Superfluidity

Superfluidity is a state of matter where fluid or a liquid can act very strangely.

Some of the things a superfluid can do are:

• It can flow extremely easily. (How easily a liquid can flow is called its viscosity.) In fact, it flows so easily that friction does not change the way it flows; it has zero viscosity. Because of this, it can actually flow out of a container, like a bowl, even when the bowl is not tipped so the liquid can spill out.
• It stays still when its container is spun, instead of starting a whirlpool like when a sink full of water is drained. However, a whirlpool does form if the container is spun at and above a certain speed.

So far, scientists have only been able to create superfluids at extremely cold temperatures. However, superfluids have quite a few uses in science today, like:

• Superfluid Helium at nearly absolute zero -271.4 degrees Celsius [-456.2 degrees Fahrenheit] was used in a special satellite in 1983 to get information on infrared waves in space.
• Superfluids can be used in gyroscopes, to help machines predict information about gravity movements that can't be picked up with regular instruments only.
• One kind of superfluid was used to trap and slow down a beam of light from its normal speed of 670,600,000 mph (1,079,000,000 km/h) to only 38.03 mph (62.2 km/h) That means the beam of light was moving at .00000567104 % of its speed in a vacuum, or 17 million times slower.

There is also another state of matter called a supersolid, although how they are formed is more complex.

Related pages

• Fluid mechanics
• Superconductor