Katherine Oppenheimer

Katherine "Kitty" Vissering Oppenheimer ( Puening; August 8, 1910 – October 27, 1972) was a German-American biologist, botanist, and a member of the Communist Party of America. She is best known as the wife of activist Joe Dallet, and then of physicist J. Robert Oppenheimer, the director of the Manhattan Project's Los Alamos Laboratory during World War II.
Early life.
Katherine "Kitty" Vissering was born in Recklinghausen, Germany, on August 8, 1910, the only child of Franz Puening and his wife Käthe Vissering. Although she claimed that her father was a prince and that her mother was related to Queen Victoria, this was untrue. Her mother was a cousin of Wilhelm Keitel, who later became a field marshal in the German Army during World War II, and was hanged in 1946.
Kitty arrived in the United States on May 14, 1913 aboard the SS "Kaiser Wilhelm der Grosse". Her father, a metallurgical engineer, had invented a new kind of blast furnace, and had gained employment with a steel company in Pittsburgh, and the family settled in the suburb of Aspinwall, Pennsylvania. Although her first language was German, she soon became fluent in English, speaking both languages without accent. Her parents regularly took her with them on summer visits to Germany.
After graduating from Aspinwall High School in June 1928, Kitty enrolled at the University of Pittsburgh. She lived at home and attended freshman classes in mathematics, biology and chemistry. Her father now worked for Koppers, and held patents for the design of blast furnaces. Kitty convinced her parents that it would be a good idea for her to study in Germany, and she sailed for Europe in March 1930. It is doubtful that she took any classes, but she did meet Frank Ramseyer, an American studying music in Paris under Nadia Boulanger, before sailing for home on 19 May.
Kitty completed the first year of her degree, but married Ramseyer before a Justice of the Peace in Pittsburgh on 24 December 1932. The couple moved to an apartment near Harvard University, where Ramseyer hoped to pursue a master's degree in music. She re-enrolled at the University of Pittsburgh in January 1933, and returned to her parents' house in Aspinwall. In June 1933 she sailed to Europe again, with her husband. When she returned, she enrolled at the University of Wisconsin, although there is no record of her ever completing any classes. She obtained an annulment of her marriage from the Superior Court of Wisconsin on 20 December 1933. She later told friends that she had discovered evidence that Ramseyer was a homosexual and a drug addict. She also had an abortion.
Communism.
At a New Year's Eve party later that year, Kitty met Joseph Dallet, Jr., the son of a wealthy Long Island businessman who had attended Dartmouth College. He had been radicalized by the 1927 executions of Sacco and Vanzetti, and had joined the Communist Party of America in 1929. He had been involved in the International Unemployment Day protest in Chicago on 6 March 1930 that had been brutally repressed by the authorities, and was currently working as a union organizer with the steel workers in Youngstown, Ohio. At one point he ran for mayor of Youngstown on the Communist Party ticket, but was not elected.
Kitty's parents had moved to Claygate, southwest of London, where her father represented a Chicago-based firm. On returning to the United States on 3 August 1934 after visiting family in Europe, she moved in with Dallet, becoming his common-law wife. They shared a room in a dilapidated boarding house that cost $5 per month. Gus Hall and John Gates had a room down the hall. They lived on the dole, $12.50 per month each, while Dallet protested against it. As the wife of a party member, Kitty was allowed to join the Communist Party, but only after proving her loyalty by hawking copies of the "Daily Worker" on the streets. Her party dues were 10c a week.
They separated in June 1936, and Kitty went to live with her parents in Claygate, where she worked as a German-to-English translator. Months went by without any word from Dallet, until Kitty discovered that her mother had been hiding his letters to her. "Her mother," her friend Anne Wilson recalled, "was a real dragon, a very repressive woman. She disappeared one day over the side of a transatlantic ship, and nobody missed her. That says it all."
The last letter from Dallet said that he was heading to Spain on the to join the International Brigades fighting in the Spanish Civil War. Kitty met up with Dallet and his best friend Steve Nelson in Cherbourg, and they travelled to Paris together. After a few days there, she returned to London, and they headed south, crossing into Spain where he joined the Mackenzie-Papineau Battalion, a unit composed of American and Canadian volunteers.
Kitty wanted to join Dallet in Spain, and finally secured permission to do so. Her trip to Spain was delayed by hospitalization for an operation on 26 August 1937 for what was initially thought to be appendicitis, but which was determined to be ovarian cysts, which were removed by the German doctors. Kitty returned to England to recuperate. Before she could depart for Spain, the news arrived that Dallet had been killed in action on 17 October 1937. His letters to her were published as "Letters from Spain by Joe Dallet, American Volunteer, to his Wife" (1938).
Kitty went to see Nelson, who was in Paris, having been wounded in August, and they returned to New York, where she stayed with Nelson and his wife Margaret at their home in Brooklyn for two months. She then headed for Philadelphia to see her friend Zelma Baker, who worked at the Cancer Research Institute at the University of Pennsylvania. Kitty enrolled at the University of Pennsylvania. There she met Richard Stewart Harrison, a medical doctor with degrees from Oxford University, who was completing his internship in the US. They were married on 23 November 1938.
Romance with Oppenheimer.
Soon after, Harrison left for Pasadena, California, for his residency at the California Institute of Technology (Caltech), while Kitty completed her bachelor's degree in botany at the University of Pennsylvania, and was offered a postgraduate research fellowship at the University of California, Los Angeles. At Caltech, Harrison worked with physicist Charles Lauritsen. The X-Ray laboratory at Caltech used for physics research was also used for experimental cancer therapy research. It was at a garden party thrown by Lauritsen and his wife Sigrid in August 1939 that Kitty met Robert Oppenheimer, a physicist who taught at Caltech for part of each year. Soon after, Kitty began an affair with Robert. They were frequently seen about town in his Chrysler coupe. Robert had dated several women since his break up with long-time girlfriend Jean Tatlock, some of them married, like Kitty. At Christmas time she went up to Berkeley without her husband, to spend time with Robert. His friend Haakon Chevalier met Kitty at a holiday dinner party thrown by the pianist Estelle Caen, one of Robert's ex-girlfriends.
Robert invited Harrison and Kitty to spend the summer at his New Mexico ranch, "Perro Caliente". Harrison declined, as he was engaged in his research, but Kitty accepted. Robert Serber and his wife Charlotte collected Kitty in Pasadena, and drove her to "Perro Caliente", where they met up with Robert, his brother Frank Oppenheimer, and his wife Jackie. The Serbers had met Kitty before, at Charlotte Serber's parents' house in Philadelphia in 1938. The Oppenheimers loved to ride through the pine and birch forests and floral meadows of the Sangre de Cristo Mountains, camping with minimal food and equipment. Kitty impressed them with her riding ability; horsemanship was a normal accomplishment for women of her social class, and she had learned to ride as a girl on the riding trails around Aspinwall. Kitty and Robert rode out to stay the night with his friend Katy Page in Los Pinos, New Mexico. The following day Page rode to "Perro Caliente" on her bay horse to return Kitty's night gown, which had been left under Robert's pillow.
Kitty later told Anne Wilson that she got Robert to marry her the "old-fashioned way"—by getting pregnant. In September 1940, Robert phoned Harrison with the happy news, and they agreed that the best way forward was for Kitty to get a divorce so she could marry Robert. Soon after, Robert shared a podium with Nelson to raise money for refugees from the Spanish Civil War, and he informed him that he was engaged to Kitty. Nelson's wife was also pregnant, and he named his daughter, who was born in November 1940, Josie in memory of Dallet. To obtain a divorce, Kitty moved to Reno, Nevada, where she stayed for six weeks to meet the state's residency requirements. The divorce was finalised on November 1, 1940, and Kitty married Robert the following day in a civil ceremony in Virginia City, Nevada, with the court janitor and clerk as witnesses.
Manhattan Project.
Their child, a son they called Peter, was born in Pasadena, on May 12, 1941, during Robert's regular session at Caltech. When they returned to Berkeley, he bought a new house at One Eagle Hill with a view over the Golden Gate. Kitty worked at the University of California as a laboratory assistant. They left Peter with the Chevaliers and a German nurse and headed out to "Perro Caliente" for the summer. The holiday was marred when Robert was trampled by a horse, and Kitty was injured when she had an accident in their Cadillac convertible. The United States entered World War II in December 1941, and Robert began recruiting staff for the Manhattan Project. Among the first were the Serbers, who moved into the apartment over the garage at One Eagle Hill.
On March 16, 1943, the couple boarded a train for Santa Fe, New Mexico. By the end of the month, they had moved to Los Alamos, New Mexico, where they occupied one of the buildings formerly belonging to the Los Alamos Ranch School. Los Alamos was known to the occupants as "the Hill" and to the Manhattan Project as Site Y. Robert became the director of Project Y. Kitty abdicated the role of post commander's wife to Martha Parsons, the wife of Robert's deputy, Navy Captain William S. Parsons. She put her biologist training to use working for the director of the Health Group at Los Alamos, Louis H. Hempelmann, conducting blood tests to assess the danger of radiation.
In 1944, Kitty became pregnant again. Her second child, a girl Katherine who she named after her mother but called Toni, was born on December 7, 1944. Like other babies born in wartime Los Alamos, Toni's birth certificate gave the place of birth as P.O. Box 1663. In April 1945, Kitty was depressed by the isolation of Los Alamos, and she left Toni with Pat Sherr, the wife of physicist Rubby Sherr; Pat had recently lost her son, Michael, to SIDS. Kitty returned with Peter to Bethlehem, Pennsylvania to live with her parents. They returned to Los Alamos in July 1945.
Later life.
With the end of the war in August 1945, Robert had become a celebrity, and Kitty had become an alcoholic. She suffered a series of bone breaks from drunken falls and car crashes. In November 1945, Robert left Los Alamos to return to Caltech, but he soon found that his heart was no longer in teaching. In 1947, he accepted an offer from Lewis Strauss to take up the directorship of the Institute for Advanced Study in Princeton, New Jersey. The job came with rent-free accommodation in the director's house, a ten-bedroom 17th-century manor with a cook and groundskeeper, surrounded by of woodlands. Robert had a greenhouse built for Kitty, where she raised orchids; for her birthdays Robert had rare species flown in from Hawaii. Olden Manor was sometimes known as "Bourbon Manor"; Kitty and Robert liked to keep the liquor cabinet well stocked, and like many of their generation, liked to celebrate cocktail hour with martinis, Manhattans, Old Fashioneds and highballs. Both were also fond of smoking, and Kitty's habit of combining too much alcohol with smoking in bed led to a plethora of holes in her bedding and at least one house fire. She sometimes took too many pills, and suffered from abdominal pains caused by pancreatitis. Pain often prompted outbursts of anger.
In 1952, Toni came down with polio, and doctors suggested that a warmer climate might help. The family flew down to the Caribbean, where they rented a ketch. Robert and Kitty discovered a mutual love of sailing, while Toni soon recovered. Henceforth, the family would spend part of each summer on Saint John in the Virgin Islands, eventually building a beach house there. On January 6, 1967, Robert was diagnosed with inoperable cancer, and he died on February 18, 1967. Kitty had his remains cremated and his ashes were placed in an urn, which she took to St. John and dropped them into the sea off the coast, within sight of the beach house. She took up with Robert Serber, whose wife Charlotte had committed suicide in May 1967. She talked him into buying a yawl, which they sailed from New York to Grenada. In 1972, they purchased a ketch, with the intention of sailing through the Panama Canal and to Japan via the Galapagos Islands and Tahiti. They set out, but Kitty became ill, and was taken to Gorgas Hospital, where she died of an embolism on October 27, 1972. Serber and Toni had her remains cremated, and they scattered her ashes near Robert's.


