Normally, it takes an effort to make fluids flow. However, this behaviour changes at really low temperatures. In 1937, Russian physicist Pyotr Kapitsa discovered that below -271 degrees Celsius liquid helium loses its resistance to flow. It even exhibits quirky habits such as turning into a thin film and climbing up the walls of its container.
Kapitsa published his findings 1938. Canadian physicist, John Allen, who had discovered it independently, also published his findings the same year.
Superfluidity in helium occurs when helium-3 and helium-4, the two isotopes of helium, are liquefied by cooling to cryogenic temperatures (-150°C to -273 °C). Superfluidity occurs at far higher temperatures in liquid helium-4 than it does in helium-3.
Superfluidity has many applications in astrophysics. Superfluid helium at -271.4 °C was used in a special device in 1983 and many other devices for astronomical observations with infrared sensors.
Picture Credit : Google
