Peter Debye
Encyclopedia
Peter Joseph William Debye FRS (March 24, 1884 – November 2, 1966) was a Dutch
physicist
and physical chemist
, and Nobel laureate in Chemistry.
, Netherlands
, Debye attended the Aachen University of Technology, Rhenish Prussia just 30 km away in 1901. He studied mathematics
and classical physics
, and, in 1905, received a degree in electrical engineering
. In 1907, he published his first paper, a mathematically elegant solution of a problem involving eddy current
s. At Aachen, he studied under the theoretical physicist Arnold Sommerfeld
, who later claimed that his most important discovery was Peter Debye.
In 1906, Sommerfeld received an appointment at Munich, Bavaria
, and took Debye with him as his assistant. Debye got his Ph.D.
with a dissertation on radiation pressure
in 1908. In 1910, he derived the Planck radiation formula using a method which Max Planck
agreed was simpler than his own.
In 1911, when Albert Einstein
took an appointment as a professor at Prague, Bohemia
, Debye took his old professorship at the University of Zurich
, Switzerland
. This was followed by moves to Utrecht
in 1912, to Göttingen in 1913, to ETH Zurich
in 1920, to Leipzig
in 1927, and in 1934 to Berlin
, where, succeeding Einstein, he became director of the Kaiser Wilhelm Institute for Physics (now named the Max-Planck-Institut) whose facilities were built only during Debye's era. He was awarded the Lorentz Medal
in 1935. From 1937 to 1939 he was the president of the Deutsche Physikalische Gesellschaft
.
In 1913, Debye married Mathilde Alberer. They had a son, Peter P. Debye (born 1916), and a daughter, Mathilde Maria (born 1921). Peter became a physicist and collaborated with Debye in some of his researches, and had a son who was also a chemist.
to the charge
distribution in asymmetric molecule
s in 1912, developing equations relating dipole moments to temperature and dielectric constant. In consequence, the units of molecular dipole moments are termed debyes in his honor. Also in 1912, he extended Albert Einstein
's theory of specific heat to lower temperatures by including contributions from low-frequency phonon
s. See Debye model
.
In 1913, he extended Niels Bohr
's theory of atomic structure, introducing elliptical orbits, a concept also introduced by Arnold Sommerfeld
. In 1914-1915, Deybe calculated the effect of temperature on X-ray diffraction
patterns of Crystal crystalline solids with Paul Scherrer
(the "Debye–Waller factor").
In 1923, together with his assistant Erich Hückel
, he developed an improvement of Svante Arrhenius
' theory of electrical conductivity in electrolytic solutions. Although an improvement was made to the Debye-Hückel equation
in 1926 by Lars Onsager
, the theory is still regarded as a major forward step in our understanding of electrolytic
solutions. Also in 1923, Debye developed a theory to explain the Compton effect, the shifting of the frequency of X-ray
s when they interact with electron
s.
of Berlin. These positions were held during the years that Adolf Hitler
ruled Nazi Germany
and, from 1938 onward, also over Austria
.
In 1939 Debye traveled to the United States of America
to deliver the Baker Lectures at Cornell University
in Ithaca, New York
. After leaving Germany in early 1940, Debye became a professor at Cornell, chaired the chemistry department for 10 years, and became a member of Alpha Chi Sigma
. In 1946 he became an American citizen. Unlike the Europe
an phase of his life, where he moved from city to city every few years, in the United States Debye remained at Cornell for the remainder of his career. He retired in 1952, but continued research until his death.
Much of Debye's work at Cornell concerned the use of light-scattering techniques (derived from his X-ray scattering work of years earlier) to determine the size and molecular weight of polymer
molecule
s. This started as a result of his research during World War II
on synthetic rubber
, but was extended to protein
s and other macromolecule
s.
In April 1966, Debye suffered a heart attack
, and in November of that year a second one proved fatal. He is buried in the Pleasant Grove Cemetery (Ithaca, New York, USA).
In light of the current situation, membership by German Jews as stipulated by the Nuremberg laws, of the Deutsche Physikalische Gesellschaft cannot be continued. According to the wishes of the board, I ask of all members to whom these definitions apply to report to me their resignation. Heil Hitler!
Many biographies published before Rispens' work, state that Debye moved to the US because he refused to accept German citizenship forced on to him by the Nazis. He planned his departure from Germany during a visit with his mother in Maastricht
in late 1939, boarded a ship in Genoa in January 1940 and arrived in New York in early February 1940. He immediately sought a permanent position in the US and accepted such an offer from Cornell in June 1940. That month, he crossed the US border into Canada and returned within days on an immigration visa. He was able to get his wife out of Germany and to the US by December 1940. Although his son already was in the US before he departed, Peter Debye's 19 year old daughter and his sister-in-law did not leave. They lived in his official residence in Berlin and were supported by Debye's official Berlin wages (he carefully maintained an official leave of absence for this purpose).
Further, Rispens alleges that Albert Einstein
in the first half of 1940 actively tried to prevent Debye from being appointed in the United States
at Cornell. Einstein allegedly wrote to his American colleagues: "I know from a reliable source that Peter Debye is still in close contact with the German (Nazi) leaders" and, according to Rispens, called upon his colleagues to do "what they consider their duty as American citizens". To support this, Rispens refers to a well-known letter from Debye to Einstein and Einstein's response to it. Van Ginkel investigated 1940 FBI reports on this matter and traced the "reliable source" to a single letter directed to Einstein and written by someone whose name is lost. This person was not known personally to Einstein and, according to Einstein, probably did not know Debye personally either. Moreover, this accusatory letter did not reach Einstein directly but was intercepted by British censors who showed it to Einstein. Einstein sent the British agent with the letter to Cornell, and the Cornell authorities told Debye about the affair. Thereupon Debye wrote his well-known 1940 letter to Einstein to which Einstein answered. The latter two letters can be found in the published Einstein correspondence.
