Anatoly Sukhorukov

Anatoly Petrovich Sukhorukov (, 29 November 1935 – 10 April 2014) was a Soviet and Russian physicist who made fundamental contributions to the development of the theory of waves and nonlinear interactions in optics, radiophysics, and acoustics.
Biography.
Graduated with honours from the Chair of Physics of Oscillations, MSU Faculty of Physics in 1961. He returned to this department in 1963 to do a PhD course after working for three years as a junior researcher at the Institute of computer control.
In 1967 he defended a PhD thesis on the topic "Diffracting beams in nonlinear media" under the supervision of academician R. V. Khokhlov. In 1974 he has passed habilitation and received a doctoral degree in physical and mathematical sciences. The topic of his Doktor nauk work was "Wave beams and pulses in nonlinear media". In 1977 he received a professor title at the Chair of General Physics and Wave Processes.
Since 1966, he had worked at the Faculty of Physics – first as a senior engineer, then assistant, senior lecturer, associate professor, and full professor (from 1976). In 1984–1989 he served as a head of Division of Radiophysics and Electronics. In 1989–1992 he worked as a dean of the Faculty of Physics. From 1988 till 2014 he was a head of the Chair of Photonics and Microwave Physics (previous department name until 2008 – Department of Radiophysics).
Scientific achievements.
Anatoly. P. Sukhorukov has made fundamental contributions to the development of the theory of waves and nonlinear interactions in optics, radiophysics, and acoustics. Among his many achievements, the results discussed here were most valued by the scientist, as being most important and influential for the subsequent development of corresponding research fields.
His scientific interests lied mainly in the area to nonlinear optics. He was one of the founders of modern theoretical nonlinear optics. He obtained, in particular, a number of pioneering results on self-focusing and parametric interactions, which were later confirmed in experiments. In a series of works on self-focusing (since 1966) he has developed for the first time the aberration-free theory of wave self-action, found exact solutions for ray patterns accounting for nonlinear aberrations, and numerically investigated different regimes of spatial resonant self-focusing. Many of his theoretical predictions have been confirmed in experiments: aberrational structures due to wave self-focusing in nematics, limited lifetime of spatial solitons in media with relaxation-type nonlinearity, dynamics of thermal defocusing in the presence of forced and free convection, self-deflection of beams in nonlinear moving media, laser-induced transparency of a cloudy medium and an ozone layer, adaptive compensation of beam distortions in nonlinear media.
Anatoly Sukhorukov has derived the general paraxial equation describing beam diffraction in anisotropic crystals, and originated the paraxial theory for three-wave interactions of beams and pulses under the presence of phase- and group-velocity mismatches, diffraction, and group velocity dispersion. He has developed a spatio-temporal analogy between optical beams and pulses, and predicted the effect of diffraction-dispersion incoherence for modulated waves, which limits the efficiency of frequency conversion and results in parametric mutual focusing in quadratic media. He has also predicted the phenomenon of anomalous diffraction in the parametric amplifier, and determined the optimal conditions for high-efficiency generation of the second and third harmonics in focused laser beams. He has first investigated the possibility of total energy conversion in the process of double phase-matched interaction between three frequency harmonics. He has developed the theory of up- and down parametric frequency conversion under the presence of group velocity mismatch, described the formation of three-frequency optical dissipative solitons, parametric pi – pulses, a giant parametric pulse (confirmed experimentally), calculated the modes of the parametrical amplifier with a pulsed pump, developed the theory of stimulated Raman scattering taking into account the relaxation time and group velocity mismatch, found the quasi-phase-matching conditions for slow and fast modes in 3D photonic crystals. He has predicted the existence of a new class of localized structures – parametric three-frequency solitons in media with quadratic nonlinearity (results published in 1974, confirmed experimentally in 1995), also discovered a new type of wave self-focusing, namely, mutual – focusing of just three beams at different frequencies in quadratic media. He has investigated the walk-off effect on quadratic solitons, analyzed dynamics of spatial soliton trapping and interactions in bulk media, in cavities (based on the full round-trip model), in gratings (model for counter-propagating waves); proposed parametric soliton model based on the analogy with coupling of three quasi-particles; considered the tunneling of slow parametric solitons through a bounded grating. He has analyzed the quasi-phase-matched hybrid interactions in periodically polled crystals (layer model), asymmetric modes of parametric solitons, properties of ultra-narrow quadratic solitons, propagation of ultra-short optical pulses inducing plasma generation, and parametric interactions of two non-axial vortices, methods of spatio-temporal vortices generation and recording, all-optical switching with parametric refraction and reflection. He developed the theory of dispersion managed interactions of few-cycle pulses in quadratically nonlinear layered media. He has investigated the nonlinear refraction, total internal reflection and scattering of optical beams and pulses in defocusing media with Kerr, cascaded quadratic, photorefractive, and thermal nonlinearities.
Educational activities.
A. P. Sukhorukov devoted much efforts to educate students. He was one of the leading lecturers at the Faculty of Physics. He has developed and taught for over 40 years a one-year course on "Theory of waves".
He has co-authored a textbook on the course subject, now in its 2nd ed., which became a reference book for students and researchers.
Scientific school created by A. P. Sukhorukov on the topic of "Physics of wave interactions in inhomogeneous and nonlinear media" is building on traditions established at Lomonosov Moscow State University by academician R. V. Khokhlov. A. P. Sukhorukov has supervised more than 80 graduate students as the Faculty of Physics, 36 PhD students, and 8 habilitation works. Together with colleagues and students, he has successfully carried out multiple scientific projects. He has organized annual Russian schools-seminars on wave phenomena for students and young scientists during 1995–2014.
Publications.
A. P. Sukhorukov has published more than 400 scientific papers and several books, including two monographs:
and two textbooks:


Paul Erman

Paul Erman (29 February 1764 – 11 October 1851) was a German physicist from Berlin, Brandenburg and a Huguenot of the fourth generation. He was the son of the historian Jean Pierre Erman (1735–1814), author of "Histoire des réfugiés".
Erman became teacher of science successively at the French gymnasium (Französisches Gymnasium Berlin) in Berlin, and at the military academy, and on the foundation of the University of Berlin in 18 months he was chosen professor of physics. His work was mainly concerned with electricity and magnetism, though he also made some contributions to optics and physiology.
Erman died in Berlin. He had a son, Georg Adolf Erman who was a physicist, and a grandson Johann Peter Adolf Erman, known as an Egyptologist.


Max Planck Institute of Quantum Optics

The Max-Planck-Institute for Quantum Optics (abbreviation: MPQ; ) is a part of the Max Planck Society which operates 87 research facilities in Germany.
The institute is located in Garching, Germany, which in turn is located 10 km north-east of Munich. Five research groups work in the fields of attosecond physics, laser physics, quantum information theory, laser spectroscopy, quantum dynamics and quantum many body systems.
Research.
The institute investigates the interaction of light and matter. Its faculty members conduct research in topics such as theoretical quantum optics, quantum information theory, ultra-high-resolution laser spectroscopy, quantum physics of ultra-cold atoms, development of components for quantum computers and quantum networks, Bose Einstein condensation of degenerate quantum gases, attosecond physics, development of new radiation and particle sources for fundamental and medical applications, etc. There used to be a group at MPQ that conducted experiments on gravitational waves.
History.
The Max-Planck-Institute for Quantum Optics was founded on January 1, 1981. It was a successor of a project group for laser research of the Max Planck Institute for Plasma Physics. The use of lasers for fusion research, quantum optics and spectroscopy were the goals of the project group, which was established in 1976 and consisted of 46 members. In 1981 the staff numbers had risen to 82 and the institute was comprising the divisions of Laser Physics (Prof. Herbert Walther), Laser Chemistry (Prof. Karl-Ludwig Kompa) and Laser Plasma (Dr. Siegbert Witkowski).
The institute was initially accommodated on the premises of the Max Planck Institute for Plasma Physics, but eventually moved to its new building in July, 1986, officially separating from the Max Planck Institute for Plasma Physics. With the appointment of Theodor Hänsch (then at Stanford University) as new director, the institute grew significantly. Hänsch established the Laser Spectroscopy Division and was also given a chair at the Ludwig Maximilian University of Munich, which ensured close links between MPQ and the university complex in Munich. After the retirement of Siegbert Witkowski in 1993, the research on the high energy laser was stopped and other research areas were started.
In 1999 Professor Gerhard Rempe (then University of Constance) was appointed as director at the MPQ, and the Quantum Dynamics Division was set up.
In 2001 the Research Group on Gravitational Waves, led by Dr. Karsten Danzmann, moved to Hanover where the first test measurements were carried out in the experiment. Since then that group has been a part of the MPI for Gravitational Physics (Potsdam) that was founded in 1995. In the same year (2001) Professor Ignacio Cirac (then University of Innsbruck) accepted a call as director at the MPQ and set up the first Theory Division at the institute.
At the beginning of 2003 Professor Herbert Walther acquired emeritus status, but continued his research work as head of the Laser Physics Emeritus Group until his death in July 2006. His successor as director at the MPQ and professor at the LMU is Professor Ferenc Krausz (previously Technical University of Vienna). Professor Krausz has led the Attosecond Physics Division since 2003.
Professor Karl-Ludwig Kompa was the last founding father of the institute to retire in 2006. In parallel with these retirements three new research divisions and several independent research groups were established: In 2004 the Attosecond Driver Laser Group was formed, whose leader Dr. Andrius Baltuska took up a professorship at the Technical University of Vienna in 2006. The same year also the Quantum Simulations with Trapped Ions Group was founded, led by Dr. Tobias Schätz (now at the University of Freiburg). In 2005 Dr. Tobias Kippenberg (now at the Ecole Polytechnique Fédérale de Lausanne) set up his Laboratory of Photonics at the MPQ. In 2006 Dr. Reinhard Kienberger (now at TU München) received funding to set up the research group Attosecond Dynamics. In 2007 a further research group was founded, on Attosecond Imaging, led by Dr. Matthias Kling. In January 2008 Dr. Masaki Hori established his group on Antimatter Spectroscopy, followed by the Ultrafast Quantum Optics group of Dr. Peter Hommelhoff (now at the University of Erlangen-Nuremberg) in April 2008. In December 2010 Dr. Elefterios Goulielmakis (now at the University of Rostock) started his research group on Attoelectronics. Dr. Randolf Pohl (now at the University of Mainz) started to establish his research group "Muonic Atoms" at the end of 2011.
Currently (in February 2020), there exist five independent research groups at MPQ. In addition to Masaki Hori's antimatter spectroscopy group, there is the Rydberg Dressed Quantum Many-Body Systems Group (Dr. Christian Groß), the Otto Hahn Group on Quantum Networks (Dr. Andreas Reiserer), the Theory of Quantum Matter Group (Dr. Richard Schmidt), and the Entanglement of Complex Quantum Systems Group (Prof. Dr. Norbert Schuch).
In 2005, Theodor W. Hänsch was awarded the Nobel Prize in Physics, together with John L. Hall, "for their contributions to the development of laser-based precision spectroscopy, including the optical frequency comb technique". The frequency comb the Nobel Prize is referring to has been developed in his Laser Spectroscopy Division in the late 1990s.
On 1 August 2008 a fifth division Quantum Many Body Systems was established by Prof. Immanuel Bloch. Prof. Bloch is successor of Prof. Theodor W. Hänsch, who normally would have retired as director at MPQ in 2009. Due to special agreements Prof. Hänsch will remain professor at the LMU and director at the MPQ at least until 2016. One research focus of Prof. Bloch is the investigation of ultracold quantum gases in optical lattices. These systems may help to model solid states and to get a better understanding of special properties such as e.g. high temperature superconductivity.


