Peter Guthrie Tait

Peter Guthrie Tait
Photograph of Tait in 1870, with signature
Born	(1831-04-28)28 April 1831 Dalkeith, Scotland
Died	4 July 1901(1901-07-04) (aged 70) Edinburgh, Scotland
Alma mater	University of Edinburgh Peterhouse, Cambridge
Known for	Knot theory Ménage problem Snark Tait conjectures Tait equation Tait–Bryan angles Tait–Kneser theorem
Awards	Smith's Prize (1852) Keith Medal (1867–69) Royal Medal (1886)
Scientific career
Fields	Mathematical physics
Institutions	University of Edinburgh Peterhouse, Cambridge
Academic advisors	William Hopkins

Peter Guthrie Tait FRSE (28 April 1831 – 4 July 1901) was a Scottish mathematical physicist and early pioneer in thermodynamics. He is best known for the mathematical physics textbook Treatise on Natural Philosophy, which he co-wrote with Lord Kelvin, and his early investigations into knot theory.

His work on knot theory contributed to the eventual formation of topology as a mathematical discipline. His name is known in graph theory mainly for Tait's conjecture on cubic graphs. He is also one of the namesakes of the Tait–Kneser theorem on osculating circles.