Solid
Solid is one of the four fundamental states of matter. In solids particles are packed, it is characterized by structural resistance to changes of shape or volume. Unlike liquid, a solid object does not flow to take on the shape of its container, nor does it expand to fill the entire volume available to it like a gas does; the atoms in a solid are bound to each other, either in a regular geometric lattice or irregularly. Solids cannot be compressed with little pressure whereas gases can be compressed with little pressure because in gases molecules are loosely packed; the branch of physics that deals with solids is called solid-state physics, is the main branch of condensed matter physics. Materials science is concerned with the physical and chemical properties of solids. Solid-state chemistry is concerned with the synthesis of novel materials, as well as the science of identification and chemical composition; the atoms, molecules or ions that make up solids may be arranged in an orderly repeating pattern, or irregularly.
Materials whose constituents are arranged in a regular pattern are known as crystals. In some cases, the regular ordering can continue unbroken over a large scale, for example diamonds, where each diamond is a single crystal. Solid objects that are large enough to see and handle are composed of a single crystal, but instead are made of a large number of single crystals, known as crystallites, whose size can vary from a few nanometers to several meters; such materials are called polycrystalline. All common metals, many ceramics, are polycrystalline. In other materials, there is no long-range order in the position of the atoms; these solids are known as amorphous solids. Whether a solid is crystalline or amorphous depends on the material involved, the conditions in which it was formed. Solids that are formed by slow cooling will tend to be crystalline, while solids that are frozen are more to be amorphous; the specific crystal structure adopted by a crystalline solid depends on the material involved and on how it was formed.
While many common objects, such as an ice cube or a coin, are chemically identical throughout, many other common materials comprise a number of different substances packed together. For example, a typical rock is an aggregate of several different minerals and mineraloids, with no specific chemical composition. Wood is a natural organic material consisting of cellulose fibers embedded in a matrix of organic lignin. In materials science, composites of more than one constituent material can be designed to have desired properties; the forces between the atoms in a solid can take a variety of forms. For example, a crystal of sodium chloride is made up of ionic sodium and chlorine, which are held together by ionic bonds. In diamond or silicon, the atoms share form covalent bonds. In metals, electrons are shared in metallic bonding; some solids most organic compounds, are held together with van der Waals forces resulting from the polarization of the electronic charge cloud on each molecule. The dissimilarities between the types of solid result from the differences between their bonding.
Metals are strong and good conductors of both electricity and heat. The bulk of the elements in the periodic table, those to the left of a diagonal line drawn from boron to polonium, are metals. Mixtures of two or more elements in which the major component is a metal are known as alloys. People have been using metals for a variety of purposes since prehistoric times; the strength and reliability of metals has led to their widespread use in construction of buildings and other structures, as well as in most vehicles, many appliances and tools, road signs and railroad tracks. Iron and aluminium are the two most used structural metals, they are the most abundant metals in the Earth's crust. Iron is most used in the form of an alloy, which contains up to 2.1% carbon, making it much harder than pure iron. Because metals are good conductors of electricity, they are valuable in electrical appliances and for carrying an electric current over long distances with little energy loss or dissipation. Thus, electrical power grids rely on metal cables to distribute electricity.
Home electrical systems, for example, are wired with copper for its good conducting properties and easy machinability. The high thermal conductivity of most metals makes them useful for stovetop cooking utensils; the study of metallic elements and their alloys makes up a significant portion of the fields of solid-state chemistry, materials science and engineering. Metallic solids are held together by a high density of shared, delocalized electrons, known as "metallic bonding". In a metal, atoms lose their outermost electrons, forming positive ions; the free electrons are spread over the entire solid, held together by electrostatic interactions between the ions and the electron cloud. The large number of free electrons gives metals their high values of electrical and thermal conductivity; the free electrons prevent transmission of visible light, making metals opaque and lustrous. More advanced models of metal properties consider the effect of the positive ions cores on the delocalised electrons.
