How does this battery zoom through the coil of wire in this vid?


I watched this video and read the description which explain the video. I still have no idea what this means. It also seems an Elon Musk-ish idea, is there a reason this could or couldn’t work for a human-sized train?

In: Physics

The magnets on the ends of the battery are **very strong**, and also conductive. Since they are conductive, they short circuit the battery through the segment of wire between them. This current, through the turns of wire, produces a magnetic field. As it turns out (and why you have to put the magnets a specific way) this magnetic field is aligned to repel the magnet at one end of the battery and attract the magnet at the other end. This moves the “train” forward a bit. Moving forward a bit connects the magnets to different loops of wire. Putting the current through different loops moves the magnetic field forward. The field moves the train forward and the train moves the field forward, and round-and-round you go until the battery runs out of current.

If you put an electrical charge into a coil of wire, you get a magnetic field as a result.

Because of the orientation of the magnets, (the south pole is touching the battery on both ends), the magnetic field generated by the electrical current, both pushes the “front” end and pulls the “back”, creating a net force that pushes it forward as long as it is within a coil of wire that it is supplying with electricity between the two end contact points.

Problems that have to be overcome include, but are not limited to:

* getting a static magnet that big (and shielding passengers from it, lest their electronic devices get messed up and/or mess with the train) may be quite cost prohibitive and I’m not sure how much neodymium exists in the world as a whole.

* overcoming the increased friction forces that would be inherent in something that much more massive.

These aren’t fatal problems necessarily, but design considerations. I don’t know exactly how well that would scale.