My question is not one of is it possible but how would it work in practice knowing the actions of metals, magnets and their respective fields.

If we placed a magnetic ball inside a rolling non magnetic sphere which was able to react to magnetic pulls and pushes independently of the outer sphere, and arranged a course of further magnets along a type of track/course, would the respective fields smoothly transfer that object around the track?

If this is possible would you be able to turn the magnetic pull/push off from a section of the track which would mean the sphere could continue linearly until acted on by another force meaning you could change the trajectory of the sphere by switching on and off magnetic fields?

My school physics classes are far behind me now and I would like to know if what I have posed is all possible.



1 Answer 1


The internal magnet, presumably also rolling (loose) inside the sphere will be attracted to the first and maybe second track permanent magnet, then stop. This will effectively be a 'magnetic-brake'. However, your second idea of energizing solenoids in sequence may propel the sphere, but will require extremely powerful solenoids to be effective. "Mag-Lev" (Magnetic Levitation) trains work on a similar principle for propulsion. Although I found no literature specific to your question, a similar project was built in the 80's for a series of 4017 IC's driving 36 solenoids for a 'roulette' type game. Wheel fixed position, while 20 mm solid steel ball (from ball-bearing) circulates. This working project was seen on You-Tube. As seen on the demo video, you would need to start off with a low-speed sequencing, to overcome inertia, otherwise the travelling track field will escape too quickly. As sphere starts rolling, crank up speed very gradually.


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