScienceDemo.org, and at RIGB.org, a video list that I put together for The Royal Institution that has our favorite STEM videos for kids… well, at least some of our favorites. There are so many.

The Floating Water Bridge, a demonstration by Dr. Elmar C. Fuchs. Two beakers are filled with triply deionized water. Electrodes are added to each, exposing the water to high d.c. voltage. A cylindrical water bridge forms between them that is stable enough to sustain itself across a few centimeters. Watch the water as the beakers are slowly separated. From FYeah Fluid Dynamics:

Gravity tends to make the water bridge sag and capillary action tries to thin the bridge, but both effects are countered by the polarization forces induced in the water by the electric field.

File under: electrohydrodynamics and do not try this at home. High voltage is dangerous and requires trained adult supervision. Check out more images at Dr. Fuchs’ site. Bonus vid: density fluctuations.

In the archives: more physics videos and more demonstrations like this: an aluminum foil boat floats on a sulphur hexafluoride sea.

Thanks, @flechevallier.