Charles Elbaum

Charles Elbaum (May 15, 1926 – March 4, 2018) was an American physicist.
Charles Elbaum was born in Lublin, Poland to parents Chil and Hannah Elbaum. After World War II, he moved to Belgium and Paris before earning a master's and doctorate from the University of Toronto.
In 1959, Elbaum began teaching at Brown University as an assistant professor of applied physics. Later, he was granted fellowship in the American Physical Society. Elbaum chaired the department of physics between 1980 and 1986, and was named the Hazard Professor of Physics in 1991. Along with colleague Leon Cooper, he founded the tech company "Nestor", dedicated to finding commercial applications for neural networks. He retired in 2001, staying on as a research professor.


The International Conference on Low Temperature Physics

The International Conference on Low Temperature Physics (LT) is an academic conference held every three years near the month of September attracting on average well over a thousand participants from all over the world. The LT conferences are endorsed by the International Union of Pure and Applied Physics (IUPAP) via its Commission on Low Temperature Physics (C5). The mandate of the LT conferences is to promote the exchange of information and views among the members of the international scientific community in the general field of Low Temperature Physics.
Usually, several other satellite meetings are also held just before or after the LT conferences in neighboring cities such as the International Conference on Ultra Low Temperature Physics series (ULT) as well as other meetings related to the topics listed below. Starting from 1998, the Symposium on Quantum Fluids and Solids (QFT) conference series was decided to be held in all non-LT years.
Topics.
The general field of low temperature physics is broad, but usually the LT conferences are divided into five parallel programs:
Prizes.
The LT conferences traditionally hand out the following prizes during their opening sessions:
Editions.
As of late, the conferences are being held in the following pattern: Europe -> Asia -> The Americas -> Europe.


Dynamic scaling

Dynamic scaling (sometimes known as Family-Vicsek scaling) is a litmus test that shows whether an evolving system exhibits self-similarity. In general a function is said to exhibit dynamic scaling if it satisfies:
Here the exponent formula_2 is fixed by the dimensional requirement formula_3. The numerical value of formula_4 should remain invariant despite the unit of measurement of formula_5 is changed by some factor since formula_6 is a dimensionless quantity.
Many of these systems evolve in a self-similar fashion in the sense that data obtained from the snapshot at any fixed time is similar to the respective data taken from the snapshot of any earlier or later time. That is, the system is similar to itself at different times. The litmus test of such self-similarity is provided by the dynamic scaling.
History.
Tamás Vicsek and Fereydoon Family first proposed the idea of dynamic scaling in the context of diffusion-limited aggregation (DLA) of clusters in two dimensions. The form of their proposal for dynamic scaling was:
Test for dynamic scaling.
In such systems we can define a certain time-dependent stochastic variable formula_8. We are interested in computing the probability distribution of formula_8 at various instants of time i.e. formula_10. The numerical value of formula_11 and the typical or mean value of formula_8 generally changes over time. The question is: what happens to the corresponding dimensionless variables? If the numerical values of the dimensional quantities change, but corresponding dimensionless quantities remain invariant then we can argue that snapshots of the system at different times are similar. When this happens we say that the system is self-similar.
One way of verifying dynamic scaling is to plot dimensionless variables formula_4 as a function of formula_14 of the data extracted at various different time. Then if all the plots of formula_11 vs formula_8 obtained at different times collapse onto a single universal curve then it is said that the systems at different time are similar and it obeys dynamic scaling. The idea of data collapse is deeply rooted to the Buckingham Pi theorem. Essentially such systems can be termed as temporal self-similarity since the same system is similar at different times.
Examples.
Many phenomena investigated by physicists are not static but evolve probabilistically with time (i.e. Stochastic process). The universe itself is perhaps one of the best examples. It has been expanding ever since the Big Bang. Similarly, growth of networks like the Internet are also ever growing systems. Another example is polymer degradation where degradation does not occur in a blink of an eye but rather over quite a long time. Spread of biological and computer viruses too does not happen over night.
Many other seemingly disparate systems which are found to exhibit dynamic scaling. For example:


Richard Sillitto

Richard M. Sillitto (1923 – 19 April 2005) was an optical physicist who wrote a useful text on quantum mechanics. He was a Fellow of the Royal Society of Edinburgh and Fellow of the Institute of Physics as well as a past president of the Scottish branch of the Institute of Physics. Sillitto was Reader and Reader Emeritus in the Physics department of the University of Edinburgh.
External links.
The proposed book "Geometrical and Physical Optics, R M Sillitto, Longman Higher Education, " was never completed.


Topological quantum number

In physics, a topological quantum number (also called topological charge) is any quantity, in a physical theory, that takes on only one of a discrete set of values, due to topological considerations. Most commonly, topological quantum numbers are topological invariants associated with topological defects or soliton-type solutions of some set of differential equations modeling a physical system, as the solitons themselves owe their stability to topological considerations. The specific "topological considerations" are usually due to the appearance of the fundamental group or a higher-dimensional homotopy group in the description of the problem, quite often because the boundary, on which the boundary conditions are specified, has a non-trivial homotopy group that is preserved by the differential equations. The topological quantum number of a solution is sometimes called the winding number of the solution, or, more precisely, it is the degree of a continuous mapping.
Recent ideas about the nature of phase transitions indicates that topological quantum numbers, and their associated solutions, can be created or destroyed during a phase transition.
Particle physics.
In particle physics, an example is given by the Skyrmion, for which the baryon number is a topological quantum number. The origin comes from the fact that the isospin is modelled by SU(2), which is isomorphic to the 3-sphere formula_1 and formula_1 inherits the group structure of SU(2) through its bijective association, so the isomorphism is in the category of topological groups. By taking real three-dimensional space, and closing it with a point at infinity, one also gets a 3-sphere. Solutions to Skyrme's equations in real three-dimensional space map a point in "real" (physical; Euclidean) space to a point on the 3-manifold SU(2). Topologically distinct solutions "wrap" the one sphere around the other, such that one solution, no matter how it is deformed, cannot be "unwrapped" without creating a discontinuity in the solution. In physics, such discontinuities are associated with infinite energy, and are thus not allowed.
In the above example, the topological statement is that the 3rd homotopy group of the three sphere is
and so the baryon number can only take on integer values.
A generalization of these ideas is found in the Wess–Zumino–Witten model.
Exactly solvable models.
Additional examples can be found in the domain of exactly solvable models, such as the sine-Gordon equation, the Korteweg–de Vries equation, and the Ishimori equation. The one-dimensional sine-Gordon equation makes for a particularly simple example, as the fundamental group at play there is
and so is literally a winding number: a circle can be wrapped around a circle an integer number of times. Quantum sine-Gordon model is equivalent to massive Thirring model.
Fundamental excitations are fermions: topological quantum number formula_5 is the number of fermions. After quantization of sine-Gordon model the topological charge become 'fractional'. Consistent consideration of ultraviolet renormalization shows that a fractional number of fermions repelled over the ultraviolet cutoff. So the formula_5 gets multiplied by a fractional number depending on Planck constant.
Solid state physics.
In solid state physics, certain types of crystalline dislocations, such as screw dislocations, can be described by topological solitons. An example includes screw-type dislocations associated with Germanium whiskers.


Pitman closeness criterion

In statistical theory, the Pitman closeness criterion, named after E. J. G. Pitman, is a way of comparing two candidate estimators for the same parameter. Under this criterion, estimator A is preferred to estimator B if the probability that estimator A is closer to the true value than estimator B is greater than one half. Here the meaning of "closer" is determined by the absolute difference in the case of a scalar parameter, or by the Mahalanobis distance for a vector parameter.


Karl Jakobs

Karl Jakobs is Professor of Particle Physics at the University of Freiburg, Germany. He has been the Spokesperson (scientific head) of the ATLAS Collaboration at the Large Hadron Collider at CERN since 2017.
Education.
Jakobs studied at the University of Bonn and received his Diplom in 1984. He went to the Heidelberg University to study the properties of the production of W and Z bosons in proton-proton collisions and received his PhD in 1988.
Awards.
In 2015 Karl Jakobs was awarded the Stern–Gerlach Medal for his contributions to the discovery of the Higgs boson.


Emil Bose

Emil Hermann Bose (October 20, 1874 in Bremen, Germany – May 25, 1911 in La Plata, Argentina), was a German physicist. He was the first director of the Department of Electrical Engineering at the University of La Plata, Argentina. He studied under Walther Nernst at the University of Göttingen, Germany and was recruited by the newly created university in Argentina, where he taught for two years until his death from typhoid fever in 1911. He was succeeded by Richard Gans.
<br>See
Bibiloni, A.G. (2005)


Primakoff effect

The Primakoff effect, named after Henry Primakoff, is the resonant production of neutral pseudoscalar mesons by high-energy photons interacting with an atomic nucleus. It can be viewed as the reverse process of the decay of the meson into two photons and has been used for the measurement of the decay width of neutral mesons.
It could also take place in stars and be a production mechanism of certain hypothetical particles, such as the axion.More precisely, the Primakoff effect is the conversion of axions into photons in the presence of very strong electromagnetic field.
The effect is predicted to lead to optical properties of the vacuum state in the presence of a strong magnetic field.