Steven Girvin

Steven M. Girvin is an American physicist, who is the Eugene Higgins Professor of Physics and deputy provost for science and technology at Yale University. Girvin is noted for his theoretical work on quantum many body systems, such as the fractional quantum Hall effect.
Biography.
Girvin was born in Austin, Texas in 1950 and went to high school in the village of Brant Lake, New York. A graduate of Bates College and the University of Maine, Girvin received his Ph.D. in physics from Princeton University in 1977 after completing a doctoral dissertation, titled "Topics in condensed matter physics: the role of exchange in the lithium K edge and the fluorescence spectrum of heavily doped cadmium sulphide", under the supervision of John J. Hopfield. Girvin worked as a post-doctoral researcher at the Indiana University, Bloomington and the National Bureau of Standards and held faculty position at Indiana University, before joining Yale as a Professor of Physics. Girvin was awarded a bronze medal for superior federal service by the Department of Commerce while serving as a physicist at the Bureau of Standards.
Girvin's research focus has been theoretical study of collective quantum behavior in strongly correlated many body systems and their phase transitions,; he has worked on problems such as quantum Hall effect, superconductor-insulator transition, quantum spin chains and so on. He works with experimentalists Rob Schoelkopf and Michel Devoret on the engineering problem of building a quantum computer, and on developing a new "circuit QED" using superconducting electrical circuits. The group was successful in experimentally implementing two-qubit quantum algorithms on a superconducting circuit. Girvin co-edited the book "The Quantum Hall Effect", which has been translated to Japanese, Chinese and Russian.
Girvin, James P. Eisenstein and Allan H. MacDonald won the 2007 Oliver E. Buckley Condensed Matter Prize for their "Fundamental experimental and theoretical research on correlated many-electron states in low dimensional systems"
In September 2020, Girvin was appointed as the director of the Co-design Center for Quantum Advantage located at Brookhaven National Laboratory. In his role, Girvin will oversee more than 80 scientists across 24 institutions as they "do the basic research needed to make dramatic advances in the performance of quantum computer modules".


Christopher T. Hill

Christopher T. Hill (born June 19, 1951) is an American theoretical physicist at the Fermi National Accelerator Laboratory who did undergraduate work in physics at M.I.T. (B.S., M.S., 1972), and graduate work at Caltech (Ph.D., 1977, Murray Gell-Mann). Hill's Ph.D. thesis, "Higgs Scalars and the Nonleptonic Weak Interactions" (1977) contains one of the first discussions of the two-Higgs-doublet model.
Hill is an originator of the idea that the Higgs boson is composed
of top and anti-top quarks. This emerged from the concept of the
top quark infrared fixed point,
which predicted (1981) that the top quark would be very heavy, contrary
to most popular ideas at the time. The fixed point prediction
lies within 20% of the observed top quark mass (1995). The fixed point implies
that the top quarks are strongly coupled at very short
distances and can form a composite Higgs boson. This led to top quark condensates, topcolor, and also dimensional deconstruction.
The binding
mechanism may be gravitation, which improves the agreement of the fixed point with the top quark mass, and predicts
that there exist many sequential, heavier Higgs bosons
with large couplings to all quarks and leptons. This may
explain the puzzle of the many small parameters in the standard model.
Several new heavy Higgs bosons, such as the b-quark Higgs bound state,
may be accessible to the LHC in the process
formula_1 (b
and anti-b quark).
Hill coauthored (with Elizabeth Simmons) a comprehensive review of strong dynamical theories
which has shaped many of the experimental searches for new physics at the Tevatron and LHC.
Heavy-light mesons contain a heavy quark and a light anti-quark, and display
remarkable chiral dynamics (see chiral symmetry breaking).
Hill co-developed the theory (with W. Bardeen and E. Eichten). This
correctly predicted an abnormally long-lived resonance,
the formula_2 and numerous decay modes which have
been confirmed by experiment.
Hill is also an originator of cosmological models of dark energy and dark matter based upon ultra-low mass bosons associated with neutrino masses and was first to propose that the cosmological constant is
connected to the neutrino mass, as formula_3.
He has also developed modern theories of the origin of ultra-high-energy nucleons and neutrinos from grand unification relics, such as cosmic strings.
More recently he has focused on spontaneously broken scale symmetry (or Weyl symmetry), where the scale of gravity (Planck mass) and the inflationary phase of the ultra-early universe are generated together as part of a unified phenomenon dubbed "inertial symmetry breaking."
This has led (with G. G. Ross) to the discovery of gravitational contact terms, which play an essential role in the consistency of Weyl transformations with quantum mechanics.
Hill is a "Distinguished Scientist" at Fermilab, former Head of the Theoretical Physics Department (2005 - 2012) and a Fellow of the American Physical Society. He has co-authored three popular books with Nobel laureate Leon Lederman
about physics and cosmology, and the commissioning of the Large Hadron Collider.


Roberto Peccei

Roberto Daniele Peccei (; January 6, 1942 – June 1, 2020) was a theoretical particle physicist whose principal interests lay in the area of electroweak interactions and in the interface between particle physics and physical cosmology. He was most known for formulating the Peccei–Quinn theory (with Helen Quinn), which attempts to resolve the strong CP problem in particle physics.
Peccei was a Vice Chancellor for Research at the University of California, Los Angeles between 2000 and 2010.
Early life and education.
The son of Aurelio Peccei (founder of the Club of Rome), Roberto Peccei was born in 1942 in Torino, Italy. He completed his secondary school in Argentina, and came to the United States in 1958 to pursue his university studies in physics. He obtained a B.S. from MIT in 1962, and M.S. from New York University (NYU) in 1964 and a Ph.D. from the MIT Center for Theoretical Physics in 1969.
Career.
After a brief period of postdoctoral work at the University of Washington, he joined the faculty of Stanford University in 1971, where (with Helen Quinn) he originated Peccei–Quinn theory, still the most famous proposed solution to the strong CP problem. In 1978, he returned to Europe as a staff member of the Max Planck Institute in Munich, Germany. He joined the "Deutsches Elektronen-Synchrotron" (DESY) Laboratory in Hamburg, Germany, as the Head of the Theoretical Group in 1984. He returned to the United States in 1989, joining the faculty of the Department of Physics at UCLA. Soon thereafter, he became Chair of the Department, a position he held until becoming Dean of the Division of Physical Sciences of the College of Letters and Sciences in 1993.
Until his death in June 2020, Peccei was on the Editorial Board of Nuclear Physics B Supplement, and the Journal of Physics G. He was a member of the Club of Rome, a Trustee of the World Academy of Art and Science and President of the Fondazione Aurelio Peccei and he was a Fellow of both the American Physical Society and the Institute of Physics in the United Kingdom. In the last 15 years, he served on numerous advisory boards both in Europe and in the U.S. He chaired both the Scientific Advisory Board for the Laboratory for Nuclear Science at Cornell University and the Visiting Committee for the Laboratory of Nuclear Science at MIT. He also was a member of the Visiting Committee for the Department of Physics at MIT and was the Convener of the Vice Chancellor for Research Council in the University of California.


PP (complexity)

