Peter S. Pershan is a prominent American

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate caus ...

Education and career

Peter Pershan earned his

B.S. A Bachelor of Science (BS, BSc, SB, or ScB; from the Latin ') is a bachelor's degree awarded for programs that generally last three to five years. The first university to admit a student to the degree of Bachelor of Science was the University ...

Polytechnic Institute of Brooklyn The New York University Tandon School of Engineering (commonly referred to as Tandon) is the engineering and applied sciences school of New York University. Tandon is the second oldest private engineering and technology school in the United Sta ...

in 1956 and his

Ph.D. A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...

Physics Physics is the natural science that studies matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. "Physical science is that department of knowledge which r ...

Harvard University Harvard University is a private Ivy League research university in Cambridge, Massachusetts. Founded in 1636 as Harvard College and named for its first benefactor, the Puritan clergyman John Harvard, it is the oldest institution of higher le ...

in 1960 for

nuclear magnetic resonance Nuclear magnetic resonance (NMR) is a physical phenomenon in which nuclei in a strong constant magnetic field are perturbed by a weak oscillating magnetic field (in the near field) and respond by producing an electromagnetic signal with a ...

under the supervision of

Nicolaas Bloembergen Nicolaas Bloembergen (March 11, 1920 – September 5, 2017) was a Dutch-American physicist and Nobel laureate, recognized for his work in developing driving principles behind nonlinear optics for laser spectroscopy. During his career, he was a p ...

. After a short postdoctoral appointment with Bloembergen he was appointed an assistant professor at Harvard University, where he is now a Frank B. Baird, Jr. Professor of Science, at both Physics Department and Division of Engineering and Applied Sciences.

Research

Pershan began his career in nuclear magnetic resonance; however, before moving on to other things, he and Bloembergen produced some of the first papers on

non-linear optics Nonlinear optics (NLO) is the branch of optics that describes the behaviour of light in ''nonlinear media'', that is, media in which the polarization density P responds non-linearly to the electric field E of the light. The non-linearity is typica ...

, a field for which Bloembergen later received

Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

in 1981. He remained active in this field until the early 1980s when he wrote a book on

liquid crystals Liquid crystal (LC) is a state of matter whose properties are between those of conventional liquids and those of solid crystals. For example, a liquid crystal may flow like a liquid, but its molecules may be oriented in a crystal-like way. Th ...

and moved into the then-new field of

synchrotron radiation Synchrotron radiation (also known as magnetobremsstrahlung radiation) is the electromagnetic radiation emitted when relativistic charged particles are subject to an acceleration perpendicular to their velocity (). It is produced artificially in ...

. Along with Jens Als-Nielsen, Pershan developed the first synchrotron X-ray reflectometer for the study of the horizontal free surface of a liquid, and carried out the first synchrotron measurements on liquid surfaces at HASYLAB,

DESY The Deutsches Elektronen-Synchrotron (English ''German Electron Synchrotron''), commonly referred to by the abbreviation DESY, is a national research center in Germany. It operates particle accelerators used to investigate the structure of matt ...

in 1982. The liquid surface spectrometers now at

Advanced Photon Source The Advanced Photon Source (APS) at Argonne National Laboratory (in Lemont, Illinois) is a storage-ring-based high-energy X-ray light source facility. It is one of five X-ray light sources owned and funded by the U.S. Department of Energy Office ...

and the

National Synchrotron Light Source The National Synchrotron Light Source (NSLS) at Brookhaven National Laboratory (BNL) in Upton, New York was a national user research facility funded by the U.S. Department of Energy (DOE). Built from 1978 through 1984, and officially shut down o ...

are all variations of the HASYLAB instrument. Since 1982 Pershan has led the field in exploration of such diverse liquid surfaces as

superfluid Superfluidity is the characteristic property of a fluid with zero viscosity which therefore flows without any loss of kinetic energy. When stirred, a superfluid forms vortices that continue to rotate indefinitely. Superfluidity occurs in two ...

helium,

water Water (chemical formula ) is an inorganic, transparent, tasteless, odorless, and nearly colorless chemical substance, which is the main constituent of Earth's hydrosphere and the fluids of all known living organisms (in which it acts as a ...

, and

liquid metal A liquid metal is a metal or a metal alloy which is liquid at or near room temperature. The only stable liquid elemental metal at room temperature is Mercury (element), mercury (Hg), which is molten above −38.8 °C (234.3 K, −37.9&nbs ...

s. Aside from sabbaticals at the

University of Paris , image_name = Coat of arms of the University of Paris.svg , image_size = 150px , caption = Coat of Arms , latin_name = Universitas magistrorum et scholarium Parisiensis , motto = ''Hic et ubique terrarum'' (Latin) , mottoeng = Here and a ...

Brookhaven National Laboratory Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base and Japanese internment c ...

, and Risø National Laboratory Pershan has been at

(where he has been a faculty member since 1961) since he arrived as a graduate student in September 1956.

Books

In addition to over 240 scientific articles Peter Pershan has published two books: *"Structure of Liquid Crystal Phases", World Scientific, 1988 () *"Liquid Surfaces and Interfaces: Synchrotron X-ray Methods" (with Mark Schlossman), Cambridge University Press, 2012. ()

External links

Peter Pershan's web pagePeter Pershan @Harvard
{{DEFAULTSORT:Pershan, Peter Year of birth missing (living people) Living people Polytechnic Institute of New York University alumni Harvard University alumni 21st-century American physicists American nuclear physicists Harvard University faculty Fellows of the American Physical Society