East Prussia was a province of the Kingdom of Prussia from 1773 to 1829 and again from 1878. Its capital city was Königsberg. East Prussia was the main part of the region of Prussia along the southeastern Baltic Coast; the bulk of the ancestral lands of the Baltic Old Prussians were enclosed within East Prussia. During the 13th century, the native Prussians were conquered by the crusading Teutonic Knights. After the conquest the indigenous Balts were converted to Christianity; because of Germanization and colonisation over the following centuries, Germans became the dominant ethnic group, while Masurians and Lithuanians formed minorities. From the 13th century, East Prussia was part of the monastic state of the Teutonic Knights. After the Second Peace of Thorn in 1466 it became a fief of the Kingdom of Poland. In 1525, with the Prussian Homage, the province became the Duchy of Prussia; the Old Prussian language had become extinct by early 18th century. Because the duchy was outside of the core Holy Roman Empire, the prince-electors of Brandenburg were able to proclaim themselves King beginning in 1701.
After the annexation of most of western Royal Prussia in the First Partition of the Polish-Lithuanian Commonwealth in 1772, eastern Prussia was connected by land with the rest of the Prussian state and was reorganized as a province the following year. Between 1829 and 1878, the Province of East Prussia was joined with West Prussia to form the Province of Prussia; the Kingdom of Prussia became the leading state of the German Empire after its creation in 1871. However, the Treaty of Versailles following World War I granted West Prussia to Poland and made East Prussia an exclave of Weimar Germany, while the Memel Territory was detached and annexed by Lithuania in 1923. Following Nazi Germany's defeat in World War II in 1945, war-torn East Prussia was divided at Joseph Stalin's insistence between the Soviet Union and the People's Republic of Poland; the capital city Königsberg was renamed Kaliningrad in 1946. The German population of the province was evacuated during the war or expelled shortly afterwards in the expulsion of Germans after World War II.
An estimated 300,000 died either in war time bombing raids, in the battles to defend the province, or through mistreatment by the Red Army. At the instigation of Duke Konrad I of Masovia, the Teutonic Knights took possession of Prussia in the 13th century and created a monastic state to administer the conquered Old Prussians. Local Old-Prussian and Polish toponyms were Germanised; the Knights' expansionist policies, including occupation of Polish Pomerania with Gdańsk/Danzig and western Lithuania, brought them into conflict with the Kingdom of Poland and embroiled them in several wars, culminating in the Polish-Lithuanian-Teutonic War, whereby the united armies of Poland and Lithuania, defeated the Teutonic Order at the Battle of Grunwald in 1410. Its defeat was formalised in the Second Treaty of Thorn in 1466 ending the Thirteen Years' War, leaving the former Polish region Pomerania/Pomerelia under Polish control. Together with Warmia it formed the province of Royal Prussia. Eastern Prussia as a fief of Poland.
1466 and 1525 arrangements by kings of Poland were not verified by the Holy Roman Empire as well as the previous gains of the Teutonic Knights were not verified. The Teutonic Order lost eastern Prussia when Grand Master Albert of Brandenburg-Ansbach converted to Lutheranism and secularized the Prussian branch of the Teutonic Order in 1525. Albert established himself as the first duke of the Duchy of Prussia and a vassal of the Polish crown by the Prussian Homage. Walter von Cronberg, the next Grand Master, was enfeoffed with the title to Prussia after the Diet of Augsburg in 1530, but the Order never regained possession of the territory. In 1569 the Hohenzollern prince-electors of the Margraviate of Brandenburg became co-regents with Albert's son, the feeble-minded Albert Frederick; the Administrator of Prussia, the grandmaster of the Teutonic Order Maximilian III, son of emperor Maximilian II died in 1618. When Maximilian died, Albert's line died out, the Duchy of Prussia passed to the Electors of Brandenburg, forming Brandenburg-Prussia.
