In the last episode of Physics Girl, Dianna Cowern used the effects of electromagnetism to assemble and power the world’s simplest electric train. This time, she uses those same physics phenomena to violently explode soda cans with a little help from her friends at Arc Attack Studios in Austin, TX.
If you haven’t heard of that latter group, they perform feats of science education through music and dynamic presentations, like their singing Tesla coils. When they’re not making music, they’re cobbling together crazy devices to show off scientific phenomena, like this powerful electromagnet that blows empty soda cans apart with explosive force.
The reason this is possible is due to a core property of electromagnetism: When an electric current runs through a coil, it generates a magnetic field, one that gets stronger as the current increases. As demonstrated, the direction of the magnetic field can be determined via the “right hand rule,” where, if the thumb of your right hand is pointed in the direction that the electrical current flows, the curl of your fingers will match the flow of the magnetic field. (You can also use this rule to determine the direction of magnetic force, which is perpendicular to both the velocity of electrical charge and the magnetic field.)
But a magnetic field alone does not cause a soda can to spontaneously tear itself apart. It’s thanks to another property of electromagnetism: Changing magnetic fields, i.e. ones that grow in strength as the current increases, can induce electrical currents in turn. This secondary current comes with its own magnetic field which is aligned with the first; you now have two very powerful magnets on top of each other, so it’s their repelling force that shears the soda can apart. Explosively. All captured at 11,000fps with a Phantom high speed camera. That’s pretty cool, even if it’s not the most practical way to get to your sugary beverage of choice.
For more fun with electromagnetism and induction, Physics Girl and Arc Attack also launch non-magnetic aluminum into the sky, shrink quarters, and have more fun with Tesla coils. Do you have any electromagnetic experiments you’d like to see? Let us know in the comments!
Images: Physics Girl