Thursday, July 22, 2010

Deceased--Gerson Goldhaber

Gerson Goldhaber
February 20th, 1924 to July 19th, 2010

"Gerson Goldhaber, world-famed physicist, dies"


David Perlman

July 22nd, 2010

San Francisco Chronicle

Gerson Goldhaber, an internationally known physicist who contributed to some of the most important discoveries of the past five decades in particle physics and cosmology, died Monday at his Berkeley home after several years of failing health. He was 86.

Dr. Goldhaber, an award-winning staff member at the Lawrence Berkeley National Laboratory and its predecessor laboratories since 1953, was a leading participant there in the exploration of particles hidden deep within the atom and the discovery of the mysterious dark energy that speeds the expansion of the universe.

"Gerson had an unerring sense of where great discoveries were to be made, from the antiproton, to the psi and charm particles, and finally to dark energy," said Robert Cahn, his longtime colleague at the lab and co-author with Dr. Goldhaber of "The Experimental Foundations of Particle Physics," published in 1989.

Dr. Goldhaber first earned distinction by contributing to the discovery in 1955 of the subatomic particle called the antiproton. He worked with his first wife, the late Sulamith Löw Goldhaber, a nuclear chemist and physicist, to confirm the particle's existence. That finding was a key contribution that led to the 1959 Nobel Prize in physics for Emilio Segre and Owen Chamberlain.

In 1960, Dr. Goldhaber and physicist George Trilling formed an experimental particle physics group that discovered the A meson, a subatomic particle. In 1972, the group worked with scientists at the Stanford Linear Accelerator Center led by Burton Richter to discover the first "charm" quark - a discovery that later became known as the J/psi particle and led to Nobel Prizes for Richter and Samuel C.C. Ting of Massachusetts Institute of Technology.

Shifting his focus to astrophysics in 1989, Dr. Goldhaber joined the Berkeley lab's search for exploding stars called supernovas. In 1997, he announced that an analysis of data from that study showed that the universe's expansion was not slowing as expected but was accelerating - the earliest dated evidence for what would quickly become famous as "dark energy."

Gerson Goldhaber was born in Chemnitz, Germany, on Feb. 20, 1924, and moved with his family to Egypt in 1933 to escape Nazi persecution. He earned his master's degree in physics at the University of Jerusalem in 1947 and his doctorate from the University of Wisconsin in 1950.

In 1965, during a family trip around the world, Sulamith Goldhaber fell ill and died, and as solace Dr. Goldhaber turned to art, focusing on painting and drawing. Four years later, he married Judith Margoshes Golwyn, a playwright and poet who was also the lead science writer at the Berkeley lab, and the two collaborated on many art projects as well as articles on scientific subjects.

Dr. Goldhaber was named California Scientist of the Year in 1977 and winner of the American Physical Society's Panofsky Prize in 1991.

He was a Fellow of the American Physical Society and of the American Academy of Arts and Sciences; a member of the National Academy of Sciences, and a foreign member of the Royal Swedish Academy of Science.

He is survived by his wife Judith, son Nathaniel, daughters Michaela and Shaya, and three grandsons.

Institute for Nuclear and Particle Astrophysics...

Gerson Goldhaber was born in Chemnitz, Germany, Feb. 20, 1924. With the rise of nazism, the family left Germany in 1933. He, an older brother, and their parents went to Cairo, Egypt where Gerson attended an English high school. In 1942 he began to study physics at the Hebrew University in Jerusalem that led to a M.Sc. degree in 1947. His thesis research, under Ernst Alexander, was a crystallographic study with X-rays.

In Jerusalem Gerson met his first wife, Sulamith Löw, then a chemistry student. They were married in 1947, the year in which she also earned her M.Sc. degree, and when they were both admitted to graduate school at the University of Wisconsin Sula pursued nuclear chemistry, and Gerson physics. At UW Gerson made his first upward move in energy from KeV X-rays to MeV protons. There he studied nuclear resonances in elements excited by protons accelerated in an electrostatic generator that had been developed by Ray Herb. For a Ph. D. thesis Gerson devised an innovative method of measuring gamma-ray spectra from observation of proton recoils produced by deuteron photodisintegration in D2O loaded photographic emulsions.

