he American Physical Society celebrates its 100th birthday in 1999. As part of this celebration the APS Centennial Committee recommended several Tprojects to inform the physics community, students, and the public about the achievements of physicists in the 20th century, including a Speakers Bureau to send hundreds of physicists and historians of phys- ics to lecture at universities and laboratories. 1998 APS President Andrew Sessler suggested that lec- tures on 20th century physics would be greatly en- hanced by pictures of the physicists whose theories and discoveries were being reviewed. This CD-ROM, welcome containing images of about 200 outstanding 20th century physicists with brief descriptions of their achievements, is the result. We hope it will be use- ful to anyone giving a survey talk on any aspect of modern physics, and that it will also be interesting to other physicists who want to see the faces that go with familiar names. How were the names chosen? The selection was done by a committee chaired by past President Sessler, consisting also of physicist-historians Stephen Brush, Gerald Holton, and Spencer Weart. Their pri- mary goal was to choose names likely to be men- tioned in lectures on 20th century physics. But there were two important limitations. First, the committee did not include anyone who died before 1900, although it included a few physicists (such as Boltzmann and Roentgen) whose most important contributions, while made before 1900, had a major impact on 20th century physics. Second, it excluded persons still alive at the end of 1997. Thus you will not find here pictures of Galileo, Newton, or Maxwell; nor, unfortunately, will you find women and minori- ties represented in the same proportion as in the current generation of active outstanding physicists. On the other hand, it interpreted the term “physicist” broadly, including several mathematicians, astronomers, chemists and earth scientists whose work is widely known and highly valued in the physics community. A third constraint was that the photos had to fit on a single CD-ROM. Thus it could not include every physicist recom- mended by one of the several groups consulted for suggestions. The committee used its own judgment to eliminate many names. While we are confident that all the persons included do in fact belong in this collection, it would be surprising if we did not receive complaints about some of the many omissions. We urge you to provide your reactions and suggestions concerning this project to the APS. We are especially in interested in learning how you found the CD-ROM useful and what changes would make it more so. The production of this CD-ROM was made possible by the resources and cooperation of the staff of the Center for History welcome of Physics at the American Center for Physics in College Park, Maryland, including the Emilio Segrè photograph collec- tion. Please note that you may use the images only for projection at lectures; permission to reproduce them in publications or in any other form must be requested from the copyright owner, indicated in the credit line for each photo. The Center for History of Physics, owns the world rights to many of these photos. To obtain permission for the remainder please contact the APS. We acknowledge also the invaluable assistance of Erika Ridgway and Elizabeth Buchan-Higgins, APS staff members, and Stephen Norton, a graduate student in the History and Philosophy of Science Program at the University of Maryland- College Park, for collecting information for the captions.

Selection Committee: Andrew Sessler (chair), Lawrence Berkeley Laboratory Stephen Brush, University of Maryland Celebrate Gerald Holton, Harvard University a Spencer Weart, Center for History of Physics Century of Physics SEARCH BY NAME A-L

Alfvén, Hannes Olaf Gösta Bragg, William Henry Ehrenfest-Afanassjeva, T.A. Hertz, Gustav Ludwig Alvarez, Luis Walter Bragg, William Lawrence Einstein, Albert Hess, Victor Franz Anderson, Carl David Brattain, Walter Houser Ellis, Robert A., Jr. de Hevesy, George Appleton, Edward Victor Breit, Gregory Fairbank, William Martin Hilbert, David Aston, Francis William Bridgman, Percy Williams Fermi, Enrico Hodgkin, Dorothy Crowfoot Ayrton, Hertha Brillouin, Léon Nicolas Feynman, Richard Phillips Hofstadter, Robert L. Bainbridge, Kenneth T. Chadwick, James Fowler, William Alfred Houtermans, Fritz Georg Bardeen, John Chandrasekhar, Subrahmanyan Franck, James Hubble, Edwin Powell Barkla, Charles Glover Chapman, Sydney Frank, Ilya Mikhailovich Imes, Elmer Samuel Becquerel, Antoine-Henri Cherenkov, Pavel Alekseyevich Frank, Philipp Ioffe, Abram F. Bell, John Stewart Cockcroft, John Douglas Franklin, Rosalind Elsie Jensen, Johannes Hans Daniel Bhabha, Homi Jehangir Compton, Arthur Holly Frenkel Yakov Ilyich Joliot, Frédéric Bitter, Francis Condon, Edward Uhler Frisch, Otto Robert Joliot-Curie, Irène Blackett, Patrick Maynard Stuart Crookes, William Fukui, Kenichi Kamerlingh-Onnes, Heike Blau, Marietta Curie, Pierre Gabor, Dennis Kapitza, Pyotr Bloch, Felix Curie, Marie Sklodowska Gamow, George von Kármán, Théodore Blodgett, Katharine Burr Davisson, Clinton Joseph Geiger, Hans Wilhelm Kastler, Alfred Bogolyubov, Nikolai Nikolaevich DeBroglie, Louis Victor Gibbs, Josiah Willard Kemble, Edward Crawford Bohm, David Debye, Petrus Göppert-Mayer, Maria Kerst, Donald William Bohr, Niels Henrik David Dicke, Robert Henry Goudsmit, Samuel Abraham Klein, Oskar Benjamin Boltzman, Ludwig E. Dirac, Paul Adrien Maurice Grad, Harold Kramers, Hendrik A. Born, Max Du Mond, Jesse William Monroe Hahn, Otto Kurchatov, Igor Bose, Satyendra Nath Eddington, Arthur Stanley Hale, George Ellery Kusch, Polykarp Bouchet, Edward Alexander Ehrenfest, Paul Heisenberg, Werner Karl Land, Edwin Herbert SEARCH BY NAME L-Z

Landau, Lev Davidovich Moseley, Henry Gwyn-Jeffreys Raman, Chandrasekhara Thomas, Llewellyn Landé, Alfred Mott, Nevill Francis Richardson, Owen Williams Thomson, George Paget Langevin, Paul Mulliken, Robert Sanderson Röntgen, Wilhelm Conrad Thomson, Joseph John Langmuir, Irving von Neumann, John Rossi, Bruno Tomonaga, Sin-itiro von Laue, Max Nier, Alfred Otto Carl Rutherford, Ernest Tuve, Merle Anthony Lawrence, Ernest Orlando Noether, Amalie Emmy Sabine, Wallace Clement Uhlenbeck, George Eugene Leavitt, Henrietta Swan Occhialini, Giuseppe Sakharov, Andrei Dmitrievich Urey, Harold Clayton Lehmann, Inge Onsager, Lars Salam, Abdus Van de Graaff, Robert J. Lemaître, Georges Oppenheimer, J. Robert Schiff, Leonard Issac Van Hove, Léon Libby, Willard Frank Patterson, Clair Cameron Schrödinger, Erwin Van Vleck, John H. Livingston, M. Stanley Paul, Wolfgang Schwarzschild, Martin Walton, Ernest Thomas Sinton London, Fritz Wolfgang Pauli, Wolfgang Schwinger, Julian Seymour Weyl, K.H. Herman Lonsdale, Kathleen Pauling, Linus Carl Segrè, Emilio Gino Wick, Gian-Carlo Lorentz, Hendrik Antoon Payne-Gaposchkin, Cecilia Serber, Robert Wideröe, Rolf Lyman, Theodore Peierls, Rudolf E. Shockley, William Wien, Wilhelm Mach, Ernst Perey, Marguerite Catherine Siegbahn, Karl Manne Georg Wiener, Norbert Marconi, Guglielmo Perrin, Jean Baptiste Slater, John Clarke Wigner, Eugene Paul Marshak, Robert Eugene Planck, Max Karl Ernst Ludwig Sommerfeld, Arnold Wood, Robert Williams Matthias, Bernd Teo Pockels, Agnes Spitzer, Lyman, Jr. Wu, Chien-Shiung McMillan, Edwin Mattison Poincaré, Jules Henri Stark, Johannes Yukawa, Hideki Meitner, Lise Powell, Cecil Frank Stern, Otto Zeeman, Pieter Michelson, Albert Abraham Prandtl, Ludwig Street, Jabez Curry Zel’dovich, Yakov B. Millikan, Robert Andrews Purcell, Edward Mills Strutt, John William Rayleigh Zernike, Fritz Minkowski, Hermann Rabi, Isidor Isaac Szilard, Leo Zwicky, Fritz von Mises, Richard Rainwater, Leo James Tamm, Igor Yevgenyevich HANNES OLAF GÖSTA

Alfvén1908-1995

The Nobel Prize in Physics 1970

“for fundamental work and discoveries in magnetohydrody- namics with fruitful applications in different parts of plasma physics”

Alfvén’s concepts such as magnetohydrodynamic waves and critical ionization velocity have also been useful in under- standing phenomena in the Earth’s ionosphere and else- where in the Solar System. AIP Emilio Segrè Visual Archives, Weber Collection LUIS WALTER

Alvarez 1911-1988

The Nobel Prize in Physics 1968

“for his decisive contributions to elementary particle physics, in particular the discovery of a large number of resonance states, made possible through his devel- opment of the technique of using hydrogen bubble chamber and data analysis”

Alvarez is well known to earth scientists as co-author of the theory that an asteroid struck the Earth about 65 million years ago, possibly resulting in the extinc- tion of dinosaurs and other species. AIP Meggers Gallery of Nobel Laureates CARL DAVID

Anderson 1905-1991

The Nobel Prize in Physics 1936

“for his discovery of the positron”

This confirmed Dirac’s prediction of the existence of an antiparticle for the electron. He also discovered, with S. H. Neddermeyer, the mu meson.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection EDWARD VICTOR

Appleton 1892-1965

The Nobel Prize in Physics 1947

“for his investigations of the physics of the upper at- mosphere, especially for the discovery of the so-called Appleton layer”

AIP Emilio Segrè Visual Archives, E. Scott Barr Collection FRANCIS WILLIAM

Aston1877-1945

The Nobel Prize in Chemistry 1922

“for his discovery, by means of his mass spectrograph, of isotopes, in a large number of nonradioactive ele- ments, and for his enunciation of the whole-number rule”

His determination of isotopic masses allowed more accurate estimates of the binding energies associated with nuclear forces.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection HERTHA

Ayrton1854-1923

Born Pheobe Sarah Marks

English physicist and engineer awarded the 1906 Hughes Medal for her work on the electric arc lamp and sand ripples. Ayrton also made important contri- butions to hydrodynamics and invented the Ayrton Fan. She was the first woman elected to the Institution of Electrical Engineers and the first woman to read one of her own papers before the Royal Society.