Rispens alleges that Debye sent a telegram to Berlin on 23 June 1941 informing his previous employers that he was able and willing to resume his responsibilities at the Kaiser Wilhelm Institut, presumably in order to maintain his leave of absence and keep the Berlin house and wages available for his daughter. A copy of this telegram has not been recovered thus far. In summer 1941, Debye filed his intent to become a US citizen and was quickly recruited in the US to participate in the Allied War research.
It has been well documented in many biographies, and also in Rispens' book, that Debye and Dutch colleagues helped his Jewish colleague Lise Meitner
in 1938-1939 (at great risk to himself and his family) cross the Dutch-German border to escape Nazi persecution and eventually obtain a position in Sweden.
Predating Rispens' work, and in contrast to it, an article by Rechenberg appeared 18 years earlier concerning Debye's letter. The article describes Debye's missive in more detail and presents a very favorable picture of Debye in his efforts to resist the Nazi activists. Moreover, this article points out that Max von Laue
, well known for his anti-Nazi views, gave his approval to the letter from the DPG chairman.
Rispens' accusations were considered harmful enough by the Board of Directors of the University of Utrecht that they announced on February 16, 2006 a name change for the Debye Institute. This was done after consultation with NIOD.
In an opinion article published on the Debye Institute website, Dr. Gijs van Ginkel, until April 2007 Senior Managing Director of the VM Debye Instituut in Utrecht deplored this decision. In his article he cites scholars who point out that the DPG was able to retain their threatened staff as long as could be expected under increasing pressure from the Nazis. He also puts forward the important argument that when Debye in 1950 received the Max Planck medal
of the DPG, nobody objected, not even the known opponent of the national socialists Max von Laue
, who would have been in a position to object. Also Einstein, with his enormous prestige, was still alive, as were other Jewish scientists such as Lise Meitner
and James Franck
who both knew Debye intimately. None of them protested against Debye's receiving the highest German scientific distinction. In fact, Albert Einstein, after many years of not participating in the voting for the Max Planck Medal nominees, joined the process again to vote for Debye.
Maastricht University also announced that it was reconsidering its position on the Peter Debye Prijs voor natuurwetenschappelijk onderzoek (Peter Debye Prize for scientific research)
In a reply on the DPG website, Dieter Hoffmann and Mark Walker also conclude that Debye was not a Nazi activist. They remark that Max von Laue also was required and obliged (as a civil servant) to sign letters with Heil Hitler. They also state that the DPG was one of the last scientific societies to purge the Jewish members and only very reluctantly. They quote the response of the Reich University Teachers League (a National Socialist organization) to the Debye letter:
Obviously the German Physical Society is still very backward and still clings tightly to their dear Jews. It is in fact remarkable that only "because of circumstances beyond our control" the membership of Jews can no longer be maintained
In May 2006, the Dutch Nobel Prize winner Martinus Veltman who had written the foreword to the Rispen book, renounced the book's description of Peter Debye, withdrew his foreword, and asked the Board of Directors of Utrecht University to rescind their decision to rename the Debye Institute.
Various historical investigations, both in The Netherlands and in the US, have been carried out subsequent to the actions of the University of Maastricht. The earliest of these investigations, carried out by the Cornell University's department of Chemistry and Chemical Biology is now complete. The report of the Cornell investigation, released on 31 May 2006, states that:
Based on the information to-date, we have not found evidence supporting the accusations that Debye was a Nazi sympathizer or collaborator or that he held anti-Semitic views. It is important that this be stated clearly since these are the most serious allegations.
It goes on to declare:
Thus, based on the information, evidence and historical record known to date, we believe that any action that dissociates Debye's name from the Department of Chemistry and Chemical Biology at Cornell is unwarranted.
In June 2006, it was reported that the scientific director of the (formerly) Debye Institute had been reprimanded by the Board of Directors of the University of Utrecht for a new publication on Debye's war years on the grounds that it was too personally biased with respect to the Institute's naming dispute. According to the board, the book should have been published not as a Debye Institute publication, but as a personal one. The book was banned by the University of Utrecht and both Directors of the (former) Debye Institute were forbidden to have any further contact with the press. A dozen professors of the Physics Faculty, amongst whom Cees Andriesse
, openly protested against the interventions of the Board and the censorship of their protest by the university.
In May 2007, the universities of Utrecht and Maastricht announced that a new committee headed by Jan Terlouw
would advise them regarding the name change. Also, in the beginning of 2007 an official report was announced, to be published by the NIOD and authorized by the Dutch Education Ministry (then scheduled for fall 2007).
it can be stated that Debye was rightly called an opportunist after his arrival in the United States. We have seen that he showed himself to be loyal to the dominant political system, first in the Third Reich and then in the United States, while at the same time keeping the back door open: in the Third Reich by retaining his Dutch nationality, in the United States by attempting to secretly maintain some contacts with Nazi Germany via the Foreign Office.
It concludes that Debye's actions in 1933-45 were based on the nineteenth-century positivist view of science which saw research in physics as generating blessings for humankind. The report states that, by his contemporaries, Debye was considered an opportunist by some and as a man of highest character by others. The report asserts that Debye was not coerced by the Nazis into writing the infamous DPG Heil Hitler letter and that he also did not follow the lead of other societies in doing so but, rather, other societies followed his lead. The NIOD report also concludes that Debye felt obliged to send the letter and that it was, for him, simply a confirmation of an existing situation. The report argues that Debye, in the Third Reich, developed a survival method of ambiguity which allowed him to pursue his scientific career despite the political turmoil. Crucial to this survival method was the need to keep ready an escape hatch, for example in his secret dealings with the Nazis in 1941, if needed.