In complexity theory, PP is the class of decision problems solvable by a probabilistic Turing machine in polynomial time, with an error probability of less than 1/2 for all instances. The abbreviation PP refers to probabilistic polynomial time. The complexity class was defined by Gill in 1977.
If a decision problem is in PP, then there is an algorithm for it that is allowed to flip coins and make random decisions. It is guaranteed to run in polynomial time. If the answer is YES, the algorithm will answer YES with probability more than 1/2. If the answer is NO, the algorithm will answer YES with probability less than or equal to 1/2. In more practical terms, it is the class of problems that can be solved to any fixed degree of accuracy by running a randomized, polynomial-time algorithm a sufficient (but bounded) number of times.
Turing machines that are polynomially-bound and probabilistic are characterized as PPT, which stands for probabilistic polynomial-time machines. This characterization of Turing machines does not require a bounded error probability. Hence, PP is the complexity class containing all problems solvable by a PPT machine with an error probability of less than 1/2.
An alternative characterization of PP is the set of problems that can be solved by a nondeterministic Turing machine in polynomial time where the acceptance condition is that a majority (more than half) of computation paths accept. Because of this some authors have suggested the alternative name "Majority-P".
Definition.
A language "L" is in PP if and only if there exists a probabilistic Turing machine "M", such that
Alternatively, PP can be defined using only deterministic Turing machines. A language "L" is in PP if and only if there exists a polynomial "p" and deterministic Turing machine "M", such that
In both definitions, "less than or equal" can be changed to "less than" (see below), and the threshold 1/2 can be replaced by any fixed rational number in (0,1), without changing the class.
PP vs BPP.
BPP is a subset of PP; it can be seen as the subset for which there are efficient probabilistic algorithms. The distinction is in the error probability that is allowed: in BPP, an algorithm must give correct answer (YES or NO) with probability exceeding some fixed constant c > 1/2, such as 2/3 or 501/1000. If this is the case, then we can run the algorithm a number of times and take a majority vote to achieve any desired probability of correctness less than 1, using the Chernoff bound. This number of repeats increases if "c" becomes closer to 1/2, but it does not depend on the input size "n".
The important thing is that this constant "c" is not allowed to depend on the input. On the other hand, a PP algorithm is permitted to do something like the following:
Because these two probabilities are so close together, especially for large "n", even if we run it a large number of times it is very difficult to tell whether we are operating on a YES instance or a NO instance. Attempting to achieve a fixed desired probability level using a majority vote and the Chernoff bound requires a number of repetitions that is exponential in "n".
PP compared to other complexity classes.
PP contains BPP, since probabilistic algorithms described in the definition of BPP form a subset of those in the definition of PP.
PP also contains NP. To prove this, we show that the NP-complete satisfiability problem belongs to PP. Consider a probabilistic algorithm that, given a formula "F"("x"1, "x"2, ..., "x""n") chooses an assignment "x"1, "x"2, ..., "x""n" uniformly at random. Then, the algorithm checks if the assignment makes the formula "F" true. If yes, it outputs YES. Otherwise, it outputs YES with probability formula_1 and NO with probability formula_2.
If the formula is unsatisfiable, the algorithm will always output YES with probability formula_3. If there exists a satisfying assignment, it will output YES with probability at least
formula_4
(exactly 1/2 if it picked an unsatisfying assignment and 1 if it picked a satisfying assignment, averaging to some number greater than 1/2). Thus, this algorithm puts satisfiability in PP. As SAT is NP-complete, and we can prefix any deterministic polynomial-time many-one reduction onto the PP algorithm, NP is contained in PP. Because PP is closed under complement, it also contains co-NP.
Furthermore, PP contains MA, which subsumes the previous two inclusions.
PP also contains BQP, the class of decision problems solvable by efficient polynomial time quantum computers. In fact, BQP is low for PP, meaning that a PP machine achieves no benefit from being able to solve BQP problems instantly. The class of polynomial time on quantum computers with postselection, PostBQP, is equal to PP (see #PostBQP below).
Furthermore, PP contains QMA, which subsumes inclusions of MA and BQP.
A polynomial time Turing machine with a PP oracle (PPP) can solve all problems in PH, the entire polynomial hierarchy. This result was shown by Seinosuke Toda in 1989 and is known as Toda's theorem. This is evidence of how hard it is to solve problems in PP. The class #P is in some sense about as hard, since P#P = PPP and therefore P#P contains PH as well.
PP strictly contains TC0, the class of constant-depth, unbounded-fan-in uniform boolean circuits with majority gates. (Allender 1996, as cited in Burtschick 1999).
PP is contained in PSPACE. This can be easily shown by exhibiting a polynomial-space algorithm for MAJSAT, defined below; simply try all assignments and count the number of satisfying ones.
PP is not contained in SIZE(nk) for any k (proof).
Complete problems and other properties.
Unlike BPP, PP is a syntactic, rather than semantic class. Any polynomial-time probabilistic machine recognizes some language in PP. In contrast, given a description of a polynomial-time probabilistic machine, it is undecidable in general to determine if it recognizes a language in BPP.
PP has natural complete problems, for example, MAJSAT. MAJSAT is a decision problem in which one is given a Boolean formula F. The answer must be YES if more than half of all assignments "x"1, "x"2, ..., "x""n" make F true and NO otherwise.
Proof that PP is closed under complement.
Let "L" be a language in PP. Let formula_5 denote the complement of "L". By the definition of PP there is a polynomial-time probabilistic algorithm "A" with the property that
We claim that without loss of generality, the latter inequality is always strict; the theorem can be deduced from this claim: let formula_7 denote the machine which is the same as "A" except that formula_7 accepts when "A" would reject, and vice versa. Then
which implies that formula_5 is in PP.
Now we justify our without loss of generality assumption. Let formula_11 be the polynomial upper bound on the running time of "A" on input "x". Thus "A" makes at most formula_11 random coin flips during its execution. In particular the probability of acceptance is an integer multiple of formula_13 and we have:
Define a machine "A"′ as follows: on input "x", "A"′ runs "A" as a subroutine, and rejects if "A" would reject; otherwise, if "A" would accept, "A"′ flips formula_15 coins and rejects if they are all heads, and accepts otherwise. Then
This justifies the assumption (since "A"′ is still a polynomial-time probabilistic algorithm) and completes the proof.
David Russo proved in his 1985 Ph.D. thesis that PP is closed under symmetric difference. It was an open problem for 14 years whether PP was closed under union and intersection; this was settled in the affirmative by Beigel, Reingold, and Spielman. Alternate proofs were later given by Li and Aaronson (see #PostBQP below).
Other equivalent complexity classes.
PostBQP.
The quantum complexity class BQP is the class of problems solvable in polynomial time on a quantum Turing machine. By adding postselection, a larger class called PostBQP is obtained. Informally, postselection gives the computer the following power: whenever some event (such as measuring a qubit in a certain state) has nonzero probability, you are allowed to assume that it takes place. Scott Aaronson showed in 2004 that PostBQP is equal to PP. This reformulation of PP makes it easier to show certain results, such as that PP is closed under intersection (and hence, under union), that BQP is low for PP, and that QMA is contained in PP.
PQP.
PP is also equal to another quantum complexity class known as PQP, which is the unbounded error analog of BQP. It denotes the class of decision problems solvable by a quantum computer in polynomial time, with an error probability of less than 1/2 for all instances. Even if all amplitudes used for PQP-computation are drawn from algebraic numbers, still PQP coincides with PP.


Dmitry Lachinov

Dmitry Aleksandrovich Lachinov () (10 May 1842 – 15 October 1902) was a Russian physicist, electrical engineer, inventor, meteorologist and climatologist.
Biography.
Dmitry Lachinov studied in the St. Petersburg University, where he was a pupil of Heinrich Lenz, Pafnuty Chebyshev and Feodor Petrushevsky. In 1862, when the University was closed because of the students' unrest, Lachinov went to Germany and for two and a half years studied there under the guidance of Gustav Kirchhoff, Robert Bunsen and Hermann Helmholtz, attending practical lessons in their laboratories in Heidelberg and Tübingen.
In a paper released in 1880, Lachinov became the first one to point out the possibility of electricity transmission over long distances, and to propose the means of achieving it — 18 months before the first publication of the article with similar conclusions by Marcel Deprez.
In 1889 Lachinov wrote the first textbook on meteorology and climatology in Russia. In its 2nd edition (July 1895) he gave the first description of the lightning detector invented earlier by Alexander Popov (the device was also a prototype of the first practical radio receiver).
Lachinov's own inventions include a mercury pump, economizer for electricity consumption, electrical insulation tester (or "defectoscope"), optical dynamometer, a special types of photometer and electrolyser. One of his main achievements was a method of industrial synthesis of hydrogen and oxygen through electrolysis (1888).
Dmitry Lachinov is great-grandfather of physical chemist Mikhail Schultz.
Lachinov was The Officer of the Order Légion d'honneur.


Density cup

A density cup is an instrument that is used to ensure quality control in a paint or lacquer. It does this by measuring the density of the paint or lacquer, and comparing this density with the density of a standard for that paint or lacquer. If the density reading is different from the standard, then there is an error in paint composition because if there were no error in paint composition, then the measurement would match up to the standard density for that paint or lacquer.
Knowing the density of a paint is essential because a consistent density assures overall consistency between products of the same color.
Density cups are precisely measured cylinders that are made of stainless steel, and usually have a hole in the top through which excess liquid and air bubbles can escape.


Henry M. Foley

Henry Michael Foley (1917–1982) was an American
experimental physicist.
He was a professor and a leading physicist at Columbia University, later serving as chairman of the physics department. In 1948, Polykarp Kusch, working with Henry Foley, discovered the anomalous magnetic dipole moment of the electron. He served on the JASON Defense Advisory Group, an independent group of scientists which advises the United States Government on matters of science and technology. He also served on the MX Missile Basing advisory panel.


F. I. G. Rawlins

Francis Ian Gregory Rawlins CBE FRSE FSA FIP (1895–2 March 1969) was a British physicist and crystallographer. Professionally he was known as Ian Rawlins however most friends called him Fig Rawlins. He was an expert on x-ray photography and shadowgraphs.
He was Vice President of the International Institute for Conservation.
Life.
He was born in 1895 the son of William Donaldson Rawlins KC (1846-1920) and educated privately. He avoided service in the First World War due to illness.
From 1919 he studied physics first at the University of Edinburgh, and then at the University of Cambridge, graduating with an MSc. He then undertook postgraduate studies at Marburg University under Professor Schaefer.
In 1929 he became Supervisor of Crystallography at Fitzwilliam College, Cambridge he was promoted to Director of Natural Studies. In 1934 he became the official physicist for the National Gallery, London overseeing scientific authentication under Kenneth Clark. He rose to the position of Deputy Keeper of the Gallery.
In 1937 he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Sir Edmund Taylor Whittaker, James Pickering Kendall, Charles Barkla and John Edwin MacKenzie.
In the Second World War he oversaw and advised on the relocation of the National Galleries artistic treasures to a quarry in Wales.
He died on 2 March 1969.