ALICE (accelerator)

Accelerators and Lasers In Combined Experiments (ALICE), or Energy Recovery Linac Prototype (ERLP) is a 35MeV energy recovery linac test facility at Daresbury Laboratory in Cheshire, England. The project was originally conceived as a test bed for 4GLS, and consists of:
The ALICE accelerator is an Energy Recovery Linac (ERL) that incorporates all the features of the 4th generation light source albeit at smaller scale. An ERL is not restricted by the dynamic properties of storage rings and, therefore, can attain an unprecedented electron beam brightness limited only by the electron gun. Energy recovery allows also a significant increase in an average power of the light sources (without building a dedicated power station nearby!).
The ability to produce ultra-short electron bunches well below 1ps and an availability of several light sources of different “colour” open up numerous possibilities for conducting investigations of fast processes on a femtosecond scale in molecular and solid state physics to name but a few.
The ALICE project was extended by addition of a 19-cavity accelerating Non-Scaling FFAG ring, known as the EMMA project. Construction of the EMMA machine began in September 2009. As of March 31, 2011, full ring circumnavigation was completed to establish proof of principle.
Principle.
A DC photoelectron gun generates short low emittance electron bunches with the length of several ps and accelerates them to a modest 350keV. The nominal bunch charge on ALICE is 80pC. The bunches are produced in trains lasting from ~10ns to 100ms and the train repetition frequency can vary from 1 to 20 Hz. Within the train, the bunches are separated by 12.3ns that corresponds to the laser pulse repetition frequency of 81.25 MHz.
The electron beam is then injected into the superconductive linac (booster), accelerated to the energy of 8.35MeV and transported to the main linac that increases the beam energy to 35MeV. Both superconductive linacs are cooled down to approximately 20 K with liquid helium. The accelerating phase of the main linac is chosen such that a specific energy chirp is introduced along the bunch so that it can be later compressed longitudinally in a magnetic chicane (bunch compressor). The beam reaches the chicane after being turned by 180° in the first triple bend achromat ARC1.
After compression, the beam, consisting now of sub-picosecond bunches, enters the magnetic undulator that constitutes a major part of the mid-IR Free Electron Laser (FEL). This laser generates IR light with the wavelength of ~5mm.
The spent electron beam is returned to the entrance of the main linac via the second ARC2 at a precise time when the RF phase is exactly opposite to the initial accelerating phase. This condition requires an accurate adjustment of the electron beam path length that is accomplished by moving the ARC1 as a whole. The beam is now decelerated thus giving its energy back to the electromagnetic field inside the linac RF cavities (energy recovery) and emerges from the linac having the original energy of 8.35MeV. This energy recovered beam is diverted to the beam dump ending its short but useful life


Principle of relativity

In physics, the principle of relativity is the requirement that the equations describing the laws of physics have the same form in all admissible frames of reference.
For example, in the framework of special relativity the Maxwell equations have the same form in all inertial frames of reference. In the framework of general relativity the Maxwell equations or the Einstein field equations have the same form in arbitrary frames of reference.
Several principles of relativity have been successfully applied throughout science, whether implicitly (as in Newtonian mechanics) or explicitly (as in Albert Einstein's special relativity and general relativity).
Basic concepts.
Certain principles of relativity have been widely assumed in most scientific disciplines. One of the most widespread is the belief that any law of nature should be the same at all times; and scientific investigations generally assume that laws of nature are the same regardless of the person measuring them. These sorts of principles have been incorporated into scientific inquiry at the most fundamental of levels.
Any principle of relativity prescribes a symmetry in natural law: that is, the laws must look the same to one observer as they do to another. According to a theoretical result called Noether's theorem, any such symmetry will also imply a conservation law alongside. For example, if two observers at different times see the same laws, then a quantity called energy will be conserved. In this light, relativity principles make testable predictions about how nature behaves, and are not just statements about how scientists should write laws.
Special principle of relativity.
According to the first postulate of the special theory of relativity:
This postulate defines an inertial frame of reference.
The special principle of relativity states that physical laws should be the same in every inertial frame of reference, but that they may vary across non-inertial ones. This principle is used in both Newtonian mechanics and the theory of special relativity. Its influence in the latter is so strong that Max Planck named the theory after the principle.
The principle requires physical laws to be the same for any body moving at constant velocity as they are for a body at rest. A consequence is that an observer in an inertial reference frame cannot determine an absolute speed or direction of travel in space, and may only speak of speed or direction relative to some other object.
The principle does not extend to non-inertial reference frames because those frames do not, in general experience, seem to abide by the same laws of physics. In classical physics, fictitious forces are used to describe acceleration in non-inertial reference frames.
In Newtonian mechanics.
The special principle of relativity was first explicitly enunciated by Galileo Galilei in 1632 in his "Dialogue Concerning the Two Chief World Systems", using the metaphor of Galileo's ship.
Newtonian mechanics added to the special principle several other concepts, including laws of motion, gravitation, and an assertion of an absolute time. When formulated in the context of these laws, the special principle of relativity states that the laws of mechanics are "invariant" under a Galilean transformation.
In special relativity.
Joseph Larmor and Hendrik Lorentz discovered that Maxwell's equations, the cornerstone of electromagnetism, were invariant only by a certain change of time and length units. This left some confusion among physicists, many of whom thought that a luminiferous aether was incompatible with the relativity principle, in the way it was defined by Henri Poincaré:
In their 1905 papers on electrodynamics, Henri Poincaré and Albert Einstein explained that with the Lorentz transformations the relativity principle holds perfectly. Einstein elevated the (special) principle of relativity to a postulate of the theory and derived the Lorentz transformations from this principle combined with the principle of the independence of the speed of light (in vacuum) from the motion of the source. These two principles were reconciled with each other (in Einstein's treatment, though not in Poincaré's) by a re-examination of the fundamental meanings of space and time intervals.
The strength of special relativity lies in its derivation from simple, basic principles, including the invariance of the laws of physics under a shift of inertial reference frames and the invariance of the speed of light in a vacuum. (See also: Lorentz covariance.)
It is possible to derive the form of the Lorentz transformations from the principle of relativity alone. Using only the isotropy of space and the symmetry implied by the principle of special relativity, one can show that the space-time transformations between inertial frames are either Galilean or Lorentzian. Whether the transformation is actually Galilean or Lorentzian must be determined with physical experiments. It is not possible to conclude that the speed of light "c" is invariant by mathematical logic alone. In the Lorentzian case, one can then obtain relativistic interval conservation and the constancy of the speed of light.
General principle of relativity.
The general principle of relativity states:
That is, physical laws are the same in "all" reference frames—inertial or non-inertial. An accelerated charged particle might emit synchrotron radiation, though a particle at rest doesn't. If we consider now the same accelerated charged particle in its non-inertial rest frame, it emits radiation at rest.
Physics in non-inertial reference frames was historically treated by a coordinate transformation, first, to an inertial reference frame, performing the necessary calculations therein, and using another to return to the non-inertial reference frame. In most such situations, the same laws of physics can be used if certain predictable fictitious forces are added into consideration; an example is a uniformly rotating reference frame, which can be treated as an inertial reference frame if one adds a fictitious centrifugal force and Coriolis force into consideration.
The problems involved are not always so trivial. Special relativity predicts that an observer in an inertial reference frame doesn't see objects he would describe as moving faster than the speed of light. However, in the non-inertial reference frame of Earth, treating a spot on the Earth as a fixed point, the stars are observed to move in the sky, circling once about the Earth per day. Since the stars are light years away, this observation means that, in the non-inertial reference frame of the Earth, anybody who looks at the stars is seeing objects which appear, to them, to be moving faster than the speed of light.
Since non-inertial reference frames do not abide by the special principle of relativity, such situations are not self-contradictory.
General relativity.
General relativity was developed by Einstein in the years 1907 - 1915. General relativity postulates that the global Lorentz covariance of special relativity becomes a local Lorentz covariance in the presence of matter. The presence of matter "curves" spacetime, and this curvature affects the path of free particles (and even the path of light). General relativity uses the mathematics of differential geometry and tensors in order to describe gravitation as an effect of the geometry of spacetime. Einstein based this new theory on the general principle of relativity, and he named the theory after the underlying principle.
Further reading.
See the special relativity references and the general relativity references.


Optica (journal)

Optica is a monthly peer-reviewed open access scientific journal published by The Optical Society. It covers the entire spectrum of theoretical and applied optics and photonics. It was established in July 2014. The founding editor-in-chief is Alex L. Gaeta (Columbia University).
In 2020, the editor-in-chief became Prem Kumar (Northwestern University, USA), assisted by an extended team of Deputy Editors: Thomas Krauss (University of York, UK), Curtis Menyuk (University of Maryland Baltimore County, USA), Irina Novikova (College of William & Mary, USA), Nathalie Picqué (Max Planck Institute of Quantum Optics, Germany) and Eric Potma (University of California, Irvine, USA).
Abstracting and indexing.
The journal is abstracted and indexed in:
According to the "Journal Citation Reports", the journal has a 2019 impact factor of 9.778.


David B. Kaplan

David B. Kaplan (born 1958) is an American physicist. He was Director of the Institute for Nuclear Theory at the University of Washington during the period 2006-2016 and is now a Senior Fellow there.
Research.
Kaplan's research deals with various aspects of quantum field theory, applied to models of physics beyond the Standard Model, cosmology, nuclear physics, and lattice QCD. He is known for his work on the theory of the composite Higgs boson, the role of the strange quark in dense matter and the phenomenon of kaon condensation, development of the theory of electroweak baryogenesis and other aspects of particle astrophysics, for lattice models with exact supersymmetry, and for the formulation of lattice gauge theory with chiral fermions. The latter is known as the theory of domain-wall fermions, and is an early example of what has later become known among condensed matter physicists as a topological insulator and the quantum spin Hall effect.
Recognition.
Kaplan is a Member of the National Academy of Sciences, the American Academy of Arts and Sciences, and the Washington State Academy of Sciences, and is a Fellow of the American Physical Society. He is a recipient of the Department of Energy Outstanding Junior Investigator Award, the National Science Foundation Presidential Young Investigator Award, and an Alfred P. Sloan Foundation fellowship.
Personal history.
Kaplan graduated from the Lakeside School in Seattle, WA in 1976. He obtained his B.S. at Stanford University in 1980 under the supervision of Melvin Schwartz and Ph.D. in 1985 at Harvard University under the supervision of Howard Georgi. He was a Junior Fellow at the Harvard Society of Fellows from 1985 to 1988 and a member of the physics department at the University of California, San Diego from 1988 to 1993, before moving to the University of Washington in 1994. He was married to Ann Nelson, also a theoretical physicist, until her death in a hiking accident in August 2019.


