Tom Osborne, age 16, of Barre, Vt., for his question:

WHAT IS SUPERFLUIDITY?

Superfluidity is a state of matter characterized by the complete absence of viscosity, or resistance to flow. The term "superfluidity" is applied primarily to phenomena observed in liquid helium at very low temperatures, but the term is also sometimes used to refer to the frictionless flow of electrons in certain metals and alloys at very low temperatures.

The phenomenon of superfluidity was discovered in 1937 by a Russian physicist named Peter Kapitza and independently in 1938 by a British scientist named John Frank Allen. They observed that liquid helium when cooled below minus 455.76 degrees Fahrenheit could flow with no difficulty through extremely small holes, which liquid helium above that temperature cannot do.

They also noticed that on the walls of its container superfluid helium formed a thin film (approximately 100 atoms thick) that flowed against gravity up and over the rim of the container.

Superfiuid is any fluid that exhibits frictionless flow, very high heat conductivity and other unusual physical properties.