Taking advantage of the Swedish invasion of Poland in 1655, instead of fulfilling his vassal's duties towards the Polish Kingdom, by joining forces with the Swedes and subsequent treaties of Wehlau and Oliva, Elector and Duke Frederick William succeeded in revoking the king of Poland's sovereignty over the Duchy of Prussia in 1660. The absolutist elector subdued the noble estates of Prussia. Although Brandenburg was a part of the Holy Roman Empire, the Prussian lands were not within the Holy Roman Empire and were with the administration by the Teutonic Order grandmasters under jurisdiction of the Emperor. In return for supporting Emperor Leopold I in the War of the Spanish Succession, Elector Frederick III was allowed to crown himself "King in Prussia" in 1701; the new kingdom ruled by the Hohenzollern dynasty became known as the Kingdom of Prussia. The designation "Kingdom of Prussia" was applied to the
Humboldt University of Berlin
Humboldt University of Berlin is a university in the central borough of Mitte in Berlin, Germany. It was established by Frederick William III on the initiative of Wilhelm von Humboldt, Johann Gottlieb Fichte and Friedrich Ernst Daniel Schleiermacher as the University of Berlin in 1809, opened in 1810, making it the oldest of Berlin's four universities. From 1810 until its closure in 1945, it was named Friedrich Wilhelm University. During the Cold War the university found itself in East Berlin and was de facto split in two when the Free University of Berlin opened in West Berlin; the university received its current name in honour of Alexander and Wilhelm von Humboldt in 1949. The university is divided into nine faculties, including its medical school shared with the Free University of Berlin, has a student enrollment of around 32,000 students, offers degree programmes in some 189 disciplines from undergraduate to postdoctorate level, its main campus is located on the Unter den Linden boulevard in central Berlin.
The university is known worldwide for pioneering the Humboldtian model of higher education, which has influenced other European and Western universities, the university has been called "the mother of all modern universities."As of 2017, the university has been associated with 55 Nobel Prize winners, is considered one of the best universities in Europe as well as one of the most prestigious universities in the world for arts and humanities. It was regarded as the world's preeminent university for the natural sciences during the 19th and early 20th century, is linked to major breakthroughs in physics and other sciences by its professors such as Albert Einstein. Former faculty and notable alumni include eminent philosophers, artists, politicians, mathematicians and Heads of State; the University of Berlin was established on 16 August 1809, on the initiative of the liberal Prussian educational politician Wilhelm von Humboldt by King Friedrich Wilhelm III, during the period of the Prussian Reform Movement.
The university was located in a palace constructed from 1748-1766 for the late Prince Henry, the younger brother of Frederick the Great. After his widow and her ninety-member staff moved out, the first unofficial lectures were given in the building in the winter of 1809. Humboldt faced great resistance to his ideas, he submitted his resignation to the King in April 1810, was not present when the school opened that fall. The first students were admitted on 6 October 1810, the first semester started on 10 October 1810, with 256 students and 52 lecturers in faculties of law, medicine and philosophy under rector Theodor Schmalz; the university celebrates 15 October 1810 as the date of its opening. From 1828 to 1945, the school was named the Friedrich Wilhelm University, in honor of its founder. Ludwig Feuerbach one of the students, made a comment on the university in 1826: "There is no question here of drinking and plesant communal outings. Compared to this temple of work, the other universities appear like public houses."The university has been home to many of Germany's greatest thinkers of the past two centuries, among them the subjective idealist philosopher Johann Gottlieb Fichte, the theologian Friedrich Schleiermacher, the absolute idealist philosopher G.
W. F. Hegel, the Romantic legal theorist Friedrich Carl von Savigny, the pessimist philosopher Arthur Schopenhauer, the objective idealist philosopher Friedrich Schelling, cultural critic Walter Benjamin, famous physicists Albert Einstein and Max Planck; the founders of Marxist theory Karl Marx and Friedrich Engels attended the university, as did poet Heinrich Heine, novelist Alfred Döblin, founder of structuralism Ferdinand de Saussure, German unifier Otto von Bismarck, Communist Party of Germany founder Karl Liebknecht, African American Pan Africanist W. E. B. Du Bois and European unifier Robert Schuman, as well as the influential surgeon Johann Friedrich Dieffenbach in the early half of the 1800s; the structure of German research-intensive universities served as a model for institutions like Johns Hopkins University. Further, it has been claimed that "the'Humboldtian' university became a model for the rest of Europe with its central principle being the union of teaching and research in the work of the individual scholar or scientist."