HITRAN

HITRAN (an acronym for High Resolution Transmission) molecular spectroscopic database is a compilation of spectroscopic parameters used to simulate and analyze the transmission and emission of light in gaseous media, with an emphasis on planetary atmospheres. The knowledge of spectroscopic parameters for transitions between energy levels in molecules (and atoms) is essential for interpreting and modeling the interaction of radiation (light) with different media.
For half a century, HITRAN has been considered to be an international standard which provides the user a recommended value of parameters for millions of transitions for different molecules. HITRAN includes both experimental and theoretical data which are gathered from articles, books, proceedings, databases, theses, reports, presentations, unpublished data, papers in-preparation and private communications. The original version of HITRAN was compiled by the Air Force Cambridge Research Laboratories (1960s), and then first made publicly available in 1973. HITRAN is a free resource and is currently maintained and developed at the Harvard-Smithsonian Center for Astrophysics, Cambridge MA, USA.
HITRAN is the worldwide standard for calculating or simulating atmospheric molecular transmission and radiance from the microwave through ultraviolet region of the spectrum. The current version, HITRAN2016, contains 49 molecules in the line-by-line portion of HITRAN and, with their respective isotopologues, totals 126 isotopologues in this section of the database. These data are archived as a multitude of high-resolution line transitions, each containing many spectral parameters required for high-resolution simulations.
In addition to the traditional the line-by-line spectroscopic absorption parameters, the HITRAN database contains information on absorption cross-sections where the line-by-line parameters are absent or incomplete. Typically HITRAN includes absorption cross-sections for heavy polyatomic molecules (with low-lying vibrational modes) which are difficult for detailed analysis due to the high density of the spectral bands/lines, broadening effects, isomerization, and overall modeling complexity. There are 327 molecular species provided as cross-section files. The cross-section files are provided in the HITRAN format described on the official HITRAN website (http://hitran.org/docs/cross-sections-definitions/).
The HITRAN compilation also provides collision-induced absorption (CIA) that was first introduced into HITRAN in the 2012 edition. CIA refers to absorption by transient electric dipoles induced by the interaction between colliding molecules. Instructions for accessing the CIA data files can be found on HITRAN/CIA. HITRAN2016 also has an aerosols refractive indices section, with data in the visible, infrared, and millimeter spectral ranges of many types of cloud and aerosol particles. This is necessary because knowledge of the refractive indices of the aerosols and cloud particles and their size distributions is necessary in order to specify their optical properties.
HITEMP is the molecular spectroscopic database analogous to HITRAN for high-temperature modeling of the spectra of molecules in the gas phase. HITEMP encompasses many more bands and transitions than HITRAN for the absorbers H2O, CO2, CO, NO, NO2, N2O, CH4 and OH.
HAPI.
A Python library HAPI (HITRAN Application Programming Interface) has been developed which serves as a tool for absorption and transmission calculations as well as comparisons of spectroscopic data sets. HAPI extends the functionality of the main site, in particular, for the calculation of spectra using several types of line shape calculations, including the flexible HT (Hartmann-Tran) profile. This HT line shape can also be reduced to a number of conventional line profiles such as Gaussian (Doppler), Lorentzian, Voigt, Rautian, Speed-dependent Voigt and speed-dependent Rautian. In addition to accounting for pressure, temperature and optical path length, the user can include a number of instrumental functions to simulate experimental spectra. HAPI is able to account for broadening of lines due to mixtures of gases, making use of all broadening parameters supplied by HITRAN. This includes the traditional broadeners (air, self) as well as additional parameters for CO2, H2O, H2 and He broadening. The following spectral functions can be calculated in the current version #1 of HAPI:
HAPIEST (an acronym for HITRAN Application Programming Interface and Efficient Spectroscopic Tools) is a graphical user interface allowing users to access some of the functionality provided by HAPI without any knowledge of python programming, including downloading data from HITRAN, and plotting of spectra and cross-sections. The source code for HAPIEST is available on GitHub, along with binary distributions for Mac and PC.


Victor Popov

Victor Nikolaevich Popov (; 27 October 1937 – 16 April 1994) was a Russian theoretical physicist known for his contribution to the quantization of non-abelian gauge fields. His work with Ludvig Faddeev on that subject introduced the fundamental objects now known as Faddeev–Popov ghosts. Popov graduated from the Department of Theoretical Physics of the Physics Faculty of Leningrad State University. Popov formed a group at LOMI in early 1965, where he remained for life.


Journal of Computational Physics

The Journal of Computational Physics is a bimonthly scientific journal covering computational physics that was established in 1966 and is published by Elsevier. As of 2015, its editor-in-chief is Remi Abgrall (University of Zurich). According to the "Journal Citation Reports", the journal has a 2018 impact factor of 2.845.


Wolfgang Wild (physicist)

Wolfgang Wild (born 20 September 1930) is a German nuclear physicist, academic administrator and politician. He was President of the Technical University of Munich between 1980 and 1986 and Bavarian Minister of Science between 1986 and 1989.
Career.
Wild studied physics at the Ludwig Maximilian University of Munich. After receiving his doctorate in 1955, he first worked as an assistant to Heinz Maier-Leibnitz at the Technical University of Munich. In 1957 he moved to Heidelberg University, where he investigated atomic nuclei with J. Hans D. Jensen, who later won the Nobel Prize.
His habilitation in 1960 was followed the following year by an associate professorship at the Free University of Berlin. In November of the same year, he took over the Chair of Theoretical Physics at the Department of Physics of the Technical University of Munich.
Political career.
After the 1986 Bavarian state election, Franz Josef Strauss appointed Wild the first Bavarian Minister of Science.


Matthew P. A. Fisher

Matthew P. A. Fisher is an American theoretical physicist and Professor of Physics at the University of California, Santa Barbara, and is known for several major contributions to condensed matter physics. He completed his bachelor's degree in engineering physics from Cornell University in 1981 and earned a Ph.D. in theoretical physics from the University of Illinois at Urbana-Champaign in 1986 with Anthony Leggett as his advisor, with part of his work done under the supervision of Eduardo Fradkin. He was awarded the Alan T. Waterman Award in 1995, and in 2015 he was a recipient of the Oliver E. Buckley Condensed Matter Prize for his work on the superconductor-insulator transition. He was elected to the American Academy of Arts and Sciences in 2003 and to the National Academy of Sciences in 2012. He is a Fellow of the American Physical Society. He is the son of English physicist Michael E. Fisher, and brother of American physicist Daniel S. Fisher.
Research.
Fisher is one of the leading figures in condensed matter physics, and has made important contributions to many areas in condensed matter physics. Some of his most important works have been in the theories of quantum phase transitions, in particular superconductor-insulator transitions (with Daniel Fisher, Steven Girvin and others) and deconfined quantum criticality (with Subir Sachdev, T. Senthil, Ashvin Vishwanath and Leon Balents). He has also made important contributions to superconductivity, in particular, introducing vortex-glass superconductivity as a possible new phase of matter and using bosonic particle-vortex dualities to describe the properties of superconductors (with Dung-Hai Lee). He has also made significant advances in the transport and other aspects of the physics of Luttinger liquids (with Charles Kane) and other one-dimensional problems in condensed matter such as the edges of quantum Hall states. He has also done important works in the area of quantum spin liquids, often using the aforementioned dualities to provide theoretical descriptions of various spin liquid phenomena (with Leon Balents, Michael Hermele, Jason Alicea, Shinsei Ryu and others). He has also made important contributions to the physics of carbon nanotubes (with Leon Balents and Charles Kane) and emergent Majorana fermions and related phenomena in quasi-one-dimensional problems (with Jason Alicea and others).
In recent years, Fisher has developed new interests in neuroscience, where in particular he has proposed the possibility (and mechanisms) of quantum information processing (specifically, quantum mind) in the human brain.


Alexander Arkadyevich Migdal

Alexander Arkadyevich Migdal (; born 22 July 1945) is a Russian-American physicist and entrepreneur, formerly at Landau Institute for Theoretical Physics, Space Research Institute, Princeton University, ViewPoint Corp, Magic Works LLC, and now at Migdal Research LLC.
Scientific career.
Alexander Migdal made important contributions to the theory of critical phenomena, quantum chromodynamics and conformal field theory. As an undergraduate student he worked out (with Alexander Polyakov) the theory of the dynamical mass generation in gauge theories, commonly
referred to as the "Higgs mechanism", in the spring of 1965,
independently
of Robert Brout, François Englert and Peter Higgs.
In 1968 he published a paper (with Vladimir Gribov) which introduced (in the context of the Reggeon field theory) scale invariance with anomalous dimensions to be determined as eigenvalues of bootstrap equations of quantum field theory. This work led to so called Migdal-Polyakov conformal bootstrap which had profound influence and helped to make progress in the theory of critical phenomena as well as the theory of strong interactions.
In the next decade Migdal made important progress in quantum chromodynamics by introducing a novel form of the renormalization group (now called Migdal-Kadanoff renormalization), and by deriving (with Yu. Makeenko) the equation for the Wilson loops. The so-called Migdal program was a precursor and provided an impetus to the Shifman-Vainshtein-Zakharov sum rule method (SVZ sum rules) in QCD
which presently plays a basic role in the calculations of hadronic properties. Later he found exact solution of quantum gravity in two dimensions (with V. Kazakov and D. Gross), starting the topic of matrix models of topological field theories which occupied the physics community for a number of years.
He also worked on the applications of quantum field theory to the theory of turbulence, and derived the exact loop equation for velocity circulation to describe this phenomenon. He initiated (with V. Gurarie, G. Falkovich, and V. Lebedev) a description of intermittency in nonlinear systems by means of Instanton solutions of the stochastic differential equations.
As of 2020, he is a research scientist at the New York University.
Entrepreneurship.
Leaving Princeton tenure in 1996, he became an inventor and entrepreneur. He holds 10+ patents in laser scanning and 3D data compression/transmission, built (with A. Lebedev and M. Petrov) first textured 3D scanner which was awarded as Best Of What's New and other industrial awards. He was director of several companies and invited speaker of numerous international conferences. Currently he is CEO of his fourth start-up company Migdal Research LLC dedicated to the stock market prediction.


