Alfred Robb
Encyclopedia
Alfred Arthur Robb or Alfred A. Robb FRS (18 January 1873 in Belfast
– 14 December 1936 in Castlereagh) was a British physicist
.
Robb studied at Queen's College in Belfast and at St John’s College
in Cambridge
. He then proceeded to University of Göttingen, where guided by Woldemar Voigt
, he wrote his dissertation on the Zeeman effect
. He also worked under J. J. Thomson
at the Cavendish Laboratory
. The Croix de Guerre
was awarded to him, and in 1921 he became a fellow of the Royal Society
.
He is known for his four works on special relativity
(1911, 1914, 1921, 1926) where he derived a spacetime
formalism of the theory in an axiomatic-geometric way. Robb therefore was sometimes called the "Euclid of relativity". In the first of these works he used a hyperbolic angle
to introduce the concept of rapidity
which clarified the relativistic velocity-addition formula
.
He also showed that the kinematic space of velocities is hyperbolic
, that is, that "instead of a Euclidean triangle of velocities, we get a Lobachevski triangle of rapidities".
However, contrary to the scientific mainstream, he believed that the works of Joseph Larmor
and Hendrik Lorentz
were more important for relativity than the works of Albert Einstein
and Hermann Minkowski
.
Belfast
Belfast is the capital of and largest city in Northern Ireland. By population, it is the 14th biggest city in the United Kingdom and second biggest on the island of Ireland . It is the seat of the devolved government and legislative Northern Ireland Assembly...
– 14 December 1936 in Castlereagh) was a British physicist
Physicist
A physicist is a scientist who studies or practices physics. Physicists study a wide range of physical phenomena in many branches of physics spanning all length scales: from sub-atomic particles of which all ordinary matter is made to the behavior of the material Universe as a whole...
.
Robb studied at Queen's College in Belfast and at St John’s College
St John's College, Cambridge
St John's College is a constituent college of the University of Cambridge. The college's alumni include nine Nobel Prize winners, six Prime Ministers, three archbishops, at least two princes, and three Saints....
in Cambridge
Cambridge
The city of Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about north of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the...
. He then proceeded to University of Göttingen, where guided by Woldemar Voigt
Woldemar Voigt
Woldemar Voigt was a German physicist, who taught at the Georg August University of Göttingen. Voigt eventually went on to head the Mathematical Physics Department at Göttingen and was succeeded in 1914 by Peter Debye, who took charge of the theoretical department of the Physical Institute...
, he wrote his dissertation on the Zeeman effect
Zeeman effect
The Zeeman effect is the splitting of a spectral line into several components in the presence of a static magnetic field. It is analogous to the Stark effect, the splitting of a spectral line into several components in the presence of an electric field...
. He also worked under J. J. Thomson
J. J. Thomson
Sir Joseph John "J. J." Thomson, OM, FRS was a British physicist and Nobel laureate. He is credited for the discovery of the electron and of isotopes, and the invention of the mass spectrometer...
at the Cavendish Laboratory
Cavendish Laboratory
The Cavendish Laboratory is the Department of Physics at the University of Cambridge, and is part of the university's School of Physical Sciences. It was opened in 1874 as a teaching laboratory....
. The Croix de Guerre
Croix de guerre
The Croix de guerre is a military decoration of France. It was first created in 1915 and consists of a square-cross medal on two crossed swords, hanging from a ribbon with various degree pins. The decoration was awarded during World War I, again in World War II, and in other conflicts...
was awarded to him, and in 1921 he became a fellow of the Royal Society
Royal Society
The Royal Society of London for Improving Natural Knowledge, known simply as the Royal Society, is a learned society for science, and is possibly the oldest such society in existence. Founded in November 1660, it was granted a Royal Charter by King Charles II as the "Royal Society of London"...
.
He is known for his four works on special relativity
Special relativity
Special relativity is the physical theory of measurement in an inertial frame of reference proposed in 1905 by Albert Einstein in the paper "On the Electrodynamics of Moving Bodies".It generalizes Galileo's...
(1911, 1914, 1921, 1926) where he derived a spacetime
Spacetime
In physics, spacetime is any mathematical model that combines space and time into a single continuum. Spacetime is usually interpreted with space as being three-dimensional and time playing the role of a fourth dimension that is of a different sort from the spatial dimensions...
formalism of the theory in an axiomatic-geometric way. Robb therefore was sometimes called the "Euclid of relativity". In the first of these works he used a hyperbolic angle
Hyperbolic angle
In mathematics, a hyperbolic angle is a geometric figure that divides a hyperbola. The science of hyperbolic angle parallels the relation of an ordinary angle to a circle...
to introduce the concept of rapidity
Rapidity
In relativity, rapidity is an alternative to speed as a framework for measuring motion. On parallel velocities rapidities are simply additive, unlike speeds at relativistic velocities. For low speeds, rapidity and speed are proportional, but for high speeds, rapidity takes a larger value. The...
which clarified the relativistic velocity-addition formula
Velocity-addition formula
In physics, a velocity-addition formula is an equation that relates the velocities of moving objects in different reference frames.- Galilean addition of velocities :...
.
He also showed that the kinematic space of velocities is hyperbolic
Hyperbolic geometry
In mathematics, hyperbolic geometry is a non-Euclidean geometry, meaning that the parallel postulate of Euclidean geometry is replaced...
, that is, that "instead of a Euclidean triangle of velocities, we get a Lobachevski triangle of rapidities".
However, contrary to the scientific mainstream, he believed that the works of Joseph Larmor
Joseph Larmor
Sir Joseph Larmor , a physicist and mathematician who made innovations in the understanding of electricity, dynamics, thermodynamics, and the electron theory of matter...
and Hendrik Lorentz
Hendrik Lorentz
Hendrik Antoon Lorentz was a Dutch physicist who shared the 1902 Nobel Prize in Physics with Pieter Zeeman for the discovery and theoretical explanation of the Zeeman effect...
were more important for relativity than the works of Albert Einstein
Albert Einstein
Albert Einstein was a German-born theoretical physicist who developed the theory of general relativity, effecting a revolution in physics. For this achievement, Einstein is often regarded as the father of modern physics and one of the most prolific intellects in human history...
and Hermann Minkowski
Hermann Minkowski
Hermann Minkowski was a German mathematician of Ashkenazi Jewish descent, who created and developed the geometry of numbers and who used geometrical methods to solve difficult problems in number theory, mathematical physics, and the theory of relativity.- Life and work :Hermann Minkowski was born...
.