Yet, the report also states that the picture of Debye should not be oversimplified as Debyes actions were also motivated by his loyalty to his daughter, who had remained in Berlin. In general, Debye developed a survival method of ambiguity, that "could pull the wool over people's eyes"
, and yet also was not a resistance hero. He was a rather pragmatic, flexible, and brilliant scientist, idealistic with respect to the pursuit of science, but only superficially oriented in politics. With respect to sending out the DPG letter, the Commission concluded that Debye found the situation inescapable. The Commission pointed out that the Royal Dutch Academy of Sciences also took away Albert Einstein's honorary membership, emphasizing the circumstances in which these decisions had be taken. The Commission stated that now, seventy years later, no judgment can be made concerning the decision of Debye to sign this letter in the exceptionally difficult circumstances in which he then found himself. Nevertheless, the Commission describes the DPG letter as an extraordinarily unpleasant fact, forming a dark page in his life history. Finally, the Commission concluded that based on the NIOD report since no bad faith on Debye’s part has been demonstrated, his good faith must be assumed and recommended that the University of Utrecht retain the name of the Debye Institute of NanoMaterials Science and that the University of Maastricht continue to associate itself with the Peter Debye Prize. Utrecht University accepted the recommendation, Maastricht University did not. But in February 2008, the Hustinx Foundation (Maastricht), originator and sponsor of the Peter Debye Prize, announced that it will continue to have the prize awarded. The City of Maastricht, Debye's birthplace, declared that it sees no reason to change the names of Debye Street and Debye Square.
. They first met around 1930 when they were both working as editors for two scientific journals. They collaborated in the escape of Lise Meitner in 1938. According to Reiding Debye was well connected in German scientific and industrial circles and could have provided MI6 with valuable information. For example as board member of the German Academy for Aviation Research he was acquainted with Hermann Goering. Reiding also offers an explanation for Debye's hasty departure on 16 January 1940 for the United States: the date coincided with the planned (but later delayed) German invasion of the Netherlands a day later, information possibly passed on to him by Rosbaud.
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
physicist
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
and physical chemist
Physical chemistry
Physical chemistry is the study of macroscopic, atomic, subatomic, and particulate phenomena in chemical systems in terms of physical laws and concepts...
, and Nobel laureate in Chemistry.
Early life
Born Petrus Josephus Wilhelmus Debije in MaastrichtMaastricht
Maastricht is situated on both sides of the Meuse river in the south-eastern part of the Netherlands, on the Belgian border and near the German border...
, Netherlands
Netherlands
The Netherlands is a constituent country of the Kingdom of the Netherlands, located mainly in North-West Europe and with several islands in the Caribbean. Mainland Netherlands borders the North Sea to the north and west, Belgium to the south, and Germany to the east, and shares maritime borders...
, Debye attended the Aachen University of Technology, Rhenish Prussia just 30 km away in 1901. He studied mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
and classical physics
Physics
Physics is a natural science that involves the study of matter and its motion through spacetime, along with related concepts such as energy and force. More broadly, it is the general analysis of nature, conducted in order to understand how the universe behaves.Physics is one of the oldest academic...
, and, in 1905, received a degree in electrical engineering
Electrical engineering
Electrical engineering is a field of engineering that generally deals with the study and application of electricity, electronics and electromagnetism. The field first became an identifiable occupation in the late nineteenth century after commercialization of the electric telegraph and electrical...
. In 1907, he published his first paper, a mathematically elegant solution of a problem involving eddy current
Eddy current
Eddy currents are electric currents induced in conductors when a conductor is exposed to a changing magnetic field; due to relative motion of the field source and conductor or due to variations of the field with time. This can cause a circulating flow of electrons, or current, within the body of...
s. At Aachen, he studied under the theoretical physicist Arnold Sommerfeld
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and groomed a large number of students for the new era of theoretical physics...
, who later claimed that his most important discovery was Peter Debye.
In 1906, Sommerfeld received an appointment at Munich, Bavaria
Kingdom of Bavaria
The Kingdom of Bavaria was a German state that existed from 1806 to 1918. The Bavarian Elector Maximilian IV Joseph of the House of Wittelsbach became the first King of Bavaria in 1806 as Maximilian I Joseph. The monarchy would remain held by the Wittelsbachs until the kingdom's dissolution in 1918...
, and took Debye with him as his assistant. Debye got his Ph.D.
Doctor of Philosophy
Doctor of Philosophy, abbreviated as Ph.D., PhD, D.Phil., or DPhil , in English-speaking countries, is a postgraduate academic degree awarded by universities...
with a dissertation on radiation pressure
Radiation pressure
Radiation pressure is the pressure exerted upon any surface exposed to electromagnetic radiation. If absorbed, the pressure is the power flux density divided by the speed of light...
in 1908. In 1910, he derived the Planck radiation formula using a method which Max Planck
Max Planck
Max Karl Ernst Ludwig Planck, ForMemRS, was a German physicist who actualized the quantum physics, initiating a revolution in natural science and philosophy. He is regarded as the founder of the quantum theory, for which he received the Nobel Prize in Physics in 1918.-Life and career:Planck came...
agreed was simpler than his own.
In 1911, when Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
took an appointment as a professor at Prague, Bohemia
Bohemia
Bohemia is a historical region in central Europe, occupying the western two-thirds of the traditional Czech Lands. It is located in the contemporary Czech Republic with its capital in Prague...
, Debye took his old professorship at the University of Zurich
University of Zurich
The University of Zurich , located in the city of Zurich, is the largest university in Switzerland, with over 25,000 students. It was founded in 1833 from the existing colleges of theology, law, medicine and a new faculty of philosophy....
, Switzerland
Switzerland
Switzerland name of one of the Swiss cantons. ; ; ; or ), in its full name the Swiss Confederation , is a federal republic consisting of 26 cantons, with Bern as the seat of the federal authorities. The country is situated in Western Europe,Or Central Europe depending on the definition....