Sumit Ranjan Das

Sumit Ranjan Das (born 11 December 1955) is a US-based Indian high energy physicist and a Professor at the University of Kentucky College of Arts and Sciences. Known for his research on string theory, Das is an elected fellow of the Indian Academy of Sciences. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology, one of the highest Indian science awards, for his contributions to physical sciences in 1998.
Biography.
Born on 11 December 1955 at Kolkata in the Indian state of West Bengal, Sumit Ranjan Das did his early schooling at South Point School and earned his graduate degree from Presidency College and master's degree from the Science College, University of Calcutta. Moving to the US, he enrolled at the University of Chicago for his doctoral studies and after securing a PhD in 1983, he did his post-doctoral studies at Fermilab (1983–85) and California Institute of Technology (1985–87). On his return to India in 1987, he joined Tata Institute of Fundamental Research where he served as a member of faculty till 2001. Subsequently, he went back to the US and joined the University of Kentucky College of Arts and Sciences where he holds the position of Jack and Linda Gill Eminent Professor. He was a senior associate at Kavli Institute for the Physics and Mathematics of the Universe during 2009–10 and a Visiting Professor at Yukawa Institute for Theoretical Physics, Kyoto University during 2014 and has held visiting positions at several universities in the US.
Legacy.
The principal focus of Das' research is string theory and quantum field theory. His work on two dimensional strings is the earliest example of holographic principle. His work on black holes in string theory assisted in resolving the information paradox with regard to black holes.
Awards and honors.
Das was a gold medalist in both his graduate and master's examinations. The Council of Scientific and Industrial Research awarded him the Shanti Swarup Bhatnagar Prize, one of the highest Indian science awards in 1998. The Indian Academy of Sciences elected him as a fellow the same year.


Center of mass (relativistic)

In physics, relativistic center of mass refers to the mathematical and physical concepts that define the center of mass of a system of particles in relativistic mechanics and relativistic quantum mechanics.
Introduction.
In non-relativistic physics there is a unique and well defined notion of the center of mass vector, a three-dimensional vector (abbreviated: "3-vector"), of an isolated system of massive particles inside the 3-spaces of inertial frames of Galilei spacetime. However, no such notion exists in special relativity inside the 3-spaces of the inertial frames of Minkowski spacetime.
In any rigidly rotating frame (including the special case of a Galilean inertial frame) with coordinates formula_1, the Newton center of mass of "N" particles of mass formula_2 and 3-positions formula_3 is the 3-vector
both for free and interacting particles.
In a special relativistic inertial frame in Minkowski spacetime with four vector coordinates formula_5 a collective variable with all the properties of the Newton center of mass does not exist. The primary properties of the non-relativistic center of mass are
It is interesting that the following three proposals for a relativistic center of mass appearing in the literature of the last century take on individually these three properties:
These three collective variables have all the same constant 3-velocity and all of them collapse into the Newton center of mass in the non-relativistic limit. In the 1970s there was a big debate on this problem, without any final conclusion.
Group theoretical definition.
In non-relativistic mechanics the phase space expression of the ten generators of the Galilei group of an isolated system of N particles with 3-positions formula_15, 3-momenta formula_16 and masses formula_17 in the inertial frame with coordinates formula_1 are formula_19 is an inter-particle potential)
They are constants of the motion generating the transformations connecting the inertial frames. Therefore, at formula_22 a group-theoretical definition of the Newton center of mass is
at formula_24:
Since the Poincaré generators depend on all the components of the isolated system even when they are at large space-like distances, this result shows that the relativistic collective variables are global (not locally defined) quantities. Therefore, all of them are non-measurable quantities, at least with local measurements. This suggests that there could be problems also with the measurement of the Newton center of mass with local methods.
The three collective variables as 4-quantities in the rest frame.
The inertial rest frames of an isolated system can be geometrically defined as the inertial frames whose space-like 3-spaces are orthogonal to the conserved time-like 4-momentum of the system: they differ only for the choice of the inertial observer origin of the 4-coordinates formula_28. One chooses the Fokker–Pryce center of inertia 4-vector formula_29 as origin since it is a 4-vector, so that it is the only collective variable which can be used for an inertial observer. If formula_30 is the proper time of the atomic clock carried by the inertial observer and formula_31 the 3-coordinates in the rest 3-spaces formula_32, spacetime locations within these 3-spaces can be described in an arbitrary inertial frame with the embeddings,
where formula_34. The time-like 4-vector formula_35 and the three space-like 4-vectors formula_36 are the columns of the Wigner boosts for time-like orbits of the Poincaré group. As a consequence the 3-coordinates formula_37 define Wigner spin-1 3-vectors which transform under Wigner rotations when one does a Lorentz transformation. Therefore, due to this Wigner-covariance, these privileged rest 3-spaces (named Wigner 3-spaces formula_38) can be shown to be intrinsically defined and do not depend on the inertial observer describing them. They allow the description of relativistic bound states without the presence of the relative times of their constituents, whose excitations have never been observed in spectroscopy.
In this framework it is possible to describe the three collective variables with 4-quantities formula_39, such that formula_40. It can be shown that they have the following expressions in terms of formula_41 (the Jacobi data at formula_42 for the canonical center of mass), formula_43 and formula_44
The locations in the privileged rest Wigner 3-space of the canonical center of mass and of the center of energy are
and
The pseudo-worldline of the canonical center of mass is always nearer to the center of inertia than the center of energy.
Møller world-tube of non-covariance.
Møller has shown that if in an arbitrary inertial frame one draws all the pseudo-worldlines of formula_50 and formula_51 associated with every possible inertial frame, then they fill a world-tube around the 4-vector formula_52 with a transverse invariant Møller radius formula_53 determined by the two Casimirs of the isolated system. This world-tube describes the region of non-covariance of the relativistic collective variables and puts a theoretical limit for the localization of relativistic particles. This can be seen by taking the difference between formula_54 and either formula_55 or formula_56. In both cases the difference has only a spatial component perpendicular to both formula_57 and formula_58 and a magnitude ranging from zero to the Møller radius as the three-velocity of the isolated particle system in the arbitrary inertial frame ranges from 0 towards c. Since the difference has only spatial component it is evident that the volume corresponds to a non-covariance world-tube around the Fokker-Pryce 4-vector formula_54.
Since the Møller radius is of the order of the Compton wavelength of the isolated system, it is impossible to explore its interior without producing pairs, namely without taking into account relativistic quantum mechanics. Moreover, the world-tube is the remnant of the energy conditions of general relativity in the flat Minkowski solution: if a material body has its material radius less that its Møller radius, then in some reference frame the energy density of the body is not definite positive even if the total energy is positive.
The difference among the three relativistic collective variables and the non-covariance world-tube are global (not locally defined) effects induced by the Lorentz signature of Minkowski spacetime and disappear in the non-relativistic limit.


Globe effect

The globe effect, sometimes called the rolling ball effect or the spinning globe effect, is an optical phenomenon that occurs with visual optical instruments, in particular binoculars and telescopes, that are designed to be free of distortion. When these instruments are panned, the moving image appears to roll over a curved, convex surface. In 1949, Horst Koehler at Zeiss (Jena) suggested adding some pincushion distortion to the optical design to eliminate the globe effect. August Sonnefeld conducted experiments with volunteers, which supported the claim that a supplementary distortion could improve the imaging of visual optical instruments. Since that time, most binocular manufacturers have followed Zeiss's example and added pincushion distortion to their optical design.
The origin of the globe effect initially remained unclear after its discovery in the first half of the past century. Koehler speculated about an "unnatural perspective generated by the binocular while panning over a three dimensional scenery", thereby ignoring the fact that the globe effect was observable at the night sky as well, where perspective distortions were absent.
Recently, the globe effect has been linked to the peculiar properties of human visual perception, which adds a certain amount of barrel distortion to the visual field. The amount of barrel distortion is subject to individual differences, which explains the fact that the perceived intensity of the globe effect varies significantly between different observers.
An alternative approach for explaining the globe effect comes from the technical journalist and optics specialist Walter E. Schön. He states that the observed effect is in fact not that of a rolling globe but that of a vertically rotating cylinder. The globe shape of the illusion seen by most observers is only because the field of view through the optical device is circular. This illusion of a rotating cylinder during panning is caused by the horizontal movement of the image being (due to the angular magnification of the device) faster and more uniform (with less parallax) compared to the naked eye and also not corresponding to the felt rotational speed of the observer's head. When the brain tries to integrate these conflicting signals, it creates the perception that the image is moving slower at the left and right edges than in the middle, giving the illusion of a rotating cylinder.


Johanna Stachel

Johanna Barbara Stachel (born 3 December 1954 in Munich) is a German nuclear physicist. She is a professor in experimental physics at the University of Heidelberg (Ruprecht-Karls-Universität Heidelberg). Stachel is a former president of the German Physical Society (DPG).
Early life and education.
Johanna Stachel completed secondary education in 1972 at the Spohn Gymnasium in Ravensburg. She studied physics and chemistry at Johannes Gutenberg University Mainz and the Swiss Federal Institute of Technology (ETH Zürich) and received a degree from the Johannes Gutenberg University Mainz in 1978. In 1982 she obtained a doctorate in physics from the same university.
Career.
From 1983 to 1996, Stachel studied and worked at the State University of New York (SUNY) at Stony Brook and Brookhaven National Laboratory where she met her future husband professor Peter Braun-Munzinger. In 1996 she was named professor at the University of Heidelberg. Stachel was spokesperson of the CERN SPS experiment CERES/NA45 and directed the developed the ALICE Transition Radiation Detector.
Stachel was elected President of the German Physical Society for a two-year term starting in 2012. Her two primary priorities as president were first to defend basic research by showing its importance and promote physics education in schools by improving the training of physics teachers and the standards across German schools.
During her career, she has delivered over 150 lectures at international workshops and conferences and has participated in over 100 seminars and colloquia.
Research interests.
Stachel's research focuses on understanding relativistic heavy-ion collisions and quark-gluon plasma. She is member of the LHC ALICE Collaboration at CERN in Geneva. Stachel is also interested in developing detectors that are needed to carry out these experiments in particle physics.
Offices and honorary offices.
Among her academic responsibilities are:
On 28 March 2014 she received the , where she is listed along with Heinrich Hertz, Albert Einstein and Otto Stern.


