Slide your train into the copper coil. It should zip down the coil and out the other side! If your train doesn't move, try flipping the train around. If it still doesn't work, try flipping one of the stacks of batteries around.Experiment by adding or subtracting the number of magnets, or making a longer coil. With a long enough copper coil, you'll be able to make a circle that the train zips around continuously!What's going on?Try this. Grab a couple of fridge magnets and flip them so they repel each other. If you place one on a table and bring the other one close, the magnet on the table will slide away. That same magnetic push is what moves your train!How? Well, placing the battery inside the coil of wire creates an electrical circuit. (In fact, it creates a short circuit, which is why the battery burns out so quickly in this experiment.)And here's the part where the connection between electricity and magnetism becomes important. An electric current creates a magnetic field. In fact, a coil of wire like you made here creates a magnetic field very similar to the magnetic field of a plain old bar magnet. Now, the neodymium magnets have their own magnetic field, and they're sitting right in the middle of the wire's magnetic field. And just like a couple of fridge magnets, those magnetic fields interact with each other. That's where the push that propels your train comes from. The neodymium magnets get pushed along by the magnetic field of the coil of wire.