In addition to the strong anchoring of traditional subjects, such as science, philosophy, history and medicine, the university developed to encompass numerous new scientific disciplines. Alexander von Humboldt, brother of the founder William, promoted the new learning. With the construction of modern research facilities in the second half of the 19th Century teaching of the natural sciences began. Famous researchers, such as the chemist August Wilhelm Hofmann, the physicist Hermann von Helmholtz, the mathematicians Ernst Eduard Kummer, Leopold Kronecker, Karl Weierstrass, the physicians Johannes Peter Müller, Albrecht von Graefe, Rudolf Virchow and Robert Koch, contributed to Berlin University's scientific fame. During this period of enlargement, the university expanded to incorporate other separate colleges in Berlin. An example would be the Pépinière and the Collegium Medico-chirurgicum. In 1717, King Friedrich I had built a quarantine house for Plague at the city gates, which in 1727 was rechristened by the "soldier king" Friedrich
Berlin is the capital and largest city of Germany by both area and population. Its 3,748,148 inhabitants make it the second most populous city proper of the European Union after London; the city is one of Germany's 16 federal states. It is surrounded by the state of Brandenburg, contiguous with its capital, Potsdam; the two cities are at the center of the Berlin-Brandenburg capital region, which is, with about six million inhabitants and an area of more than 30,000 km², Germany's third-largest metropolitan region after the Rhine-Ruhr and Rhine-Main regions. Berlin straddles the banks of the River Spree, which flows into the River Havel in the western borough of Spandau. Among the city's main topographical features are the many lakes in the western and southeastern boroughs formed by the Spree and Dahme rivers. Due to its location in the European Plain, Berlin is influenced by a temperate seasonal climate. About one-third of the city's area is composed of forests, gardens, rivers and lakes; the city lies in the Central German dialect area, the Berlin dialect being a variant of the Lusatian-New Marchian dialects.
First documented in the 13th century and situated at the crossing of two important historic trade routes, Berlin became the capital of the Margraviate of Brandenburg, the Kingdom of Prussia, the German Empire, the Weimar Republic, the Third Reich. Berlin in the 1920s was the third largest municipality in the world. After World War II and its subsequent occupation by the victorious countries, the city was divided. East Berlin was declared capital of East Germany. Following German reunification in 1990, Berlin once again became the capital of all of Germany. Berlin is a world city of culture, politics and science, its economy is based on high-tech firms and the service sector, encompassing a diverse range of creative industries, research facilities, media corporations and convention venues. Berlin serves as a continental hub for air and rail traffic and has a complex public transportation network; the metropolis is a popular tourist destination. Significant industries include IT, biomedical engineering, clean tech, biotechnology and electronics.
Berlin is home to world-renowned universities, orchestras and entertainment venues, is host to many sporting events. Its Zoological Garden is one of the most popular worldwide. With the world's oldest large-scale movie studio complex, Berlin is an popular location for international film productions; the city is well known for its festivals, diverse architecture, contemporary arts and a high quality of living. Since the 2000s Berlin has seen the emergence of a cosmopolitan entrepreneurial scene. Berlin lies in northeastern Germany, east of the River Saale, that once constituted, together with the River Elbe, the eastern border of the Frankish Realm. While the Frankish Realm was inhabited by Germanic tribes like the Franks and the Saxons, the regions east of the border rivers were inhabited by Slavic tribes; this is why most of the villages in northeastern Germany bear Slavic-derived names. Typical Germanised place name suffixes of Slavic origin are -ow, -itz, -vitz, -witz, -itzsch and -in, prefixes are Windisch and Wendisch.
