Quantum Levitation Demonstration! Superconducting Sapphire Crystal Allows for Stabilized Levitation Over Magnetic FieldSubmitted by RobHino on Tue, 06/25/2013 - 19:51
...The key to the levitator is the disc, which is made of superconducting material sandwiched between layers of gold and sapphire crystal. A piece of foam is placed on top and held in place with household plastic wrap. The disc is then dipped into a brew of liquid nitrogen (temperature: minus-300 degrees Fahrenheit).
This creates a superconductor — an object that conducts electricity without resistance and no energy loss.
When placed atop a powerful magnet, the disc appears to float or be trapped by the magnetic field. The combination of magnetism and superconductivity create the levitation.
Quantum levitation is nothing new — scientists have been studying it for decades, Ringlein said. But the materials used in the museum's levitator take the technology several steps further.
The disc doesn't have to remain flat but can be tilted and will maintain the same angle as long as it's above the magnet. You can even flip the magnet over without the disc falling off.
Ringlein said the sapphire crystal coating is the key to the device's stability — and its high cost. The two discs included with the levitator represent about two-thirds of the device's total cost, he said.
The magnets also are expensive and powerful enough to wreak havoc on credit cards and cell phones if you stand too close to them, said Amanda Eckinger, the North Museum's marketing and membership coordinator...