Archives of the Institution of Electrical Engineers, London KENNETH T.

Bainbridge 1904-1996

American experimental physicist who developed high accuracy mass spectrographs and showed that radio- active half-life may be affected by high pressure. He directed “Trinity”—the first atomic bomb explosion on July 16, 1945, some sixty miles northwest of Alamogordo, New Mexico.

Photo by Charles Newton, courtesy AIP Emilio Segrè Visual Archives, Bainbridge Collection JOHN

Bardeen 1908-1991

The Nobel Prize in Physics 1956

was awarded to J. Bardeen, W. Brattain, W. Shockley “for their researches on semiconductors and their dis- covery of the transistor effect”

The Nobel Prize in Physics 1972

was awarded to J. Bardeen, L. Cooper, J. Schrieffer “for their jointly developed theory of superconductiv- ity, usually called the BSC-theory”

AIP Emilio Segrè Visual Archives, Physics Today Collection CHARLES GLOVER

Barkla1877-1944

The Nobel Prize in Physics 1917

“for his discovery of the characteristic Röntgen radia- tion of the elements”

He provided evidence for the wave nature of X rays.

Photo by Gen. Stab. Lit. Anst., courtesy AIP Emilio Segrè Visual Archives ANTOINE-HENRI

Becquerel 1852-1908

The Nobel Prize in Physics 1903

“in recognition of the extraordinary services he has ren- dered by his discovery of spontaneous radioactivity”

Photo by Gen. Stab. Lit. Anst., courtesy AIP Emilio Segrè Visual Archives JOHN STEWART

Bell 1928-1990

Irish nuclear physicist best known for his work on the foundations of quantum mechanics and its philosophi- cal implications. He showed that certain hidden-vari- able theories are inconsistent with the predictions of quantum mechanics.

Photo by Kurt Gottfried, courtesy AIP Emilio Segrè Visual Archives HOMI JEHANGIR

Bhabha1909-1966

Indian theoretical physicist whose major contributions to particle physics and quantum-electrodynamics in- clude the discovery of “Bhabha scattering” and the prediction of vector mesons.

AIP Emilio Segrè Visual Archives, Physics Today Collection FRANCIS

Bitter1902-1967

American physicist noted for his contributions to the study of magnetism and optical pumping. His most important invention, the Bitter Magnet , produces ex- tremely intense magnetic fields.

Massachusetts Institute of Technology, courtesy AIP Emilio Segrè Visual Archives PATRICK MAYNARD STUART

Blackett 1897-1974

The Nobel Prize in Physics 1948

“for his development of the Wilson cloud chamber method, and his discoveries therewith in the fields of nuclear physics and cosmic radiation”

AIP Emilio Segrè Visual Archives MARIETTA

Blau1894-1970

Austrian physicist nominated several times for the Nobel Prize by Schrödinger. She developed photographic- emulsion methods allowing observation and measure- ment of high energy particle tracks. She and Wambacher were the first to observe “Blau-Wambacher Stars”—emulsion effects due to cosmic ray disintegra- tions of heavy nuclei.

Courtesy of Leopold Halpern FELIX

Bloch1905-1983

The Nobel Prize in Physics 1952

was awarded to F. Bloch and E. Purcell “for their development of new methods for nuclear magnetic precision measurements and discoveries in connection therewith”

This led to the development of magnetic resonance for medical and other applications. Bloch was a founder of the quantum theory of electrons in metals, and in- troduced the concept of spin waves in ferromagnetism.

AIP Meggers Gallery of Nobel Laureates KATHARINE BURR

Blodgett 1898-1979

Fellow of the American Physical Society, she was awarded the 1951 Garvan Medal for her work on monomolecular films. She was the first woman to receive a Ph.D. in physics from Cambridge University and first woman scientist hired by General Electric. She invented “invisible” (non-reflecting) glass, aircraft wing de-icing methods, and poison gas absorbents.

General Electric Research Lab., Courtesy AIP Emilio Segrè Visual Archives NIKOLAI NIKOLAEVICH

Bogolyubov 1909-1992

Soviet mathematical physicist who made significant contributions to the study of nonlinear systems, super- conductivity, superfluidity, and introduced the quark quantum number “color.” His most important achieve- ment was the creation of an axiomatic quantum field theory.

AIP Emilio Segrè Visual Archives, Physics Today Collection DAVID

Bohm 1917-1992

American-British physicist who made pioneering con- tribution to the theory of plasmas. He is best known for his casual interpretation of quantum mechanics, sometimes called “hidden-variable theory,” and for the prediction of the Aharonov-Bohm effect.

London Still Pictures Company NIELS HENRIK DAVID

Bohr1885-1962

The Nobel Prize in Physics 1922

“for his services in the investigation of the structure of atoms and of the radiation emanating from them”

In addition to his 1913 model, which pioneered the application of the quantum principle to the structure and spectra of atoms, Bohr developed the “Copenhagen Interpretation” of quantum mechanics and engaged in a series of debates with Einstein about quantum paradoxes. With J. A. Wheeler and others he developed a theory of nuclear structure that guided early research on fission. AIP Emilio Segrè Visual Archives, W. F. Meggers Collection LUDWIG

Boltzman 1844-1906

Austrian physicist who developed the kinetic theory of gases and formulated the basic principles of statistical mechanics. He established the connection between entropy and disorder. The “Boltzmann equation” gov- erns the flow of molecules in gases, neutrons in reac- tors, and other phenomena. It also entails the “H theo- rem,” which appears to show that entropy must al- ways increase or remain constant, thereby initiating a debate (not yet settled) on the cause of irreversibility (direction of time). Boltzmann also derived the tem- perature-dependence of black-body radiation (Stefan- Boltzmann law), a fundamental step towards the discovery of quantum theory. University of Vienna, courtesy AIP Emilio Segrè Visual Archives MAX

Born1882-1970

The Nobel Prize in Physics 1954

“for his fundamental research in quantum mechanics, especially for his statistical interpretation of the wavefunction”

Born and his colleagues also developed the theory of crystal lattice vibrations, and the statistical theory of fluids (“BBGKY equations”).

AIP Emilio Segrè Visual Archives, Lande Collection SATYENDRA NATH

Bose 1894-1974

Indian mathematician noted for his collaboration with Einstein which led to their developing “Bose-Einstein statistics”—a theoretical treatment of the gas-like prop- erties of electromagnetic radiation.

Indian National Council of Science Museums, courtesy of Physics Today Collection EDWARD ALEXANDER

Bouchet 1852-1918

Physicist who in 1874 became the first African Ameri- can to graduate from Yale College. He was also the first African American to earn a doctoral degree from an American university (Yale, 1876). Bouchet’s early work was on refractive indices. He taught physics and chemistry for twenty-six years at the Institute for Colored Youth in Philadelphia, PA.

Yale University Library WILLIAM HENRY

Bragg1862-1942

The Nobel Prize in Physics 1915

was awarded to W. H. Bragg and his son W. L. Bragg “for their services in the analysis of crystal structure by means of X-rays”

AIP Emilio Segrè Visual Archives, E. Scott Barr Collection WILLIAM LAWRENCE

Bragg1890-1971

The Nobel Prize in Physics 1915

was awarded to W. L. Bragg and his father W. H. Bragg

“for their services in the analysis of crystal structure by means of X-rays”

Born in Australia, he succeeded Rutherford as Direc- tor of the Cavendish Laboratory in Cambridge (1938- 1953) where J. D. Watson and F. H. C. Crick discov- ered the structure of DNA. AIP Emilio Segrè Visual Archives, W.F. Meggers Collection WALTER HOUSER

Brattain 1902-1987

The Nobel Prize in Physics 1956

was awarded to W. Brattain, J. Bardeen and W. Shockley “for their researches on semiconductors and their discovery of the transistor effect”

AIP Meggers Gallery of Nobel laureates GREGORY

Breit1899-1981

Russian-born American electrical engineer and physi- cist noted for his radio-detection of the ionosphere with Tuve. He also did pioneering work producing the high voltages necessary for accelerating charged par- ticles, organizing quantum electrodynamics, and de- veloping the theory of nuclear resonances.

AIP Emilio Segrè Visual Archives PERCY WILLIAMS

Bridgman 1882-1961

The Nobel Prize in Physics 1946

“for the invention of an apparatus to produce extremely high pressures, and for the discoveries he made there- with in the field of high pressure physics”

Bridgman was also well known for his “operational” philosophy of scientific research -- one should use in science only those concepts that can be defined by specific laboratory operations. AIP Emilio Segrè Visual Archives LÉON NICOLAS

Brillouin 1889-1969

French physicist noted for his work on quantum theory, solid state physics, and information theory. His most significant achievement came as co-developer of the semiclassical (J)BWK-solution to Schrödinger’s equations.