As most metals have crystalline structure, those ions are arranged into a periodic lattice. Mathematically, the potential of the ion cores can be treated by various models, the simplest being the nearly free electron model. Minerals are
Werner Heisenberg
Werner Karl Heisenberg was a German theoretical physicist and one of the key pioneers of quantum mechanics. He published his work in 1925 in a breakthrough paper. In the subsequent series of papers with Max Born and Pascual Jordan, during the same year, this matrix formulation of quantum mechanics was elaborated, he is known for the Heisenberg uncertainty principle, which he published in 1927. Heisenberg was awarded the 1932 Nobel Prize in Physics "for the creation of quantum mechanics", he made important contributions to the theories of the hydrodynamics of turbulent flows, the atomic nucleus, cosmic rays, subatomic particles, he was instrumental in planning the first West German nuclear reactor at Karlsruhe, together with a research reactor in Munich, in 1957. He was a principal scientist in the Nazi German nuclear weapon project during World War II, he travelled to occupied Copenhagen where he discussed the German project with Niels Bohr. Following World War II, he was appointed director of the Kaiser Wilhelm Institute for Physics, which soon thereafter was renamed the Max Planck Institute for Physics.
He was director of the institute until it was moved to Munich in 1958, when it was expanded and renamed the Max Planck Institute for Physics and Astrophysics. Heisenberg was president of the German Research Council, chairman of the Commission for Atomic Physics, chairman of the Nuclear Physics Working Group, president of the Alexander von Humboldt Foundation. Werner Karl Heisenberg was born in Würzburg, Germany, to Kaspar Ernst August Heisenberg, a secondary school teacher of classical languages who became Germany's only ordentlicher Professor of medieval and modern Greek studies in the university system, his wife, Annie Wecklein, he studied physics and mathematics from 1920 to 1923 at the Ludwig Maximilian University of Munich and the Georg-August University of Göttingen. At Munich, he studied under Wilhelm Wien. At Göttingen, he studied physics with James Franck and mathematics with David Hilbert, he received his doctorate at Munich under Sommerfeld. At Göttingen, under Born, he completed his habilitation in 1924 with a Habilitationsschrift on the anomalous Zeeman effect.
Because Sommerfeld had a sincere interest in his students and knew of Heisenberg's interest in Niels Bohr's theories on atomic physics, Sommerfeld took Heisenberg to Göttingen to attend the Bohr Festival of June 1922. At the event, Bohr was a guest lecturer and gave a series of comprehensive lectures on quantum atomic physics. There, Heisenberg met Bohr for the first time, it had a significant and continuing effect on him. Heisenberg's doctoral thesis, the topic of, suggested by Sommerfeld, was on turbulence; the problem of stability was investigated by the use of the Orr–Sommerfeld equation, a fourth order linear differential equation for small disturbances from laminar flow. He returned to this topic after World War II. In his youth he was a member and Scoutleader of the Neupfadfinder, a German Scout association and part of the German Youth Movement. In August 1923 Robert Honsell and Heisenberg organized a trip to Finland with a Scout group of this association from Munich. Heisenberg arrived at Munich in 1919 as a member of the Freikorps to fight the Bavarian Soviet Republic established a year earlier.
Five decades he recalled those days as youthful fun, like "playing cops and robbers and so on. From 1924 to 1927, Heisenberg was a Privatdozent at Göttingen, meaning he was qualified to teach and examine independently, without having a chair. From 17 September 1924 to 1 May 1925, under an International Education Board Rockefeller Foundation fellowship, Heisenberg went to do research with Niels Bohr, director of the Institute of Theoretical Physics at the University of Copenhagen, his seminal paper, "Über quantentheoretische Umdeutung kinematischer und mechanischer Beziehungen", was published in September 1925. He returned to Göttingen and, with Max Born and Pascual Jordan over a period of about six months, developed the matrix mechanics formulation of quantum mechanics. On 1 May 1926, Heisenberg began his appointment as a university lecturer and assistant to Bohr in Copenhagen, it was in Copenhagen, in 1927, that Heisenberg developed his uncertainty principle, while working on the mathematical foundations of quantum mechanics.
