1926Heike Kamerlingh Onnes, Dutch physicist and academic, Nobel Prize laureate (born 1853)[†]
Heike Kamerlingh Onnes was a Dutch experimental physicist who became the first to liquefy helium, cooling it to near 1.5 kelvin, at the time the coldest temperature achieved on Earth. For this research, he was awarded the Nobel Prize in Physics in 1913. Using liquid helium to investigate the electrical conductivity of solid mercury, he found in 1911 that at 4.2 K, its electrical resistance vanishes, thus discovering superconductivity.