The name Berlin has its roots in the language of West Slavic inhabitants of the area of today's Berlin, may be related to the Old Polabian stem berl-/birl-. Since the Ber- at the beginning sounds like the German word Bär, a bear appears in the coat of arms of the city, it is therefore a canting arm. Of Berlin's twelve boroughs, five bear a Slavic-derived name: Pankow, Steglitz-Zehlendorf, Marzahn-Hellersdorf, Treptow-Köpenick and Spandau. Of its ninety-six neighborhoods, twenty-two bear a Slavic-derived name: Altglienicke, Alt-Treptow, Buch, Gatow, Kladow, Köpenick, Lankwitz, Lübars, Marzahn, Prenzlauer Berg, Schmöckwitz, Stadtrandsiedlung Malchow, Steglitz and Zehlendorf; the neighborhood of Moabit bears a French-derived name, Französisch Buchholz is named after the Huguenots. The earliest evidence of settlements in the area of today's Berlin are a wooden beam dated from 1192, remnants of a house foundation dated to 1174, found in excavations in Berlin Mitte; the first written records of towns in the area of present-day Berlin date from the late 12th century.
Spandau is first mentioned in 1197 and Köpenick in 1209, although these areas did not join Berlin until 1920. The central part of Berlin can be traced back to two towns. Cölln on the Fischerinsel is first mentioned in a 1237 document, Berlin, across the Spree in what is now called the Nikolaiviertel, is referenced in a document from 1244. 1237 is considered the founding date of the city. The two towns over time formed close economic and social ties, profited from the staple right on the two important trade routes Via Imperii and from Bruges to Novgorod. In 1307, they formed an alliance with a common external policy, their internal administrations still being separated. In 1415, Frederick I became the elector of the Margraviate of Brandenburg, which he ruled until 1440. During the 15th century, his successors established Berlin-Cölln as capital of the margraviate, subsequent members of the Hohenzol
Kaliningrad is a city in the administrative centre of Kaliningrad Oblast, a Russian exclave between Poland and Lithuania on the Baltic Sea. In the Middle Ages it was the site of the Old Prussian settlement Twangste. In 1255, during the Northern Crusades, a new fortress named Königsberg was built by the Teutonic Knights. Königsberg became the capital of the Duchy of Prussia, a fiefdom of Poland from 1525 to 1657, East Prussia, Germany, it was damaged during World War II, its population fled or were removed by force. Königsberg became a Russian city, renamed Kaliningrad in 1946. At the 2010 Census, Kaliningrad's population was 431,902. Königsberg was preceded by a Sambian fort called meaning Oak Forest. During the conquest of the Sambians by the Teutonic Knights in 1255, Twangste was destroyed and replaced with a new fortress named Königsberg; the declining Old Prussian culture became extinct around the 17th century, after the surviving Old Prussians were integrated through assimilation and Germanization.
The settlement at the site of the present day Kaliningrad was founded as a military fortress in 1255 after the Prussian Crusade by the Teutonic Knights against Baltic Prussians, a non-Germanic ethnic group related to the ancestors of the present-day Lithuanians and Latvians. The new town was named in honor of the Bohemian King Ottokar II; the crusade was followed by other regions of Western Europe. Within the following seven centuries, the area became predominantly German, with Polish and Lithuanian minorities. During World War II the city of Königsberg was damaged by a British bombing attack in 1944 and the massive Soviet siege in spring 1945. At the end of World War II in 1945, the city became part of the Soviet Union. At the Potsdam Conference of July/August 1945 the Allies agreed on the Soviet annexation pending the final determination of territorial questions at the peace settlement: The Conference has agreed in principle to the proposal of the Soviet Government concerning the ultimate transfer to the Soviet Union of the City of Koenigsberg and the area adjacent to it as described above subject to expert examination of the actual frontier.
