Spinning levitating cube magnets with bismuth

Two 1/8 inch cube neodymium magnets spin in mid air, suspended between 2 bismuth discs and pulled upwards by a large magnet above the construction. The magnets were set in motion before the film starts by blowing air against the edge. It takes almost 3 minutes to come to a stop, only due to air friction.

At the end of the movie the pulling magnet is wiggled a bit so you can see how steady the setup is once correctly installed.

Category:

Science & Technology

Tags:

• levitation
• magnet
• bismuth
• neodymium

[007Benm]

I think it should spin for a very long time in a vaccuum. The problem would be getting it to spin though, since i set it in motion by blowing air to one side using a straw.

In a vacuum you'd need to speed it up using some coils on the outside of the jar, and ramping current through those just like you would rotate a stepper motor.

[vmelkon]

What happens if you don't have a large magnet above the construction. What is the large magnet for?

[007Benm]

@vmelkon - the big magnet on top is what pulls the little magnets up against gravity. The two bismuth discs repel the small magnet, so it doesnt shoot up or drop down.

[1BustedMyth]

Love to see it in a vacuum :)