Wilhelm Carl Werner Otto Fritz Franz Wien was a German physicist who, in 1893, used theories about heat and electromagnetism to deduce Wien's displacement law, which calculates the emission of a blackbody at any temperature from the emission at any one reference temperature.
Rudolf Julius Emanuel Clausius was a German physicist and mathematician and is considered one of the central founding fathers of the science of thermodynamics. By his restatement of Sadi Carnot's principle known as the Carnot cycle, he gave the theory of heat a truer and sounder basis. His most important paper, "On the Moving Force of Heat", published in 1850, first stated the basic ideas of the second law of thermodynamics. In 1865 he introduced the concept of entropy. In 1870 he introduced the virial theorem, which applied to heat.
Thermionic emission is the liberation of charged particles from a hot electrode whose thermal energy gives some particles enough kinetic energy to escape the material's surface. The particles, sometimes called thermions in early literature, are now known to be ions or electrons. Thermal electron emission specifically refers to emission of electrons and occurs when thermal energy overcomes the material's work function.
Johann Wolfgang Döbereiner was a German chemist who is known best for work that was suggestive of the periodic law for the chemical elements, and for inventing the first lighter, which was known as the Döbereiner's lamp. He became a professor of chemistry and pharmacy for the University of Jena.
The year 1905 in science and technology involved some significant events, particularly in physics, listed below.
Max Abraham was a German physicist known for his work on electromagnetism and his opposition to the theory of relativity.
The history of special relativity consists of many theoretical results and empirical findings obtained by Albert A. Michelson, Hendrik Lorentz, Henri Poincaré and others. It culminated in the theory of special relativity proposed by Albert Einstein and subsequent work of Max Planck, Hermann Minkowski and others.
The annus mirabilis papers are the four papers that Albert Einstein published in Annalen der Physik, a scientific journal, in 1905. These four papers were major contributions to the foundation of modern physics. They revolutionized science's understanding of the fundamental concepts of space, time, mass, and energy. Because Einstein published all four of these papers in a single year, 1905 is called his annus mirabilis.
- The first paper explained the photoelectric effect, which established the energy of the light quanta , and was the only specific discovery mentioned in the citation awarding Einstein the 1921 Nobel Prize in Physics.
- The second paper explained Brownian motion, which established the Einstein relation and led reluctant physicists to accept the existence of atoms.
- The third paper introduced Einstein's theory of special relativity, which used the universal constant speed of light to derive the Lorentz transformations.
- The fourth, a consequence of the theory of special relativity, developed the principle of mass–energy equivalence, expressed in the equation and which led to the discovery and use of atomic energy decades later.
"Über die von der molekularkinetischen Theorie der Wärme geforderte Bewegung von in ruhenden Flüssigkeiten suspendierten Teilchen" is the 1905 journal article, by Albert Einstein, that proved the reality of atoms, which were first proposed in 1808 by John Dalton. It is one of the four groundbreaking papers Einstein published in 1905, in Annalen der Physik, in his miracle year.
First quantization is a procedure for converting equations of classical particle equations into quantum wave equations. The companion concept of second quantization converts classical field equations in to quantum field equations.
The Kaufmann–Bucherer–Neumann experiments measured the dependence of the inertial mass of an object on its velocity. The historical importance of this series of experiments performed by various physicists between 1901 and 1915 is due to the results being used to test the predictions of special relativity. The developing precision and data analysis of these experiments and the resulting influence on theoretical physics during those years is still a topic of active historical discussion, since the early experimental results at first contradicted Einstein's then newly published theory (1905), but later versions of this experiment confirmed it. For modern experiments of that kind, see Tests of relativistic energy and momentum, for general information see Tests of special relativity.
Kurd Friedrich Rudolf von Mosengeil, also Curd Friedrich Rudolf von Mosengeil, was a German physicist.
Jakob Johann Laub was a physicist from Austria-Hungary, who is best known for his work with Albert Einstein in the early period of special relativity.
Alfred Heinrich Bucherer was a German physicist, who is known for his experiments on relativistic mass. He also was the first who used the phrase "theory of relativity" for Einstein's theory of special relativity.
Paul Gerber was a German physics teacher. He studied in Berlin from 1872 to 1875. In 1877 he became a teacher at the Realgymnasium in Stargard in Pommern. Gerber is known for his controversial work on the speed of gravity and the perihelion shift of Mercury's orbit.
Mellitic anhydride, the anhydride of mellitic acid, is an organic compound with the formula C12O9.
Vladimir Sergeyevitch Ignatowski, or Waldemar Sergius von Ignatowsky and similar names in other publications, was a Russian physicist.
Eduard August Grüneisen was a German physicist. He is best known for the Grüneisen parameter, the Mie–Grüneisen equation of state and the Bloch–Grüneisen temperature. He served as director of the Physics Department at the University of Marburg for 20 years, and was editor of Annalen der Physik together with Max Planck.
In physics, a quantum is the minimum amount of any physical entity involved in an interaction. Quantum is a discrete quantity of energy proportional in magnitude to the frequency of the radiation it represents. The fundamental notion that a property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light of a specific frequency. Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom. Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact is part of the fundamental framework for understanding and describing nature.
Wilhelm Gottlieb Hankel was a German physicist who was among the first to identify pyroelectric effects and the rotation of the plane of optical polarization in fluorspar upon application of electricity.