The U. S. President Harry Truman and the British Prime Minister Clement Attlee declared that they would support the proposal of the Conference at the forthcoming peace settlement. On 4 July 1946 the Soviet authorities renamed Königsberg to Kaliningrad following the death on 3 June 1946 of the Chairman of the Presidium of the Supreme Soviet of the USSR, Mikhail Kalinin, one of the original Bolsheviks; the survivors of the German population were forcibly expelled in 1946–1949, the city was repopulated with Soviet citizens. The city's language of administration was changed from German to Russian; the city was rebuilt, as the westernmost territory of the USSR, the Kaliningrad Oblast became a strategically important area during the Cold War. The Soviet Baltic Fleet was headquartered in the city in the 1950s; because of its strategic importance, Kaliningrad Oblast was closed to foreign visitors. In 1957 an agreement was signed and came into force which delimited the border between Poland and the Soviet Union.
The town of Baltiysk, just outside Kaliningrad, is the only Russian Baltic Sea port said to be "ice-free" all year round, the region hence plays an important role in maintenance of the Baltic Fleet. Due to the collapse of the Soviet Union in 1991, the Kaliningrad Oblast became an exclave, geographically separated from the rest of Russia; this isolation from the rest of Russia became more pronounced politically when Poland and Lithuania became members of NATO and subsequently the European Union in 2004. All military and civilian land links between the region and the rest of Russia have to pass through members of NATO and the EU. Special travel arrangements for the territory's inhabitants have been made through the Facilitated Transit Document and Facilitated Rail Transit Document. While in the 1990s many Soviet-era city names commemorating Communist leaders were changed, Kaliningrad remains named as it was. Since the early 1990s, the Kaliningrad oblast has been a Free Economic Zone. In 2005 the city marked 750 years of existence as Königsberg/Kaliningrad.
In July 2007, Russian First Deputy Prime Minister Sergei Ivanov declared that if US-controlled missile defense systems were deployed in Poland nuclear weapons might be deployed in Kaliningrad. On November 5, 2008, Russian leader Dmitry Medvedev said that installing missiles in Kaliningrad was a certainty; these plans were suspended, however, in January 2009. But during late 2011, a long range Voronezh radar was commissioned to monitor missile launches within about 6,000 kilometres, it is situated in the settlement of Pionersky in Kaliningrad Oblast. Though the current German government has stated it has no claim over Kaliningrad, the former Königsberg, the possibility of such a return to German rule at some future time continues to come up in discussion, creating what is known as "The Kaliningrad question". In 2018, Kaliningrad hosted some games of the World Cup. Kaliningrad is the administrative centre of the oblast. Within the framework of administrative divisions, it is incorporated as the city of oblast significance of Kaliningrad—an administrative unit with the status equal to that of the districts.
As a municipal division, the city of oblast significance of Kaliningrad is incorporated as Kaliningrad Urban Okrug. As of 2014, the city was divided into three administrative districts: Two administrative districts were abolished in Ju
Spectroscopy is the study of the interaction between matter and electromagnetic radiation. Spectroscopy originated through the study of visible light dispersed according to its wavelength, by a prism; the concept was expanded to include any interaction with radiative energy as a function of its wavelength or frequency, predominantly in the electromagnetic spectrum, though matter waves and acoustic waves can be considered forms of radiative energy. Spectroscopic data are represented by an emission spectrum, a plot of the response of interest as a function of wavelength or frequency. Spectroscopy in the electromagnetic spectrum, is a fundamental exploratory tool in the fields of physics and astronomy, allowing the composition, physical structure and electronic structure of matter to be investigated at atomic scale, molecular scale, macro scale, over astronomical distances. Important applications arise from biomedical spectroscopy in the areas of tissue analysis and medical imaging. Spectroscopy and spectrography are terms used to refer to the measurement of radiation intensity as a function of wavelength and are used to describe experimental spectroscopic methods.