AIP Emilio Segrè Visual Archives, Brillouin Collection JAMES

Chadwick 1891-1974

The Nobel Prize in Physics 1935

“for his discovery of the neutron”

AIP Meggers Gallery of Nobel Laureates SUBRAHMANYAN

Chandrasekhar 1901-1995

The Nobel Prize in Physics 1983

“for his theoretical studies of the physical processes of importance to the structure and evolution of the stars”

Born in India, Chandrasekhar spent most of his ca- reer at the University of Chicago. By applying rela- tivistic quantum mechanics to the electron gas he showed that a star cannot be stable if its mass is greater than about 1.5 times that of the Sun (“Chandrasekhar limit”). The collapse of a more mas- sive star may lead to a supernova explosion, leaving AIP Emilio Segrè Visual Archives, S. Chandrasekhar Collection a neutron star as predicted in 1934 by F. Zwicky. SYDNEY

Chapman 1888-1979

British physicist and geophysicist whose early works were on thermal conductivity, gas diffusion, and ther- mal diffusion. His most significant contribution was to the understanding of geomagnetism, for which he was awarded the 1964 Copley Medal.

AIP Emilio Segrè Visual Archives PAVEL ALEKSEYEVICH

Cherenkov 1904-1990

The Nobel Prize in Physics 1958

was awarded to P. Cherenkov, I. Frank and I. Tamm “for the discovery and the interpretation of the Cherenkov effect”

The Cherenkov effect is the emission of radiation by a charged particle (e.g. an electron) moving through a material at a speed which is greater than the speed of light in that material. AIP Meggers Gallery of Nobel Laureates J O H N D O U G L A S

Cockcroft 1897-1967

The Nobel Prize in Physics 1951

was awarded to Sir John Douglas Cockcroft and E. Walton “for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles”

AIP Meggers Gallery of Nobel Laureates A R T H U R H O L L Y

Compton 1892-1962

The Nobel Prize in Physics 1927

“for his discovery of the effect named after him”

The Compton effect showed that electromagnetic ra- diation (especially X-rays) can be scattered by single electrons as one would expect if a photon has mo- mentum hυ/c, thereby confirming the particle nature of light at a time when it was doubted by other physicists.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection EDWARD UHLER

Condon 1902-1974

American physicist noted for his researches in atomic spectroscopy. He provided a quantum mechanical ba- sis for Franck’s classical-based rules governing molecular transitions—the Franck-Condon principle. The “tunneling” theory of α-decay, proposed by Condon and R. Gurney and independently by G. Gamow, was the first successful application of quan- tum mechanics to nuclear physics.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection WILLIAM

Crookes 1832-1919

British chemist and physicist known for his cathode ray studies, pioneering work in spectroscopy, and dis- covery of thallium. His “radiometer,” once believed to operate by light pressure, is now understood as the first visible demonstration of gas-surface effects in rarefied gas dynamics.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection PIERRE

Curie1859-1906

The Nobel Prize in Physics 1903

was awarded to Pierre Curie and M. Curie “in recog- nition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel”

Before his work on radioactivity with his wife Marie Curie, he was known for his researches on magne- tism. The “Curie point” is the temperature above which spontaneous magnetization vanishes. AIP Meggers Gallery of Nobel Laureates MARIE SKLODOWSKA

Curie1867-1934

The first of only three scientists to win two Nobel Prizes in science:

The Nobel Prize in Physics 1903

was awarded to Marie Curie and P. Curie “in recognition of the extraordinary services they have rendered by their joint researches on the radiation phenomena discovered by Professor Henri Becquerel”

Marie Curie also contributed to the discoveries by Ruther- ford and others by making available radium as an intense source of radioactivity.

The Nobel Prize in Chemistry 1911

“in recognition of her services to the advancement of chem- istry by the discovery of the elements radium and polo- nium, by the isolation of radium and the study of the nature and compounds of this remarkable element”

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection C L I N T O N J O S E P H

Davisson 1881-1958

The Nobel Prize in Physics 1937

was awarded to Clinton Davisson and G. Thomson “for their experimental discovery of the diffraction of electrons by crystals”

Davisson, with L.H. Germer, confirmed the wave na- ture of the electron, postulated by L. de Broglie.

AIP Emilio Segrè Visual Archives L O U I S V I C T O R

DeBroglie 1892-1987

The Nobel Prize in Physics 1929

“for his discovery of the wave nature of electrons”

AIP Emilio Segrè Visual Archives, Physics Today Collection PETRUS JOSEPHUS WILHELMUS

Debye 1884-1966

The Nobel Prize in Chemistry 1936

“for his contributions to our knowledge of molecular structure through his investigations on dipole moments and on the diffraction of X-rays and electrons in gases”

Photo by Francis Simon, courtesy AIP Emilio Segrè Visual Archives ROBERT HENRY

Dicke1916-1997

American physicist best known for his prediction of background radiation due to the Big Bang, and for the Brans-Dicke theory of gravitation. He did funda- mental work on coherent radiation, helping set the stage for the development of the laser. He was awarded the 1971 National Medal of Science.

AIP Emilio Segrè Visual Archives P A U L A D R I E N M A U R I C E

Dirac1902-1984

The Nobel Prize in Physics 1933

was awarded to Paul Dirac and E. Schrodinger “for the discovery of new productive forms of atomic theory”

Dirac developed the mathematical theory of quantum mechanics and proposed antisymmetric wave func- tions for systems of several identical particles (elec- trons, protons or neutrons) — systems that obey “Fermi- Dirac statistics.” He also proposed a relativistic quan- tum equation that included spin in a natural way; it led him to predict antiparticles and in particular the positron, later discovered by C. D. Anderson.

Photo by A. Bortzells Tryckeri, courtesy AIP Emilio Segrè Visual Archives JESSE WILLIAM MONROE

Du Mond 1892-1976

French physicist whose experiments on the Compton modified line structure provided support for the Ruth- erford-Bohr atomic model.

Boye Studios, courtesy AIP Emilio Segrè Visual Archives ARTHUR STANLEY

Eddington 1882-1944

English astronomer and one of the founders of mod- ern astrophysics. He established the mass luminosity law and explained Cepheid variables. He also led the 1919 solar eclipse expedition which confirmed the gravitational bending of light.

AIP Emilio Segrè Visual Archives PAUL

Ehrenfest 1880-1933

Austrian-born Dutch physicist who collaborated ex- tensively with his wife Tatyana in clearing-up contro- versies over statistical methods in physics. His “adia- batic principle” assumed a foundational status within quantum mechanics, showing logical interpretations were possible that maintained connections with sta- tistical mechanics.

AIP Emilio Segrè Visual Archives, Margrethe Bohr Collection TATYANA ALEXEYEVNA

Ehrenfest-Afanassjeva 1876-1964

Russian-born Dutch mathematician who collaborated extensively with her husband Paul. Their Ehrenfest model of diffusion helped illuminate Boltzmann’s sta- tistical interpretation of the second law of thermo- dynamics.

V. Ya. Frenkel, Leningrad Physico-Technical Institute, courtesy AIP Emilio Segrè Visual Archives ALBERT

Einstein 1879-1955

The Nobel Prize in Physics 1921

“for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect”

This citation indirectly refers to his pioneering formulation of the quantum theory but many physicists think he should have received the Prize for his special and general theories of relativity. In addition he proposed a theory of Brownian motion (used by Jean Perrin to establish the reality of atoms), a quantum theory of the specific heats of solids, and a gen- eralization of S. N. Bose’s quantum theory of radiation that predicted the “Bose-Einstein condensation.” He disagreed with N. Bohr and other physicists on the interpretation and completeness of quantum mechanics, asserting that “God does not play dice” and defending the principle that sub- atomic particles and processes have a real existence apart from our observation of them. AIP Emilio Segrè Visual Archives, W. F. Meggers Collection ROBERT A., JR.

Ellis1918-1989

African-American physicist and pioneer in modern ex- perimental plasma physics. He joined Project Matterhorn (now the Princeton Plasma Physics Labo- ratory) in 1956, to work on controlling fusion, where he later became head of experimental projects. He was a key member of the team that first documented ohmic heating, anomalous transport across magnetic fields, radiofrequency plasma heating at lower-hybrid frequencies, and nonlinear cyclotron harmonic interactions. AIP Emilio Segrè Visual Archives, Physics Today Collection WILLIAM MARTIN

Fairbank 1917-1989

American physicist known for his experiments with liquid helium and superconductors as well as for his low-temperature techniques used in exploring elementary particles, gravitational waves, and general relativity.

Stanford Univ., courtesy AIP Emilio Segrè Visual Archives ENRICO

Fermi1901-1954

The Nobel Prize in Physics 1938

“for his demonstrations of the existence of new radio- active elements produced by neutron irradiation, and for his related discovery of nuclear reactions brought about by slow neutrons”

Although the “new radioactive elements” for which Fermi won the Nobel Prize turned out to be fission products of known elements, his work on the produc- tion of radioactive elements by neutron irradiation was path-breaking. He went on to achieve the first controlled fission chain reaction in Chicago. Earlier, Fermi had become known for the creation of a vigor- ous physics group in Rome and for his theoretical work, including the quantum theory of multi-electron sys- tems (Fermi-Dirac statistics) and the theory of $-decay.