Vincenzo Miotti

Vincenzo Miotti (25 July 1712, Murano - 15 February 1787, Murano) was an Italian physicist and astronomer.
Life.
Born in the parish of Santo Stefano on Murano to Daniele Miotti and Angela Licini, he was the first of three brothers and two sisters. He came from a wealthy family of glaziers which owned a furnace, but he left the family business in the hands of his brother Alvise, preferring a career in the church.
After studying in the patriarchal seminary in Venice at San Cipriano, run by the Somaschi Fathers, he distinguished himself in classics, mathematics, physics and astronomy. He joined the Camaldolese cultural circle at San Michele in Isola, where he met Angelo Calogerà and Fortunato Mandelli.
He became a priest at Santa Maria e San Donato and led a cloistered life, declining the many academic posts offered to him and devoting himself to designing and building instruments for physics and astronomy demonstrations, which were used and highly valued by Jérôme Lalande, Paolo Frisi, Ruggiero Giuseppe Boscovich and Alessandro Volta. Mainly main of card and wood, few of them now survive, though one for demonstrating the tautochrone curve of a cycloid and another for parabolic motion do remain. Many small fragments and gadgets also survive in the Murano Glass Museum.


Henry Philip Freund

Henry Philip Freund from the Science Applications International Corporation, was awarded the status of Fellow in the American Physical Society, after they were nominated by their Division of Plasma Physics in 1997, for "seminal contributions to the theory of collective radiation mechanisms in plasma and relativistic electron beans, and the application of the theory to runaway electron instabilities in tokamaks and to coherent radiation sources such as Free-Electron Lases and Cerenkov Masers."


Azriel Genack

Azriel Genack is an American physicist, currently a Distinguished Professor at Queens College, City University of New York, and also a published author.


Proton radius puzzle

The proton radius puzzle is an unanswered problem in physics relating to the size of the proton. Historically the proton charge radius was measured by two independent methods, which converged to a value of about 0.877 femtometres (1 fm = 10−15 m). This value was challenged by a 2010 experiment using a third method, which produced a radius about 4% smaller than this, at 0.842 femtometres. New experimental results reported in the autumn of 2019 agree with the smaller measurement. While some believe that this difference has been resolved, this opinion is not yet universally held.
Problem.
Prior to 2010, the proton charge radius was measured using one of two methods: one relying on spectroscopy, and one relying on nuclear scattering.
Spectroscopy method.
The spectroscopy method uses the energy levels of electrons orbiting the nucleus. The exact values of the energy levels are sensitive to the nuclear radius. For hydrogen, whose nucleus consists only of one proton, this indirectly measures the proton radius. Measurements of hydrogen's energy levels are now so precise that the proton radius is the limiting factor when comparing experimental results to theoretical calculations. This method produces a proton radius of about (or ), with approximately 1% relative uncertainty.
Nuclear scattering.
The nuclear method is similar to Rutherford's scattering experiments that established the existence of the nucleus. Small particles such as electrons can be fired at a proton, and by measuring how the electrons are scattered, the size of the proton can be inferred. Consistent with the spectroscopy method, this produces a proton radius of about (or ).
2010 experiment.
In 2010, Pohl et al. published the results of an experiment relying on muonic hydrogen as opposed to normal hydrogen. Conceptually, this is similar to the spectroscopy method. However, the much higher mass of a muon causes it to orbit 207 times closer than an electron to the hydrogen nucleus, where it is consequently much more sensitive to the size of the proton. The resulting radius was recorded as , 5 standard deviations (5σ) smaller than the prior measurements. The newly measured radius is 4% smaller than the prior measurements, which were believed to be accurate within 1%. (The new measurement's uncertainty limit of only 0.1% makes a negligible contribution to the discrepancy.)
Since 2010, additional measurements using electrons have slightly reduced the estimated radius to (), but by reducing the uncertainty even more the disagreement has worsened to over 7σ.
A follow-up experiment by Pohl et al. in August 2016 used a deuterium atom to create muonic deuterium and measured the deuteron radius. This experiment allowed the measurements to be 2.7 times more accurate, but also found a discrepancy of 7.5 standard deviations smaller than the expected value. In 2017 Pohl's group performed yet another experiment, this time using hydrogen atoms that had been excited by two different lasers. By measuring the energy released when the excited electrons fell back to lower-energy states, the Rydberg constant could be calculated, and from this the proton radius inferred. The result is again ~5% smaller than the generally-accepted proton radius. In 2019, another experiment reported a measurement of the proton size using a method that was independent of the Rydberg constant -- its result, 0.833 femtometers, agreed with the smaller 2010 value once more.
Proposed resolutions.
The anomaly remains unresolved and is an active area of research. There is as yet no conclusive reason to doubt the validity of the old data. The immediate concern is for other groups to reproduce the anomaly.
The uncertain nature of the experimental evidence has not stopped theorists from attempting to explain the conflicting results. Among the postulated explanations are the three-body force, interactions between gravity and the weak force, or a flavour-dependent interaction, higher dimension gravity, a new boson, and the quasi-free hypothesis.
Measurement artefact.
Randolf Pohl, the original investigator of the puzzle, stated that while it would be "fantastic" if the puzzle led to a discovery, the most likely explanation is not new physics but some measurement artefact. His personal assumption is that past measurements have misgauged the Rydberg constant and that the current official proton size is inaccurate.
Quantum chromodynamic calculation.
In a paper by Belushkin "et al". (2007) including different constraints and pertubative quantum chromodynamics predicted a smaller proton radius than the 0.877 femtometres which was the accepted value at the time.
Proton radius extrapolation.
Papers from 2016 suggested that the problem was with the extrapolations that had typically been used to extract the proton radius from the electron scattering data though these explanation would require that there was also a problem with the atomic Lamb shift measurements.
Data analysis method.
In one of the most recent attempts to resolve the puzzle without new physics, Alarcón, "et al". (2018), at Jefferson Labs, have proposed that a different technique to fit the experimental scattering data in a theoretically as well as analytically justified manner produces a proton charge radius from the existing electron scattering data that is consistent with the muonic hydrogen measurement. Effectively, this approach attributes the cause of the proton radius puzzle to a failure to use a theoretically motivated function for the extraction of the proton charge radius from the experimental data. Another recent paper has pointed out how a simple, yet theory motivated change to previous fits will also give the smaller radius.
Relativistic reference frame issues.
Other investigators have suggested that the analysis used for the electron-based proton charge radius may not properly consider the rest frames of the different components of the experiments, in the light of special relativity. Polarization factors in muonic hydrogen which are not material in ordinary hydrogen have also been proposed as a possible solution.
Yet another paper in April 2019 suggested that scale relativity may provide an answer based on the relativistic sizes of protons and muons.
2019 measurements.
In September 2019, Bezginov et al. reported the remeasurement of the proton's charge radius for electronic hydrogen and found a result consistent with Pohl's value for muonic hydrogen. In November W. Xiong et al. reported a similar result using extremely low momentum transfer electron scattering.
Their results support the smaller proton charge radius, but do not explain why the results before 2010 came out larger. It is likely future experiments will be able to both explain and settle the proton radius puzzle.


Jerry Paul Draayer

Jerry Paul Draayer is the Roy P. Daniels Professor of Physics at Louisiana State University. He was elected as a fellow of the American Physical Society, for "enhancing our understanding of collective phenomena in atomic nuclei through algebraic shell-model analyses, statistical spectroscopy studies of strength distributions, explorations involving pseudo-spin symmetry, and the application of nonlinear methods."


Spacetime curvature


Zapple Monitor

The Zapple Monitor was a firmware-based product developed by Roger Amidon at Technical Design Laboratories (also known as "TDL"). TDL was based in Princeton, New Jersey, USA in the 1970s and early 1980s.
The "Zapple" monitor was a primitive operating system which could be expanded and used as a Basic Input/Output Services (BIOS) 8080 and Z80 based computers. Much of the functionality of Zapple would find its way into applications like 'Debug' in MS-DOS.
Zapple commands would allow a user to examine and modify memory, I/O, execute software (Goto or Call) and had a variety of other commands. The program required little in the way of then expensive Read Only Memory or RAM. An experienced user could use Zapple to test and debug code, verify hardware function, test memory, and so on.
A typical command line would start with a letter such as 'X' (examine memory) followed by a hexadecimal word (the memory address 01AB) and [enter] or [space]. After this sequence the content of the memory location would be shown [FF] and the user could enter a hexadecimal byte [00] to replace the contents of the address, or hit [space] or [enter] to move to the next address [01AB]. An experienced user could enter a small program in this manner, entering machine language from memory.
Because of the simple structure of the program, consisting of a vector table (one for each letter) and a small number of subroutines, and because the source code was readily available, adding or modifying Zapple was straightforward. The dominant operating system of the era, CP/M, required the computer manufacturer or hobbyist to develop hardware specific BIOS. Many users tested their BIOS subroutines using Zapple to verify, for example, a floppy disk track seek command, or read sector command, etc., was functioning correctly by extending Zapple to accommodate these operations in the hardware environment.
The general structure of Zapple lives on in the code of many older programmers working on embedded systems as it provides a simple mechanism to test the hardware before moving to more advanced user interfaces.


The Fifth Essence

The Fifth Essence: The Search for the Dark Matter in the Universe is the debut book by the American physicist Lawrence M. Krauss, published in 1989. Krauss talks about dark matter and its importance to our understanding of the universe. The book also contains information about modern astrophysics and Greek philosophers. The book was later updated and re-released as "" in 2000.


Jiuzhang (quantum computer)

Jiuzhang is the first photonic quantum computer to attain quantum supremacy. It was developed by a team from University of Science and Technology of China (USTC) led by Jian-Wei Pan and Chao-Yang Lu. The computer is named after "Jiuzhang suanshu", an ancient Chinese mathematical classic.
On 3 December 2020, USTC announced in "Science" that Jiuzhang successfully performed Gaussian boson sampling in 200 seconds, with a maximum of 76 detected photons. The USTC group estimated that it would take 2.5 billion years for the Sunway TaihuLight supercomputer to perform the same calculation. In addition to a quantum computational advantage, Jiuzhang has a Hilbert space 10 billion times larger than Google's superconductor-based Sycamore processor, and as such, is harder to simulate classically.