Spectral measurement devices are referred to as spectrometers, spectrophotometers, spectrographs or spectral analyzers. Daily observations of color can be related to spectroscopy. Neon lighting is a direct application of atomic spectroscopy. Neon and other noble gases have characteristic emission frequencies. Neon lamps use collision of electrons with the gas to excite these emissions. Inks and paints include chemical compounds selected for their spectral characteristics in order to generate specific colors and hues. A encountered molecular spectrum is that of nitrogen dioxide. Gaseous nitrogen dioxide has a characteristic red absorption feature, this gives air polluted with nitrogen dioxide a reddish-brown color. Rayleigh scattering is a spectroscopic scattering phenomenon. Spectroscopic studies were central to the development of quantum mechanics and included Max Planck's explanation of blackbody radiation, Albert Einstein's explanation of the photoelectric effect and Niels Bohr's explanation of atomic structure and spectra.
Spectroscopy is used in physical and analytical chemistry because atoms and molecules have unique spectra. As a result, these spectra can be used to detect and quantify information about the atoms and molecules. Spectroscopy is used in astronomy and remote sensing on Earth. Most research telescopes have spectrographs; the measured spectra are used to determine the chemical composition and physical properties of astronomical objects. One of the central concepts in spectroscopy is its corresponding resonant frequency. Resonances were first characterized in mechanical systems such as pendulums. Mechanical systems that vibrate or oscillate will experience large amplitude oscillations when they are driven at their resonant frequency. A plot of amplitude vs. excitation frequency will have a peak centered at the resonance frequency. This plot is one type of spectrum, with the peak referred to as a spectral line, most spectral lines have a similar appearance. In quantum mechanical systems, the analogous resonance is a coupling of two quantum mechanical stationary states of one system, such as an atom, via an oscillatory source of energy such as a photon.
The coupling of the two states is strongest when the energy of the source matches the energy difference between the two states. The energy of a photon is related to its frequency by E = h ν where h is Planck's constant, so a spectrum of the system response vs. photon frequency will peak at the resonant frequency or energy. Particles such as electrons and neutrons have a comparable relationship, the de Broglie relations, between their kinetic energy and their wavelength and frequency and therefore can excite resonant interactions. Spectra of atoms and molecules consist of a series of spectral lines, each one representing a resonance between two different quantum states; the explanation of these series, the spectral patterns associated with them, were one of the experimental enigmas that drove the development and acceptance of quantum mechanics. The hydrogen spectral series in particular was first explained by the Rutherford-Bohr quantum model of the hydrogen atom. In some cases spectral lines are well separated and distinguishable, but spectral lines can overlap and appear to be a single transition if the density of energy states is high enough.
Named series of lines include the principal, sharp and fundamental series. Spectroscopy is a sufficiently broad field that many sub-disciplines exist, each with numerous implementations of specific spectroscopic techniques; the various implementations and techniques can be classified in several ways. The types of spectroscopy are distinguished by the type of radiative energy involved in the interaction. In many applications, the spectrum is determined by measuring changes in the intensity or frequency of this energy; the types of radiative energy studied include: Electromagnetic radiation was the first source of energy used for spectroscopic studies. Techniques that employ electromagnetic radiation are classified by the wavelength region of the spectrum and include microwave, terahe
Franz Ernst Neumann
Franz Ernst Neumann was a German mineralogist and mathematician. Neumann was born in Margraviate of Brandenburg, near Berlin. In 1815 he interrupted his studies at Berlin to serve as a volunteer in the Hundred Days against Napoleon, was wounded in the Battle of Ligny. Subsequently, he entered Berlin University as a student of theology, but soon turned to scientific subjects, his earlier papers were concerned with crystallography, the reputation they gained him led to his appointment as Privatdozent at the University of Königsberg, where in 1828 he became extraordinary, in 1829 ordinary, professor of mineralogy and physics. His 1831 study on the specific heats of compounds included what is now known as Neumann's Law: the molecular heat of a compound is equal to the sum of the atomic heats of its constituents. Devoting himself next to optics, he produced memoirs which earned him a high place among early searchers of a true dynamical theory of light. In 1832, by the aid of a particular hypothesis as to the constitution of the ether, he reached by a rigorous dynamical calculation results agreeing with those obtained by Augustin Louis Cauchy, succeeded in deducing laws of double refraction resembling those of Augustin-Jean Fresnel.
