Carl Paul Gottfried Linde (11 June 1842 – 16 November 1934) was a German scientist and engineer who discovered a refrigeration cycle and invented the first industrial-scale air separation and gas liquefaction processes. These breakthroughs laid the backbone for the 1913 Nobel Prize in physics. Linde was a member of scientific and engineering associations, including being on the board of trustees of the Physikalisch-Technische Reichsanstalt and the Bavarian Academy of Sciences and Humanities. Linde was also the founder of what is now known as The Linde Group, the world's largest industrial gases company, and ushered the creation of the supply chain of industrial gases as a profitable line of businesses. He was knighted in 1897 as Ritter von Linde.