On 23 February, Heisenberg wrote a letter to fellow physicist Wolfgang Pauli, in which he first described his new principle. In his paper on the principle, Heisenberg used the word "Ungenauigkeit", not uncertainty, to describe it. In 1927, Heisenberg was appointed ordentlicher Professor of theoretical physics and head of the department of physics at the University of Leipzig. In his first paper published from Leipzig, Heisenberg used the Pauli exclusion principle to solve the mystery of ferromagnetism. During Heisenberg's tenure at Leipzig, the high quality of the doctoral students and post-graduate and research associates who studied and worked with him is clear from the acclaim many earned. At various times they included Erich Bagge, Felix Bloch, Ugo Fano, Siegfried Flügge, William Vermillion Houston, Friedrich Hund, Robert S. Mulliken, Rudolf Peierls, George Placzek, Isidor Isaac Rabi, Fritz Sauter, John C. Slater, Edward Teller, John Hasbrouck van Vleck, Victor Frederick Weisskopf, Carl Friedrich von Weizsäcker, Gregor Wentzel, Clarence Zener.
In early
Law for the Restoration of the Professional Civil Service
The Law for the Restoration of the Professional Civil Service known as Civil Service Law, Civil Service Restoration Act, Law to Re-establish the Civil Service, was a law passed by the National Socialist regime of Germany on 7 April 1933, two months after Adolf Hitler had attained power. Article 1 of the Law claimed that in order to re-establish a "national" and "professional" civil service, members of certain groups of tenured civil servants were to be dismissed. Civil servants who were not of Aryan descent were to retire. Non-Aryans were defined as someone descended from non-Aryans those descended from Jewish parents, or grandparents. Members of the Communist Party, or any related or associated organisation were to be dismissed; this meant that Jews, other non Aryans, political opponents could not serve as teachers, judges, or other government positions. Shortly afterward, a similar law was passed concerning lawyers, tax consultants and notaries; as the law was first drafted by the Interior Minister Wilhelm Frick, all those of "non-Aryan descent" were to be fired at the Reich, Länder and municipal levels of government.
However, the President of Germany, Paul von Hindenburg objected to the bill until it had been amended to exclude three classes of civil servants from the ban: World War I veterans who had served at the front those, in the civil service continuously since 1 August 1914 those who lost a father or son in combat in the Great WarHitler agreed to these amendments and the bill was signed into law on 7 April 1933. In practice, the amendments excluded most Jewish civil servants and not until after Hindenburg's death in 1934, were they disallowed. Nonetheless, passage of the Berufsbeamtengesetz was a crucial turning point in the history of German Jewry for it marked the first time since the last German Jews had been emancipated in 1871 that an anti-Semitic law had been passed in Germany. In one notable example of the law's effect, Albert Einstein resigned his position at the Prussian Academy of Sciences and emigrated to the United States before he could be expelled. Following the decree, Albert Gorter redefined the term'Aryan' in the Aryan paragraph as: The Aryans are one of the three branches of the Caucasian.
Non-Aryans are therefore: 1. The members of two other races, namely the Mongolian and the Negroid races; the members of the two other branches of the Caucasian race, namely the Semites and Hamites. The Finns and the Hungarians belong to the Mongoloid race. Thus... the non-Jewish members of the European Volk are Aryans... However, this definition was unacceptable. Achim Gercke redefined this unacceptable definition as the one used by the Expert Advisor for Population and Racial Policy which stated "An Aryan is one, tribally related to German blood. An Aryan is the descendant of a Volk domiciled in Europe in a closed tribal settlement since recorded history." This new definition allowed the Civil Service Law to differentiate between'Aryans' and'non-Aryans'. However, the quantity of how much Jewish blood an individual was allowed to have until it was considered to damage the German Volk remained untenable. Political opponents of national socialism should either be forced into retirement or let go from their jobs.
