Raymond Eldred Siday (1912–1956) was an English

mathematician A mathematician is someone who uses an extensive knowledge of mathematics in their work, typically to solve mathematical problems. Mathematicians are concerned with numbers, data, quantity, structure, space, models, and change. History On ...

specialising in

quantum mechanics Quantum mechanics is a fundamental theory in physics that provides a description of the physical properties of nature at the scale of atoms and subatomic particles. It is the foundation of all quantum physics including quantum chemistry, ...

. He obtained his B.Sc. in Special Physics and later worked at

Edinburgh University 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 1582 ...

. He began collaborating with Werner Ehrenberg in 1933. Raymond Siday is known for the Ehrenberg–Siday effect.

Family

He was the brother of

Eric Siday Eric Siday (1 November 1905 – 26 March 1976) was a British-American composer and musician. While most commonly known for his pioneering work in electroacoustic music, his early career was that of a hot-jazz violinist in the London dance bands ...

, a pioneer of

electronic music Electronic music is a genre of music that employs electronic musical instruments, digital instruments, or circuitry-based music technology in its creation. It includes both music made using electronic and electromechanical means ( electroac ...

and Gentleman racing driver

Ehrenberg–Siday–Aharonov–Bohm effect

The Ehrenberg–Siday effect, later known as the

Aharonov–Bohm effect The Aharonov–Bohm effect, sometimes called the Ehrenberg–Siday–Aharonov–Bohm effect, is a quantum mechanical phenomenon in which an electrically charged particle is affected by an electromagnetic potential (φ, A), despite being confined ...

, is a quantum mechanical phenomenon by which a charged particle is affected by

electromagnetic field An electromagnetic field (also EM field or EMF) is a classical (i.e. non-quantum) field produced by (stationary or moving) electric charges. It is the field described by classical electrodynamics (a classical field theory) and is the classical c ...

s in regions from which the particle is excluded. The earliest form of this effect was predicted by Ehrenberg and Siday in 1949, and similar effects were later rediscovered by Aharonov and Bohm in 1959. Such effects are predicted to arise from both

magnetic field A magnetic field is a vector field that describes the magnetic influence on moving electric charges, electric currents, and magnetic materials. A moving charge in a magnetic field experiences a force perpendicular to its own velocity and to ...

s and

electric field An electric field (sometimes E-field) is the physical field that surrounds electrically charged particles and exerts force on all other charged particles in the field, either attracting or repelling them. It also refers to the physical field fo ...

s, but the magnetic version has been easier to observe. In general, the consequence of Aharonov–Bohm effects is that knowledge of the classical electromagnetic field acting locally on a particle is not sufficient to predict its quantum-mechanical behavior.

Selected papers

* * * *

References

Siday, R. E. Siday, R. E. Siday, Raymond Eldred British mathematicians {{UK-scientist-stub