George Robert Carruthers

George Robert Carruthers (October 1, 1939 – December 26, 2020) was an African American inventor, physicist, engineer and space scientist. Carruthers perfected a compact and very powerful ultraviolet camera/spectrograph for NASA to use when it launched Apollo 16 in 1972. He designed it so astronauts could use it on the lunar surface, making all adjustments inside their bulky space suits. Upon instructions from Carruthers, they used the camera to record the Earth's outermost atmosphere, noting its variations, and also mapped portions of the far-ultraviolet sky recording stars and galaxies, and the gaseous media between them. In 1970, sending his instruments aboard Aerobee sounding rockets, he had demonstrated that molecular hydrogen exists in the interstellar medium. Among numerous citations and awards, in 2003, Carruthers was inducted into the National Inventor's Hall of Fame. He received an honorary doctorate for Engineering from Michigan Technological University, and in 2013 the 2012 National Medal for Technology and Invention from President Barack Obama.
Life and work.
Carruthers, who is African-American, was born October 1, 1939, in Cincinnati, Ohio to George and Sophia Carruthers. His father was a civil engineer and his mother was a homemaker. His family initially lived in Milford, Ohio. At an early age George, through reading popular space fiction and the early 1950s Colliers' series on space flight, developed an interest in physics, science and astronomy, which his father also encouraged. At the age of 10, he built his first telescope out of cardboard tubing and lenses purchased using money he earned as a delivery boy.
His father died when Carruthers was 12, and at that time his family moved to the South Side of Chicago where they stayed with relatives until George went to college. He did not perform well in elementary school, earning poor grades in math and physics. However, he won three separate science fair awards during this time. Also as a child, he enjoyed visiting Chicago museums, libraries and the Adler Planetarium that supplemented his avid science-fiction reading. After Sputnik he experimented with model rocketry, becoming a member of the junior division of the Chicago Rocket Society and various science clubs.
After graduating from Englewood High School, he entered the College of Engineering at the University of Illinois at Urbana–Champaign, and received a Bachelor of Science degree in aeronautical engineering in 1961. Carruthers did his graduate work at the University of Illinois and earned Master's degree in nuclear engineering in 1962. Carruthers received a Ph.D. in aeronautical and astronautical engineering in 1964. While conducting his graduate studies, Carruthers worked as researcher and teaching assistant studying plasma and gases. As he completed his thesis, he applied for a postdoctoral appointment at the U.S. Naval Research Laboratory funded by NSF, and spent the next 38 years of his life there.
During the 1980s, Carruthers helped create a program called the Science & Engineers Apprentice Program, which allows high school students to spend a summer working with scientists at the Naval Research Laboratory. Carruthers also worked with NRL's community outreach organization, and as such helped support several educational activities in the sciences in the Washington D.C. area.
Since 1983 he was Chairman of the Editing and Review Committee and Editor, "Journal of the National Technical Association".
During the summers of 1996 and 1997 he taught a course in Earth and Space Science for D.C. Public Schools Science teachers. He also helped develop a series of videotapes on Earth and Space science for high-school students.
Since 2002, retiring from NRL, Carruthers taught a two-semester course in Earth and Space Science at Howard University sponsored by a NASA Aerospace Workforce Development Grant.
On February 12, 2009, Carruthers was honored as a Distinguished Lecturer at the Office of Naval Research for his achievements in the field of space science.
On February 1, 2013, Dr. Carruthers was awarded the 2012 National Medal of Technology and Innovation by President Barack Obama at the White House.
He was a member of the American Astronomical Society, the American Geophysical Union, the American Institute of Aeronautics and Astronautics, the American Association for the Advancement of Science and the National Society of Black Physicists.
He lived most of his life in Washington, DC.
Carruthers died of congestive heart failure on December 26, 2020 in Washington D.C.
Inventions and discoveries.
Carruthers is considered the inventor of the first far-ultraviolet electronographic detector design that was robust enough to operate in space as the heart of a ultraviolet camera/spectrograph. His early work with this design detected an upper limit to the amount of molecular hydrogen that exists in the interstellar medium, answering numerous questions astronomers were asking at that time about what was then referred to as the "missing mass" problem.
In 1964, Carruthers began employment for the U.S. Naval Research Laboratory in Washington, D.C., where his work focused on far ultraviolet astronomy. 1969 was the year he received a patent for his invention, the "Image Converter," which detected electromagnetic radiation in short wavelengths, and in 1970, he made the first examination of molecular hydrogen in space.
Two years later, Carruthers developed the first moon-based observatory, the Far Ultraviolet Camera/Spectrograph, which was used in the Apollo 16 mission. In 1986, one of Carruthers' inventions captured an ultraviolet image of Halley's Comet. Among other projects, in 1991, he developed a camera that was used in a Space Shuttle Mission.


Stephen Streiffer

Stephen K. Streiffer (born 6 January 1966) is an American engineer from the Argonne National Laboratory. He attended Rice University and received his PhD from Stanford University. He was awarded the status of Fellow in the American Physical Society, after they were nominated by their Division of Materials Physics in 2007, for "experimental studies of ferroelectric thin film physics, that have established the relationships between epitaxial strain, ferroelectric phase transition behavior and domain structure, and size effects, and for advancing the fundamental understanding of complex oxide thin film microstructure."


Perley G. Nutting

Perley Gilman Nutting (1873–1949) was an American optical physicist and the founder of the Optical Society of America (OSA). He served as its first president from 1916 to 1917. OSA is now known as the Optical Society.
Born August 22, 1873, in Randolph, Wisconsin, Nutting was a graduate of Stanford University (BA, 1897), the University of California, Berkeley (MA, 1899), and Cornell University (PhD, 1903). He joined the National Bureau of Standards as a physicist in 1903. It is claimed that in 1904, Nutting constructed one of the earliest, if not the first, neon sign, which was displayed at the 1904 Louisiana Purchase Exposition; however, this story has been disputed.
In 1910, Nutting joined the staff of Eastman Kodak Company prior to the arrival of Kodak's first research director Kenneth Mees, in 1912. He was the author of the 1912 book "Outlines of Applied Optics", which called for an increased level of academic study in the applied optics field. In 1915, Nutting convened a series of meetings among Rochester, New York–based physicists that resulted in the founding of the OSA in January 1916.
Nutting moved from Kodak to Westinghouse Electric Company in 1917. In 1924 he returned to government work, moving to the United States Geological Survey where he remained until his retirement in 1943. He died August 8, 1949.
Nutting's son, Perley G. Nutting Jr., was the tireless grad student known as observer PGN for the demonstration of the MacAdam ellipse.


Munnerlyn Formula

The Munnerlyn Formula is the theoretical formula discovered by Charles Munnerlyn, which gives the depth an excimer laser will need to ablate during LASIK surgery or similar medical interventions. The formula states that the depth of the ablation (in micrometres) per diopter of refractive change is equal to the square of the diameter of the optical ablation zone measured in millimeters, divided by three. For example, to change refraction by 4 diopters with an optical zone of 3 mm would require ablation of 12 μm. As the depth of ablation is proportional to the square of the optical zone, changing the refraction by 4 diopters but with an optical zone of 6 mm would require a much deeper ablation of approximately 48 μm. The ablation depth does not include the transition zone of the surgery.
The actual ablation depth and surface shape will be slightly different from the theoretical Munnerlyn formula. Many factors must be taken into account at the time of the surgery. The sex, age, and race of the patient, and such things as the barometric pressure and ambient humidity will change slightly the required ablation.
The formula was derived based on creating a theoretical lenticular surface in a polymethylmethacrylate (PMMA) model, and modified by testing on in vivo animal tissue.


Frances Pleasonton

Frances Pleasonton (1912–1990) was a Particle Physicist at the Oak Ridge National Laboratory. She was an active teacher and researcher, and a member of the team who first demonstrated neutron decay in 1951.
Early life and education.
Pleasonton earned her Bachelor's degree at Bryn Mawr College. She was an editor of the Bryn Mawr College yearbook. She went on to teach at Winsor School, Girls Latin School of Chicago and Brearley School. She returned to Bryn Mawr College for her Master's degree, working as a Warden at Pembroke East, and graduated in 1943. She was demonstrator-elect in physics and took a leave of absence for government service in 1942. During her Master's degree she identified the crystal structure of Rochelle salt.
Research.
Pleasonton was an active researcher in neutron decay. There were several attempts to measure neutron half-life before the second world war, all of which failed due to the lack of availability of intense neutron sources. Arthur Snell and Leonard Miller built the Oak Ridge Graphite Reactor, which could focus beams of neutrons and allow scientists to observe their decay. They measured the half-life of a neutron in 1951. Pleasonton was supported by the United States Atomic Energy Commission and published broadly. In 1958 they examined the decay of helium-6, Pleasonton and Snell monitoring the directions of neutrinos and electrons. This result confirmed the electron-neutrino theory of beta decay. In 1973 she authored several sections of the report for the Nuclear Regulatory Commission. At Oak Ridge National Laboratory, Pleasonton's laboratory was visited by the Queen of Greece and the King of Jordan. Pleasonton went on to study the ionisation of xenon x-rays.
Pleasonton remained in Tennessee after her retirement from Oak Ridge National Laboratory and was involved in citizens groups to protect the environment.


Angela Clayton

Angela Helen Clayton MBE (1959 – 8 January 2014) was an internationally known physicist working in the fields of Nuclear Criticality Safety and Health Physics. She was also a campaigner for the rights of transgender people.
Professional career.
Her professional accomplishments included:
She held various roles in Safety Committees and the Reactor Safety Panel at the Atomic Weapons Establishment (now AWE, plc). She was interested in the subjects of criticality safety and Radiological Protection - Health Physics.
Clayton was also active in national and local Prospect trade union activities, including serving on the pension National Executive Committee (NEC) Advisory Sub Committee and was an elected trustee of the AWE Pension Scheme from 1 February 2009 - 1 February 2011.
After her early retirement in March 2011 on medical grounds due to complications from an old automobile accident in 1996, she pursued various artistic and intellectual activities including acquiring a large telescope with which she could engage in a lifelong love of astronomy.
Her most recent degree was in Law from the Open University. She graduated with a first in April 2009.
Personal life.
Her early interactions with medical practitioners were described as traumatic, leading her to transition without medical support. After living several years as a woman, she reengaged with medical practitioners to obtain surgery.
She worked as a campaigner with Press for Change beginning in 1999 and later served as their vice-president. Her interest in the role of trade unions in promoting equality for trans people led her to become the first “trans observer” to the UK Trades Union Congress (TUC) LGBT Committee. She was also involved in the development and implementation of the Gender Recognition Act 2004.
She was appointed a Member of the Order of the British Empire (MBE) in June 2005 "for services to gender issues". Clayton was a speaker at the Greater London LGBT Organising Day in February 2008. She contributed to the "Trans Data Position Paper" for the National Statistics: UK Statistics Authority in 2009.