Moreover, civil servants should be let go if they had started their jobs after 1918 and were now unable to demonstrate that they had acquired all the training necessary for their careers. These people were called "membership book officials" in the language of National Socialist propaganda. According to § 3 of the "First Ordinace for the accomplishment of the Law for the Restoration of the Professional Civil Service, officials without "Aryan" heritage were those who had just one Jewish grandparent, they could be prematurely forced into retirement. According to § 3, however, "non-Aryan" officials should be left in their positions if they had occupied those positions since a date before August 1914; those Jewish civil servants who had a son or father, killed in the First World War were spared from being sacked. This loophole applied to "Frontkämpfer". All persons in the civil service would have to be able to produce the Ariernachweis in order to prove that they had no ancestors of the Jewish faith.
The loophole was closed by the Nuremberg Laws. Jewish civil servants still holding their posts were given notice by 31 December 1935 at the latest. According to § 6 of the law, civil servants could be forced into retirement without cause "for the simplification of administration"; the vacant positions created by this action were not to be refilled. In rapid succession numerous regulations were dispensed with, as well as many employees and laborers in civil service as well as in the Reichsbank. Pensions were not allowed for all groups of people fo
German Empire
The German Empire known as Imperial Germany, was the German nation state that existed from the unification of Germany in 1871 until the abdication of Kaiser Wilhelm II in 1918. It was founded in 1871 when the south German states, except for Austria, joined the North German Confederation. On 1 January 1871, the new constitution came into force that changed the name of the federal state and introduced the title of emperor for Wilhelm I, King of Prussia from the House of Hohenzollern. Berlin remained its capital, Otto von Bismarck remained Chancellor, the head of government; as these events occurred, the Prussian-led North German Confederation and its southern German allies were still engaged in the Franco-Prussian War. The German Empire consisted of 26 states, most of them ruled by royal families, they included four kingdoms, six grand duchies, five duchies, seven principalities, three free Hanseatic cities, one imperial territory. Although Prussia was one of several kingdoms in the realm, it contained about two thirds of Germany's population and territory.
Prussian dominance was established constitutionally. After 1850, the states of Germany had become industrialized, with particular strengths in coal, iron and railways. In 1871, Germany had a population of 41 million people. A rural collection of states in 1815, the now united Germany became predominantly urban. During its 47 years of existence, the German Empire was an industrial and scientific giant, gaining more Nobel Prizes in science than any other country. By 1900, Germany was the largest economy in Europe, surpassing the United Kingdom, as well as the second-largest in the world, behind only the United States. From 1867 to 1878/9, Otto von Bismarck's tenure as the first and to this day longest reigning Chancellor was marked by relative liberalism, but it became more conservative afterwards. Broad reforms and the Kulturkampf marked his period in the office. Late in Bismarck's chancellorship and in spite of his personal opposition, Germany became involved in colonialism. Claiming much of the leftover territory, yet unclaimed in the Scramble for Africa, it managed to build the third-largest colonial empire after the British and the French ones.
As a colonial state, it sometimes clashed with other European powers the British Empire. Germany became a great power, boasting a developing rail network, the world's strongest army, a fast-growing industrial base. In less than a decade, its navy became second only to Britain's Royal Navy. After the removal of Otto von Bismarck by Wilhelm II in 1890, the Empire embarked on Weltpolitik – a bellicose new course that contributed to the outbreak of World War I. In addition, Bismarck's successors were incapable of maintaining their predecessor's complex and overlapping alliances which had kept Germany from being diplomatically isolated; this period was marked by various factors influencing the Emperor's decisions, which were perceived as contradictory or unpredictable by the public. In 1879, the German Empire consolidated the Dual Alliance with Austria-Hungary, followed by the Triple Alliance with Italy in 1882, it retained strong diplomatic ties to the Ottoman Empire. When the great crisis of 1914 arrived, Italy left the alliance and the Ottoman Empire formally allied with Germany.
