Alfred J. Lotka

Alfred James Lotka ( born March 2, 1880 in Lemberg, Austria - Hungary, now: Lviv, Ukraine; † December 5, 1949 in New York City ) was an Austrian- American chemist, actuary and demographer.

Life and work

Lotkas parents were U.S. citizens. He went to school in France and received in 1901 his Bachelor of Science at the University of Birmingham. The following year, he studied at the University of Leipzig chemistry. In particular, the lectures of Wilhelm Ostwald and its physical chemistry have a lasting impact on Lotka. After emigrating to the United States in 1902, he worked as a chemical assistant at the General Chemical Company. Lotkas first publications deal with mixing processes of gases (1907 ), periodic reactions in physical chemistry (1910 ), but also with demographic phenomena such as the birth and death rates (1907 ) or the age distribution in the population ( 1911). Also in the early period of creativity falls a first article, which seeks to explain evolution by physical processes. The latter interest is also in the background of his major work of 1925: Elements of Physical Biology ( Reprint of 1956 was titled Elements of Mathematical Biology ). With this work Lotka wanted a new branch of science - the physical biology - launch, which was to transfer physical principles to biological systems. Basic assumption was that making all developments (including ' Evolution' ) by the laws of thermodynamics describe as energy conversion. In such a model the entire inanimate and animate nature appears as a huge energy conversion system. It was of interest to both system theorists such as Ludwig von Bertalanffy and for the ecologists of the 1960s and 1970s Through this approach, after his death.

Became known Lotka mainly by its mathematical formulation of laws of population dynamics, which he first published in Elements of Physical Biology. These laws can in an idealized predator-prey relationship calculate the number of regular development of the two species and predict. Regardless of Lotka was Vito Volterra, a Roman mathematician and physicist, met with the same differential equations and the formulation of the same population dynamical laws. After Vito Volterra brought the legislation for publication in 1926, an exchange of letters between the two scientists took place. Although Volterra rather put the focus on the differences in their two approaches, the equations now call Lotka -Volterra equations, or the Lotka -Volterra equations. Another law, came across the Lotka is that in bibliometrics under the name Lotkas law ( Lotka 's Law ) known relationship between the number of publications of a person and the number of people with an equally high publication output.

Lotka worked at a variety of employers: the General Chemical Company, the U.S. Patent Office, the National Bureau of Standards, 1911-1914 as an editor of Scientific American Supplement, 1922 to 1924 as an employee of Johns Hopkins University and from 1924 until his retirement for life insurance institution Metropolitan Life Insurance Company in New York.

In 1935, he married Romola Beattie; The marriage remained childless.

He was 1938-1939 President of the Population Association of America and in 1942 president of the American Statistical Association. He was Vizepräsiedent the International Union for the Scientific Study of Population and Chairman of the United States National Committee of the Union 1948 until 1949.

The estate of Alfred J. Lotka located in the Seeley G. Mudd Manuscript Library at Princeton.

Publications (selection)

• Note on the Volume Change on Mixing Two gas. In: Engineering and Mining Journal. 83, 1907, p 956
• Relation Between Birth and Death Council Council. In: Science. 26, 1907, pp. 21-22.
• On the theory of periodic reactions. In: Journal of physical chemistry. 72, 1910, p 508
• With F. R. Sharpe: A problem in age distribution. In: Philosophical Magazine. 21, 1911, p 435
• The evolution from the standpoint of physics. In: Ostwald annals of natural philosophy. 10, 1911, p 59
• Elements of Physical Biology. Williams and Wilkins, Baltimore 1925; Reprint: Elements of Mathematical Biology. Dover Publications, New York 1956, ISBN 0-486-60346-6
• The frequency distribution of scientific productivity. In: Journal of the Washington Academy of Sciences. 16, 1926, pp. 317-323.
• Louis I. Dublin: The Money Value of a Man. Ronald Press Co., New York 1930; Arno Press, New York 1977, ISBN 0-405-09814-6
• Analytical Theory of Biological Populations ( = The Plenum Series on Demographic Methods and Population Analysis). Plenum Press, New York 1998, ISBN 0-306-45927-2