AIP Emilio Segrè Visual Archives R I C H A R D P H I L L I P S

Feynman 1918-1988 The Nobel Prize in Physics 1965

was awarded to Richard Feynman, J. Schwinger and S. Tomonaga “for their fundamental work in quantum electro- dynamics, with deep-ploughing consequences for the phys- ics of elementary particles” Feynman invented a convenient method for visualizing the interactions of subatomic par- ticles, which also facilitated accurate calculations; “Feynman diagrams” are now widely used. A striking by-product of this approach was the idea that positrons behave as if they are electrons moving backward in time. Feynman also con- tributed important ideas that helped solve many problems in physics and technology, ranging from the superfluidity of liquid helium to ultra-miniaturization of machines. Feynman became known to the public late in life when he served on the commission to investigate the Challenger space shuttle disaster, and demonstrated by a simple experiment how O- rings could fail to work at low temperatures. AIP Meggers Gallery of Nobel Laureates WILLIAM ALFRED

Fowler1911-1995

The Nobel Prize in Physics 1983

“for his theoretical and experimental studies of the nuclear reactions of importance in the formation of the chemical elements in the universe”

AIP Meggers Gallery of Nobel Laureates JAMES

Franck1882-1964

The Nobel Prize in Physics 1925

was awarded to James Franck and G. Hertz “for their discovery of the laws governing the impact of an elec- tron upon an atom”

The Franck-Hertz experiment was later regarded as the first direct proof of Bohr’s hypothesis on the rela- tion between atomic energy levels and the frequency of spectral lines.

AIP Emilio Segrè Visual Archives, W. F. Meggers Collection ILYA MIKHAILOVICH

Frank1908-1990

The Nobel Prize in Physics 1958

was awarded to Ilya Frank, P. Cherenkov and I. Tamm “for the discovery and the interpretation of the Cherenkov effect”

Sovfoto PHILIPP

Frank1884-1966

Austrian physicist-philosopher and student of Boltzmann whose researches included work on varia- tional calculus, geometrical optics, wave mechanics, and relativity theory. Frank also worked to identify and correct misinterpretations of relativity theory and quantum mechanics that were being used in support of questionable philosophical doctrines.

AIP Emilio Segrè Visual Archives, Lande Collection ROSALIND ELSIE

Franklin 1920-1958

British molecular-chemist noted for her contributions to x-ray crystallography and to the discovery of the molecular structures of DNA and RNA. She is cred- ited with discoveries that established the density of DNA and its helical conformation. Franklin also col- laborated on studies that showed RNA was a single- strand helix.

Cold Spring Harbor Laboratory Archives YAKOV ILYICH

Frenkel 1894-1954

Soviet physicist and one of the founders of the quan- tum theory of liquid and solid state. Published the first theoretical demonstration that electrons can move with- out resistance in a perfectly periodic crystal lattice. Developed the concept of quasiparticles and, in par- ticular, gave his name to frenkel exciton and Frenkel defects found in crystals.

V. Ia Frenkel, Leningrad of Physico-Technical Institute, courtesy AIP Emilio Segrè Visual Archives OTTO ROBERT

Frisch1904-1979

Austrian physicist who, in 1938, together with Lise Meinter, first understood the process of nuclear fission. His 1939 paper with Peierls on the explosive force generated by a U235 chain reaction spurred development of the atomic bomb.

AIP Emilio Segrè Visual Archives Physics Today Collection KENICHI

Fukui1918-1998

The Nobel Prize in Chemistry 1981

was awarded to Kenichi Fukui and R. Hoffmann “for their theories, developed independently, concerning the course of chemical reactions”

Fukui’s “frontier orbital” theory demonstrated the use- fulness of the molecular orbital theory based on quantum mechanics.

The Nobel Foundation, courtesy AIP Emilio Segrè Visual Archives DENNIS

Gabor1900-1979

The Nobel Prize in Physics 1971

“for his invention and development of the holographic method”

AIP Meggers Gallery of Nobel Laureates GEORGE

Gamow1904-1968

Russian-American theoretical physicist who made im- portant contributions to nuclear physics, cosmology, and molecular biology. Developed the first quantum theory of alpha decay and, together with Alpher, the first scenarios of the Big Bang cosmology.

AIP Emilio Segrè Visual Archives Physics Today Collection HANS WILHELM

Geiger1882-1945

German physicist and pioneer in nuclear physics. He developed various instruments and techniques for mea- suring charged particles—the most famous being the “Geiger Counter.” His alpha particle scattering in- vestigation with Marsden led to Rutherford’s nuclear theory for the atom.

AIP Emilio Segrè Visual Archives JOSIAH WILLARD

Gibbs1839-1903

Regarded by many as the greatest American-born theorectical physicist, he did fundamental work on vector analysis and through application of thermody- namics to physical processes developed a general method of statistical mechanics applicable to all three states of matter. His formulas were so general they could be applied to quantum systems.

AIP Emilio Segrè Visual Archives MARIA

Göppert-Mayer 1906-1972

The Nobel Prize in Physics 1963

was awarded to Göppert-Mayer and M. J. Jensen “for their discoveries concerning nuclear shell structure”

She also contributed to several areas of chemical phys- ics and was co-author, with her husband Joseph Mayer, of a widely-used book on statistical mechanics.

AIP Meggers Gallery of Nobel Laureates SAMUEL ABRAHAM

Goudsmit 1902-1978

Dutch-born American physicist and leading authority on atomic energy and nuclear research. His most important achievement was formulating the concept of electron spin with George Uhlenbeck.

AIP Emilio Segrè Visual Archives HAROLD

Grad 1923-1987

Awarded the 1986 James Clerk Maxwell Prize for plasma physics, he also did important work in kinetic theory and statistical mechanics. He founded and di- rected (1956-81) the Magneto-fluid Dynamics Division of New York University’s Courant Institute.

Pasquale Del Riccio, courtesy AIP Emilio Segrè Visual Archives OTTO

Hahn 1879-1968

The Nobel Prize in Chemistry 1944

“for his discovery of the fission of heavy nuclei”

AIP Emilio Segrè Visual Archives GEORGE ELLERY

Hale 1868-1938

American astronomer noted for his astronomical in- struments, including the spectroheliograph, and his solar researches, particularly his discovery of mag- netic fields in sunspots.

Hale’s most important contribution was the construc- tion of large telescopes (especially the 100" and 200" in California), which established the United States as the leader in observational astronomy in the 20th century.

Yerkes Observatory, Univ. Of Chicago, courtesy AIP Emilio Segrè Visual Archives WERNER KARL

Heisenberg 1901-1976

The Nobel Prize in Physics 1932

“for the creation of quantum mechanics, the applica- tion of which has, inter alia, led to the discovery of the allotropic forms of hydrogen”

Heisenberg proposed the first form of quantum me- chanics, subsequently known as “matrix mechanics,” before Schrödinger proposed the more popular form known as “wave mechanics.” Heisenberg is also known for his “Indeterminacy Principle” and his pro- ton-neutron theory of the nucleus. His decision to re- main in Germany during World War II helped moti- vate other physicists to develop the atomic bomb in the United States, fearing that Heisenberg would de- velop it for Hitler (although in fact he failed to do so.) AIP Emilio Segrè Visual Archives, gift of E.T.S. Walton GUSTAV LUDWIG

Hertz 1887-1975

The Nobel Prize in Physics 1925

was awarded to G. Hertz and J. Franck “for their discovery of the laws governing the impact of an elec- tron upon an atom”

The Franck-Hertz experiment was later regarded as the first direct proof of Bohr’s hypothesis on the rela- tion between atomic energy levels and the frequency of spectral lines. Gift of Jost Lemmerich, courtesy AIP Emilio Segrè Visual Archives VICTOR FRANZ

Hess 1883-1964

The Nobel Prize in Physics 1936

“for his discovery of cosmic radiation”

This discovery was made in 1912 by sending a bal- loon carrying radiometers up to a height greater than 5000 meters.

AIP Emilio Segrè Visual Archives, W. F. Meggers Collection G E O R G E C H A R L E S de Hevesy 1885-1966

The Nobel Prize in Chemistry 1943

“for his work on the use of isotopes as tracers in the study of chemical processing”

With D. Coster he discovered hafnium.

Niels Bohr Archive, courtesy AIP Emilio Segrè Visual Archives DAVID

Hilbert 1862-1943

German mathematician whose contributions to kinetic gas and radiation theory significantly advanced math- ematical physics. His work on infinite-dimensional spaces, now known as Hilbert Spaces, proved cru- cial to the development of quantum mechanics. He arrived at equations for general relativity shortly after Einstein.

AIP Emilio Segrè Visual Archives, Lande Collection D O R O T H Y C R O W F O O T

Hodgkin 1910-1994

The Nobel Prize in Chemistry 1964

“for her determinations by X-ray techniques of the struc- tures of important biochemical substances”

AIP Emilio Segrè Visual Archives Physics Today Collection ROBERT L.

Hofstadter 1915-1990

The Nobel Prize in Physics 1961

“for his pioneering studies of electron scattering in atomic nuclei and for his thereby achieved discover- ies concerning the structure of the nucleons”

AIP Meggers Gallery of Nobel Laureates FRITZ GEORG

Houtermans 1903-1966

Austrian physicist very influential in both earth sci- ences and astronomy. He developed a method to estimate the age of the Earth from abundances of lead isotopes. He and Atkinson were the first to sug- gest the mechanism responsible for thermonuclear reactions inside stars. He also made important con- tributions to the use of scintillator detectors in particle physics.

Courtesy of Niedersächsische Staats-Und- Universitätsbibliothek Göttingen EDWIN POWELL

Hubble1889-1953

American astronomer who pioneered extragalactic astronomy. He confirmed the existence of other galaxies and provided the first evidence of an ex- panding universe when he discovered galaxies were receding from the Milky Way at velocities propor- tional to their distance—Hubble’s Law.

Hale Observatories, courtesy AIP Emilio Segrè Visual Archives E L M E R S A M U E L

Imes 1883-1941

Only the second African American to earn a Ph.D. in physics in the United States, Imes served as head of Fisk University’s Physics Department from 1930 until his death in 1941. A member of the Physical Society, he did research on infrared spectra.

Special Collections, Fisk University Library, Nashville, Tennessee. ABRAM FEDOROVICH

Ioffe1880-1960

Known as the “father” of Soviet physics, Ioffe founded the Physico-Technical Institute and initiated pioneer- ing semiconductor research. Research by Ioffe and his students contributed significantly to the modern understanding of dielectric phenomena. He made im- portant contributions to controlled thermonuclear phys- ics: including Ioffe Bars for stabilizing mirror machines.