In the First World War, German plans to capture Paris in the autumn of 1914 failed. The war on the Western Front became a stalemate; the Allied naval blockade caused severe shortages of food. However, Imperial Germany had success on the Eastern Front; the German declaration of unrestricted submarine warfare in early 1917, contributed to bringing the United States into the war. The high command under Paul von Hindenburg and Erich Ludendorff controlled the country, but in October after the failed offensive in spring 1918, the German armies were in retreat, allies Austria-Hungary and the Ottoman Empire had collapsed, Bulgaria had surrendered; the Empire collapsed in the November 1918 Revolution with the abdications of its monarchs. This left a postwar federal republic and a devastated and unsatisfied populace, which led to the rise of Adolf Hitler and Nazism; the German Confederation had been created by an act of the Congress of Vienna on 8 June 1815 as a result of the Napoleonic Wars, after being alluded to in Article 6 of the 1814 Treaty of Paris.
German nationalism shifted from its liberal and democratic character in 1848, called Pan-Germanism, to Prussian prime minister Otto von Bismarck's pragmatic Realpolitik. Bismarck sought to extend Hohenzollern hegemony throughout the German states, he envisioned a Prussian-dominated Germany. Three wars led to military successes and helped to persuade German people to do this: the Second Schleswig War against Denmark in 1864, the Austro-Prussian War in 1866, the Franco-Prussian War against France in 1870–71; the German Confederation ended as a result of the Austro-Prussian War of 1866 between the constituent Confederation entities of the Austrian Empire and its allies on one side and the Kingdom of Prussia and its allies on the other. The war resulted in the partial replacement of the Confederation in 1867 by a North German Confederation, comprising the 22 states north of the Main; the patriotic fervour generated by the Franco-Prussian War overwhelmed the remaining opposition to a unified Germany in the four stat
Walter Heitler
Walter Heinrich Heitler was a German physicist who made contributions to quantum electrodynamics and quantum field theory. He brought chemistry under quantum mechanics through his theory of valence bonding. In 1922, Heitler began his study of physics at the Karlsruhe Technische Hochschule, in 1923 at the Humboldt University of Berlin, in 1924 at the Ludwig Maximilians University of Munich, where he studied under both Arnold Sommerfeld and Karl Herzfeld; the latter was his thesis advisor when he obtained his doctorate in 1926. From 1926 to 1927, he was a Rockefeller Foundation Fellow for postgraduate research with Niels Bohr at the Institute for Theoretical Physics at the University of Copenhagen and with Erwin Schrödinger at the University of Zurich, he became an assistant to Max Born at the Institute for Theoretical Physics at the Georg-August University of Göttingen. Heitler completed his Habilitation, under Born, in 1929, remained as a Privatdozent until 1933. In that year, he was let go by the university.
At the time Heitler received his doctorate, three Institutes for Theoretical Physics formed a consortium which worked on the key problems of the day, such as atomic and molecular structure, exchanged both scientific information and personnel in their scientific quests. These institutes were located at the LMU, under Arnold Sommerfeld, the University of Göttingen, under Max Born, the University of Copenhagen, under Niels Bohr. Furthermore, Werner Heisenberg and Born had just published their trilogy of papers which launched the matrix mechanics formulation of quantum mechanics. In early 1926, Erwin Schrödinger, at the University of Zurich, began to publish his quintet of papers which launched the wave mechanics formulation of quantum mechanics and showed that the wave mechanics and matrix mechanics formulations were equivalent; these papers put the personnel at the leading theoretical physics institutes onto applying these new tools to understanding atomic and molecular structure. It was in this environment that Heitler went on his Rockefeller Foundations Fellowship, leaving LMU and within a period of two years going to do research and study with the leading figures of the day in theoretical physics, Bohr's personnel in Copenhagen, Schrödinger in Zurich, Born in Göttingen.
