Larry saying

Larry Spruch (born January 1, 1923 in Brooklyn , New York City , † August 10, 2006 in New York City) was an American physicist who dealt with theoretical atomic physics.

Life

Spruch studied at Brooklyn College (bachelor's degree in 1943) and received his doctorate in 1948 with Leonard Schiff at the University of Pennsylvania with a thesis on the beta decay of tritium . He then served two years as a postdoctoral fellow at the Massachusetts Institute of Technology , where he is at Herman Feshbach and Victor Weisskopf with nuclear physics employed. In 1950 he became an Assistant Professor, 1955 Associate Professor and 1961 Professor at New York University , where he retired in 1994, but continued his research. He was visiting scholar at University College London (1963/64), at the Institute for Astrophysics in Paris (1969), at Harvard College Observatory (1977/78) and was at the Institute for Advanced Study in 1982/82 . Spruch worked as a consultant for the Lawrence Livermore National Laboratory from 1959 to 1966 and in 1979 at the Los Alamos National Laboratory .

plant

Spruch began as a nuclear physicist and dealt primarily with atomic physics, but also with its application in astrophysics. In the 1950s he applied methods developed by Feshbach from nuclear scattering in atomic physics and introduced (with colleagues such as Thomas F. O'Malley and Yukap Hahn) variation principles (after Walter Kohn ) for few-particle scattering processes in atomic physics a. He expanded this with his students in the 1960s and derived, for example, limits for the scattering lengths from principles of variation. The investigation of scattering processes with the principles of variation in atomic physics was put on just as solid a basis as the theory of bound states with the Ritz principle of variation . In 1983, he and colleagues presented a general formalism for the calculation of the most varied of atomic physical quantities with variation principles in an article in Reviews of Modern Physics .

In 1961, with O'Malley and Leonard Rosenberg, he applied the theory of effective range (which must be modified for this case) to the scattering of electrons and other charged particles (atoms polarized by the interaction).

With E. Kelsey in 1978 he showed how retardation effects in highly excited Rydberg atoms modify the potential from the usual to the type. The effects are of a quantum electrodynamic nature and represent generalizations of the Casimir effect . Later he also developed semi-classical theories for simpler explanations and estimates of Casimir-like effects in atomic physics. ${\displaystyle r^{-4}}$ ${\displaystyle r^{-5}}$

In 1968 he became a Fellow of the American Physical Society (APS). In 1985 he received a Senior Humboldt Award. In 1992 he received the APS Davisson-Germer Prize . The laudation highlighted his numerous contributions in various areas of atomic physics , including variational principles and bounds, theory of effective range, statistical models of the atom, collisions with rearrangement collisions, delay effects .

With his wife Grace Marmor Spruch, who is also a physicist, he wrote two popular science books.

Fonts

• Minimal principles in scattering theory , in Brittin, Downs, Downs (Ed.) Lectures in theoretical physics Vol. 4, Boulder 1961, Interscience 1962, pp. 161-263
• with Grace Marmor saying: The ubiquitous atom , Scribner 1974
• with Grace Spruch: 21 Astounding Science Quizzes , Barnes and Noble Books, New York 1982
• with E. Gerjuoy, ARP Rau: A unified formulation of the construction of variational principles , Rev.Mod. Phys., Vol. 55, 1983, p. 725
• Pedagogical notes on Thomas-Fermi theory (and on some improvements): atoms, stars, and the stability of bulk matter , Rev. Mod. Phys., Vol. 63, 1991, pp. 151-209
• with Robin Shakeshaft: Mechanisms for charge transfer (or for the capture of any light particle) at asymptotically high impact velocities , Rev. Mod. Phys., Vol. 51, 1979, p. 369 (rearrangement collisions)
• Retarded, or Casimir, Long-Range Forces , Physics Today, Vol. 39, Nov. 1986

Web links

• Larry saying. Biography. In: Physics History Network. AIP(English). 
• Ben Bederson: Larry Spruch 1923-2006. August 14, 2006 (English, website dedicated to him with reprints of his work). 
• Benjamin Bederson, Leonard Rosenberg, ARP Rau and Robin Shakeshaft: Larry Spruch . In: Physics Today . tape 60 , no. 1 , 2007, p. 68 , doi : 10.1063 / 1.2709567 (English, obituary).
• Literature by and about Larry Spruch in the WorldCat bibliographic database

References

1. ↑ Yukap Hahn on the work of Spruch and his school on principles of variation for scattering parameters, website in memory of Spruch at New York University, see web links
2. ↑ TF O'Malley, L. Rosenberg, Spruch: Modification of Effective-Range Theory in the Presence of a Long-Range Potential ${\displaystyle r^{-4}}$ , J. Math. Phys. Vol. 2, 1961, p. 491, the same Low energy scattering of a charged particle by a neutral polarizable system , Phys. Rev. Vol. 125, 1962, p. 1300
3. ↑ Kelsey, Spruch: Retardation effects on high Rydberg states: A retarded polarization potential ${\displaystyle r^{-5}}$ , Phys. Rev. A, Vol. 18, 1978, p. 15, the same Vacuum fluctuation and retardation effects on long-range potentials , Phys. Rev. A, Vol. 18, 1978, p. 845
4. ↑ Or Casimir Polder Effects. They work between two polarizable bodies, Casimir effects between two surfaces
5. ^ Thomas-Fermi theory
6. ↑ numerous contributions to many areas of atomic physics, including variational principles and bounds, effective-range theory, statistical models of the atom, rearrangement collisions, and retardation effects.