Superconductivity and carbon nanotubes, are Type I, while almost all impure and compound superconductors are Type II. Conversely, a spinning superconductor generates a magnetic field, precisely aligned with the spin axis. The effect, the London moment, was put to good use in Gravity Probe B. This experiment measured the magnetic fields of four superconducting gyroscopes to determine their spin axes. This was critical to the experiment since it is one of the few ways to accurately determine the spin axis of an otherwise featureless sphere. Superconductivity was discovered on April 8, 1911 by Heike Kamerlingh Onnes, who was studying the resistance
Lowest temperature recorded on Earth 1960, held the record until a temperature of was measured at the Soviet Vostok Station, on the Antarctic Plateau, on July 21, 1983. This remains the record for a directly recorded temperature. In 1904 Dutch scientist Heike Kamerlingh Onnes created a special lab in Leiden with the aim of producing liquid helium. In 1908 he managed to lower the temperature to less than −269 °C (-452.2 F, 4 K), which is less than four degrees above absolute zero. Only in this exceptionally cold state will helium liquefy, the boiling point of helium being at −268.94 °C (-452.092 F). Kamerlingh Onnes