In Zurich, with Fritz London, Heitler applied the new quantum mechanics to deal with the saturable, nondynamic forces of attraction and repulsion, i.e. exchange forces, of the hydrogen molecule. Their valence bond treatment of this problem, was a landmark in that it brought chemistry under quantum mechanics. Furthermore, their work influenced chemistry through Linus Pauling, who had just received his doctorate and on a Guggenheim Fellowship visited Heitler and London in Zurich, as Pauling spent much of his career studying the nature of the chemical bond; the application of quantum mechanics to chemistry would be a prominent theme in Heitler's career. While Heitler was at Göttingen, Adolf Hitler came to power in 1933. With the rising prominence of anti-Semitism under Hitler, Born took it upon himself to take the younger Jewish generation under his wing. In doing so, Born arranged for Heitler to get a position that year as a Research Fellow at the University of Bristol, with Nevill Francis Mott.
At Bristol, Heitler was a Research Fellow of the Academic Assistance Council, in the H. H. Wills Physics Laboratory. At Bristol, among other things, he worked on quantum field theory and quantum electrodynamics on his own, as well as in collaboration with other scientific refugees from Hitler, such as Hans Bethe and Herbert Fröhlich, who left Germany in 1933. With Bethe, he published a paper on pair production of gamma rays in the Coulomb field of an atomic nucleus, in which they developed the Bethe-Heitler formula for Bremsstrahlung. Heitler contributed to the understanding of cosmic rays, as well as predicted the existence of the electrically neutral pi meson. In 1936, Heitler published his major work on quantum electrodynamics, The Quantum Theory of Radiation, which marked the direction for future developments in quantum theory; the book appeared in many editions and printings being translated in Russian. After the fall of France in 1940, Heitler was interned on the Isle of Man for several months.
Heitler remained at Bristol eight years, until 1941, when he became a professor at the Dublin Institute for Advanced Studies, arranged there by Erwin Schrödinger, Director of the School for Theoretical Physics. At Dublin, Heitler's work with H. W. Peng on radiation damping theory and the meson scattering process resulted in the Heitler-Peng integral equation. During the 1942–1943 academic year, Heitler gave a course on elementary wave mechanics, during which W. S. E. Hickson took notes and prepared a finished copy; these notes were the basis for Heitler's book Elementary Wave Mechanics: Introductory Course of Lectures, first published in 1943. A new edition was published as Elementary Wave Mechanics in 1945; this version was revised and republished many times, as well as being translated into French and Italian and published in 1949 and in German in 1961. A further revised version appeared as Elementary Wave Mechanics With Applications to Quantum Chemistry in 1956, as well as in German in 1961.
Schrödinger resigned as Director of the School for Theoretical Physics in 1946, but stayed at Dublin, whereupon Heitler became Director. Heitler stayed at Dublin until 1949, when he accepted a position as Ordinarius Professor for Theoretical Physics and Director of the Institute for Theoretical Physics at the University
Lorentz Medal
Lorentz Medal is a distinction 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; the medal is given for important contributions to theoretical physics, though in the past there have been some experimentalists among its recipients. Many of the award winners received a Nobel Prize
Erwin Schrödinger
Erwin Rudolf Josef Alexander Schrödinger, sometimes written as Erwin Schrodinger or Erwin Schroedinger, was a Nobel Prize-winning Austrian physicist who developed a number of fundamental results in the field of quantum theory: the Schrödinger equation provides a way to calculate the wave function of a system and how it changes dynamically in time. In addition, he was the author of many works in various fields of physics: statistical mechanics and thermodynamics, physics of dielectrics, colour theory, general relativity, cosmology, he made several attempts to construct a unified field theory. In his book What Is Life? Schrödinger addressed the problems of genetics, looking at the phenomenon of life from the point of view of physics, he paid great attention to the philosophical aspects of science and oriental philosophical concepts and religion. He wrote on philosophy and theoretical biology, he is known for his "Schrödinger's cat" thought-experiment. On 12 August 1887, Schrödinger was born in Erdberg, Austria, to Rudolf Schrödinger and Georgine Emilia Brenda Schrödinger.
