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, mathematical structure, structure, space, Mathematica ...

specialising in

quantum mechanics Quantum mechanics is the fundamental physical Scientific theory, theory that describes the behavior of matter and of light; its unusual characteristics typically occur at and below the scale of atoms. Reprinted, Addison-Wesley, 1989, It is ...

. He obtained his BSc in Special Physics and later worked at the

University of Edinburgh The University of Edinburgh (, ; abbreviated as ''Edin.'' in Post-nominal letters, post-nominals) is a Public university, public research university based in Edinburgh, Scotland. Founded by the City of Edinburgh Council, town council under th ...

. 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 ban ...

, a pioneer of

electronic music Electronic music broadly is a group of music genres that employ electronic musical instruments, circuitry-based music technology and software, or general-purpose electronics (such as personal computers) in its creation. It includes both music ...

and amateur 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 mechanics, quantum-mechanical phenomenon in which an electric charge, electrically charged point particle, particle is affected by an elect ...

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

electromagnetic field An electromagnetic field (also EM field) is a physical field, varying in space and time, that represents the electric and magnetic influences generated by and acting upon electric charges. The field at any point in space and time can be regarde ...

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 (sometimes called B-field) is a physical 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 ...

s and

electric field An electric field (sometimes called E-field) is a field (physics), physical field that surrounds electrically charged particles such as electrons. In classical electromagnetism, the electric field of a single charge (or group of charges) descri ...

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