CDHS experiment

CDHS was a neutrino experiment at CERN taking data from 1976 until 1984. The experiment was officially referred to as "WA1". CDHS was a collaboration of groups from CERN, Dortmund, Heidelberg, Saclay and later Warsaw. The collaboration was led by Jack Steinberger. The experiment was designed to study deep inelastic neutrino interactions in iron.
Experimental setup.
The core of the detector consisted of 19 (later 20) magnetized iron modules. In the spacings between these, drift chambers for track reconstruction were installed. Additionally, plastic scintillators were inserted into the iron. Each iron module therefore served successively as an interaction target, where the neutrinos hit and produced hadron showers, a calorimeter that measured those hadrons' energy and a spectrometer, determining the momenta of produced muons via magnetic deflection.
At the time of its completion in 1976, the overall detector was 20 m long and weighed approximately 1250 tons.
The experiment was located in CERN's West Area, in building 182. The neutrinos (and antineutrinos) were produced by protons from the Super Proton Synchrotron (SPS) at energies of around 400 GeV, which were shot onto a beryllium target.
History.
The experiment was first proposed in July 1973 by a group led by Jack Steinberger as a two-piece detector. The front should serve as the neutrino target and hadronic shower detector, the following second part should detect the muon traces. It was planned that the four proposing groups from Saclay, Dortmund, Heidelberg and CERN would contribute with complementary expertise and manpower. For example, Saclay was assigned to be in charge of the drift chambers, whereas CERN should handle the iron core magnets. It were also these four groups that gave the experiment its name: "CERN Dortmund Heidelberg Saclay (CDHS)".
Approximately 30 people should form the final experiment group.
After prolongued discussions with the SPS Committee, that was in charge of approving the proposals and distributing available money, an updated proposal for the new detector was submitted in March 1974. The suggested detector was a modular setup consisting of magnetized iron modules in combination with drift chambers and plastic scintillators. This new proposal was approved by the committee in April 1974. Construction started soon after and was completed in 1976. The experiment's official name was "WA1", since it was the first approved experiment at CERN's West Area.
The estimated cost of the detector ranged between 6 and 8 million CHF.
In 1979, an upgrade of the experimental setup was proposed. The main reason for this upgrade was the comparably low resolution of eight of the 19 detector modules. This situation should be improved by inserting twelve new and better modules, resulting in a slightly longer and significantly more accurate machine. The proposal also included the suggestion for a group from Warsaw University, led by Adam Para, to join the project.
Starting with the long shutdown of the Super Proton Synchrotron (SPS) from summer 1980 on, the requested changes were implemented. Eventually, half of the experiment's target calorimeters got replaced and the total number of detector modules was increased from 19 to 20. This led to four times higher spatial resolution of the produced particles as well as 25 % more accurate measurements of the deposited hadronic energy. Additionally, four new drift chambers were installed, improving the reconstruction of muon tracks. Later, a liquid hydrogen tank was added in front of the detector as a target to measure the structure function of protons.
CDHS took data with neutrinos delivered by the SPS from late 1976 until September 1984.
Results and discoveries.
The scientific goal of the CDHS experiment was to study high energy neutrino interactions. When the incoming neutrinos (or antineutrinos) were interacting with the target iron, either charged current ( + Fe → + anything) or neutral current ( + Fe → + anything) events could be produced.
One of the main objectives of the experiment was to determine the ratio between the neutral and the charged inclusive neutrino cross sections, from which the Weinberg angle could be inferred. Neutral currents had previously been discovered by the Gargamelle experiment, which had also provided first estimates of the Weinberg angle. The results were confirmed and measured with much higher precision by CDHS, allowing to predict the mass of the top quark, before it was discovered at the Tevatron, with approximately ±40 GeV precision.
Other measurements regarding the electroweak interaction within the standard model included the measurement of more than one muon; i.e. dimuon and trimuon events.
Results obtained at CDHS provided experimental validation of the standard model, at a time when this model was still in the testing phase. An important step in this regard was the falsification of the alleged "high-y anomaly". The value y characterizes the inelasticity of neutrino collisions, i.e. it measures the amount of energy that an incoming neutrino transfers to the hadrons during their collision. Experiments at Fermilab had found the so-called "high-y anomaly", which challenged the standard model. However, results from CDHS disproved those findings, strengthening the standard model.
CDHS examined the nucleon structure functions, which enabled scientists to confirm the theory of quantum chromodynamics (QCD). This work included the determination of the QCD coupling constant formula_1, verification of the quark's (s = ) and gluon's (s = 1) spin, as well as the falsification of both abelian theories of strong interactions and theories based on scalar gluons.
Additionally, the experiments provided insights into the structure of the nucleon, examining the distribution of gluons, quarks and antiquarks within it. Results from CDHS were in line with the quark parton model, that assigned quarks to be point-like partons. In this context, it was also confirmed that the number of valence quarks in a nucleon is 3. Finally, the CDHS results allowed to determine the momentum distribution of strange quarks and antiquarks within a nucleon.
During its last years of operation, the CDHS collaboration engaged in the search for neutrino oscillations. Although this phenomenon could not be confirmed using CERN's large energy neutrino beam, this attempt influenced the following experiments that eventually discovered neutrino oscillations.


Albert Einstein House

The Albert Einstein House at 112 Mercer Street in Princeton, Mercer County, New Jersey, United States was the home of Albert Einstein from 1935 until his death in 1955. His wife Elsa Einstein died in 1936 while living in this house.
The house was built sometime before 1876, as it originally stood on Alexander Street where Stuart Hall of the Princeton Theological Seminary was built in that year, also displacing the house now at 108 Mercer. The home is a simple pattern-book cottage and not in itself of unusual significance. Elsa Einstein purchased the home from Mary Clark Marden on July 24, 1935 for an undisclosed sum according to the deed which was recorded by the Mercer County Clerk's Office on August 1, 1935. For many years, Albert Einstein lived in the house with three women: his sister Maja, his step-daughter Margot Einstein-Marianoff (1899–1986), and his secretary Helen Dukas.
Albert Einstein reportedly requested that this house not be made a museum, and the family did not want it to be recognized as such. Nonetheless it was added to the National Register of Historic Places and further designated a U.S. National Historic Landmark in 1976.
After Albert Einstein, the house was owned by his sculptor step-daughter Margot Einstein until her death in 1986.
The house was owned by Eric Maskin and his family until 2012. He was the Albert O. Hirschman Professor in the School of Social Science at the Institute for Advanced Study in Princeton until 2011, and the 2007 Nobel Prize winner with two others. He is currently a Professor of Economics at Harvard University. Previously it was occupied by 2004 Nobel prize winner physicist Frank Wilczek when he was a professor in IAS between 1989 and 2001. Reportedly he requested the house from the IAS as his condition to move to Princeton, and he had been holding evening seminars in the house for graduate students. The house is now a private residence even though it is owned by IAS, and is not open to the public. There is no historical marker explaining the house's significance; however, there are strategically placed "Private Residence" signs around the house.


Bill Blevin

William Roderick Blevin AM DSc FAA FTSE FAIP FIP (born 31 October 1929, Inverell, New South Wales) is an Australian physicist. He was elected a Fellow of the Australian Academy of Science in 1985 and appointed a Member of the Order of Australia in 1989.


NA35 experiment

The NA35 experiment was a particle physics experiment that took place in the North Area of the Super Proton Synchrotron (SPS) at CERN. It used a streamer chamber with comprehensive hadronic and electromagnetic calorimetry. This experiment was used to observe the properties of nucleus-nucleus collisions at 60 and 200 GeV/nucleon, to understand the degree of stopping and thermalization, determine the energy densities achievable in those conditions, and to measure other related properties and quantities.
The first signature of quark–gluon plasma was observed by the NA35 experiment in 1995.
The NA35 experiment was approved on 03 February 1983 and completed on 31 May 1999. It was succeeded by the NA49 experiment. The spokesperson for the experiment was Peter Seyboth.


GENLN2

GENLN2 is suite of software programs that provide a general purpose line by line atmospheric transmittance and radiance model.


