On this day 172 years ago, on September 21, 1853 (August 19, 1853 lunar calendar), Dutch physicist and discoverer of superconductivity, Heike Kamerin Onnis was born. Heike Kamerin Onnis (HeikeKamerlinghOnnes, September 21, 1853 - February 21, 1926), Dutch physicist, discoverer of superconductivity, and founder of low temperature physics. Onnis was born in Groningen, the Netherlands in 1853, entered the University of Groningen in 1870, and went to Heidelberg, Germany the following year to study with physicists Bunsen and Kirchhoff. In 1876, Onnis graduated from the University of Groningen with a bachelor's degree, and in 1879 he received a doctorate from the school. In 1882, Onnes became a professor of physics and head of the physics laboratory at Leiden University in the Netherlands, and set the main direction of the laboratory as low-temperature physics. At that time, the main means of obtaining low temperature was liquefied gas. Before 1882, only hydrogen and helium had not been liquefied. After more than 20 years of research, the British physicist Dewar liquefied hydrogen for the first time in 1898. The physics laboratory of Leiden University developed rapidly under the leadership of Onnes. In 1894, the low-temperature physics laboratory of Leiden University was established, and a large liquefied gas plant was established. Oxygen was liquefied in 1904, hydrogen was liquefied two years later, and helium was liquefied for the first time on July 10, 1908, setting a new record for artificial low temperature at -269 ° C (4K). Then liquid helium was used to obtain an even lower temperature of 0.9K. Onnes became known as "Mr. Absolute Zero." In 1911, Onnes used liquid helium to cool gold and platinum below 4.3K and found that the resistance of platinum was a constant. Then he took mercury below 4.2K and measured that its resistance dropped to almost zero, which is a phenomenon of superconductivity. In 1913, Onnes discovered that tin and lead are also superconducting like mercury. In the same year, Onnes was awarded the Nobel Prize in Physics for his research on the properties of matter at low temperatures and for liquefying helium. Under Onnes's leadership, the Leiden University Physics Laboratory became the world's research center for low-temperature physics. Onnes retired in 1923 and died in Leiden in 1926. In memory of him, the Physics Laboratory of Leiden University was named "Karmalin Onnis Laboratory" in 1932. Comment: Who knows superconductivity! Heike Karmalin Onnis made a great discovery!