Thanks to YouTuber Physics Girl, we have what may be the best illustration of the interrelated effects of electricity and magnetism since Magneto schooled Storm. In this “World’s Easiest DIY Electric Train” video, science communicator Dianna Cowern shows you everything you need to assemble your own simplified version of an electric train using nothing but batteries, neodymium magnets, a copper coil, and the power of physics. You might not have all of the components laying around the house–though they can easily be ordered online or picked up at a local hardware store–but this is one of the easier science experiments to do at home or in the classroom.
As Cowern shows, a battery with a strong, rare-earth magnet attached to either end of it will zip through a copper coil passageway with relative ease. It’s electric! (Boogie, woogie, woogie.) Cowern explains that the battery acts as the power source for the train as electrons flow from the negative to positive terminals, coursing through the magnets and the copper coil itself to form a closed circuit. Rather than drive a motor of some sort, these electrons are used to generate an electric field.
One of the coolest phenomena of electromagnetism is that, when electricity runs through a coil, a magnetic field is generated. It’s the effect of this magnetic field on the magnets themselves that actually propels the battery forward along the track. More specifically, the effects of this non-uniform magnetic field are stronger between the magnets than outside of them, allowing the train to proceed out of the station–if you’ve got the magnetic poles lined up right–rather than simply sitting still.
Check out the original source video that inspired Physics Girl’s superior explanation below:
You’re probably also wondering if there are any practical applications for this phenomena outside of fun DIY science experiments. There are, but before you get carried away with thoughts of perpetual motion machines or energy-free transportation, keep in mind that these basic physics principles have long since been applied to everything from electric motors, to Maglev trains, and numerous other applications. But that shouldn’t stop you from thinking big; you could very well be the next James Clerk Maxwell, Hans Christian Ørsted, André-Marie Ampère or Michael Faraday! Or, if you prefer, the next Physics Girl!