Aplanatic lens

An aplanatic lens is a lens that is free of both spherical and coma aberrations. Aplanatic lenses can be made by combining two or three lens elements. A single-element aplanatic lens is an aspheric lens whose surfaces are surfaces of revolution of a cartesian oval.


History of hard disk drives

In 1953, IBM recognized the immediate application for what it termed a "Random Access File" having high capacity and rapid random access at a relatively low cost. After considering technologies such as wire matrices, rod arrays, drums, drum arrays, etc., the engineers at IBM's San Jose California laboratory invented the hard disk drive. The disk drive created a new level in the computer data hierarchy, then termed Random Access Storage but today known as secondary storage, less expensive and slower than main memory (then typically drums and later core memory) but faster and more expensive than tape drives.
The commercial usage of hard disk drives (HDD) began in 1957, with the shipment of a production IBM 305 RAMAC system including IBM Model 350 disk storage. US Patent 3,503,060 issued March 24, 1970, and arising from the IBM RAMAC program is generally considered to be the fundamental patent for disk drives.
Each generation of disk drives replaced larger, more sensitive and more cumbersome devices. The earliest drives were usable only in the protected environment of a data center. Later generations progressively reached factories, offices and homes, eventually becoming ubiquitous.
Disk media diameter was initially 24 inches in diameter, but over time it has been reduced to today's 3.5-inch and 2.5-inch standard sizes. Drives with the larger 24-inch- and 14-inch-diameter media were typically mounted in standalone boxes (resembling washing machines) or large equipment rack enclosures. Individual drives often required high-current AC power due to the large motors required to spin the large disks. Drives with smaller media generally conformed to de facto standard form factors.
The capacity of hard drives has grown exponentially over time. When hard drives became available for personal computers, they offered 5-megabyte capacity. During the mid-1990s the typical hard disk drive for a PC had a capacity of about 1 gigabyte. , desktop hard disk drives typically had a capacity of 1 to 8 terabytes, with the largest-capacity drives reaching 20 terabytes (single-disk drives, "dual" drives are available up to 24 TB). Smaller, laptop internal 2.5-inch drives, are available up to 5 TB.
Unit production peaked in 2010 at about 650 million units and has been in a slow decline since then.
1950s–1970s.
The IBM 350 Disk File was developed under the code-name RAMAC by an IBM San Jose team led by Reynold Johnson. It was announced in 1956 with the then new IBM 305 RAMAC computer. A variant, the IBM 355 Disk File, was simultaneously announced with the IBM RAM 650 computer, an enhancement to the IBM 650.
The IBM 350 drive had fifty platters, with a total capacity of five million 6-bit characters (3.75 megabytes). A single head assembly having two heads was used for access to all the platters, yielding an average access time of just under 1 second.
The RAMAC disk drive created a new level in the computer data hierarchy, today known as secondary storage, less expensive and slower than main memory (then typically core or drum) but faster and more expensive than tape drives. Subsequently there was a period of about 20 years in which other technologies competed with disks in the secondary storage marketplace, for example tape strips, e.g., NCR CRAM, tape cartridges, e.g., IBM 3850, and drums, e.g., Burroughs B430, UNIVAC FASTRAND, but all ultimately were displaced by HDDs. Today SSDs compete with HDDs in the marketplace.
The IBM 1301 Disk Storage Unit, announced in 1961, introduced the usage of heads having self-acting air bearings (self-flying heads) with one head per each surface of the disks. It was followed in 1963 by the IBM 1302, with 4 times the capacity.
Also in 1961, Bryant Computer Products introduced its 4000 series disk drives. These massive units stood tall, long, and wide, and had up to 26 platters, each in diameter, rotating at up to 1,200 rpm. Access times were from 50 to 205 milliseconds (ms). The drive's total capacity, depending on the number of platters installed, was up to 205,377,600 bytes (205 MB).
The first disk drive to use removable media was the IBM 1311 drive. It was introduced in 1962 using the IBM 1316 disk pack to store two million characters. It was followed by the IBM 2311 (1964) using the IBM 1316 disk pack to store 5 megabyte, IBM 2314 (1965) using the IBM 2316 disk pack to store 29 megabytes, the IBM 3330 using 3336 disk packs to store 100 megabytes and the 3330-11 using the 3336-11 to store 200 megabytes.
Memorex shipped the first HDD, the Memorex 630, in 1968, plug compatible to an IBM model 2311 marking the beginning of independent competition (Plug Compatible Manufacturers or PCMs) for HDDs attached to IBM systems. It was followed in 1969 by the Memorex 660, an IBM 2314 compatible, which was OEM'ed to DEC and resold as the RP02.
In 1964, Burroughs introduced the B-475 disk drive, with a head per track, as part of the B5500.
In 1970, IBM introduced the 2305 disk drive, with a head per track.
In 1973, Control Data Corporation introduced the first of its series of SMD disk drives using conventional disk pack technology. The SMD family became the predominant disk drive in the minicomputer market into the 1980s.
Also in 1973, IBM introduced the IBM 3340 "Winchester" disk drive and the 3348 data module, the first significant commercial use of low mass and low load heads with lubricated platters and the last IBM disk drive with removable media. This technology and its derivatives remained the standard through 2011. Project head Kenneth Haughton named it after the Winchester 30-30 rifle because it was planned to have two 30 MB spindles; however, the actual product shipped with two spindles for data modules of either 35 MB or 70 MB. The name 'Winchester' and some derivatives are still common in some non-English speaking countries to generally refer to any hard disks (e.g. Hungary, Russia).
In 1974 IBM introduced the "Swinging arm" actuator, made possible because Winchester recording heads function well when skewed to the recorded tracks. The simple design of the 62GV (Gulliver) drive, invented at IBM's UK Hursley Labs, became IBM's most licensed electro-mechanical invention of all time, being adopted in the 1980s for all HDDs, and still used nearly 40 years and 10 Billion arms later.
Also in 1973, Control Data Corporation introduced the first of its series of SMD disk drives using conventional disk pack technology. The SMD family became the predominant disk drive in the minicomputer market into the 1980s.
Smaller diameter media came into usage during the 1970s and by the end of the decade standard form factors had been established for drives using nominally 8-inch media (e.g., Shugart SA1000) and nominally 5.25-inch media (e.g., Seagate ST-506).
During the 1970s, captive production, dominated by IBM's production for its own use, remained the largest revenue channel for HDDs, though the relative importance of the OEM channel grew. Led by Control Data, Diablo Systems, CalComp and Memorex, the OEM segment reached $631 million in 1979, but still well below the $2.8 billion associated with captive production.
1980s, the transition to the PC era.
The 1980s saw the minicomputer age plateau as PCs were introduced. Manufacturers such as DEC and Hewlett-Packard continued to manufacture minicomputer compatible hard drive systems as industry demanded higher storage. Hewlett-Packard introduced the HP 7935 as one such drive. But it was clear that smaller Winchester storage systems were eclipsing large platter hard drives.
Hard disk drives for personal computers (PCs) were initially a rare and very expensive optional feature; systems typically had only the less expensive floppy disk drives or even cassette tape drives as both secondary storage and transport media. However by the late '80s, hard disk drives were standard on all but the cheapest PC and floppy disks were used almost solely as transport media.
Most hard disk drives in the early 1980s were sold to PC end users by systems integrators such as the Corvus Disk System or the systems manufacturer such as the Apple ProFile. The IBM PC XT in 1983, included an internal standard 10 MB hard disk drive, and soon thereafter internal hard disk drives proliferated on personal computers, one popular type was the ST506/ST412 hard drive and MFM interface.
HDDs continued to get smaller with the introduction of the 3.5-inch form factor in the middle of the decade Rodime 1983 and the 2.5-inch form factor PrairieTek 1988.
Industry participation peaked with about 75 active manufacturers in 1985 and then declined thereafter even though volume continued to climb: by 1989 reaching 22 million units and US$23 billion in revenue.
1990s.
Even though there were a number of new entrants, industry participants continued to decline in total to 15 in 1999. Unit volume and industry revenue monotonically increased during the 1990s to 174 million units and $26 billion.
The industry production consolidated around the 3.5-inch and 2.5-inch form factors; the larger form factors dying off while several smaller form factors were offered but achieved limited success, e.g. HP 1.3-inch Kittyhawk, IBM 1-inch Microdrive, etc.
2000 to present.
In 2001 the HDD industry experienced its first ever decline in units and revenue.
The number of industry participants decreased to 6 in 2009 and to 3 in 2013.
In 2009 – Fujitsu exits by selling HDD business to Toshiba
In 2011 – Floods hit many hard drive factories. Predictions of a worldwide shortage of hard disk drives cause prices to double.
In 2012 Western Digital announced the first 2.5-inch, 5 mm thick drive, and the first 2.5-inch, 7 mm thick drive with two platters
Unit production peaked in 2010 at about 650 million units. Unit shipment has been in a slow decline since then, shipping about 276 million units in 2018 with a somewhat slower decline projected thereafter.
As of August 2020, the largest hard drive is 20 TB (while SSDs can be much bigger at 100 TB, mainstream consumer SSDs cap at 8 TB). Smaller, laptop internal 2.5-inch drives, are available up to 5 TB.
Manufacturing history.
Manufacturing began in California's Silicon Valley in 1957 with IBM's production shipment of the first HDD, the IBM RAMAC 350. The industry grew slowly at first with three additional companies in the market by 1964, Anelex Corp., Bryant Computer Products and Data Products Corp. The industry grew rapidly in the late 1960s and again in the 1980s reaching a peak of 75 manufacturers in 1984. There have been at least 221 companies manufacturing hard disk drives but most of that industry has vanished through bankruptcy or mergers and acquisitions. Surviving manufacturers are Seagate, Toshiba and Western Digital (WD) with Toshiba as the senior participant having entered the market in 1977, twenty years after IBM started the market.
From beginning and into the early 1980s manufacturing was mainly by US firms in the United States at locations such as Silicon Valley, Los Angeles, Minnesota and Oklahoma City. In the 1980s US firms, beginning with Seagate, began to shift production to Singapore and then other locations in southeast Asia. In a span of seven years, 1983 to 1990, Singapore became the single largest location of HDD production, amounting to 55% of worldwide production. Japanese HDD companies later also moved their production to southeast Asia. Today the three remaining firms all produce their units in the Pacific Rim.
By the 1990s the dollar value of magnetic recording devices produced by companies located in California's "Silicon Valley" exceeded the dollar value of semiconductor devices produced there leading some to suggest that a more appropriate name for this area would be "Iron Oxide Valley," after the magnetic material coating the disks. All three remaining firms still have significant activities in Silicon Valley, but no HDD manufacturing. Western Digital still manufactures its read-write head wafers in Fremont CA.


