Celsius Celsius scale are defined by absolute zero and the triple point of Vienna Standard Mean Ocean Water (VSMOW), a specially purified water. This definition also precisely relates the Celsius scale to the Kelvin scale, which defines the SI base unit of thermodynamic temperature with symbol K. Absolute zero, the lowest temperature possible, is defined as being exactly 0 K and −273.15 °C. The temperature of the triple point of water is defined as exactly . This means that a temperature difference of one degree Celsius and that of one kelvin are exactly the same. In 1742, Swedish astronomer Anders Celsius
David Kennedy (astronomer) he was the provincial superior of the Society of Mary in New Zealand. He died in Wellington on 10 March 1936. David Kennedy (astronomer) David Kennedy (27 April 1864 – 10 March 1936) was born at Lyttelton, New Zealand, the son of an Irish mother and a Scottish father who came to New Zealand from Melbourne in 1863. He became the first New Zealand born priest of the Society of Mary (Marists), a noted astronomer and educator. As a boy he showed a keen interest in both theology and science. Because of his undoubted intelligence and promise he was sent