# George N. Hatsopoulos

George Nicholas Hatsopoulos (January 7, 1927 – September 20, 2018) was a Greek American mechanical engineer noted for his work in thermodynamics and for having co-founded Thermo Electron.

## Early life

Hatsopoulos was born in Athens, Greece in 1927 and is related to the former rector of the Athens Polytechnic School, Nicolas Kitsikis. He attended Athens Polytechnic before entering MIT, where he received his Bachelor and Master of Science (1950), Mechanical Engineer (1954), and Doctorate of Science (1956).

## Hatsopoulos-Keenan reformulation of thermodynamics

In 1965, he and Joseph Keenan published their textbook Principles of General Thermodynamics, which restates the second law of thermodynamics in terms of the existence of stable equilibrium states. Their formulation of the second law of thermodynamics states that:
   When an isolated system performs a process after the removal of a series of internal constraints, it will reach a unique state of equilibrium: this state of equilibrium is independent of the order in which the constraints are removed.
The Hatsopoulos-Keenan statement of the Second Law entails the Clausius, Kelvin-Planck, and Carathéodory statements of the Second Law, and has provided a basis to extend the traditional definition of entropy to the non-equilibrium domain. Hatsopoulus and Keenan maintained that it is unlikely to identify a satisfactory definition of heat without a prior statement of the second law.
In 1976, Hatsopoulos also contributed to a formulation of a unified theory of mechanics and thermodynamics, arguably a precursor of the emerging field of quantum thermodynamics.

## Academic and industry leader

While at MIT, Hatsopoulos was head of the engineering division of Matrad Corporation of New York. Matrad Corporation and MIT also provided financial support for his doctoral thesis The Thermo-Electron Engine. Matrad Corporation was owned by the family of Peter M. Nomikos, a Harvard Business School graduate. In 1956, Nomikos and Hatsopoulos co-founded the Thermo Electron Corporation. Several years later, George asked his brother (John Hatsopoulos) to join the company as financial controller. Under George Hatsopoulos, Thermo Electron became a major provider of analytical instruments and services for a variety of domains. John Hatsopoulos, and Arvin Smith. In 1965, George Hatsopoulos was president of the Thermo Electron Engineering Corporation and Senior Lecturer in Mechanical Engineering at M.I.T..

## Recognition

In 1961, Hatsopoulos received the Golden Plate Award of the American Academy of Achievement. In 1996, Hatsopoulos won the John Fritz Medal, which is the highest American award in the engineering profession and presented each year for scientific or industrial achievement in any field of pure or applied science. In 1997, he was awarded the 3rd Annual Heinz Award in Technology, the Economy and Employment.
In 2011, along with Arvin Smith and John Hatsopoulos, he was awarded the 2011 Pittcon Heritage Award from the Chemical Heritage Foundation.
Hatsopoulos is also a recipient of The International Center in New York's Award of Excellence.
He died on September 20, 2018, at the age of 91. His net worth was reported as US$481 million in 2017.