Divergence (statistics)

In statistics and information geometry, divergence or a contrast function is a function which establishes the "distance" of one probability distribution to the other on a statistical manifold. The divergence is a weaker notion than that of the distance, in particular the divergence need not be symmetric (that is, in general the divergence from "p" to "q" is not equal to the divergence from "q" to "p"), and need not satisfy the triangle inequality.
Definition.
Suppose "S" is a space of all probability distributions with common support. Then a divergence on "S" is a function satisfying
The dual divergence "D*" is defined as
Geometrical properties.
Many properties of divergences can be derived if we restrict "S" to be a statistical manifold, meaning that it can be parametrized with a finite-dimensional coordinate system "θ", so that for a distribution we can write .
For a pair of points with coordinates "θ""p" and "θ""q", denote the partial derivatives of "D"("p" || "q") as
Now we restrict these functions to a diagonal , and denote
By definition, the function "D"("p" || "q") is minimized at , and therefore
where matrix "g"("D") is positive semi-definite and defines a unique Riemannian metric on the manifold "S".
Divergence "D"(· || ·) also defines a unique torsion-free affine connection ∇("D") with coefficients
and the dual to this connection ∇* is generated by the dual divergence "D"*.
Thus, a divergence "D"(· || ·) generates on a statistical manifold a unique dualistic structure ("g"("D"), ∇("D"), ∇("D"*)). The converse is also true: every torsion-free dualistic structure on a statistical manifold is induced from some globally defined divergence function (which however need not be unique).
For example, when "D" is an f-divergence for some function ƒ(·), then it generates the metric and the connection , where "g" is the canonical Fisher information metric, ∇("α") is the α-connection, , and .
Examples.
The two most important divergences are the relative entropy (Kullback–Leibler divergence, KL divergence), which is central to information theory and statistics, and the squared Euclidean distance (SED). Minimizing these two divergences is the main way that linear inverse problem are solved, via the principle of maximum entropy and least squares, notably in logistic regression and linear regression.
The two most important classes of divergences are the "f"-divergences and Bregman divergences; however, other types of divergence functions are also encountered in the literature. The only divergence that is both an "f"-divergence and a Bregman divergence is the Kullback–Leibler divergence; the squared Euclidean divergence is a Bregman divergence (corresponding to the function ), but not an "f"-divergence.
f-divergences.
This family of divergences are generated through functions "f"("u"), convex on and such that . Then an "f"-divergence is defined as
If a Markov process has a positive equilibrium probability distribution formula_7 then formula_8 is a monotonic (non-increasing) function of time, where the probability distribution formula_9 is a solution of the Kolmogorov forward equations (or Master equation), used to describe the time evolution of the probability distribution in the Markov process. This means that all "f"-divergencies formula_8 are the Lyapunov functions of the Kolmogorov forward equations. Reverse statement is also true: If formula_11 is a Lyapunov function for all Markov chains with positive equilibrium formula_7 and is of the trace-form
(formula_13) then formula_14, for some convex function "f". Bregman divergences in general do not have such property and can increase in Markov processes.
Bregman divergences.
Bregman divergences correspond to convex functions on convex sets. Given a strictly convex, continuously-differentiable function on a convex set, known as the "Bregman generator", the Bregman divergence measures the convexity of: the error of the linear approximation of from as an approximation of the value at :
The dual divergence to a Bregman divergence is the divergence generated by the convex conjugate of the Bregman generator of the original divergence. For example, for the squared Euclidean distance, the generator is , while for the relative entropy the generator is the negative entropy .
History.
The term "divergence" for a statistical distance was used informally in various contexts from c. 1910 to c. 1940. Its formal use dates at least to , entitled "On a measure of divergence between two statistical populations defined by their probability distributions", which defined the Bhattacharyya distance, and , entitled "On a Measure of Divergence between Two Multinomial Populations", which defined the Bhattacharyya angle. The term was popularized by its use for the Kullback–Leibler divergence in , its use in the textbook , and then by generally, for the class of "f"-divergences. The term "Bregman distance" is still found, but "Bregman divergence" is now preferred. In information geometry, alternative terms were initially used, including "quasi-distance" and "contrast function" , though "divergence" was used in for the -divergence, and has become standard (e.g., ).


Relativistic star

A relativistic star is a rotating star whose behavior is well described by general relativity, but not by classical mechanics. The first such object to be identified was radio pulsars, which consist of rotating neutron stars. Rotating supermassive stars are a hypothetical form of a relativistic star. Relativistic stars are one possible source to allow gravitational waves to be studied.
Another definition of a relativistic star is one with the equation of state of a special relativistic gas. This can happen when the core of a massive main-sequence star becomes hot enough to generate electron-positron pairs. Stability analysis shows that such a star is only marginally bound, and is unstable to either collapse or explode. This instability is believed to limit the mass of main-sequence stars to a couple of hundred solar masses or so. Stars of this size and larger are able to directly collapse into a black hole of either intermediate or supermassive size.


Paul Barbara

Paul Frank Barbara (April 24, 1953 – October 31, 2010) was an American chemist. His research interests focused on the understanding of the molecular structure and dynamics of complex chemical systems, including organic semi-conductors for photovoltaic applications, proton and electron transfer reactions, the hydrated electron and intermediates in the reverse transcription mechanism of HIV-1. His laboratory developed and applied novel ultrafast and single molecule spectroscopies to study the complexity of these chemical system.
Paul Barbara was a full professor at the University of Texas at Austin. He held the R.J.V. Johnson-Welch Endowed Chair in the Department of Chemistry and Biochemistry at UT-Austin. He was also Director of UT-Austin’s Center for Nano- and Molecular Science and Technology, and Senior Editor for Accounts of Chemical Research.
Education.
Paul Barbara received his bachelor's degree in 1974 at Hofstra University and completed his doctoral work in 1978 at Brown University under the supervision of Ronald G. Lawler. From 1978 to 1980 he carried out postdoctoral work at Bell Laboratories with Peter M. Rentzepis and Louis E. Brus. He joined the faculty of Department of Chemistry at the University of Minnesota in 1980, achieving the rank of full professor in 1990. He moved to the University of Texas at Austin in 1998, as full professor in the Department of Chemistry and Biochemistry until his death.
Awards.
Paul Barbara was named 3M-Alumni Distinguished Professor of Chemistry in 1995, elected a Fellow of the American Academy of Arts and Sciences in 1999. a Fellow of the American Physical Society in 1993, a fellow of the American Association for Advancement of Science in 2004 and a member of the United States National Academy of Sciences in 2006. Other awards include an Alfred P. Sloan Fellowship in 1983–85, a Presidential Young Investigator Award in 1984-89, a NSF Creativity Award in 1998, Inter-American Photochemical Society Award in 2002 and the 2009 E. Bright Wilson Award in Spectroscopy in 2008 from The American Chemical Society.
The Barbara research group is nicknamed the ‘Barbarians’.
Death.
Paul Barbara died on October 31, 2010, two weeks after a cardiac arrest sent him into a coma.
A memorial service was held on December 12, 2010, on UT campus to celebrate the life of Paul F. Barbara. He is survived by his wife Sharon, daughter Juliet and son Jason.


John Love (scientist)

John Love (2 October 1942 – 19 June 2016) was a pioneer in the field of fibre optics, who co-authoring the widely used textbook "Optical Waveguide Theory" and was Emeritus Professor of guided wave photonics at Australian National University (ANU).
Biography.
Born in England, Love received a masters and DPhil in applied mathematics from the University of Cambridge and University of Oxford. He was a postdoc in San Diego and Toronto, before moving to Australia in 1973, where he became a postdoc fellow in ANU's applied mathematics department. He was a Life Member of the Australian Optical Society (AOS) and in 2009 received the most prestigious award of the AOS, the Beattie Steel medal.
As an Emeritus Professor at ANU he helped create the Wanda Henry Scholarship in Photonics. and later the Love Scholarship.
In 2015 Love cofounded the Australian company Modular Photonics.


Guenter Brueckner

Guenter E. Brueckner (1934–1998) was a solar physicist who spent much of his career at the US Naval Research Lab. His life's efforts included research into aspects of the sun relevant to radio signal quality, terrestrial weather, space weather and applications of plasmas such as in fusion energy. He is known for work on coronal mass ejections; various innovations in solar observing optical systems, in particular the Skylab mission, design and development (with John-David F. Bartoe) of the Solar Ultraviolet Spectral Irradiance Monitor (SUSIM) on the Upper Atmosphere Research Satellite (UARS); and for being the principal investigator for the LASCO instrument.
In the 1970s, he worked with Richard Tousey to make several notable observations including the coronal mass ejections mentioned above, lithium ions in solar flares, and various other things.


Marjorie Corcoran

Marjorie Diane Blasius Corcoran (1950 – February 3, 2017) was an American particle physicist who worked as a professor at Rice University.
Biography.
Born as Marjorie Blasius, she grew up in Beavercreek, Ohio, and was 1968 co-valedictorian of Beavercreek High School.
She earned a bachelor's degree in physics in 1972 from the University of Dayton, graduating "summa cum laude",
and in the same year married Christopher Corcoran, taking his surname. As a graduate student at Indiana University Bloomington, she began doing high-energy physics research at Fermilab. Her 1977 doctoral dissertation, "Measurement of the polarization parameter in proton-proton elastic scattering for beam momenta ranging from 20 GeV/c to 200 GeV/c", was supervised by Homer Neal. She joined the Rice University faculty in 1980.
She died while bicycling on February 3, 2017 in Houston, from a collision with a METRORail train.
Contributions.
As a professor at Rice, Corcoran continued her work at Fermilab as part of several large collaborative physics projects
including the D0 experiment, KTeV collaboration, and muon-to-electron-conversion experiment.
She also worked in physics outreach activities that included founding the Houston QuarkNet Program for high school physics students and teachers, helping to found a Women in Physics Group at Rice, sending undergraduates to physics conferences, and otherwise encouraging other women to participate in physics.
Awards and honors.
In 1992, the American Physical Society (APS) named her as a fellow "for contributions to experiments studying spin asymmetries in hadronic collision". In 2015, the APS listed her as their January 2015 Woman of the Month.