. This was followed by moves to Utrecht
Utrecht University
Utrecht University is a university in Utrecht, Netherlands. It is one of the oldest universities in the Netherlands and one of the largest in Europe. Established March 26, 1636, it had an enrollment of 29,082 students in 2008, and employed 8,614 faculty and staff, 570 of which are full professors....
in 1912, to Göttingen in 1913, to ETH Zurich
ETH Zurich
The Swiss Federal Institute of Technology Zurich or ETH Zürich is an engineering, science, technology, mathematics and management university in the City of Zurich, Switzerland....
in 1920, to Leipzig
University of Leipzig
The University of Leipzig , located in Leipzig in the Free State of Saxony, Germany, is one of the oldest universities in the world and the second-oldest university in Germany...
in 1927, and in 1934 to Berlin
Humboldt University of Berlin
The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...
, where, succeeding Einstein, he became director of the Kaiser Wilhelm Institute for Physics (now named the Max-Planck-Institut) whose facilities were built only during Debye's era. He was awarded the Lorentz Medal
Lorentz Medal
Lorentz Medal is a prize awarded every four years by the Royal Netherlands Academy of Arts and Sciences. It was established in 1925 on the occasion of the 50th anniversary of the doctorate of Hendrik Lorentz. This solid gold medal is given for important contributions to theoretical physics, though...
in 1935. From 1937 to 1939 he was the president of the Deutsche Physikalische Gesellschaft
Deutsche Physikalische Gesellschaft
The Deutsche Physikalische Gesellschaft is the world's largest organization of physicists. The DPG's worldwide membership is cited as 60,000, as of 2011...
.
In 1913, Debye married Mathilde Alberer. They had a son, Peter P. Debye (born 1916), and a daughter, Mathilde Maria (born 1921). Peter became a physicist and collaborated with Debye in some of his researches, and had a son who was also a chemist.
Scientific contributions
His first major scientific contribution was the application of the concept of dipole momentElectric dipole moment
In physics, the electric dipole moment is a measure of the separation of positive and negative electrical charges in a system of charges, that is, a measure of the charge system's overall polarity with SI units of Coulomb-meter...
to the charge
Electric charge
Electric charge is a physical property of matter that causes it to experience a force when near other electrically charged matter. Electric charge comes in two types, called positive and negative. Two positively charged substances, or objects, experience a mutual repulsive force, as do two...
distribution in asymmetric molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s in 1912, developing equations relating dipole moments to temperature and dielectric constant. In consequence, the units of molecular dipole moments are termed debyes in his honor. Also in 1912, he extended Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
's theory of specific heat to lower temperatures by including contributions from low-frequency phonon
Phonon
In physics, a phonon is a collective excitation in a periodic, elastic arrangement of atoms or molecules in condensed matter, such as solids and some liquids...
s. See Debye model
Debye model
In thermodynamics and solid state physics, the Debye model is a method developed by Peter Debye in 1912 for estimating the phonon contribution to the specific heat in a solid. It treats the vibrations of the atomic lattice as phonons in a box, in contrast to the Einstein model, which treats the...
.
In 1913, he extended Niels Bohr
Niels Bohr
Niels Henrik David Bohr was a Danish physicist who made foundational contributions to understanding atomic structure and quantum mechanics, for which he received the Nobel Prize in Physics in 1922. Bohr mentored and collaborated with many of the top physicists of the century at his institute in...
's theory of atomic structure, introducing elliptical orbits, a concept also introduced by Arnold Sommerfeld
Arnold Sommerfeld
Arnold Johannes Wilhelm Sommerfeld was a German theoretical physicist who pioneered developments in atomic and quantum physics, and also educated and groomed a large number of students for the new era of theoretical physics...
. In 1914-1915, Deybe calculated the effect of temperature on X-ray diffraction
X-ray scattering techniques
X-ray scattering techniques are a family of non-destructive analytical techniques which reveal information about the crystallographic structure, chemical composition, and physical properties of materials and thin films...
patterns of Crystal crystalline solids with Paul Scherrer
Paul Scherrer
Paul Scherrer was a Swiss physicist. Born in Herisau, Switzerland, he studied at Göttingen, Germany, before becoming a lecturer there. Later, Scherrer became head of the Department of Physics at ETH Zürich....
(the "Debye–Waller factor").
In 1923, together with his assistant Erich Hückel
Erich Hückel
Erich Armand Arthur Joseph Hückel was a German physicist and physical chemist. He is known for two major contributions:*The Debye–Hückel theory of electrolytic solutions...
, he developed an improvement of Svante Arrhenius
Svante Arrhenius
Svante August Arrhenius was a Swedish scientist, originally a physicist, but often referred to as a chemist, and one of the founders of the science of physical chemistry...
' theory of electrical conductivity in electrolytic solutions. Although an improvement was made to the Debye-Hückel equation
Debye-Hückel equation
The Debye–Hückel equation and Debye–Hückel limiting law, were derived by Peter Debye and Erich Hückel, who developed a theory with which to calculate activity coefficients of electrolyte solutions. Activities, rather than concentrations, are needed in many chemical calculations because solutions...
in 1926 by Lars Onsager
Lars Onsager
Lars Onsager was a Norwegian-born American physical chemist and theoretical physicist, winner of the 1968 Nobel Prize in Chemistry.He held the Gibbs Professorship of Theoretical Chemistry at Yale University....
, the theory is still regarded as a major forward step in our understanding of electrolytic
Electrolyte
In chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
solutions. Also in 1923, Debye developed a theory to explain the Compton effect, the shifting of the frequency of X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
s when they interact with electron
Electron
The electron is a subatomic particle with a negative elementary electric charge. It has no known components or substructure; in other words, it is generally thought to be an elementary particle. An electron has a mass that is approximately 1/1836 that of the proton...
s.