Toroidal ring model

The toroidal ring model, known originally as the Parson magneton or magnetic electron, is a physical model of subatomic particles. It is also known as the plasmoid ring, vortex ring, or helicon ring. This physical model treated electrons and protons as elementary particles, and was first proposed by Alfred Lauck Parson in 1915.
Theory.
Instead of a single orbiting charge, the toroidal ring was conceived as a collection of infinitesimal charge elements, which orbited or circulated along a common continuous path or "loop". In general, this path of charge could assume any shape, but tended toward a circular form due to internal repulsive electromagnetic forces. In this configuration the charge elements circulated, but the ring as a whole did not radiate due to changes in electric or magnetic fields since it remained stationary. The ring produced an overall magnetic field ("spin") due to the current of the moving charge elements. These elements circulated around the ring at the speed of light "c", but at frequency "ν" = "c"/2π"R", which depended inversely on the radius "R". The ring's inertial energy increased when compressed, like a spring, and was also inversely proportional to its radius, and therefore proportional to its frequency "ν". The theory claimed that the proportionality constant was Planck's constant "h", the conserved angular momentum of the ring.
According to the model, electrons or protons could be viewed as bundles of "fibers" or "plasmoids" with total charge ±"e". The electrostatic repulsion force between charge elements of the same sign was balanced by the magnetic attraction force between the parallel currents in the fibers of a bundle, per Ampère's law. These fibers twisted around the torus of the ring as they progressed around its radius, forming a Slinky-like helix. Circuit completion demanded that each helical plasmoid fiber twisted around the ring an integer number of times as it proceeded around the ring. This requirement was thought to account for "quantum" values of angular momentum and radiation. Chirality demanded the number of fibers to be odd, probably three, like a rope. The helicity of the twist, was thought to distinguish the electron from the proton .
The toroidal or "helicon" model did not demand a constant radius or inertial energy for a particle. In general its shape, size, and motion adjusted according to the external electromagnetic fields from its environment. These adjustments or reactions to external field changes constituted the emission or absorption of radiation for the particle. The model, then, claimed to explain how particles linked together to form atoms.
History.
Beginnings.
The development of the helicon or toroidal ring began with André-Marie Ampère, who in 1823 proposed tiny magnetic "loops of charge" to explain the attractive force between current elements. In that same era Carl Friedrich Gauss and Michael Faraday also uncovered foundational laws of classical electrodynamics, later collected by James Maxwell as Maxwell's equations. When Maxwell expressed the laws of Gauss, Faraday, and Ampère in differential form, he assumed point particles, an assumption that remains foundational to relativity theory and quantum mechanics today. In 1867 Lord Kelvin suggested that the vortex rings of a perfect fluid discovered by Hermann von Helmholtz represented "the only true atoms". Then shortly before 1900, as scientists still debated over the very existence of atoms, J. J. Thomson and Ernest Rutherford sparked a revolution with experiments confirming the existence and properties of electrons, protons, and nuclei. Max Planck added to the fire when he solved the blackbody radiation problem by assuming not only discrete particles, but discrete frequencies of radiation emanating from these "particles" or "resonators". Planck's famous paper, which incidentally calculated both Planck's constant "h" and Boltzmann's constant "k"B, suggested that something in the "resonators" themselves provided these discrete frequencies.
Numerous theories about the structure of the atom developed in the wake of all the new information, of which the 1913 model of Niels Bohr came to predominate. The Bohr model proposed electrons in circular orbit around the nucleus with quantized values of angular momentum. Instead of radiating energy continuously, as classical electrodynamics demanded from an accelerating charge, Bohr's electron radiated discretely when it "leaped" from one state of angular momentum to another.
Parson magneton.
In 1915, Alfred Lauck Parson proposed his "magneton" as an improvement over the Bohr model, depicting finite-sized particles with the ability to maintain stability and emit and absorb radiation from electromagnetic waves. At about the same time Leigh Page developed a classical theory of blackbody radiation assuming rotating "oscillators", able to store energy without radiating. Gilbert N. Lewis was inspired in part by Parson's model in developing his theory of chemical bonding. Then David L. Webster wrote three papers connecting Parson's magneton with Page's oscillator and explaining mass and alpha scattering in terms of the magneton. In 1917 Lars O. Grondahl confirmed the model with his experiments on free electrons in iron wires. Parson's theory next attracted the attention of Arthur Compton, who wrote a series of papers on the properties of the electron, and H. Stanley Allen, whose papers also argued for a "ring electron".
Current status.
The aspect of the Parson magneton with the most experimental relevance (and the aspect investigated by Grondahl and Webster) was the existence of an electron magnetic dipole moment; this dipole moment is indeed present. However, later work by Paul Dirac and Alfred Landé showed that a pointlike particle could have an intrinsic quantum spin, and also a magnetic moment. The highly successful modern theory, Standard Model of particle physics describes a pointlike electron with an intrinsic spin and magnetic moment. On the other hand, the usual assertion that an electron is pointlike may be conventionally associated only with a "bare" electron. The pointlike electron would have a diverging electromagnetic field, which should create a strong vacuum polarization. In accordance with QED, deviations from the Coulomb law are predicted at Compton scale distances from the centre of electron, 10−11 cm. Virtual processes in the Compton region determine the spin of electron and renormalization of its charge and mass. It shows that the Compton region of the electron should be considered as a coherent whole with its pointlike core, forming a physical ("dressed") electron. Notice that the Dirac theory of electron also exhibits the peculiar behaviour of the Compton region. In particular, electrons display zitterbewegung at the Compton scale. From this point of view, the ring model does not contradict QED or the Dirac theory and some versions could possibly be used to incorporate gravity in quantum theory.
The question of whether the electron has a substructure of any sort must be decided by experiment. All experiments to date agree with the Standard Model of the electron, with no substructure, ring-like or otherwise. The two major approaches are high-energy electron–positron scattering and high-precision atomic tests of quantum electrodynamics, both of which agree that the electron is point-like at resolutions down to 10−20 m. At present, the Compton region of virtual processes, 10−11 cm across, is not exhibited in the high-energy experiments on electron–positron scattering.
References.
 27- David L. Bergman, J. Paul Wesley ; "Spinning Charged Ring Model of Electron
 Yielding Anomalous Magnetic Moment", Galilean Electrodynamics. Vol. 1, 63-67 (Sept./Oct. 1990).


Forces of Nature (book)

Forces of Nature is a 2016 book by Professor Brian Cox and Andrew Cohen. The book accompanied the BBC One TV series of the same name, Forces of Nature.
Overview.
The book attempts to provide deep answers to simple questions, ranging from the nature of motion to the uniqueness of a snowflake. It uncovers how some of our planet's beautiful sights and events are forged by just a handful of natural forces.


W state

The W state is an entangled quantum state of three qubits which has the following shape
and which is remarkable for representing a specific type of multipartite entanglement and for occurring in several applications in quantum information theory. Particles prepared in this state reproduce the properties of Bell's theorem, which states that no classical theory of local hidden variables can produce the predictions of quantum mechanics. The state is named after Wolfgang Dür, who first reported the state together with Guifré Vidal, and Ignacio Cirac in 2002.
Properties.
The W state is the representative of one of the two non-biseparable classes of three-qubit states, the other being the Greenberger–Horne–Zeilinger state, which cannot be transformed (not even probabilistically) into each other by local quantum operations. Thus formula_2 and formula_3 represent two very different kinds of tripartite entanglement.
This difference is, for example, illustrated by the following interesting property of the W state: if one of the three qubits is lost, the state of the remaining 2-qubit system is still entangled. This robustness of W-type entanglement contrasts strongly with the GHZ state, which is fully separable after loss of one qubit.
The states in the W class can be distinguished from all other 3-qubit states by means of multipartite entanglement measures. In particular, W states have non-zero entanglement across any bipartition, while the 3-tangle vanishes, which is also non-zero for GHZ-type states.
Generalization.
The notion of W state has been generalized for formula_4 qubits and then refers to the quantum superpostion with equal expansion coefficients of all possible pure states in which exactly one of the qubits is in an "excited state" formula_5, while all other ones are in the "ground state" formula_6:
Both the robustness against particle loss and the LOCC-inequivalence with the (generalized) GHZ state also hold for the formula_4-qubit W state.
Applications.
In systems in which a single qubit is stored in an ensemble of many two-level systems the logical "1" is often represented by the W state, while the logical "0" is represented by the state formula_9. Here the W state's robustness against particle loss is a very beneficial property ensuring good storage properties of these ensemble-based quantum memories.


Robert Hamilton Austin

Robert Hamilton Austin (born 1946) is an American physicist and a professor of physics at Princeton University.
Life.
He was born in St. Charles, Illinois in 1946.
He received his BA in 1968 from Hope College. He received his M.S. and Ph.D. in physics from the University of Illinois at Urbana-Champaign. His current work concerns biological systems evolution and the research behind it.
Career.
He is currently Professor of Physics at Princeton University.
He is a Fellow of the American Physical Society (1988) and the American Association for the Advancement of Science. He was elected as a member of the National Academy of Sciences in 1999 and a member of the American Academy of Arts and Sciences in 2008.
In 2005, he received the Julius Edgar Lilienfeld Prize.


Telent

Telent Limited (styled as telent) is a British radio, telecommunications, and digital infrastructure systems installation and services provision company. The name was used from 2006 for those parts of the United Kingdom and German services businesses of Marconi Corporation (formerly General Electric Company, GEC) which had not been acquired by Ericsson. Companies with Marconi in their name can trace their ultimate origins, through mergers and takeovers, to The Marconi Company Ltd, founded by Guglielmo Marconi in 1897 as The Wireless Telegraph & Signal Company.
History.
The company's predecessor was formed in September 1961 as GEC Telecommunications Limited, a division of the GEC conglomerate. In 1988 the division became part of the GEC Plessey Telecommunications joint venture, and following the breakup of GPT during the 1990s it was renamed Marconi Communications Limited in 1998, when GEC decided to switch to use the better known Marconi brand name which it had owned for some time.
In January 2006, following Ericsson's acquisition of most Marconi assets, including the rights to the Marconi name, the remaining UK and German services business of Marconi Corporation which was not acquired and no longer had the rights to use the Marconi name was renamed Telent. In May 2007, Telent announced its move from Coventry to Warwick's Opus 40 business park.
In November 2007 Telent, which had inherited GEC's £2.5 billion pension scheme with several tens of thousands of members, was purchased by Pension Corporation for £400 million; the following month its shares were delisted and Telent became a private company.
In 2008 Telent made various acquisitions, including intelligent traffic systems group TSEU in March, leading communications infrastructure provider, the Alan Campbell Group, in July and telecoms service provider Premises Networks in September.
In September 2019 the pension scheme, described by Telent as a "disproportionately large liability", was bought out by Rothesay Life.
In September 2020, it was announced that Telent were awarded a contract with Openreach to support a £12 billion project for the UK's largest ultrafast broadband build, which would bring 'Full Fibre' broadband to thousands of homes and businesses.
Operations.
The company provides a range of network and communications services to industries including Rail, Traffic, Public Safety, Defence, Service Providers, Enterprise and Public Sector. Products include enterprise software systems, emergency services communications and logistics, integrated warehouse logistics systems and rail and metro systems. Customers include BAE Systems, BT, Highways England, HM Coastguard, Interoute, London Ambulance Service, Merseyside Fire & Rescue, Metropolitan Police, Network Rail, RNLI, Sky, Transport for London, Virgin Media and Vodafone.
The company has many operational sites within the UK and Ireland, including at Chorley in Lancashire, Warwick, Camberley in Surrey, Harbour Exchange in London, and Dublin. A team of telecommunications technicians and engineers provide support and new features development for the TDM System X network used by BT, Virgin Media, Kingston Communications, Vodafone, and Gibtelecom.
People.
From its formation in 2006, Telent's CEO was Mark Plato. He died in a motorcycle accident in September 2019. Non-executive director Frank McKay, former CEO of Travis Perkins and Brakes Group, was appointed as his temporary replacement and was succeeded in July 2020 by Jo Gretton, a Telent executive since 2006.


