Induced Current Spin-Up

This great little lab stirrer (which I modified to have a transparent top) can be used in many investigations and demonstrations: 
From Amazon: BUY NOW Magnetic Stirrer 

Inexpensive concave lenses make great spinning platforms- get one here: 
From Amazon: BUY NOW Concave Lens Spin Station 

Get a PhiTOP in aluminum here (will work nicely in this demo):
From Educational Innovations: BUY NOW PhiTOP 
From Art of Play: BUY NOW PhiTOP

Copper version avaiable here: 
From Etsy: BUY NOW: Copper PhiTOP

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Induced Current Spin-Up: copper is not magnetic, but magnets can interact with conductors. Here spinning magnets in the magnetic stirrer induce electric currents to flow in the solid copper PhiTOP- these currents then create their own magnetic field which opposes the magnets underneath and pushes the PhiTOP to spin. Credit to astrophysicist Kenneth Brecher, the creator of the PhiTOP and this unique means of using Lenz’s Law to spin it up. This top stands up vertically (when spun with sufficient rotational velocity) due to physics similar to that of the tippe-top. The concave lens keeps the top from wandering off of magnetic stirrer