In studying double refraction, with his deduction of the elastic constants Neumann employed the assumption that the symmetry of the elastic behavior of a crystal was equal to that of its form. In other words, he assumed that the magnitudes of the components of a physical property in symmetric positions are equivalent; this assumption reduced the number of independent constants and simplified the elastic equations. However, four decades passed before Neumann elaborated his application of symmetry in a course on elasticity in 1873; this principle was formalized by his student Woldemar Voigt in 1885: ‘‘the symmetry of the physical phenomenon is at least as high as the crystallographic symmetry,’’ which became a fundamental postulate of crystal physics known as ‘‘Neumann’s principle’’. In 1900, Voigt attributed this principle to Neumann's 1832 paper though, at most, all, present in that work was an implicit assumption that the symmetry of the phenomenon was equal to that of the crystal. Bernhard Minnigerode, another student of Neumann, first expressed this relation in written form in 1887 in the journal Neues Jahrb.
Mineral Geol. Paleontol.. Neumann attacked the problem of giving mathematical expression to the conditions holding for a surface separating two crystalline media, worked out from theory the laws of double refraction in strained crystalline bodies, he made important contributions to the mathematical theory of electrodynamics, in papers published in 1845 and 1847 established mathematically the laws of the induction of electric currents. His last publication, which appeared in 1878, was on spherical harmonics. With the mathematician Carl Gustav Jacobi, he founded in 1834 the mathematisch-physikalisches Seminar which operated in two sections, one for mathematics and one for mathematical physics. Not every student took both sections. In his section on mathematical physics Neumann taught mathematical methods and as well as the techniques of an exact experimental physics grounded in the type of precision measurement perfected by his astronomer colleague Friedrich Wilhelm Bessel; the objective of his seminar exercises was to perfect one's ability to practice an exact experimental physics through the control of both constant and random experimental errors.
Only a few students produced original research in the seminar. This seminar was the model for many others of the same type established after 1834, including Kirchhoff's own at Heidelberg University. Neumann retired from his professorship in 1876, died at Königsberg in 1895 at the age of 96, his children were talented. His son, Carl Gottfried Neumann, became in 1858 Privatdozent, in 1863 extraordinary professor of mathematics at Halle, he was appointed to the ordinary chair of mathematics successively at Basel, Tübingen and Leipzig. Beiträge zur Krystallonomie Beiträge zur Theorie der Kugelfunctionen Franz Neumanns Gesammelte werke This article incorporates text from a publication now in the public domain: Chisholm, Hugh, ed.. "Neumann, Franz Ernst". Encyclopædia Britannica. Cambridge University Press. Olesko, Kathryn M. Physics as a Calling: Discipline and Practice in the Koenigsberg Seminar for Physics. Ithaca, NY & London: Cornell University Press, 1991. O'Connor, John J.. Franz Ernst Neumann at the Mathematics Genealogy Project Primary sources on Neumann
Robert Wilhelm Eberhard Bunsen was a German chemist. He investigated emission spectra of heated elements, discovered caesium and rubidium with the physicist Gustav Kirchhoff. Bunsen developed several gas-analytical methods, was a pioneer in photochemistry, did early work in the field of organoarsenic chemistry. With his laboratory assistant, Peter Desaga, he developed the Bunsen burner, an improvement on the laboratory burners in use; the Bunsen–Kirchhoff Award for spectroscopy is named after Bunsen and Kirchhoff. Robert Bunsen was born at Göttingen in what is now the state of Lower Saxony in Germany. Bunsen was the youngest of four sons of the University of Göttingen's chief librarian and professor of modern philology, Christian Bunsen. After attending school in Holzminden, Bunsen matriculated at Göttingen in 1828 and studied chemistry with Friedrich Stromeyer as well as mineralogy with Johann Friedrich Ludwig Hausmann and mathematics with Carl Friedrich Gauss. After obtaining a PhD in 1831, Bunsen spent 1832 and 1833 traveling in Germany and Austria.