CUSB

CUSB (Columbia University-Stony Brook) was a particle detector at the Cornell Electron Storage Ring. CUSB, along with CLEO, discovered both the Υ(3S) and Υ(4S) meson resonances.
They also produced studies of the photon transitions between the Upsilon states and B meson decays.


Francesco Iachello

 Francesco Iachello (; born 11 January 1942, in Francofonte) is an Italian nuclear engineer and theoretical physicist, who works mainly on nuclear and molecular physics. He and his collaborator Akito Arima are the creators of the "interacting boson model".
Biography.
Iachello attained a doctorate 1964 as a nuclear technology engineer at the polytechnic institute in Turin and 1969 a doctorate in physics at the MIT Center for Theoretical Physics. Since 1978 he has been at Yale University, where he is at present J. W. Gibbs professor for physics and chemistry.
Iachello received the Chiaudano prize in 1968 and was a Fulbright Fellow in 1964. He was awarded in 1990 the Wigner Medal, in 1991 both the Taormina Prize and the Dutch AKZO Prize, and in 1993, along with Akito Arima, the Tom W. Bonner Prize of the American Physical Society. Iachello became a foreign member of the Royal Netherlands Academy of Arts and Sciences in 1996. He is also member of the Croatian Academy of Sciences. In 1997 he received the Centennial Prize of the Italian Physical Society. In 2002 he received the Meitner Prize of the European Physical Society. He has honorary doctorates from the University of Ferrara, the University of Seville, and Chung Yuan University in China.
Iachello is famous for the application of algebraic methods (Lie algebras) to the investigation of the spectra of atomic nuclei and molecules. In 1974 with Akito Arima he introduced the "Interacting Boson Model" into nuclear physics. This important model describes collective nuclear states with the help of the unitary group U(6). The underlying concept is to derive a model with pairs of neutrons and protons instead of unpaired nucleons. The pairs are treated as bosons with different quantum spin (s- and d- bosons, as named according to spin 0 and 2). In an extension of the model, the analogous effect with unpaired fermions has a description using supersymmetrical algebras.
In recent times he has worked mainly on the investigation of the quantum mechanical dynamics of molecules (e.g. quantum phase transitions, polymer dynamics) with algebraic methods, on which Iachello already began to work in 1981 (Vibron Model).


Richard Majeski

Richard Peter Majeski (born March 14, 1952) is an American physicist from the Princeton Plasma Physics Laboratory. He earned his bachelor's (1973) and master's (1974) degrees from the University of Scranton and his PhD in physics from Dartmouth College (1979).
He was awarded the status of Fellow in the American Physical Society, after they were nominated by their Division of Plasma Physics in 2007, for "fundamental studies of radio-frequency heating and plasma-wall interactions, including the first observation of Alfvén wave heating in a tokamak, the first demonstration of mode-conversion current drive, and pioneering work in the use of liquid lithium as a plasma-facing component."


Physics Reports

Physics Reports is a peer-reviewed scientific journal, a review section of "Physics Letters" that has been published by Elsevier since 1971. The journal publishes long and deep reviews on all aspects of physics. In average, the length of these reports is the same of a short book. These reports aim to make their main points intelligible to non-specialists. According to the "Journal Citation Reports", the journal has a 2014 impact factor of 20.033, as reported in the official website of the Journal.


G. W. C. Kaye

George William Clarkson Kaye (8 April 1880 – 16 April 1941) was an English physicist. He is best known as one of the authors, together with Thomas Laby, of the authoritative scientific reference work "Tables of Physical and Chemical Constants and Some Mathematical Functions", first published in 1911 and better known as "Kaye and Laby".
He was a driving force behind the formation and early years of the ‘International X-ray and Radium Protection Committee’ (IXRPC), the world's first international radiological protection body, created in 1928.
Kaye was born in Honley in West Yorkshire. Kaye attended the University of Cambridge from 1905. His career included working as an assistant to J. J. Thomson at the Cavendish Laboratory, and work for the Metrology Department of the National Physical Laboratory. He was made a Fellow of the Royal Society in 1939.


Chatoyancy

In gemology, chatoyancy ( ), or chatoyance or cat's eye effect, is an optical reflectance effect seen in certain gemstones, woods, and carbon fibre. Coined from the French "œil de chat", meaning "cat's eye", chatoyancy arises either from the fibrous structure of a material, as in tiger's eye quartz, or from fibrous inclusions or cavities within the stone, as in cat's eye chrysoberyl. The precipitates that cause chatoyance in chrysoberyl are the mineral rutile, composed mostly of titanium dioxide. Examined samples have yielded no evidence of tubes or fibres. The rutile precipitates all align perpendicularly with respect to cat's eye effect. It is reasoned that the lattice parameter of the rutile matches only one of the three orthorhombic crystal axes of the chrysoberyl, resulting in preferred alignment along that direction.
The effect can be likened to the sheen off a spool of silk: The luminous streak of reflected light is always perpendicular to the direction of the fibres. For a gemstone to show this effect best it must be cut en cabochon (rounded with a flat base rather than faceted), with the fibers or fibrous structures parallel to the base of the finished gem. The best finished specimens show a single sharply defined band of light that moves across the stone when it is rotated. Chatoyant stones of lesser quality display a banded effect as is typical with cat's-eye varieties of quartz. Faceted stones do not show the effect well.
Gem species known for this phenomenon include the aforementioned quartz, chrysoberyl, beryl (especially var. aquamarine), charoite, tourmaline, labradorite, selenite, feldspar, apatite, moonstone, thomsonite and scapolite amongst others. Glass optical cable can also display chatoyancy if properly cut, and has become a popular decorative material in a variety of vivid colors.
The term "cat's eye", when used by itself as the name of a gemstone, refers to a cat's eye chrysoberyl. It is also used as an adjective which indicates the chatoyance phenomenon in another stone, e.g., cat's eye aquamarine.
In woodworking.
Chatoyancy in wood occurs in various species – particularly hardwoods, and particularly where stresses from the weight of the growing tree result in denser patches, or where stresses cause burl or "bird’s eye". This ‘figure’, which has a striking three-dimensional appearance, is highly prized by woodworkers and their clients alike, and is featured regularly in furniture, musical instruments, and other decorative wood products. Figuring takes on a variety of forms and is referred to as "flame", "ribbon", "tiger stripe", "quilting", among other names.
This effect is sometimes called "wet look", since wetting wood with water often displays the chatoyancy, albeit only until the wood dries. Certain finishes cause the wood grain to become more pronounced. Oil finishes, epoxy, and shellac can strongly bring out the "wet look" effect. When the refractive index of the finish nearly matches that of the wood, light scattering no longer occurs at the wood surface, adding the appearance of depth to the wood's figure.


Jeremy England

Jeremy England is an American physicist who uses statistical physics arguments to explain the spontaneous emergence of life, and consequently, the modern synthesis of evolution. England terms this process "dissipation-driven adaptation".
Early life.
England's mother was the daughter of Polish Jewish Holocaust survivors while his father was a non-observant Lutheran. England was born in Boston and raised in a college town in New Hampshire. He was raised Jewish but did not study Judaism until he attended graduate school at Oxford University. He now considers himself an Orthodox Jew.
England earned a bachelor's degree in biochemistry from Harvard in 2003. After being awarded a Rhodes Scholarship, he studied at St. John's College, Oxford from 2003 until 2005. He earned his Ph.D. in physics at Stanford in 2009. In 2011, he joined the Massachusetts Institute of Technology Physics Department as an Assistant Professor. In 2019, he joined GlaxoSmithKline as a Senior Director in artificial intelligence and machine learning.
Theoretical work.
England has developed a hypothesis of the physics of the origins of life, that he calls 'dissipation-driven adaptation'. The hypothesis holds that random groups of molecules can self-organize to more efficiently absorb and dissipate heat from the environment. His hypothesis states that such self-organizing systems are an inherent part of the physical world.
Pulitzer-Prize winning science historian Edward J. Larson said that if England can demonstrate his hypothesis to be true, "he could be the next Darwin."
In popular culture.
England and his 'dissipation-driven adaptation' theory features in Dan Brown's novel "Origin".
The fictional character is not related to the real Jeremy England.
Awards.
England shared APS 2021 Irwin Oppenheim Award with Sumantra Sarkar. He is also listed in a Forbes "30 under 30" in science.
England was selected as Rhodes Scholar in 2003. Also in 2003, the Hertz Foundation awarded England a Hertz Fellowship.
References.
 Forbes.com seems to have lost most of the content on his profile and lists a broken link to the 2012 30-under-30 in Science. The Hertz Foundation profile mentions the 2018 Forbes 30-under-30. However, neither the 2012 nor the 2018 official listing pages on Forbes.com list England.


The Einstein Theory of Relativity

The Einstein Theory of Relativity (1923) is a silent short film directed by Dave Fleischer and released by Fleischer Studios.
History.
In August 1922, "Scientific American" published an article explaining their position that a silent film would be unsuccessful in presenting the theory of relativity to the general public, arguing that only as part of a broader educational package including lecture and text would such film be successful. "Scientific American" then went on to review frames from an unnamed German film reported to be financially successful.
Six months later, on February 8, 1923, the Fleischers released their relativity film, produced in collaboration with popular science journalist Garrett P. Serviss to accompany his book on the same topic. Two versions of the Fleischer film are reported to exist – a shorter two-reel (20 minute) edit intended for general theater audiences, and a longer five-reel (50 minute) version intended for educational use.
The Fleischers lifted footage from the German predecessor, "Die Grundlagen der Einsteinschen Relativitäts-Theorie", directed by Hanns-Walter Kornblum, for inclusion into their film. Presented here are images from the Fleischer film and German film. If actual footage was not recycled into "The Einstein Theory of Relativity", these images and text from the "Scientific American" article suggest that original visual elements from the German film were.
This film, like much of the Fleischer's work, has fallen into the public domain. Unlike Fleischer Studio's "Superman" or "Betty Boop" cartoons, "The Einstein Theory of Relativity" has very few existing prints and is available in 16mm from only a few specialized film preservation organizations.