Olof Celsius Olof Celsius Olof Celsius (the elder) (19 July 1670 – 24 June 1756) was a Swedish botanist, philologist and clergyman, He was a professor at Uppsala University, Sweden. Celsius was a mentor of the botanist and scientist Carl Linnaeus. Celsius wrote his most famous book on biblical plants, "Hierobotanicon", in 1745-47. Olof Celsius's nephew Anders Celsius was an astronomer who invented a temperature scale where 100 represented the freezing point of water and 0 represented the boiling point. Jean-Pierre Christin, in 1744 reversed the scale to create the centigrade scale, renamed in 1948 to the Celsius scale in use today.
Planck temperature Planck temperature Planck temperature, denoted by "T", is the unit of temperature in the system of natural units known as Planck units. It serves as the defining unit of the Planck temperature scale. In this scale the magnitude of the Planck temperature is equal to 1, while that of absolute zero is 0. Other temperatures can be converted to Planck temperature units. For example, = = . In SI units, the Planck temperature is about kelvin (equivalently, degrees Celsius, since the difference is trivially small at this scale), or degrees Fahrenheit or Rankine. What today is known as the Planck