Search

Abstract: Rudolph Clausius (1822–1888) played an important role in advancing the theory of heat during the 19th century. His contributions concerned the development of the two fundamental principles of heat as well as the microscopic approach of kinetic theory where he introduced the new concept of the mean free path. He always strictly separated these two fields. When Clausius took up his studies the idea that heat belonged to the so-called imponderables which were weightless and invisible had not yet disappeared. Carnot had still used that idea for his well-known cycle. Clausius was able to make the Carnot-cycle compatible with the concept of heat as a kind of motion. His research opened the way for thermodynamics later chiefly advocated by Planck as well as for modern statistical physics mainly connected with the names of Maxwell and Boltzmann. Scientific education and research of Clausius will be discussed here in the context of the development of the theory of heat. As he published most of his important papers on this subject already during the first two decades of his career we confine on this period. Clausius began his studies in Berlin in 1840, habilitated there in 1850 and was appointed at the newly founded Polytechnical School in Zürich in 1855. It will be shown that Clausius remained an outsider in the physics community of his time as he himself did not perform any research experiments. [Copyright &y& Elsevier]

Modernity stands on the shoulders of ancestors. Their historical foundations support and inspire our today. In 19th century Germany, Heinrich Rudolf Hertz was such a historical person. Hertz, a brilliant physicist, had the ability to integrate theoretical book knowledge with fundamental bench experimentation. Hertz's eclectic talents and research accomplishments ranged from drafting in architecture to meticulous manipulation of standard laboratory equipment often redesigned for his relentless curiosity (Buchwald 1994). He was the first to conclusively prove the existence of electromagnetic waves with precise experimental procedures and instrumentation he engineered to generate and detect waves (radio pulses) across space. His touchstone research verified Maxwell's theory and proved that all forms of electromagnetic radiation are propagated as waves at a finite velocity - the speed of light (Heinrich Hertz 2012). In recognition of his pivotal discoveries, Hertz's name is the universal synonym for frequency. Categorizing electroencephalographic (EEG) patterns by frequency is the primary emphasis of an EEG recording. The distribution of frequencies, amplitude, and polarity of electrocerebral potentials as recorded on the computer screen and/or graph paper result from numerous electrical fields of neuronal dipoles. Hertz's images drawn as the paper dipole remain the standard method for describing electrocerebral dipoles and the electrical fields of epileptiform activity recorded on a patient's electroencephalograph. Hertz's intended and inadvertent discoveries became the launch pad for numerous medical and media technologies. His former student Philipp Lenard won the 1905Nobel-Prize for Physics when he developed a version of the cathode tube and studied penetration by x-rays based on Hertz's cathode ray experiments in 1892. Additionally, Hertz did not pursue his ancillary discovery of the photoelectric effect in 1887. Albert Einstein would later explain features of the phenomenon and earn the Nobel Prize in Physics in 1921 (Photoelectric effect 2012). The gestation of Hertz's scientific discoveries has developed the comforts and pleasures of 21st century life. The electromagnetic spectrum spans from longest wavelength to shortest: radio waves, microwaves, infrared, optical, ultraviolet, x-rays, and gamma-rays - all measured in Hz (Electromagnetic waves 2000). [ABSTRACT FROM AUTHOR]

This article discusses the close relationship that developed during the 1850s and 1860s between Hermann von Helmholtz (1821-94), one of the leading German scientists during the second half of the nineteenth century, and the British scientific elite generally. It focuses especially on the importance of the law of conservation of energy to both sides of that relationship as the law emerged and became popularized. In presenting this Anglo-German relationship, the article relates Helmholtz's friendships or acquaintanceships with numerous members of the British elite, including William Thomson, John Tyndall, Henry Enfield Roscoe, Michael Faraday, Edward Sabine, Henry Bence Jones, George Gabriel Stokes, James Clerk Maxwell, Peter Guthrie Tait, George Biddell Airy and James Thomson. It suggests that the building of these social relationships helped create a sense of trust between Helmholtz and the British elite that, in turn, eased the revision of the understanding of the law of conservation of force into that of energy and consolidated its acceptance, and that laid the personal groundwork for Helmholtz's future promotion of Maxwell's electromagnetic theory in Germany and for Anglo-German agreements in electrical metrology. [ABSTRACT FROM AUTHOR]

Idealistic morphology as articulated by the botanist Wilhelm Troll, the main target of the critique voiced by the early phylogeneticists, was firmly embedded in its contemporary scientific, cultural, and political context. Troll appealed to theoretical developments in contemporary physics in support of his research program. He understood burgeoning quantum mechanics not only to threaten die unity of physics, but also die validity of die principle of causality. Troll used this insight in support of his claim of a dualism in biology, relegating die causal-analytical approach to physiology, while rejuvenating the Goediean paradigm in comparative morphology. This embedded idealistic morphology in the völkisch tradition that characterized German culture during die Weimar Republic and its aftermath. In contrast, die contemporary phylogeneticists anchored their research program in the rise of logical positivism and in Darwin's principle of natural selection. This, in turn, brought phylogenetic systematists of the late 1930s and early 1940s into the orbit of national-socialist racial theory and eugenics. In conclusion, die early debate between idealistic morphologists and phylogenetic systematists was not only ideologically tainted, but also implied a philosophical impasse that is best characterized as a conflict between the Goediean and Newtonian paradigm of natural science. [ABSTRACT FROM AUTHOR]

I sketch the early history of the Deutsches Elektronen-Synchrotron in Hamburg, Germany, and establish links to some current issues of science policy in Europe. [ABSTRACT FROM AUTHOR]

While it is a commonplace in the historiography of electricity that itinerant lecturers and instrument makers were 'somehow' part of the 'electrical flare' of the 18th century, very little is actually known about them, about their background, their careers and their self-understanding. Yet, research focusing on these practitioners of experimental physics outside the established institutions can contribute immensely to our understanding of the scientific culture of the Enlightenment. The development of electrical machines, the supply for increasing demand for instruments and instruction, the creation of interest in electricity through public demonstrations, relied heavily on these men. Furthermore, these 'scientific salesmen' offered a perfect contrast, a foil for the natural philosophers from whom to distinguish themselves. Natural philosophers tried to discredit their extra-academic competitors, thereby forging their own image as serious, honest, truth-seeking, independent researchers. This essay focuses on this situation in the German Empire, tracing the steps of the itinerant lecturer Jakob von Bianchy on his way from court to college, from the workshop to the theatre, from Lake Como, to Vienna and Paris. [ABSTRACT FROM AUTHOR]

A guided tour of significant sides pertaining to the history of physics is conducted around the area of the Technische Universitat and the Physikalisch-Technische Reichsanstalt in Berlin-Charlottenburg, of the Institutes of the former Kaiser Wilhelm Society in Berlin-Dahlem, as well as to some points of interest in the area of Potsdam. [ABSTRACT FROM AUTHOR]