AIP Emilio Segrè Visual Archives, V. Ya. Frenkel Collection JOHANNES HANS DANIEL

Jensen1907-1973

The Nobel Prize in Physics 1963

was awarded to J. Jensen and M. Göppert-Mayer “for their discoveries concerning nuclear shell structure”

AIP Meggers Gallery of Nobel Laureates FRÉDÉRIC

Joliot1900-1958

The Nobel Prize in Chemistry 1935

was awarded to F. Joliot and I. Joliot-Curie

“in recognition of their synthesis of new radioactive elements”

Photo by Studio France Presse, courtesy AIP Emilio Segrè Visual Archives IRÈNE

Joliot-Curie 1897-1956

The Nobel Prize in Chemistry 1935

was awarded to I. Joliot-Curie and F. Joliot

“in recognition of their synthesis of new radioactive elements”

Photo by Studio France Presse, courtesy AIP Emilio Segrè Visual Archives HEIKE

Kamerlingh Onnes 1853-1926

The Nobel Prize in Physics 1913

“for his investigation on the properties of matter at low temperatures which led, inter alia, to the produc- tion of liquid helium”

He also discovered superconductivity.

Courtesy AIP Emilio Segrè Visual Archives PYOTR LEONIDOVICH

Kapitza 1894-1984

The Nobel Prize in Physics 1978

“for his basic inventions and discoveries in the area of low-temperature physics”

He found that liquid helium, at temperatures below the 8-transition, flows through very small spaces with essentially no resistance (“superfluidity”).

Photo by Francis Simon, courtesy AIP Emilio Segrè Visual Archives THÉODORE von Kármán 1881-1963

Hungarian-American engineer who helped establish the U.S. aircraft and rocket industries. He observed and described vortex shedding or “Kármán Vorti- ces”—alternating vortices behind obstacles placed in fluid flows. With Max Born he developed the theory of vibrations of crystal lattices. Kármán was awarded the first National Medal of Science (1963).

AIP Emilio Segrè Visual Archives ALFRED

Kastler 1902-1984

The Nobel Prize in Physics 1966

“for the discovery and development of optical meth- ods for studying hertzian resonances in atoms”

This method allows the use of light to observe very low frequency resonances in atoms.

AIP Meggers Gallery of Nobel Laureates EDWIN CRAWFORD

Kemble 1889-1984

American physicist who made important contributions to quantum mechanics and figured significantly in the development of theoretical physics in the United States. Kemble explained the known second absorption band

in CO2. He also predicted and experimentally con- firmed harmonic spectra in other gases.

Walter R. Fleischer, courtesy AIP Emilio Segrè Visual Archives DONALD WILLIAM

Kerst1911-1993

American physicist best known for constructing the first betatron—a device capable of accelerating beta particles to near-light speeds—at the University of Illinois in 1940.

AIP Emilio Segrè Visual Archives Physics Today Collection OSKAR BENJAMIN

Klein1894-1977

Swedish physicist whose wide-ranging and signifi- cant contributions to quantum mechanics, relativity, and cosmology include the Klein-Gordon equations, the Klein-Nishima formula, and the Klein-Alvén model for the universe. He served as a member of the Nobel committee on Physics.

AIP Emilio Segrè Visual Archives Physics Today Collection HENDRIK ANTHONY

Kramers 1894-1952

Dutch theoretical physicist known for his important contributions to quantum mechanics. He predicted the Raman effect and derived the Kramers-Kronig elec- tromagnetic dispersion relations.

AIP Emilio Segrè Visual Archives, Lindsay Collection IGOR VASILYEVICH

Kurchatov 1903-1960

Soviet nuclear physicist who directed the work on the USSR’s first nuclear pile and chain reaction (1946) and generally supervised the entire Soviet atomic project, including their first atomic bomb (1949), the world’s first hydrogen bomb (1953) and nuclear power plant (1954).

VNIIEF Museum & Archive, courtesy AIP Emilio Segrè Visual Archives POLYKARP

Kusch1911-1993

The Nobel Prize in Physics 1955

“for his precision determination of the magnetic moment of the electron”

AIP Emilio Segrè Visual Archives Physics Today Collection EDWIN HERBERT

Land 1909-1991

American inventor with over 500 optical, chemical and other patents. He developed the polarizer Polaroid-J used in sunglasses and optical instruments, founded the Polaroid Corporation, and invented the first instant-developing film and Polaroid-Land Cam- era which produced prints in 60 seconds.

AIP Emilio Segrè Visual Archives Physics Today Collection LEV DAVIDOVICH

Landau1908-1968

The Nobel Prize in Physics 1962

“for his pioneering theories for condensed matter, especially liquid helium”

He made important contributions to plasma physics (Landau damping) and many to particle physics (Landau poles). He established a school of theoreti- cal physics in Russia.

AIP Emilio Segrè Visual Archives ALFRED

Landé1888-1975

German-born American physicist known for the Landé splitting factor in quantum mechanics. He collabo- rated with Paschen and others to investigate the split- ting of spectral lines under the action of strong mag- netic fields.

AIP Meggers Gallery of Nobel Laureates PAUL

Langevin 1872-1946

French physicist best known for establishing the mod- ern theory of magnetism. He also studied ionized gases and Brownian motion. His echo-location tech- nique for detecting submarines was the basis for sonar.

Photo by Francis Simon, courtesy AIP Emilio Segrè Visual Archives IRVING

Langmuir 1881-1957

The Nobel Prize in Chemistry 1932

“for his discoveries and investigations in surface chemistry”

He improved the electric light bulb and developed a shared-electron theory of chemical bonds.

AIP Emilio Segrè Visual Archives MAX THEODOR FELIX von Laue 1879-1960

The Nobel Prize in Physics 1914

“for his discovery of the diffraction of X-rays by crystals”

AIP Emilio Segrè Visual Archives ERNEST ORLANDO

Lawrence 1901-1958

The Nobel Prize in Physics 1939

“for the invention and development of the cyclotron and for results obtained with it, especially with re- gard to artificial radioactive elements”

He pioneered the concept of research with teams of scientists and engineers, which has become the domi- nant method of research in much of physics in the latter half of this century. AIP Meggers Gallery of Nobel Laureates H E N R I E T T A S W A N

Leavitt 1865-1921

American astronomer noted for developing the pe- riod- luminosity relation for Cepheid-variable stars which is the basis for determining distances of galax- ies. She also discovered over 2400 variable stars and developed standard photographic measurement techniques widely adopted around the world.

AIP Emilio Segrè Visual Archives, Shapley Collection INGE

Lehmann 1888-1993

Danish seismologist awarded the 1971 William Bowie Medal of the American Geophysical Union in recognition of her “outstanding contributions to fun- damental geophysics and unselfish cooperation in re- search.” Her seismic wave observations led to her discovery of the Earth’s solid inner core. She also dis- covered the Lehmann discontinuity 220 km below the Earth’s surface.

Dr. Bruce A. Bolt, Geology and Geophysics Department, University of California, Berkeley. GEORGES EDOUARD

Lemaître 1894-1966

Belgian astronomer best known as originator of an early version of the Big Bang theory in which the universe is conceived to have evolved from a cata- clysmic explosion of an immeasurably dense primal atom.

Photo by Dorothy Davis Locanthi, courtesy AIP Emilio Segrè Visual Archives W I L L A R D F R A N K

Libby1908-1980

The Nobel Prize in Chemistry 1960

“for his method to use carbon-14 for age determina- tion in archaeology, geology, geophysics, and other branches of science”

Jules LeBaron, courtesy AIP Emilio Segrè Visual Archives M. STANLEY

Livingston 1905-1986

Livingston worked with Lawrence in developing and building the first cyclotron. He was chairman of the Brookhaven team that built the Cosmotron, of the Harvard-MIT team that built the Cambridge Electron Accelerator, and associate director of The Fermi Na- tional Accelerator Laboratory during construction of its first major machine (1967-1970).

MIT, courtesy AIP Emilio Segrè Visual Archives FRITZ WOLFGANG

London 1900-1954

German-American physicist who, with R. Eisenschitz, used quantum mechanics to calculate the force between atoms (“dispersion force”). With W. Heitler he devised the first quantum mechani- cal treatment of the hydrogen molecule, using a method that was later generalized by L. Pauling and became known as the “valence bond” method in quantum chemistry. He showed that the 8-transi- tion of liquid helium could be approximately de- scribed as a Bose-Einstein condensation. AIP Emilio Segrè Visual Archives Physics Today Collection K A T H L E E N Y A R D L E Y

Lonsdale 1903-1971

Irish-born English crystallographer awarded the 1957 Davy Medal. In 1945 she, along with Marjory Stephenson, became one of the first two female mem- bers of the Royal Society. Lonsdale applied X-ray dif- fraction analysis to organic crystals and is best known for her experimental confirmation of the planar ring structure of benzene. She was the first woman presi- dent of both the International Union of Crystallogra- phy (1966) and the British Association for the Advancement of Science (1968). AIP Emilio Segrè Visual Archives HENDRIK ANTOON

Lorentz 1853-1928

The Nobel Prize in Physics 1902

was awarded to H. Lorentz and P. Zeeman “in recog- nition of the extraordinary service they rendered by their researches into the influence of magnetism upon radiation phenomena”

Lorentz developed a theory of electrons and arrived at the equations for spatial contraction and time dila- tion that were incorporated into relativity theory by Einstein.

AIP Meggers Gallery of Nobel Laureates THEODORE

Lyman1874-1954

American physicist famous for his pioneering work in ultraviolet spectroscopy. Lyman discovered the fun- damental series of hydrogen spectral lines which bear his name. He served as president of the American Physical Society from 1921-1922.

