Carl Eckart

Carl Henry Eckart (May 4, 1902 – October 23, 1973) was an American physicist, physical oceanographer, geophysicist, and administrator. He co-developed the Wigner–Eckart theorem and is also known for the Eckart conditions in quantum mechanics, the Eckart–Young theorem in linear algebra, and his work on non-equilibrium thermodynamics and continuum mechanics, including a relativistic treatment. Provided by Wikipedia