Later work
From 1934 to 1939 Debye was director of the physics section of the prestigious Kaiser Wilhelm Institute in Berlin. From 1936 onwards he was also professor of Theoretical Physics at the Frederick William UniversityHumboldt University of Berlin
The Humboldt University of Berlin is Berlin's oldest university, founded in 1810 as the University of Berlin by the liberal Prussian educational reformer and linguist Wilhelm von Humboldt, whose university model has strongly influenced other European and Western universities...
of Berlin. These positions were held during the years that Adolf Hitler
Adolf Hitler
Adolf Hitler was an Austrian-born German politician and the leader of the National Socialist German Workers Party , commonly referred to as the Nazi Party). He was Chancellor of Germany from 1933 to 1945, and head of state from 1934 to 1945...
ruled Nazi Germany
Nazi Germany
Nazi Germany , also known as the Third Reich , but officially called German Reich from 1933 to 1943 and Greater German Reich from 26 June 1943 onward, is the name commonly used to refer to the state of Germany from 1933 to 1945, when it was a totalitarian dictatorship ruled by...
and, from 1938 onward, also over Austria
Austria
Austria , officially the Republic of Austria , is a landlocked country of roughly 8.4 million people in Central Europe. It is bordered by the Czech Republic and Germany to the north, Slovakia and Hungary to the east, Slovenia and Italy to the south, and Switzerland and Liechtenstein to the...
.
In 1939 Debye traveled to the United States of America
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
to deliver the Baker Lectures at Cornell University
Cornell University
Cornell University is an Ivy League university located in Ithaca, New York, United States. It is a private land-grant university, receiving annual funding from the State of New York for certain educational missions...
in Ithaca, New York
Ithaca, New York
The city of Ithaca, is a city in upstate New York and the county seat of Tompkins County, as well as the largest community in the Ithaca-Tompkins County metropolitan area...
. After leaving Germany in early 1940, Debye became a professor at Cornell, chaired the chemistry department for 10 years, and became a member of Alpha Chi Sigma
Alpha Chi Sigma
Alpha Chi Sigma is a professional fraternity specializing in the field of chemistry. It has both collegiate and professional chapters throughout the United States consisting of both men and women and numbering more than 63,400 members...
. In 1946 he became an American citizen. Unlike the Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
an phase of his life, where he moved from city to city every few years, in the United States Debye remained at Cornell for the remainder of his career. He retired in 1952, but continued research until his death.
Much of Debye's work at Cornell concerned the use of light-scattering techniques (derived from his X-ray scattering work of years earlier) to determine the size and molecular weight of polymer
Polymer
A polymer is a large molecule composed of repeating structural units. These subunits are typically connected by covalent chemical bonds...
molecule
Molecule
A molecule is an electrically neutral group of at least two atoms held together by covalent chemical bonds. Molecules are distinguished from ions by their electrical charge...
s. This started as a result of his research during World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
on synthetic rubber
Synthetic rubber
Synthetic rubber is is any type of artificial elastomer, invariably a polymer. An elastomer is a material with the mechanical property that it can undergo much more elastic deformation under stress than most materials and still return to its previous size without permanent deformation...
, but was extended to protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s and other macromolecule
Macromolecule
A macromolecule is a very large molecule commonly created by some form of polymerization. In biochemistry, the term is applied to the four conventional biopolymers , as well as non-polymeric molecules with large molecular mass such as macrocycles...
s.
In April 1966, Debye suffered a heart attack
Myocardial infarction
Myocardial infarction or acute myocardial infarction , commonly known as a heart attack, results from the interruption of blood supply to a part of the heart, causing heart cells to die...
, and in November of that year a second one proved fatal. He is buried in the Pleasant Grove Cemetery (Ithaca, New York, USA).
2006 controversy
In January 2006, a book (in Dutch) appeared in The Netherlands, written by Sybe Rispens, entitled Einstein in the Netherlands. One chapter of this book treats the relationship between Einstein and Debye. Rispens discovered documents that, as he believed, were new and proved that, during his directorship of the Kaiser Wilhelm Society, Debye was actively involved in cleansing German science institutions of Jewish and other "non-Aryan elements". Rispens records that on December 9, 1938, Debye wrote in his capacity as chairman of the Deutsche Physikalische Gesellschaft (DPG) to all the members of the DPG:In light of the current situation, membership by German Jews as stipulated by the Nuremberg laws, of the Deutsche Physikalische Gesellschaft cannot be continued. According to the wishes of the board, I ask of all members to whom these definitions apply to report to me their resignation. Heil Hitler!
Many biographies published before Rispens' work, state that Debye moved to the US because he refused to accept German citizenship forced on to him by the Nazis. He planned his departure from Germany during a visit with his mother in Maastricht
Maastricht
Maastricht is situated on both sides of the Meuse river in the south-eastern part of the Netherlands, on the Belgian border and near the German border...
in late 1939, boarded a ship in Genoa in January 1940 and arrived in New York in early February 1940. He immediately sought a permanent position in the US and accepted such an offer from Cornell in June 1940. That month, he crossed the US border into Canada and returned within days on an immigration visa. He was able to get his wife out of Germany and to the US by December 1940. Although his son already was in the US before he departed, Peter Debye's 19 year old daughter and his sister-in-law did not leave. They lived in his official residence in Berlin and were supported by Debye's official Berlin wages (he carefully maintained an official leave of absence for this purpose).
Further, Rispens alleges that Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
in the first half of 1940 actively tried to prevent Debye from being appointed in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
at Cornell. Einstein allegedly wrote to his American colleagues: "I know from a reliable source that Peter Debye is still in close contact with the German (Nazi) leaders" and, according to Rispens, called upon his colleagues to do "what they consider their duty as American citizens". To support this, Rispens refers to a well-known letter from Debye to Einstein and Einstein's response to it. Van Ginkel investigated 1940 FBI reports on this matter and traced the "reliable source" to a single letter directed to Einstein and written by someone whose name is lost. This person was not known personally to Einstein and, according to Einstein, probably did not know Debye personally either. Moreover, this accusatory letter did not reach Einstein directly but was intercepted by British censors who showed it to Einstein. Einstein sent the British agent with the letter to Cornell, and the Cornell authorities told Debye about the affair. Thereupon Debye wrote his well-known 1940 letter to Einstein to which Einstein answered. The latter two letters can be found in the published Einstein correspondence.
