Peter Nicholas Pusey (born 30 December 1942) is a British physicist. He is an Emeritus Professor of Physics at the School of Physics and Astronomy of the

University of Edinburgh The University of Edinburgh ( sco, University o Edinburgh, gd, Oilthigh Dhùn Èideann; abbreviated as ''Edin.'' in post-nominals) is a public research university based in Edinburgh, Scotland. Granted a royal charter by King James VI in 15 ...

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University of Edinburgh, retrieved 2016-03-12.

Research

Pusey is a pioneer of

dynamic light scattering Dynamic light scattering (DLS) is a technique in physics that can be used to determine the size distribution profile of small particles in suspension or polymers in solution. In the scope of DLS, temporal fluctuations are usually analyzed usin ...

(DLS) and is known for elucidating the structure and dynamics of concentrated

colloidal suspension A colloid is a mixture in which one substance consisting of microscopically dispersed insoluble particles is suspended throughout another substance. Some definitions specify that the particles must be dispersed in a liquid, while others extend ...

s. He contributed to the development, underlying theory and applications of DLS. He was among the first to apply photon correlation techniques and, with colleagues, developed the now standard method of cumulant analysis for particle sizing. His theory, with William van Megen, of DLS by non-ergodic media resolved long-standing difficulties, allowing DLS studies of amorphous solid-like systems such as

polymer A polymer (; Greek ''poly-'', "many" + '' -mer'', "part") is a substance or material consisting of very large molecules called macromolecules, composed of many repeating subunits. Due to their broad spectrum of properties, both synthetic and ...

gel A gel is a semi-solid that can have properties ranging from soft and weak to hard and tough. Gels are defined as a substantially dilute cross-linked system, which exhibits no flow when in the steady-state, although the liquid phase may still di ...

s and

glass Glass is a non-Crystallinity, crystalline, often transparency and translucency, transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most ...

y colloidal suspensions. With his work on the

Brownian motion Brownian motion, or pedesis (from grc, πήδησις "leaping"), is the random motion of particles suspended in a medium (a liquid or a gas). This pattern of motion typically consists of random fluctuations in a particle's position insi ...

s of strongly interacting particles, Pusey was one of the first to apply microscopic approaches to colloidal suspensions. His research exploited analogies and differences between concentrated suspensions of ''hard-sphere'' colloids and atomic materials, to investigate such fundamental phenomena as

crystallisation Crystallization is the process by which solid forms, where the atoms or molecules are highly organized into a structure known as a crystal. Some ways by which crystals form are precipitating from a solution, freezing, or more rarely depo ...

, the

glass transition The glass–liquid transition, or glass transition, is the gradual and reversible transition in amorphous materials (or in amorphous regions within semicrystalline materials) from a hard and relatively brittle "glassy" state into a viscous or rub ...

and the formation of ordered binary

superlattice A superlattice is a periodic structure of layers of two (or more) materials. Typically, the thickness of one layer is several nanometers. It can also refer to a lower-dimensional structure such as an array of quantum dots or quantum wells. Dis ...

s. With Eric Jakeman, Pusey also introduced

K-distribution In probability and statistics, the generalized K-distribution is a three-parameter family of continuous probability distributions. The distribution arises by compounding two gamma distributions. In each case, a re-parametrization of the usual f ...

s; these have proved powerful in describing the statistical properties of, for example,

microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequency, frequencies between 300 MHz and 300 GHz respectively. Different sources define different fre ...

s scattered by the sea surface and

laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word "laser" is an acronym for "light amplification by stimulated emission of radiation". The firs ...

light propagating through the atmosphere.

Awards and honours

Pusey was elected a Fellow of the Royal Society (FRS) in 1996 One or more of the preceding sentences may incorporate text from the royalsociety.org website where "all text published under the heading 'Biography' on Fellow profile pages is available under

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." and Fellow of the

Royal Society of Edinburgh The Royal Society of Edinburgh is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was established i ...

in the same year. In 2005, he was awarded the Rhodia Prize by the European Colloid and Interface Society for his ''Outstanding contributions in the experimental study of dynamically arrested (

particulate matter Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The t ...

, especially in relation to

hard sphere Hard spheres are widely used as model particles in the statistical mechanical theory of fluids and solids. They are defined simply as impenetrable spheres that cannot overlap in space. They mimic the extremely strong ("infinitely elastic bouncing" ...

fluids with added

''.

References

{{DEFAULTSORT:Pusey, Peter Living people University of Pittsburgh alumni Fellows of the Royal Society Academics of the University of Edinburgh 1942 births