In 1833 Bunsen became a lecturer at Göttingen and began experimental studies of the solubility of metal salts of arsenous acid. His discovery of the use of iron oxide hydrate as a precipitating agent is still today the most effective antidote against arsenic poisoning; this interdisciplinary research was carried on and published in conjunction with the physician Arnold Adolph Berthold. In 1836, Bunsen succeeded Friedrich Wöhler at the Polytechnic School of Kassel. Bunsen taught there for three years, accepted an associate professorship at the University of Marburg, where he continued his studies on cacodyl derivatives, he was promoted to full professorship in 1841. While at University of Marburg, Bunsen participated in the 1846 expedition for the investigation of Iceland's volcanoes. Bunsen's work brought him quick and wide acclaim because cacodyl, toxic and undergoes spontaneous combustion in dry air, is so difficult to work with. Bunsen died from arsenic poisoning, an explosion with cacodyl cost him sight in his right eye.
In 1841, Bunsen created the Bunsen cell battery, using a carbon electrode instead of the expensive platinum electrode used in William Robert Grove's electrochemical cell. Early in 1851 he accepted a professorship at the University of Breslau, where he taught for three semesters. In late 1852 Bunsen became the successor of Leopold Gmelin at the University of Heidelberg. There he used electrolysis to produce pure metals, such as chromium, aluminum, sodium, barium and lithium. A long collaboration with Henry Enfield Roscoe began in 1852, in which they studied the photochemical formation of hydrogen chloride from hydrogen and chlorine. From this work, the reciprocity law of Bunsen and Roscoe originated, he discontinued his work with Roscoe in 1859 and joined Gustav Kirchhoff to study emission spectra of heated elements, a research area called spectrum analysis. For this work and his laboratory assistant, Peter Desaga, had perfected a special gas burner by 1855, influenced by earlier models; the newer design of Bunsen and Desaga, which provided a hot and clean flame, is now called the "Bunsen burner", a common laboratory equipment.
There had been earlier studies of the characteristic colors of heated elements, but nothing systematic. In the summer of 1859, Kirchhoff suggested to Bunsen that he should try to form prismatic spectra of these colors. By October of that year the two scientists had invented an appropriate instrument, a prototype spectroscope. Using it, they were able to identify the characteristic spectra of sodium and potassium. After numerous laborious purifications, Bunsen proved that pure samples gave unique spectra. In the course of this work, Bunsen detected unknown new blue spectral emission lines in samples of mineral water from Dürkheim, he guessed. After careful distillation of forty tons of this water, in the spring of 1860 he was able to isolate 17 grams of a new element, he named the element "caesium", after the Latin word for deep blue. The following year he discovered rubidium, by a similar process. In 1860, Bunsen was elected a foreign member of the Royal Swedish Academy of Sciences. In 1877, Robert Bunsen together with Gustav Robert Kirchhoff were the first recipients of the prestigious Davy Medal "for their researches & discoveries in spectrum analysis".
Bunsen was one of the most universally admired scientists of his generation. He was a master teacher, devoted to his students, they were devoted to him. At a time of vigorous and caustic scientific debates, Bunsen always conducted himself as a perfect gentleman, maintaining his distance from theoretical disputes, he much preferred to work in his laboratory, continuing to enrich his science with useful discoveries. As a matter of principle he never took out a patent, he never married. Despite his lack of pretension, Bunsen was a vivid "chemical character," had a well-developed sense of humor, is the subject of many amusing anecdotes; when Bunsen retired at the age of 78, he shifted his work to geology and mineralogy, interests which he had pursued throughout his career. He died in Heidelberg at the age of 88. Bunsen reaction Bunsenite Pneumatolysis List of German inventors and discoverers Media related to Robert Bunsen at Wikimedia Commons Robert Wilhelm Bunse