Berni Julian Alder (September 9, 1925 – September 7, 2020) was a German-born American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

specialized in

statistical mechanics In physics, statistical mechanics is a mathematical framework that applies statistical methods and probability theory to large assemblies of microscopic entities. Sometimes called statistical physics or statistical thermodynamics, its applicati ...

, and a pioneer of computational modelling of matter.

Biography

Alder was born in

Duisburg Duisburg (; , ) is a city in the Ruhr metropolitan area of the western States of Germany, German state of North Rhine-Westphalia. Lying on the confluence of the Rhine (Lower Rhine) and the Ruhr (river), Ruhr rivers in the center of the Rhine-Ruh ...

, Prussia, in September 1925, to Jewish parents, a

chemist A chemist (from Greek ''chēm(ía)'' alchemy; replacing ''chymist'' from Medieval Latin ''alchemist'') is a graduated scientist trained in the study of chemistry, or an officially enrolled student in the field. Chemists study the composition of ...

and a homemaker. After the

Nazi Nazism (), formally named National Socialism (NS; , ), is the far-right politics, far-right Totalitarianism, totalitarian socio-political ideology and practices associated with Adolf Hitler and the Nazi Party (NSDAP) in Germany. During H ...

s came to power, the family moved to

Zurich Zurich (; ) is the list of cities in Switzerland, largest city in Switzerland and the capital of the canton of Zurich. It is in north-central Switzerland, at the northwestern tip of Lake Zurich. , the municipality had 448,664 inhabitants. The ...

, Switzerland. Fearing an invasion by Nazi Germany after the outbreak of

World War II World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

, the family applied for a visa to the United States, which was granted in 1941. They left by sealed train from neutral Switzerland to (formally neutral) Spain, then to Portugal, where they took a ship to the US. Following a stint in the US Navy after US entry into the war, he obtained a BSc in chemistry from the University of California at Berkeley and a master's degree in chemical engineering from the same institution in 1947. He went to the California Institute of Technology to study under John Gamble Kirkwood for his PhD in 1948 and worked for the investigation of phase transitions in hard-sphere gas with Stan Frankel, where he got the idea to use the

Monte Carlo method Monte Carlo methods, or Monte Carlo experiments, are a broad class of computational algorithms that rely on repeated random sampling to obtain numerical results. The underlying concept is to use randomness to solve problems that might be ...

. After he finished at Caltech in 1952, Alder went to Berkeley and worked part-time at Berkeley to teach chemistry and part-time as a consultant under the suggestion of Edward Teller in the nuclear weapons program for the Lawrence Livermore National Laboratory to help with the equations of state. In collaboration with Thomas Everett Wainwright, and Mary Ann Mansigh, he developed techniques for molecular dynamics simulation in the mid-1950s, including the liquid-solid phase transition for hard sphere and the velocity autocorrelations function decay in liquids. Alder, along with Teller, was one of the founders of the Department of Applied Science in 1963. He was a professor of applied science at the University of California at Davis, and later professor emeritus. Alder died on September 7, 2020, of

heart failure Heart failure (HF), also known as congestive heart failure (CHF), is a syndrome caused by an impairment in the heart's ability to Cardiac cycle, fill with and pump blood. Although symptoms vary based on which side of the heart is affected, HF ...

Honors

In 2001, he was awarded the Boltzmann Medal for inventing technique of molecular dynamics simulation. Alder was elected a Fellow of the

American Academy of Arts and Sciences The American Academy of Arts and Sciences (The Academy) is one of the oldest learned societies in the United States. It was founded in 1780 during the American Revolution by John Adams, John Hancock, James Bowdoin, Andrew Oliver, and other ...

in 2008. In 2009, he was awarded the

National Medal of Science The National Medal of Science is an honor bestowed by the President of the United States to individuals in science and engineering who have made important contributions to the advancement of knowledge in the fields of behavioral science, behavior ...

. Alder was a Guggenheim Fellow. He was the editor of the book series Methods in Computational Physics and the founder of the magazine Computing.

References

External links

An Interview with Bernie Alder by George Michael, Stories of the Development of Large Scale Scientific Computing at Lawrence Livermore National Laboratory

Oral History interview transcript for Berni Alder on 18 June 1990, American Institute of Physics, Niels Bohr Library and Archives
{{DEFAULTSORT:Alder, Berni 1925 births 2020 deaths 21st-century American physicists American people of German-Jewish descent California Institute of Technology alumni Fellows of the American Academy of Arts and Sciences Fellows of the American Physical Society Jewish emigrants from Nazi Germany to the United States Lawrence Livermore National Laboratory staff Members of the United States National Academy of Sciences National Medal of Science laureates Scientific computing researchers UC Berkeley College of Chemistry alumni University of California, Berkeley College of Letters and Science faculty University of California, Davis faculty German emigrants to Switzerland Recipients of the Boltzmann Medal