He was their only child. His mother was of half half English descent. Although he was raised in a religious household as a Lutheran, he called himself an atheist. However, he had strong interests in Eastern religions and pantheism, he used religious symbolism in his works, he believed his scientific work was an approach to the godhead, albeit in a metaphorical sense. He was able to learn English outside school, as his maternal grandmother was British. Between 1906 and 1910 Schrödinger studied in Vienna under Franz S. Friedrich Hasenöhrl, he conducted experimental work with Karl Wilhelm Friedrich "Fritz" Kohlrausch. In 1911, Schrödinger became an assistant to Exner. At an early age, Schrödinger was influenced by Arthur Schopenhauer; as a result of his extensive reading of Schopenhauer's works, he became interested throughout his life in colour theory and philosophy. In his lecture "Mind and Matter", he said that "The world extended in space and time is but our representation." This is a repetition of the first words of Schopenhauer's main work.
In 1914 Erwin Schrödinger achieved Habilitation. Between 1914 and 1918 he participated in war work as a commissioned officer in the Austrian fortress artillery. In 1920 he became the assistant to Max Wien, in Jena, in September 1920 he attained the position of ao. Prof. equivalent to Reader or associate professor, in Stuttgart. In 1921, he became o. Prof. in Breslau. In 1921, he moved to the University of Zürich. In 1927, he succeeded Max Planck at the Friedrich Wilhelm University in Berlin. In 1934 Schrödinger decided to leave Germany, he became a Fellow of Magdalen College at the University of Oxford. Soon after he arrived, he received the Nobel Prize together with Paul Dirac, his position at Oxford did not work out well. In 1934, Schrödinger lectured at Princeton University. Again, his wish to set up house with his wife and his mistress may have created a problem, he had the prospect of a position at the University of Edinburgh but visa delays occurred, in the end he took up a position at the University of Graz in Austria in 1936.
He had accepted the offer of chair position at Department of Physics, Allahabad University in India. In the midst of these tenure issues in 1935, after extensive correspondence with Albert Einstein, he proposed what is now called the Schrödinger's cat thought experiment. In 1938, after the Anschluss, Schrödinger had problems because of his flight from Germany in 1933 and his known opposition to Nazism, he issued a statement recanting this opposition. However, this did not appease the new dispensation and the University of Graz dismissed him from his job for political unreliability, he suffered harassment and received instructions not to leave the country, but he and his wife fled to Italy. From there, he went to visiting positions in Ghent University. In the same year he received a personal invitation from Ireland's Taoiseach, Éamon de Valera – a mathematician himself – to reside in Ireland and agree to help establish an Institute for Advanced Studies in Dublin, he moved to Clontarf, became the Director of the School for Theoretical Physics in 1940 and remained there for 17 years.
He retained his Austrian citizenship. He wrote around 50 further publications on various topics, including his explorations of unified field theory. In 1944, he wrote What Is Life?, which contains a discussion of negentropy and the concept of a complex molecule with the genetic code for living organisms. According to James D. Watson's memoir, DNA, the Secret of Life, Schrödinger's book gave Watson the inspiration to research the gene, which led to the discovery of the DNA double helix structure in 1953. Francis Crick, in his autobiographical book What Mad Pursuit, described how he was influenced by Schrödinger's speculations about how genetic information might be stored in molecules. Schrödinger stayed in Dublin until retiring in 1955, he had a lifelong inter