Rispens alleges that Debye sent a telegram to Berlin on 23 June 1941 informing his previous employers that he was able and willing to resume his responsibilities at the Kaiser Wilhelm Institut, presumably in order to maintain his leave of absence and keep the Berlin house and wages available for his daughter. A copy of this telegram has not been recovered thus far. In summer 1941, Debye filed his intent to become a US citizen and was quickly recruited in the US to participate in the Allied War research.
It has been well documented in many biographies, and also in Rispens' book, that Debye and Dutch colleagues helped his Jewish colleague Lise Meitner
Lise Meitner
Lise Meitner FRS was an Austrian-born, later Swedish, physicist who worked on radioactivity and nuclear physics. Meitner was part of the team that discovered nuclear fission, an achievement for which her colleague Otto Hahn was awarded the Nobel Prize...
in 1938-1939 (at great risk to himself and his family) cross the Dutch-German border to escape Nazi persecution and eventually obtain a position in Sweden.
Predating Rispens' work, and in contrast to it, an article by Rechenberg appeared 18 years earlier concerning Debye's letter. The article describes Debye's missive in more detail and presents a very favorable picture of Debye in his efforts to resist the Nazi activists. Moreover, this article points out that Max von Laue
Max von Laue
Max Theodor Felix von Laue was a German physicist who won the Nobel Prize in Physics in 1914 for his discovery of the diffraction of X-rays by crystals...
, well known for his anti-Nazi views, gave his approval to the letter from the DPG chairman.
International response
Debye's son, Peter P. Debye, interviewed in 2006 at age 89 recollects that his father was completely apolitical and that in the privacy of their home politics were never discussed. According to his son, Debye just wanted to do his job at the Kaiser Wilhelm Institute and as long as the Nazis did not bother him was able to do so. He recalls that his mother urged him (the son) to stay in the US in the event of war. Debye's son had come to the US on a planned 2-month vacation during the summer of 1939 and never returned to Germany because war did, indeed, break out.Rispens' accusations were considered harmful enough by the Board of Directors of the University of Utrecht that they announced on February 16, 2006 a name change for the Debye Institute. This was done after consultation with NIOD.
In an opinion article published on the Debye Institute website, Dr. Gijs van Ginkel, until April 2007 Senior Managing Director of the VM Debye Instituut in Utrecht deplored this decision. In his article he cites scholars who point out that the DPG was able to retain their threatened staff as long as could be expected under increasing pressure from the Nazis. He also puts forward the important argument that when Debye in 1950 received the Max Planck medal
Max Planck medal
The Max Planck medal is an award for extraordinary achievements in theoretical physics. It is awarded annually by the Deutsche Physikalische Gesellschaft , the world's largest organization of physicists.-List of recipients:...
of the DPG, nobody objected, not even the known opponent of the national socialists Max von Laue
Max von Laue
Max Theodor Felix von Laue was a German physicist who won the Nobel Prize in Physics in 1914 for his discovery of the diffraction of X-rays by crystals...
, who would have been in a position to object. Also Einstein, with his enormous prestige, was still alive, as were other Jewish scientists such as Lise Meitner
Lise Meitner
Lise Meitner FRS was an Austrian-born, later Swedish, physicist who worked on radioactivity and nuclear physics. Meitner was part of the team that discovered nuclear fission, an achievement for which her colleague Otto Hahn was awarded the Nobel Prize...
and James Franck
James Franck
James Franck was a German Jewish physicist and Nobel laureate.-Biography:Franck was born to Jacob Franck and Rebecca Nachum Drucker. Franck completed his Ph.D...
who both knew Debye intimately. None of them protested against Debye's receiving the highest German scientific distinction. In fact, Albert Einstein, after many years of not participating in the voting for the Max Planck Medal nominees, joined the process again to vote for Debye.
Maastricht University also announced that it was reconsidering its position on the Peter Debye Prijs voor natuurwetenschappelijk onderzoek (Peter Debye Prize for scientific research)
In a reply on the DPG website, Dieter Hoffmann and Mark Walker also conclude that Debye was not a Nazi activist. They remark that Max von Laue also was required and obliged (as a civil servant) to sign letters with Heil Hitler. They also state that the DPG was one of the last scientific societies to purge the Jewish members and only very reluctantly. They quote the response of the Reich University Teachers League (a National Socialist organization) to the Debye letter:
Obviously the German Physical Society is still very backward and still clings tightly to their dear Jews. It is in fact remarkable that only "because of circumstances beyond our control" the membership of Jews can no longer be maintained
In May 2006, the Dutch Nobel Prize winner Martinus Veltman who had written the foreword to the Rispen book, renounced the book's description of Peter Debye, withdrew his foreword, and asked the Board of Directors of Utrecht University to rescind their decision to rename the Debye Institute.
Various historical investigations, both in The Netherlands and in the US, have been carried out subsequent to the actions of the University of Maastricht. The earliest of these investigations, carried out by the Cornell University's department of Chemistry and Chemical Biology is now complete. The report of the Cornell investigation, released on 31 May 2006, states that:
Based on the information to-date, we have not found evidence supporting the accusations that Debye was a Nazi sympathizer or collaborator or that he held anti-Semitic views. It is important that this be stated clearly since these are the most serious allegations.
It goes on to declare:
Thus, based on the information, evidence and historical record known to date, we believe that any action that dissociates Debye's name from the Department of Chemistry and Chemical Biology at Cornell is unwarranted.
