This cryostat is a replica of a device used by Pyotr Kapitsa around 1940 to study superfluid helium. A glass “spindle”with six capillaries is balanced on a needle in a container with liquid helium. If a ray of light is focused on the device so that the liquid is heated, the spindle begins to rotate. The explanation is that at temperatures below 2.19 Kelvin, liquid helium is a mixture of normal liquid helium and a suprafluid helium. When heated, the superfluid quantum liquid is transformed into normal liquid and squirts out through the capillaries. Because the superfluid liquid can seep in along the walls of the capillaries, this process goes on for as long as heat is added.
The cryostat was manufactured at the Moscow Institute of Physics and Technology, which Pyotr Kapitsa helped to found. It was acquired by the Nobel Prize Museum in 2001.
Russian physicist Pyotr Kapitsa had a specially-designed key cut for the Mond Laboratory at Cambridge where he worked in the 1920s and 1930s. The key’s design was inspired by Kapitsa’s nickname for his mentor and 1908 chemistry laureate Ernest Rutherford, “The Crocodile”. This later became Kapitsa’s own nickname. There are several theories on how the nickname came about. Kapitsa’s wife Anna revealed in her later years that none of the more imaginative ones were true, but they are interesting nonetheless. Kapitsa himself offered one explanation: “In Russia, the crocodile is a symbol of the head of the family, and is both feared and admired because of its stiff neck and inability to move in any direction but forward. It just keeps on going straight ahead with its jaws wide open – just like science, just like Rutherford.”
This key is a copy of the original, which is kept at Kapitsa’s laboratory in Moscow. The replica was acquired by the Nobel Prize Museum in 2001.