AIP Emilio Segrè Visual Archives, W. F. Meggers Collection ERNST

Mach 1838-1916

Austrian physicist who made contributions to mechan- ics, acoustics, thermodynamics, experimental psychol- ogy, and history and philosophy of science. His cam- paign to eliminate metaphysics from science influ- enced young Einstein and some authors of quantum mechanics, especially those of Bohr’s Copenhagen school.

AIP Emilio Segrè Visual Archives Physics Today Collection GUGLIELMO

Marconi 1874-1937

The Nobel Prize in Physics 1909

was awarded to G. Marconi and C. Braun “in rec- ognition of their contributions to the development of wireless telegraphy”

Photo by Gen. Stab. Lit. Anst., courtesy AIP Emilio Segrè Visual Archives ROBERT EUGENE

Marshak 1916-1993

American physicist nominated several times for the Nobel Prize in physics. His most significant scientific contribu- tion was the V-A Theory of Weak Interactions, proposed with G. Sudarshan. He also explained high-tempera- ture shockwave or “Marshak wave” behavior.

AIP Gallery of Member Society Presidents BERND TEO

Matthias 1918-1980

German-born American physicist noted primarily for his extensive work on superconducting materials. He empirically determined various properties of semicon- ductors. This led to his discovery of new higher- temperature semiconductoring alloys such as niobium-germanium.

Bell Telephone Labs, courtesy AIP Emilio Segrè Visual Archives EDWIN MATTISON

McMillan 1907-1991

The Nobel Prize in Chemistry 1951

was awarded to E. McMillan and G. Seaborg “for their discoveries in the chemistry of the transura- nium elements”

He also discovered (independently from Veksler) the concept of “phase focusing” which has become the basis of all modern accelerators. He built the first elec- tron synchrotron and was Director of the Lawrence Radiation Laboratory (1959-1973). AIP Emilio Segrè Visual Archives LISE

Meitner 1878-1968

Austrian physicist and first female physics professor in Germany. She discovered uranium-fission with Hahn and Strassmann for which all received the 1966 Enrico Fermi Award. She and Frisch also provided its physical explanation. Meitner also discovered pro- tactinium with Hahn.

AIP Emilio Segrè Visual Archives ALBERT ABRAHAM

Michelson 1852-1931

The Nobel Prize in Physics 1907

“for his optical precision instruments and the spectro- scopic and meteorological investigations carried out with their aid”

With E. Morley he attempted to determine the motion of the Earth relative to the ether. Their failure to ob- serve the expected result was later explained by Einstein’s special theory of relativity (a theory that Michelson rejected). AIP ESVA, W.F. Meggers Collection ROBERT ANDREWS

Millikan 1868-1953

The Nobel Prize in Physics 1923

“for his work on the elementary charge of electricity and on the photoelectric effect”

Millikan’s verification of Einstein’s formula for the pho- toelectric effect was considered a confirmation of quantum theory.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection HERMANN

Minkowski 1864-1909

German mathematician noted for combining the three dimensions of physical space with time into a four- dimensional space known as “Minkowski Space” which laid the mathematical foundation for Einstein’s general theory of relativity.

H. Minkowski, Das Relatitatsprinzie, courtesy AIP Emilio Segrè Visual Archives RICHARD von Mises 1883-1953

Austrian-American mathematician and aerodynami- cist who significantly advanced the theory of flight through his work on boundary-layer flow and airfoil design. He also contributed to the development of probability theory and statistics, and was a prominent philosopher of science.

AIP Emilio Segrè Visual Archives, von Mises Collection H E N R Y G W Y N J E F F R E Y S

Moseley 1887-1915

English physicist who derived a relationship between an element’s X-ray wavelengths and its atomic num- ber (Moseley’s Law) which allowed him to predict the existence of several then unknown elements and link chemical behavior to atomic number. His promis- ing career was cut short by his death in World War I.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection N E V I L L F R A N C I S

Mott 1905-1996

The Nobel Prize in Physics 1977

was awarded to N. Mott, P. Anderson and J. Van Vleck “for their fundamental theoretical investigations of the electronic structure of magnetic and disordered systems”

Earlier he had provided one of the first tests of the new quantum mechanics by deducing a formula for the scattering of two identical particles (“Mott scattering”).

AIP Emilio Segrè Visual Archives, courtesy Sir Nevill Mott R O B E R T S A N D E R S O N

Mulliken 1896-1986

The Nobel Prize in Chemistry 1966

“for his fundamental work concerning chemical bonds and the electronic structure of molecules by the molecular orbital method”

Having competed with Pauling’s valence bond method for two decades, Mulliken’s molecular orbital method was generally adopted by quantum chemists after the 1950s. Harris & Ewing, courtesy AIP Emilio Segrè Visual Archives JOHN von Neumann 1903-1957

Hungarian-American mathematician who made im- portant contributions to quantum mechanics, logic, meteorology, the development of electronic comput- ers, and game theory. He was the first director of the Institute for Advanced Study, Princeton.

AIP Emilio Segrè Visual Archives ALFRED OTTO CARL

Nier 1911-1994

American physicist and geologist whose design in- novations and fundamental work with the mass spec- trometer set the stage for advances made in under- standing the chronology of the Earth’s formation. He worked on the problem of separating U235 and U238 isotopes of uranium for the Manhattan Project.

Univ of Minnesota, courtesy AIP Emilio Segrè Visual Archives AMALIE “EMMY”

Noether 1882-1935

World renowned German-born American mathema- tician whose contributions to abstract algebra inspired the “Noether School.” Her application of algebraic invariants yielded pure mathematical formulations for aspects of Einstein’s General Theory of Relativity. She also produced the theorem bearing her name which relates symmetries to conservation principles.

Bryn Mawr College Library GIUSEPPE PAOLO STANISLAO

Occhialini 1907-1993

Italian physicist and co-discoverer of the pi-meson with Cecil Powell. Occhialini also produced the first pho- tographic evidence of the existence of the positron with Patrick Blackett.

Amaldi Archives, Dipartimento di Fisica, Università “la Sapienza,” Rome, courtesy AIP Emilio Segrè Visual Archives LARS

Onsager 1903-1976

The Nobel Prize in Chemistry 1968

“for the discovery of the reciprocal relations bearing his name, which are fundamental for the thermody- namics of irreversible processes”

He is best known for his remarkable exact solution of the two-dimensional Ising model, a feat that revolu- tionized the theory of phase transitions.

AIP Emilio Segrè Visual Archives JULIUS ROBERT

Oppenheimer 1904-1967

American physicist awarded the 1963 Enrico Fermi Award. His research on protons and their relation to electrons led directly to the discovery of the positron. Oppenheimer established and served as director of Los Alamos Laboratory during development of the atomic bomb.

Los Alamos National Laboratory, courtesy AIP Emilio Segrè Visual Archives CLAIR CAMERON

Patterson 1922-1995

American geochemist awarded the 1975 J. Lawrence Smith Medal. He discovered dramatic increases in environmental lead levels and fought to reduce them. In 1953 he calculated Earth’s age to be 4.6 billion years.

courtesy Archives, California Institute of Technology WOLFGANG

Paul 1913-1993

The Nobel Prize in Physics 1989

was awarded to Wolfgang Paul and H. Dehmelt “for the development of the ion trap technique”

AIP Meggers Gallery of Nobel Laureates WOLFGANG ERNST

Pauli1900-1958

The Nobel Prize in Physics 1945

“for the discovery of the Exclusion Principle, also called the Pauli Principle”

This principle was needed for the quantum-mechani- cal explanation of the electronic structure and chemi- cal properties of atoms. In order to account for the apparent violation of energy conservation in ß-de- cay, Pauli postulated the existence of an unseen par- ticle, called the “neutrino” by Fermi. (It was later discovered by F. Reines and C. Cowan.) AIP Emilio Segrè Visual Archives LINUS CARL

Pauling 1901-1994

First person to receive two unshared Nobel Prizes in two different fields.

The Nobel Prize in Chemistry 1954

“for his research into the nature of the chemical bond and its application to the elucidation of the structure of complex substances”

Pauling also received the Nobel Peace Prize, 1962, for his leadership in the campaign for a nuclear test ban as a first step toward nuclear disarmament.

The Nobel Peace Prize 1962

“for warning against the dangers of radioactive fall- out from nuclear weapons testing” AIP Emilio Segrè Visual Archives, W.F. Meggers Collection CECELI HELENA

Payne-Gaposchkin 1900-1979

Awarded the Henry Norris Russell Prize “to commemo- rate a lifetime of pre-eminence in astronomical re- search.” This English-born American astrophysicist was an authority on stellar development, variable stars, and galactic structure. She discovered the chemi- cal composition of stars, and therefore the universe, to be primarily hydrogen and helium. In 1926, at age 26, she became the youngest scientist listed in American Men of Science. AIP Emilio Segrè Visual Archives Physics Today Collection RUDOLF ERNST

Peierls 1907-1995

German-British physicist who contributed to solid-state physics, quantum mechanics, and nuclear physics. He developed the theory of diamagnetism in metals and worked on both British and American atomic- bomb projects during the war.