In June 2006, it was reported that the scientific director of the (formerly) Debye Institute had been reprimanded by the Board of Directors of the University of Utrecht for a new publication on Debye's war years on the grounds that it was too personally biased with respect to the Institute's naming dispute. According to the board, the book should have been published not as a Debye Institute publication, but as a personal one. The book was banned by the University of Utrecht and both Directors of the (former) Debye Institute were forbidden to have any further contact with the press. A dozen professors of the Physics Faculty, amongst whom Cees Andriesse
Cornelis Dirk Andriesse
Cornelis Dirk Andriesse is a Dutch physicist, writer and historian of science. Internationally he is best known for his scientific biography of Christiaan Huygens.- Education :...
, openly protested against the interventions of the Board and the censorship of their protest by the university.
In May 2007, the universities of Utrecht and Maastricht announced that a new committee headed by Jan Terlouw
Jan Terlouw
Jan Cornelis Terlouw is a Dutch scientist, politician, and author.- Background :Jan Terlouw was born in Kamperveen, Overijssel. He was the eldest son in his family, he has two brothers and two sisters and grew up in the Veluwe...
would advise them regarding the name change. Also, in the beginning of 2007 an official report was announced, to be published by the NIOD and authorized by the Dutch Education Ministry (then scheduled for fall 2007).
2007 NIOD report
The report describes Rispens' presentation of Debye, as an opportunist who had no objection to the Nazis, as a caricature.it can be stated that Debye was rightly called an opportunist after his arrival in the United States. We have seen that he showed himself to be loyal to the dominant political system, first in the Third Reich and then in the United States, while at the same time keeping the back door open: in the Third Reich by retaining his Dutch nationality, in the United States by attempting to secretly maintain some contacts with Nazi Germany via the Foreign Office.
It concludes that Debye's actions in 1933-45 were based on the nineteenth-century positivist view of science which saw research in physics as generating blessings for humankind. The report states that, by his contemporaries, Debye was considered an opportunist by some and as a man of highest character by others. The report asserts that Debye was not coerced by the Nazis into writing the infamous DPG Heil Hitler letter and that he also did not follow the lead of other societies in doing so but, rather, other societies followed his lead. The NIOD report also concludes that Debye felt obliged to send the letter and that it was, for him, simply a confirmation of an existing situation. The report argues that Debye, in the Third Reich, developed a survival method of ambiguity which allowed him to pursue his scientific career despite the political turmoil. Crucial to this survival method was the need to keep ready an escape hatch, for example in his secret dealings with the Nazis in 1941, if needed.
Yet, the report also states that the picture of Debye should not be oversimplified as Debyes actions were also motivated by his loyalty to his daughter, who had remained in Berlin. In general, Debye developed a survival method of ambiguity, that "could pull the wool over people's eyes"
2008 Terlouw report
In January 2008 the Terlouw Commission advised the Boards of Utrecht and Maastricht Universities to continue to use Peter Debye’s name for the chemistry and physics institute in Utrecht, and to continue awarding the science prize in Maastricht. The Commission concluded that Debye was not a party member, was not an anti-semite, did not further Nazi propaganda, did not cooperate with the Nazi war machine, was not a collaboratorCollaborationism
Collaborationism is cooperation with enemy forces against one's country. Legally, it may be considered as a form of treason. Collaborationism may be associated with criminal deeds in the service of the occupying power, which may include complicity with the occupying power in murder, persecutions,...
, and yet also was not a resistance hero. He was a rather pragmatic, flexible, and brilliant scientist, idealistic with respect to the pursuit of science, but only superficially oriented in politics. With respect to sending out the DPG letter, the Commission concluded that Debye found the situation inescapable. The Commission pointed out that the Royal Dutch Academy of Sciences also took away Albert Einstein's honorary membership, emphasizing the circumstances in which these decisions had be taken. The Commission stated that now, seventy years later, no judgment can be made concerning the decision of Debye to sign this letter in the exceptionally difficult circumstances in which he then found himself. Nevertheless, the Commission describes the DPG letter as an extraordinarily unpleasant fact, forming a dark page in his life history. Finally, the Commission concluded that based on the NIOD report since no bad faith on Debye’s part has been demonstrated, his good faith must be assumed and recommended that the University of Utrecht retain the name of the Debye Institute of NanoMaterials Science and that the University of Maastricht continue to associate itself with the Peter Debye Prize. Utrecht University accepted the recommendation, Maastricht University did not. But in February 2008, the Hustinx Foundation (Maastricht), originator and sponsor of the Peter Debye Prize, announced that it will continue to have the prize awarded. The City of Maastricht, Debye's birthplace, declared that it sees no reason to change the names of Debye Street and Debye Square.
Debye the spy
In a 2010 publication Jurrie Reiding asserts that Debye may have been an MI6 spy Reiding discovered that Debye was befriended with the well-documented spy Paul RosbaudPaul Rosbaud
Paul Rosbaud , was a metallurgist and scientific adviser for Springer Verlag in Germany before and during World War II....
. They first met around 1930 when they were both working as editors for two scientific journals. They collaborated in the escape of Lise Meitner in 1938. According to Reiding Debye was well connected in German scientific and industrial circles and could have provided MI6 with valuable information. For example as board member of the German Academy for Aviation Research he was acquainted with Hermann Goering. Reiding also offers an explanation for Debye's hasty departure on 16 January 1940 for the United States: the date coincided with the planned (but later delayed) German invasion of the Netherlands a day later, information possibly passed on to him by Rosbaud.
Awards and honors
- 1930 - Rumford MedalRumford MedalThe Rumford Medal is awarded by the Royal Society every alternating year for "an outstandingly important recent discovery in the field of thermal or optical properties of matter made by a scientist working in Europe". First awarded in 1800, it was created after a 1796 donation of $5000 by the...
for work relating to specific heats and X-ray spectroscopy - 1937 - Franklin MedalFranklin MedalThe Franklin Medal was a science and engineering award presented by the Franklin Institute, of Philadelphia, PA, USA.-Laureates:*1915 - Thomas Alva Edison *1915 - Heike Kamerlingh Onnes *1916 - John J...
from The Franklin Institute. - 1936 - Nobel Prize in ChemistryNobel Prize in ChemistryThe Nobel Prize in Chemistry is awarded annually by the Royal Swedish Academy of Sciences to scientists in the various fields of chemistry. It is one of the five Nobel Prizes established by the will of Alfred Nobel in 1895, awarded for outstanding contributions in chemistry, physics, literature,...
