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The Discovery of Superfluidity

Updated: Jul 21, 2023

#17 Science in History

08 January 1938


On this day in 1938, the journal Nature publishes two articles describing the superfluidity of liquid helium at a temperature near absolute zero.




A thin film creeps up the inside wall of the cup and down the outside.


The drop on the underside will fall into the reservoir of liquid helium below






This phenomenon was discovered, independently, by Pyotr Kapitsa in Moscow and by John Allen and Don Misener in Cambridge.


Superfluidity is a state in which a liquid can flow without friction, and it occurs when liquid helium is cooled just a few degrees below its boiling point of –269°C. Helium will remain liquid down to absolute zero (-273.15°C), the temperature at which, in theory, atoms stop moving. Helium atoms are so light and weakly attracted to each other that they never solidify – the atoms act as one and don’t collide with each other, which is why superfluid helium can flow without friction. A superfluid material can trickle through molecule-thin cracks, climb up and over the sides of a container, and remain still even when the container is set spinning. So, what can superfluid materials be used for?

  • A coolant for high-field magnets

  • Cooling materials to very low temperatures allows them to be studied in a unique state.

  • Creating ultra-precise sensors to detect gravitational waves

  • Applications in ultra-efficient engines and pumps.


Photo credit

Wikipedia. 2022. "Superfluidity." Wikimedia Foundation. Last modified December 8, 2022. https://en.wikipedia.org/wiki/Superfluidity. Original photograph by Alfred Leitner

 

As part of his quest to understand what one degree of temperature is, Ben Miller visits Oxford's

Clarendon Laboratory. Here scientists produce temperatures just a few degrees above absolute zero. Ben Miller explores the bizarre effects of these temperatures on helium.







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