AIP Emilio Segrè Visual Archives Physics Today Collection M A R G U E R I T E C A T H E R I N E

Perey 1909-1975

French nuclear chemist selected first female corre- sponding member of the Académie des Sciences (1962), which had been closed to women for three centuries since its founding in 1666. She discovered the element francium, the last radioactive element dis- covered in nature. The remarkable nature of Perey’s discovery is highlighted once it is realized the esti- mated total quantity of francium in the Earth’s crust is less than 24.5 grams. AIP Emilio Segrè Visual Archives JEAN BAPTISTE

Perrin1870-1942

The Nobel Prize in Physics 1926

“for his work on the discontinuous structure of matter, and especially for his discovery of sedimentation equi- librium”

Although physical and chemical theories throughout the 19th century had been based on atoms, skeptics argued that there was no direct evidence for their existence. Perrin, through his confirmation of Einstein’s theory of Brownian motion, finally persuaded scien- tists that matter is really composed of atoms whose properties can be quantitatively determined. AIP Meggers Gallery of Nobel Laureates MAX KARL ERNST LUDWIG

Planck1858-1947

The Nobel Prize in Physics 1918

“in recognition of the services he rendered to the ad- vancement of physics by his discovery of energy quanta”

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection AGNES

Pockels 1862-1935

Self-educated scientist who did pioneering research in the physics of surface films. Her exceptional ex- perimental work on surfactants and surface tension were performed at home while caring for her ailing parents. Many of her techniques are still standard procedure today.

Courtesy of Technische Universität Braunschweig JULES HENRI

Poincaré 1854-1912

French mathematician noted for his discovery of automorphic functions, and contributions to the de- velopment of relativity theory. His work on the 3-body problem and the equations of dynamics includes the discovery of the “recurrence theorem” and anticipates some of the results of modern chaos theory.

AIP Emilio Segrè Visual Archives Physics Today Collection CECIL FRANK

Powell1903-1969

The Nobel Prize in Physics 1950

“for his development of the photographic method of studying nuclear processes and his discoveries regard- ing mesons made with this method”

AIP Meggers Gallery of Nobel Laureates LUDWIG

Prandtl 1875-1953

German engineer considered the “father of aerody- namics.” His discovery of the boundary layer helped bridge the gap between empirical hydraulics and modern hydrodynamics and aerodynamics. He be- came Director of the Kaiser Wilhelm (now Max Planck) Institute for Fluid Dynamics in 1925.

AIP Emilio Segrè Visual Archives EDWARD MILLS

Purcell 1912-1997

The Nobel Prize in Physics 1952

was awarded to Edward Purcell and F. Bloch “for their development of new methods for nuclear mag- netic precision measurements and discoveries in con- nection therewith”

This led to the development of magnetic resonance for medical and other applications. With H. I. Ewan he detected the hyperfine line radiation of neutral hy- drogen at 21 cm, which permitted astronomers to plot the distribution of hydrogen in our Galaxy and determine galactic rotation. NARA, courtesy AIP Emilio Segrè Visual Archives ISIDOR ISAAC

Rabi 1898-1988

The Nobel Prize in Physics 1944

“for his resonance method for recording the magnetic properties of atomic nuclei”

He developed a school of experimental physics which was instrumental in developing physics in America. He also established the field of nuclear magnetic reso- nance which is the basis for magnetic resonance im- aging (MRI) widely used in medicine and industry. AIP Emilio Segrè Visual Archives LEO JAMES

Rainwater 1917-1986

The Nobel Prize in Physics 1975

was awarded to Leo Rainwater, A. Bohr and B. Mottelson “for the discovery of the connection be- tween collective motion and particle motion in atomic nuclei and the development of the theory of the struc- ture of the atomic nucleus based on this connection”

AIP Emilio Segrè Visual Archives Physics Today Collection CHANDRASEKHARA

Raman1888-1970

The Nobel Prize in Physics 1930

“for his work on the scattering of light and for the discovery of the effect named after him”

AIP Meggers Gallery of Nobel Laureates O W E N W I L L I A M S

Richardson 1879-1959

The Nobel Prize in Physics 1928

“for his work on the thermionic phenomenon and es- pecially for the discovery of the law named after him”

AIP Meggers Gallery of Nobel Laureates WILHELM CONRAD

Röntgen 1845-1923

The Nobel Prize in Physics 1901

“in recognition of the extraordinary services he has rendered by the discovery of the remarkable rays sub- sequently named after him”

The discovery of X-rays is often regarded as the be- ginning of 20th century physics.

AIP Emilio Segrè Visual Archives, W. F. Meggers Collection BRUNO BENEDETTI

Rossi1905-1993

Italian born American physicist noted for his seminal contribution to cosmic ray and elementary particle physics. He discovered cosmic rays to be positively charged particles and found the first astronomical x-ray source.

AIP Emilio Segrè Visual Archives ERNEST

Rutherford 1871-1937

The Nobel Prize in Chemistry 1908

“for his investigations into the disintegration of the elements, and the chemistry of radioactive substances”

Rutherford was born and received his early educa- tion in New Zealand, but pursued his career mainly in England. With F. Soddy he showed that radioac- tivity involves transmutation of one element into an- other, thus undermining a fundamental principle of chemistry. Rutherford established the nature of the V and $ rays emitted in radioactive decay and intro- duced the statistical concept of “half-life.” He pro- posed the nuclear model of the atom on the basis of scattering experiments by Geiger and Marsden. He produced the first man-made transmutation by bombard- ing nitrogen with particles (helium nuclei), obtaining oxy- gen and hydrogen. AIP Emilio Segrè Visual Archives, Wm. G. Myers Collection WALLACE CLEMENT

Sabine1868-1919

American physicist and founder of scientific architec- tural acoustics. He undertook the systematic study of building acoustics, eventually formulating a relation between reverberation time and room material, size, and shape known as Sabine’s Law.

AIP Emilio Segrè Visual Archives ANDREI DMITRIEVICH

Sakharov 1921-1989

The Nobel Prize for Peace 1975

"has fought against the abuse of power and all forms of violation of human dignity, and he has fought no less courageously for the idea of government based on the rule of law. In a convincing manner Sakharov has emphasised that Man's inviolable rights provide the only safe foundation for genuine and enduring international cooperation. In this way, in a particu- larly effective manner, working under difficult condi- tions, he has enhanced respect for the values that rally all true peacelovers."

Soviet physicist who made the crucial contribution to the creation of the hydrogen bomb, and later to the defense of human rights and the democratic reform in the Soviet Union. VNIIEF Museum & Archives, courtesy AIP Emilio Segrè Visual Archives ABDUS

Salam 1926-1996

The Nobel Prize in Physics 1979

was awarded to Abdus Salem, S. Glashow and S. Weinberg “for their contributions to the theory of the unified weak and electromagnetic interaction between elementary particles, including inter alia, the predic- tion of the weak neutral current”

A native of Pakistan who pursued his scientific career in England. Salam founded the International Center for Theoretical Physics in Trieste to promote research by scientists from developing countries.

AIP Emilio Segrè Visual Archives, Marshak Collection LEONARD ISSAC

Schiff1915-1971

American physicist known for his textbook Quantum Mechanics and his researches on scattering theory and general relativity. He served as chairman of Stanford University’s physics department for eighteen years.

Stanford University, courtesy AIP Emilio Segrè Visual Archives ERWIN

Schrödinger 1887-1961

The Nobel Prize in Physics 1933

was awarded to Erwin Schrödinger and P. Dirac “for the discovery of new productive forms of atomic theory”

Schrödinger proposed the widely-used version of quantum mechanics known as “wave mechanics,” a development of L. de Broglie’s hypothesis. Schrödinger’s equation governs the structure and prop- erties of all atoms, molecules, and macroscopic bod- ies except where relativistic effects are important; it is the most important equation in 20th century physical science.

Photo by Francis Simon, courtesy AIP Emilio Segrè Visual Archives MARTIN

Schwarzschild 1912-1997

German-born American astronomer. He made sig- nificant contributions to the study of stellar structure and stellar evolution and pioneered the use of space telescopes carried aloft by high-altitude hot-air balloons.

AIP Emilio Segrè Visual Archives, Irwin Collection JULIAN SEYMOUR

Schwinger 1918-1994

The Nobel Prize in Physics 1965

was awarded to Julian Schwinger, R. Feynman and S. Tomonaga “for their fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles”

AIP Emilio Segrè Visual Archives EMILIO GINO

Segrè1905-1989

The Nobel Prize in Physics 1959

was awarded to E. Segrè and O. Chamberlain “for their discovery of the antiproton”

AIP Meggers Gallery of Nobel Laureates ROBERT

Serber1909-1997

American physicist who pioneered the theory of high- energy nuclear physics and made significant contri- butions to the understanding of nuclear forces. He was Oppenheimer’s chief research assistant and a prominent member of the Manhattan Project.

AIP Emilio Segrè Visual Archives Physics Today Collection W I L L I A M B R A D F O R D

Shockley 1910-1989

The Nobel Prize in Physics 1956

was awarded to W. Shockley, J. Bardeen and W. Brattain “for their researches on semiconductors and their discovery of the transistor effect”

AIP Emilio Segrè Visual Archives Physics Today Collection KARL MANNE GEORG

Siegbahn 1886-1978

The Nobel Prize in Physics 1924

“for his discoveries and research in the field of X-ray spectroscopy”

AIP Meggers Gallery of Nobel Laureates J O H N C L A R K E

Slater1900-1976

American physicist who pioneered the development and application of quantum mechanics to atoms, mol- ecules, and the solid state. His Slater determinants are well-known, as is the Slater orbital—an extremely useful atomic orbit approximation.

MIT, courtesy AIP Emilio Segrè Visual Archives A R N O L D J O H A N N E S W I L H E L M

Sommerfeld 1868-1951

German physicist whose investigations of atomic spec- tra led him to postulate elliptical orbits for electrons in the Bohr model of the atom. He also introduced the azimuthal and magnetic quantum numbers.

AIP Emilio Segrè Visual Archives Physics Today Collection LYMAN, JR. . Spitzer 1914-1997

American astrophysicist whose researches on ionized gases (plasmas) advanced knowledge of interstellar processes and led to the field of plasma physics. He was the vision behind the Hubble Space Telescope and he pioneered efforts to harness nuclear fusion.