(entry at nobelprize.org) "for his contributions to the study of molecular structure," primarily referring to his work on dipole moments and X-ray diffraction - 1963 - Priestley MedalPriestley MedalThe Priestley Medal is the highest honor conferred by the American Chemical Society and is awarded for distinguished service in the field of chemistry. Established in 1922, the award is named after Joseph Priestley, the discoverer of oxygen who immigrated to the United States of America in 1794...
- 1965 - National Medal of ScienceNational Medal of ScienceThe 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 and social sciences, biology, chemistry, engineering, mathematics and...
Legacy
- Debye shieldingElectric field screeningScreening is the damping of electric fields caused by the presence of mobile charge carriers. It is an important part of the behavior of charge-carrying fluids, such as ionized gases and conduction electrons in semiconductors and metals....
- In plasmasPlasma (physics)In physics and chemistry, plasma is a state of matter similar to gas in which a certain portion of the particles are ionized. Heating a gas may ionize its molecules or atoms , thus turning it into a plasma, which contains charged particles: positive ions and negative electrons or ions...
, semiconductorSemiconductorA semiconductor is a material with electrical conductivity due to electron flow intermediate in magnitude between that of a conductor and an insulator. This means a conductivity roughly in the range of 103 to 10−8 siemens per centimeter...
s and electrolyteElectrolyteIn chemistry, an electrolyte is any substance containing free ions that make the substance electrically conductive. The most typical electrolyte is an ionic solution, but molten electrolytes and solid electrolytes are also possible....
s, the process by which a fixed electric charge is shielded by redistributing mobile charged particles around it. - Debye lengthDebye lengthIn plasma physics, the Debye length , named after the Dutch physicist and physical chemist Peter Debye, is the scale over which mobile charge carriers screen out electric fields in plasmas and other conductors. In other words, the Debye length is the distance over which significant charge...
- The typical distance in a plasma required for full Debye shielding. - Debye modelDebye modelIn thermodynamics and solid state physics, the Debye model is a method developed by Peter Debye in 1912 for estimating the phonon contribution to the specific heat in a solid. It treats the vibrations of the atomic lattice as phonons in a box, in contrast to the Einstein model, which treats the...
- A model of the heat capacityHeat capacityHeat capacity , or thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance's temperature by a given amount...
of solids as a function of temperature - DebyeDebyeThe debye is a CGS unit of electric dipole momentElectric dipole moment is defined as charge times displacement: Historically the debye was defined as the dipole moment resulting from two charges of opposite sign but an equal magnitude of 10-10 statcoulomb10-10 statcoulomb is approximately 0.2083...
- a unit of electric dipole moment - Debye relaxation - The dielectric relaxation response of an ideal, noninteracting population of dipoles to an alternating external electric field.
- Debye sheathDebye sheathThe Debye sheath is a layer in a plasma which has a greater density of positive ions, and hence an overall excess positive charge, that balances an opposite negative charge on the surface of a material with which it is in contact...
- The non-neutral layer, several Debye lengths thick, where a plasma contacts a material surface. - Debye-Hückel equationDebye-Hückel equationThe Debye–Hückel equation and Debye–Hückel limiting law, were derived by Peter Debye and Erich Hückel, who developed a theory with which to calculate activity coefficients of electrolyte solutions. Activities, rather than concentrations, are needed in many chemical calculations because solutions...
- A method of calculating activity coefficientActivity coefficientAn activity coefficient is a factor used in thermodynamics to account for deviations from ideal behaviour in a mixture of chemical substances. In an ideal mixture, the interactions between each pair of chemical species are the same and, as a result, properties of the mixtures can be expressed...
s - Debye function - A function used in the calculation of heat capacityHeat capacityHeat capacity , or thermal capacity, is the measurable physical quantity that characterizes the amount of heat required to change a substance's temperature by a given amount...
. - Debye-Scherrer method - A technique used in x-ray powder diffraction.
- Debye-Waller factorDebye-Waller factorThe Debye–Waller factor , named after Peter Debye and Ivar Waller, is used in condensed matter physics to describe the attenuation of x-ray scattering or coherent neutron scattering caused by thermal motion. It has also been called the B factor or the temperature factor...
- A measure of disorder in a crystal lattice. - 30852 Debye30852 Debye30852 Debye is a main-belt asteroid discovered on October 2, 1991 by F. Borngen and L. D. Schmadel at Tautenburg.- External links :*...
- A minor planetMeanings of asteroid names (30001-31000)Minor planets not yet given a name have not been included in this list....
(originally named 1991 TR6). - Lorenz-Mie-Debye theoryMie theoryThe Mie solution to Maxwell's equations describes the scattering of electromagnetic radiation by a sphere...
Theory of light scattering by a spherical particle. - Debye (crater)Debye (crater)Debye is a lunar crater that is located in the northern hemisphere on the Moon's far side, as seen from the Earth. It lies to the south of the crater Chappell, and to the southwest of the walled plain Rowland....
- A lunar crater located on the far side and in the northern hemisphere of the moon.
External links
- Debye Biography - Institute of Chemistry, Hebrew University
- Debye Biography - Nobel Prize
- Debye Biography - NNDB
- Debye Biography - IUCR
- Museum Boerhaave Negen Nederlandse Nobelprijswinnaars
- Deutsche Physikalische Gesellschaft (DPG)
- Kennislink
- Dr. Rispens research
- Debye Institute
- Oral History interview transcript with Peter Debye 3 & 4 May 1962, American Institute of Physics, Niels Bohr Library and Archives