Upon attaining the degree in 1950 he took up a position as Instructor at Columbia University. At Columbia's Nevis Lab. Gerson took his next step up in energy, and into particle physics, working at its newly commissioned 340 MeV cyclotron. Here, after a foray with David Bodansky into development of scintillation counters to measure pulse-height spectra, he returned to his loaded-emulsion technique to study pion interactions with protons and deuterons. Sula and their young son Amos Nathaniel joined Gerson at Nevis. She, having morphed from chemist to physicist, joined Gerson in a very successful career of joint experimental work that continued productively until her sudden death in 1965.

Perhaps the most ambitious, certainly the cleverest, application of the loaded emulsion technique was a search for evidence of what later became famous as the 33 pion-nucleon resonance. To observe pions of appropriate energy, which sorry to say could not escape the cyclotron’s magnetic field, Gerson and Leon Lederman, in a technological tour de force, exposed the loaded emulsions inside the cyclotron vacuum tank. Alas, the chosen pion energies being just below and just above the resonance energy they missed an important discovery.

Then, in 1953, Gerson made his last move, joining the Physics faculty at the University of California at Berkeley and the research staff at its Radiation Laboratory (now the Lawrence Berkeley National Lab., LBNL). Here he moved up further in energy to the soon to be commissioned 6 BeV (now GeV) Bevatron proton synchrotron. He and Sula, together with other Rad Lab people at times, vigorously attacked the outstanding questions in particle physics, again with emulsion detectors. Their research included determination of many properties - masses, lifetimes, decay schemes - of the "strange" K-mesons and hyperons. These results contributed to the tau-theta puzzle that finally was solved by T. D. Lee and C. N. Yang whose analysis led to the shocking discovery that parity is not conserved in weak interactions. Then, following the observation by Chamberlain, Segre, Ypsilantis, and Wiegand of putative antiprotons, Gerson and Gosta Ekspong nailed their identity in annihilations on nuclei in emulsions exposed to a beam of those particles. Gerson spent much of the next few years studying and elucidating details of the annihilation process. The emulsion gave way to the bubble chamber as the principal device with which to study elementary particle properties and interactions. During somewhat more than a decade, Gerson and collaborators found Bose-Einstein correlations in multi-pion states, showed the striking differences in K+ and K-.behavior, determined the spin of the K* resonance, discovered the A and the anti-Omega-, studied the Q-meson and made other studies of pion and K+ interactions.

In 1969 Gerson married Judith Margoshes Golwyn, a science writer, playwright, and poet. They are parents of two daughters, Michaela and Shaya.

In the next two decades the LBL/SLAC collaboration built and operated an electronic detector, a triggered tracking, time-of-flight and calorimetric device with which he and colleagues studied products of electron-positron annihilations made in the SPEAR storage ring at Stanford University. They produced many astonishing results, chief, perhaps, among them the discovery of bound and bare Charm quarks dressed into Psions and D-Mesons, that provided crucial support to validate the current quantum-chromodynamics strong-interaction paradigm. Later, the group measured the mass and width of the Z0 boson with the enhanced MkII detector at the new SLC collider at SLAC.

Then Gerson made a remarkable shift in research from particle to cosmic physics. Since 1989 Gerson has been associated with the Supernova Cosmology Project at LBNL, studying properties of very distant supernovae, those with redshift parameter up to z ~1. Since, as they have shown, these type Ia supernovae can be calibrated as "standard candles", their observed properties can provide information about the cosmological deceleration of the expanding universe. The extremely surprising result was that, contrary to all expectations, the universe’s expansion in fact is accelerating. This seems to imply that a mysterious dark energy with repulsive gravity permeates all space. With these results the SCP people have presented scientists with the outstanding challenge to come to an understanding of the nature of this most peculiar energy.

Among the honors awarded Gerson Goldhaber are:
Ford Foundation Fellowships, 1960-61 and 1966
Guggenheim Fellowship, 1972
Loeb Lecturer, Harvard University, 1976
California Scientist of the Year, 1977
Doctorate of Philosophy honoris causa, University of Stockholm, 1986
Panofsky Prize of the American Physical Society, 1991 (co-recipient with Francois Pierre)

Gerson Goldhaber is a Fellow of the American Physical Society and of the American Academy of Arts and Sciences, an elected Foreign Member of the Royal Swedish Academy of Science, and an elected member of the U. S. National Academy of Science

Gerson Goldhaber [Wikipedia]

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