Aviva Gileadi

Aviva E. Gileadi (In Hebrew: אביבה גלעדי, born Eva Fischmann November 26, 1917 – June 8, 2001) was an Israeli nuclear scientist, a professor at the Israel Institute of Technology (Technion) in the department of Nuclear Engineering. She was a specialist in the use of Nuclear reactors for energy production and Desalination. She was the first woman in the Western Bloc to receive a license for the operation of a nuclear reactor and the only one with such a license in 1963.
Biography.
Eva Fischmann was born on November 26, 1917, in Budapest, Hungary, to Samuel Fischmann and Gizella (née Kupferstein). She studied at the University of Budapest where she received her PhD. During World War II she was sent to a concentration camp.
In 1948 she emigrated to Israel, where she changed her name to Aviva, met and married Michael Gileadi, who was her second husband and worked as a radiographer. Aviva Gileadi taught at the high school of Kibbutz Givat HaShlosha and also worked for a time at the Weizmann Institute of Science.
In 1955, Gileadi moved to Haifa, and started working at the Technion, initially at the Department of Physics, and in 1958, upon the founding of the Department of Nuclear Engineering, she became a professor in that department.
In 1960, she won a scholarship to study for a year at the Argonne National Laboratory, and to research for a semester at the department of Nuclear Physics at the University of Michigan.
When the scholarship came to an end, she accepted an offer of another year to earn a degree in Nuclear sciences. During that time she enrolled on a course for operating nuclear reactors and she received an operator licence. Newspapers in 1963 claimed that Gileadi was the only women in the western world to hold such a license.
In 1965 Gileadi was invited by the US government to assist in activating the Boiling Nuclear Superheater (BONUS) Reactor Facility in Puerto Rico. As part of her job, she instructed a team of engineers in the operation the nuclear reactor. In addition, she taught a Master of Science class in Nuclear Engineering.
Gileadi Died in 2001, in Tampa, Florida.
Personal life.
Gileadi was married twice. She married Hungarian mathematician and teacher Ivan Seres (1907–1966). Before emigrating to Israel, she divorced Seres. In Israel, she married Michael Gileadi, and they had two children.


Vasily Astratov

Vasily Astratov is a full professor of Physics and Optical Science at the University of North Carolina at Charlotte. He became known for launching synthetic opals as new self-assembled photonic crystals for visible light in 1995 in his former group at Ioffe Institute in Russia (jointly with Yurii Vlasov, Alexander Kaplyanskii and co-authors). This work has resulted in a quest for inverse opals with a complete three-dimensional Photonic band gap
Early life.
He received his M.S. from the Saint Petersburg State University, Russia, in 1981, and received his Ph.D. degree from the A.F. Ioffe Physical-Technical Institute, St. Petersburg, in 1986. At this institution he had accomplished a career as a research scientist, rising through the ranks from staff member (1981-1992), group leader (1992-1997), to senior member of staff in 1997. In 1997-2001 he worked as a postdoctoral scholar at the University of Sheffield where he developed novel surface coupling techniques for studying photonic crystal waveguides and semiconductor microcavities.
Research.
Prof. V. N. Astratov joined UNC-Charlotte in 2002. His current research is devoted to microspherical photonics including applications of photonic nanojets, coupled-cavity arrays and waveguides resonant light pressure effects and super-resolution microscopy. He was a topical editor for the journal "Optics Express" in 2005-2011 and an editor and co-editor for two Focus Issues of this journal. He has served as a technical committee member for major international conferences including CLEO 2006-07 and 2012–14, IEEE Photonics 2014–17, Photonics West 2017, ICTON 2009–17, and OECC/ACOFT 2008 and 2014. He co-/authored 15 patents in the US and Russia, and about 180 research publications which eventually brought him an h-index of 44.
Awards.
He is a recipient of a number of awards including International Visitor Award in France by Triangle de la Physique in 2011, Senior Visiting EPSRC Fellow Award in the UK in 2006, Award of the Exchange Program adopted between Royal Society and Russian Academy of Sciences in 1996, and the Award in the Annual Competition from A.F. Ioffe Physical-Technical Institute in 1985.


John Dirk Walecka

John Dirk Walecka, often quoted as "J. Dirk Walecka" (born March 11, 1932) is an American theoretical nuclear and particle physicist. He is a fellow of the American Physical Society and the author of numerous textbooks in physics. Walecka is currently the Governor's Distinguished CEBAF Professor of Physics, Emeritus at the College of William and Mary.
Life.
Walecka studied at Harvard University as an undergraduate, reviving a Bachelor of Arts in 1954, and received his doctorate in 1958 under Victor Weisskopf at the Massachusetts Institute of Technology. Walecka moved to Stanford University in 1959, where he was made Assistant Professor in 1960, upon completing his NSF fellowship, and Professor in 1966. From 1977 to 1982 he was head of the physics faculty and from 1987 he holds the title of Emeritus Professor of Physics. From 1986 to 1992 he was the scientific director of the Continuous Electron Beam Accelerator Facility (CEBAF) in Newport News, Virginia. From 1992 he was the Distinguished CEBAF Professor of Physics at the College of William and Mary, where he headed the Nuclear Physics Institute and the Physics Faculty. In 1991 he served as the Distinguished Ship Lecturer at Stanford. Also from 1992 he worked at the Thomas Jefferson National Accelerator Facility.
Walecka is the author of a standard work on quantum mechanical many-body theory with Alexander Fetter and a book on many-body methods in theoretical nuclear physics. He was particularly concerned with electron scattering on nuclei. In 2000 he edited Felix Bloch's lectures on statistical mechanics (World Scientific).
Awards.
Walecka has been a fellow of the American Physical Society since 1971. and was a fellow of the National Science Foundation from 1958 through 1960, while at CERN and then Stanford.
In 1996 Walecka received the Tom W. Bonner Prize in Nuclear Physics. for "his preeminent theoretical guidance and inspirational leadership in exploiting electromagnetic and weak probes of the nucleus and for his fundamental contributions to the understanding of the nucleus as a relativistic quantum many-body system."
In 2009 he received the Eugene Feenberg Memorial Medal "for theoretical contributions in electroweak interactions with nuclei, the development of relativistic field theories of the nuclear many-body problem and unparalleled achievements in the education of a generation of young nuclear many-body physicists".


Richard Hammond (physicist)

Richard Hammond is an Adjunct Professor at the University of North Carolina at Chapel Hill and the author of the book "The Unknown Universe: The Origin of the Universe, Quantum Gravity, Wormholes, and Other Things Science Still Can't Explain". He also works for the United States Army Research Laboratory as a theoretical physicist. He has authored several academic papers on general relativity and quantum mechanics.


Applied Physics Express

Applied Physics Express or APEX is a scientific journal publishing letters, with usually no more than three pages per (concise) article. The main purpose is to rapidly publish original, timely, and novel research papers in applied physics. As part of its aim, the journal intends for papers to be novel research that has a strong impact on relevant fields and society. It is notable that the journal considers satisfaction of this criterion as showing the paper merits priority handling in the review and publication processes. In keeping with this aim, its issues are published online on a weekly basis. The print version is published monthly.
The journal is the successor of "Japanese Journal of Applied Physics Part 2", i.e., the "letter" and "express letter" sections.
Indexing and abstracting.
APEX is abstracted and indexed in "Journal Citation Reports", SCImago Journal Rank, SCOPUS, Science Citation Index, and Current Contents.


M. Parker Givens

Miles Parker Givens (Richmond, Virginia, 9 June 1916 — 11 January 2013) was an American optical physicist, former acting director and professor emeritus at The Institute of Optics at the University of Rochester.
His work spanned several topics in physical optics, including holography and photogrammetry. He made important contributions to the development of optical data processing and synthetic holography.
Career.
After graduating in 1937 from the University of Richmond, Givens studied physics at Cornell University, with particular focus on the spectroscopy of metal surfaces. He received a doctorate degree from Cornell in 1942.
Between 1942 and 1946, Givens served as instructor of physics at the Pennsylvania State University. He also spent a year with the proximity fuze group of Johns Hopkins University's Applied Physics Laboratory.
In 1947, Givens became an assistant professor at The Institute of Optics, where he would spend the rest if his career, eventually becoming an emeritus professor there.
He served as acting director of the Institute from 1975 to 1977
Although Givens officially retired in 1981 at the mandatory age of 65 (at that time a federal law), he continued to teach for another 22 years, and even served as Acting Dean of Rochester University's in 1984-1985.
Givens retired for the second time in 2004.
Personal life.
M. Parker Givens was born in Richmond, Virginia, on 9 June 1916.
He was married to Gene M. Givens, and together they had a daughter, Jean F. Givens, and two sons, Robert P. Givens and R. Wayne Givens.
The family lived in Williamson, New York, about an hour away from the University of Rochester.
Givens died on 11 January 2013, at 96 years of age, having outlived his wife and his two sons — he was survived by Jean F. Givens, his only daughter. He was buried next to his wife, in Crewe, Virginia.
Legacy.
While very successful in research, Givens said the main object of his career was helping people to learn.
Givens' doctoral student James C. Wyant and his wife endowed the "", in recognition of his success as an inspirational educator. The first recipient of the chair was Robert W. Boyd.


Richard Edward Hughes

Richard Edward Hughes is an American physicist.
Hughes earned a bachelor's degree in electrical engineering and a doctorate in physics, both from the University of Pennsylvania. He pursued postdoctoral research at the University of Rochester before joining the Ohio State University faculty as an assistant professor in 1996. Hughes became an associate professor in 2001, and was promoted to full professor in 2005. He was elected a fellow of the American Physical Society in 2010, "[f]or his contributions to the heavy flavor program at the Tevatron. For the development of bottom quark tagging used in the discovery of the top quark and his contributions and leadership of the Level 1 tracking and triggering system crucial to the Run II physics program at CDF."