Photo by Ulli Steltger, courtesy AIP Emilio Segrè Visual Archives JOHANNES

Stark1874-1957

The Nobel Prize in Physics 1919

“for his discovery of the Doppler effect in canal rays and the splitting of spectral lines in electric fields”

Photo by A.B. Lagrelius & Westphal, courtesy AIP Emilio Segrè Visual Archives OTTO

Stern 1888-1969

The Nobel Prize in Physics 1943

“for his contribution to the development of the mo- lecular ray method and his discovery of the magnetic movement of the proton”

With W. Gerlach he confirmed experimentally the space quantization predicted by the Bohr-Sommerfeld theory.

AIP Meggers Gallery of Nobel Laureates JABEZ CURRY

Street1906-1989

American physicist best known for his 1937 discov- ery of the muon with Stevenson, independently of C.D. Anderson and S.H. Neddermeyer. He also directed wartime research on ground and ship radar as well as the prototype Loran Navigation System.

The Smithsonian Institution, Science Service Collection, courtesy AIP Emilio Segrè Visual Archives J O H N W I L L I A M R A Y L E I G H

Strutt1842-1919

The Nobel Prize in Physics 1904

“for his investigations of the densities of the most im- portant gases and for his discovery of argon in con- nection with these studies”

AIP Emilio Segrè Visual Archives Physics Today Collection LEO

Szilard 1898-1964

Hungarian-born American physicist who was one of the leading contributors to the development of nuclear energy and atomic weapons. Together with Fermi he organized the work on the first controlled nuclear chain reaction. He worked tirelessly to prevent the use of nuclear weapons. He formed the Bulletin of Atomic Scientists (1945) and The Council for a Liv- able World (1962).

AIP Emilio Segrè Visual Archives I G O R Y E V G E N Y E V I C H

Tamm 1885-1971

The Nobel Prize in Physics 1958

was awarded to I. Tamm, P. Cherenkov and I. Frank “for the discovery and the interpretation of the Cherenkov effect”

Dr. V. Frenkel and the Leningrad Physico-Technical Institute, courtesy AIP Emilio Segrè Visual Archives L L E W E L L Y N H E L L E T H

Thomas 1903-1992

American physicist best remembered for his work in atomic physics, the Thomas Factor, and also for his development (concurrently with Enrico Fermi) of the statistical model of the atom—the Thomas-Fermi Model.

AIP Emilio Segrè Visual Archives G E O R G E P A G E T

Thomson 1892-1975

The Nobel Prize in Physics 1937

was awarded to G. Thomson and C. Davisson

“for their experimental discovery of the diffraction of electrons by crystals”

They independently confirmed the wave nature of the electron, proposed by L. de Broglie.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection J O S E P H J O H N

Thomson 1856-1940

The Nobel Prize in Physics 1906

“in recognition of the great merits of his theoretical and experimental investigations on the conduction of electricity by gases”

Thomson is best known for the “discovery of the elec- tron,” i.e. his experimental proof that cathode rays are streams of charged particles (whose charge/mass ratio he determined) rather than electromagnetic waves, as believed by some other physicists. AIP Emilio Segrè Visual Archives, W. F. Meggers Collection SIN-ITIRO

Tomonaga 1906-1979

The Nobel Prize in Physics 1965

was awarded to S. Tomonaga, R. Feynman and J. Schwinger “for their fundamental work in quantum electrodynamics, with deep-ploughing consequences for the physics of elementary particles”

AIP Meggers Gallery of Nobel Laureates MERLE ANTHONY

Tuve 1901-1982

American geophysicist noted for radio-wave explo- ration of the upper atmosphere. He later used high- voltage experiments to investigate atomic structure, verifying the existence of the neutron and measuring atomic nuclei bonding forces.

AIP Emilio Segrè Visual Archives GEORGE EUGENE

Uhlenbeck 1900-1988

Dutch-American physicist who proposed the concept of electron spin with Samuel Goudsmit. He was awarded the 1977 National Medal of Science. Uhlenbeck later became a leader in statistical me- chanics research.

AIP Gallery of Member Society Presidents HAROLD CLAYTON

Urey 1893-1981

The Nobel Prize in Chemistry 1934

“for his discovery of heavy hydrogen”

After World War II, Urey applied chemistry to prob- lems in planetary science and inspired a number of physicists and chemists to enter that field. He also influenced the U. S. space program with his theories about the Moon and its origin.

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection ROBERT JEMISON

Van de Graaff 1901-1967

American physicist and inventor of the Van de Graaff generator—a high-voltage electrostatic particle ac- celerator that was widely used in atomic research, medicine, and industry.

AIP Emilio Segrè Visual Archives LÉON CHARLES

Van Hove 1924-1990

Belgian physicist who did extensive work on field theory, transport equations, and showed that statisti- cal mechanics can describe phase transitions. He also paved the way for the application of neutron diffrac- tion to the study of condensed matter. He was research director-general of CERN from 1976 to 1980.

AIP Emilio Segrè Visual Archives Physics Today Collection JOHN HASBROUCK

Van Vleck 1899-1980

The Nobel Prize in Physics 1977

was awarded to J. Van Vleck, P. Anderson and N. Mott “for their fundamental theoretical investigations of the electronic structure of magnetic and disordered systems”

AIP Emilio Segrè Visual Archives ERNEST THOMAS SINTON

Walton1903-1995

The Nobel Prize in Physics 1951

J. Cockroft

“for their pioneer work on the transmutation of atomic nuclei by artificially accelerated atomic particles”

AIP Emilio Segrè Visual Archives HERMAN KLAUS HUGO

Weyl 1885-1955

German mathematician whose development of affine and differential geometry proved important to the de- velopment of general relativity. His contributions to group theory and theory of Hilbert spaces and op- erators likewise proved valuable in solving problems in quantum mechanics.

AIP Emilio Segrè Visual Archives, Nina Courant Collection GIAN-CARLO

Wick 1909-1992

Italian physicist who made significant contributions to nuclear and particle physics. He showed how hydrogen molecule magnetic moments could be cal- culated, extended Fermi’s beta-decay theory, and formulated the theorem bearing his name important in relativistic quantum field theory.

AIP Emilio Segrè Visual Archives Physics Today Collection ROLF

Wideröe 1902-1996

Norwegian physicist who discovered the famous Wideröe 1:2 condition for accelerators relating mag- netic field strength at beam orbits to magnetic flux inside those orbits, developed the principle of RF ac- celeration to build the first linear accelerator, and suggested colliding high-energy beams in storage rings instead of bombarding stationary targets.

Fotoatelier Elis, courtesy AIP Emilio Segrè Visual Archives WILHELM

Wien 1864-1928

The Nobel Prize in Physics 1911

“for his discoveries regarding the laws governing the radiation of heat”

Photo by Ullstein, courtesy AIP Emilio Segrè Visual Archives NORBERT

Wiener1894-1964

American mathematician who advanced the study of quantum mechanics, established the science of cy- bernetics and applied statistical methods to gun con- trol. Wiener received the 1933 Bôcher Prize.

The MIT Museum and Historical Collections EUGENE PAUL

Wigner1902-1995

The Nobel Prize in Physics 1963

“for his contributions to the theory of the atomic nucleus and the elementary particles, particularly through the discovery and application of fundamental symmetry principles”.

With F. Seitz, Wigner pioneered the application of quan- tum mechanics to the study of electrons in metals.

AIP Emilio Segrè Visual Archives Physics Today Collection ROBERT WILLIAMS

Wood 1868-1955

American physicist whose major contributions were in spectroscopy and optics. He extended Raman spec- troscopy, observed field emissions, and invented Wood’s glass—a filter nearly opaque to visible light yet transparent to ultraviolet rays.

AIP Emilio Segrè Visual Archives Physics Today Collection CHIEN-SHIUNG

Wu 1912-1997

Chinese-born American physicist best known for her classic beta-decay experiments which provided the first experimental proof that parity conservation does not hold in weak subatomic interactions. She also experimentally confirmed the conservation of vector current in nuclear beta decay. Wu received the 1975 National Medal of Science and was the first woman to receive a Research Corporation Award (1959).

AIP Emilio Segrè Visual Archives HIDEKI

Yukawa 1907-1981

The Nobel Prize in Physics 1949

“for his prediction of the existence of mesons on the basis of theoretical work on nuclear forces”

The Nobel Prize was awarded after the discovery of the pi meson, the particle then believed to carry nuclear forces in the manner proposed by Yukawa. He was also instrumental in starting a school of theo- retical physics in Japan. AIP Emilio Segrè Visual Archives, E. Scott Barr Collection PIETER

Zeeman 1865-1943

The Nobel Prize in Physics 1902

was awarded to P. Zeeman and H. Lorentz

“in recognition of the extraordinary service they ren- dered by their researches into the influence of mag- netism upon radiation phenomena”

Zeeman discovered the splitting of spectral lines in magnetic fields.

AIP Meggers Gallery of Nobel Laureates YAKOV BORISOVICH

Zel’dovich 1914-1987

Soviet physicist who determined the mechanism of ni- trogen oxidation during explosions and published (to- gether with Khariton) the theory of the critical mass in nuclear chain reactions. He also made significant con- tributions to cosmology, explaining, in particular, the dynamics of neutron emission in black hole formation.

VNIIEF Museum & Archive, courtesy AIP Emilio Segrè Visual Archives FRITZ

Zernike 1888-1966

The Nobel Prize in Physics 1953

“for his demonstration of the phase contrast method, especially for his invention of the phase contrast microscope”

AIP Emilio Segrè Visual Archives, W.F. Meggers Collection FRITZ

Zwicky1898-1974

Swiss astronomer and physicist who made substan- tial contributions to jet propulsion, solid state phys- ics, and gaseous ionization. His most important work was on the theory of supernovae and on neutron star formation.

AIP Emilio Segrè Visual Archives Physics Today Collection