Richard Q. Twiss
Encyclopedia
Richard Q. Twiss is famous for his work on the Hanbury-Brown and Twiss effect
with Robert Hanbury Brown
. This led to the development of the Hanbury Brown-Twiss intensity interferometer in the UK in 1954. Their work was controversial as it appeared to contradict the established beliefs about quantum interference. He and Brown received the Eddington Medal
of the Royal Astronomical Society
for their work in 1968.
Richard Twiss was born in Simla
in India
but was educated in England
. He read mathematics
at Cambridge
, completing the Mathematical Tripos with distinction, but his early contributions were to the theory of radar
and basic electronics
. His work in this area was
included in the famous "five foot shelf"--a series of reference books in electronic engineering
compiled at MIT that was the circuit designer's bible in the 1950s. He was awarded a Doctor of Science
degree by MIT in 1949.
Twiss went on to help construct the Narrabri Stellar Intensity Interferometer
. Observations with the interferometer began in 1965. Measurements made between 1965 and 1974 were used to establish the temperature scale for star
s hotter than the Sun
and this scale is still in use.
The intensity interferometer has a very poor signal-to-noise ratio compared to the classical "Michelson
" stellar interferometer. Twiss decided to pursue the Michelson alternative at the National Physical Laboratory
at Teddington
in the UK. John Davis worked with him for a short while on this project.
When the Royal Observatory, Edinburgh
established its outstation at Monte Porzio Catone
just south of Rome
, Twiss decided to move his Michelson interferometer there. Not only was the weather more conducive to astronomy, the food and wine were much superior to what was available in Teddington!
Speckle interferometry
was discovered during that period by Antoine Labeyrie
. This stimulated a renewed interest around the world in interferometry. In particular, John Davis and Hanbury Brown became convinced that a Michelson interferometer would be cheaper to build and have superior performance to a new intensity interferometer.
In the mid-1970s Twiss's non-scientific interests gradually took over and he effectively retired from active involvement in science.
In the 1970s he made it clear that he regarded Australia
as a colonial backwater. His reaction when told that William J. Tango was going to join Davis and Brown in Sydney was typical. "But William," he said, "they eat peas out of tins!"
In spite of that, a few years before his death Twiss visited Australia and fell in love with it. In 2004 he applied for permanent residence. He died on 20 May 2005.
He is mentioned in the book "BOFFIN : A Personal Story of the Early Days of Radar, Radio Astronomy and Quantum Optics" ISBN 0-7503-0130-9, by Hanbury Brown
He was awarded the Albert A. Michelson Medal of the Franklin Institute
in 1982, jointly with Robert Hanbury Brown
.
Hanbury-Brown and Twiss effect
The Hanbury Brown and Twiss effect is any of a variety of correlation and anti-correlation effects in the intensities received by two detectors from a beam of particles. HBT effects can generally be attributed to the dual wave-particle nature of the beam, and the results of a given experiment...
with Robert Hanbury Brown
Robert Hanbury Brown
Robert Hanbury Brown, AC FRS was a British astronomer and physicist born in Aruvankadu, India. He made notable contributions to the development of radar and he later conducted pioneering work in the field of radio astronomy...
. This led to the development of the Hanbury Brown-Twiss intensity interferometer in the UK in 1954. Their work was controversial as it appeared to contradict the established beliefs about quantum interference. He and Brown received the Eddington Medal
Eddington Medal
The Eddington Medal, named after Sir Arthur Eddington, is awarded by the Royal Astronomical Society nominally once every two years for investigations of outstanding merit in theoretical astrophysics.- Recipients :* 1953 Georges Lemaître...
of the Royal Astronomical Society
Royal Astronomical Society
The Royal Astronomical Society is a learned society that began as the Astronomical Society of London in 1820 to support astronomical research . It became the Royal Astronomical Society in 1831 on receiving its Royal Charter from William IV...
for their work in 1968.
Richard Twiss was born in Simla
Shimla
Shimla , formerly known as Simla, is the capital city of Himachal Pradesh. In 1864, Shimla was declared the summer capital of the British Raj in India. A popular tourist destination, Shimla is often referred to as the "Queen of Hills," a term coined by the British...
in India
India
India , officially the Republic of India , is a country in South Asia. It is the seventh-largest country by geographical area, the second-most populous country with over 1.2 billion people, and the most populous democracy in the world...
but was educated in England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
. He read mathematics
Mathematics
Mathematics is the study of quantity, space, structure, and change. Mathematicians seek out patterns and formulate new conjectures. Mathematicians resolve the truth or falsity of conjectures by mathematical proofs, which are arguments sufficient to convince other mathematicians of their validity...
at Cambridge
University of Cambridge
The University of Cambridge is a public research university located in Cambridge, United Kingdom. It is the second-oldest university in both the United Kingdom and the English-speaking world , and the seventh-oldest globally...
, completing the Mathematical Tripos with distinction, but his early contributions were to the theory of radar
Radar
Radar is an object-detection system which uses radio waves to determine the range, altitude, direction, or speed of objects. It can be used to detect aircraft, ships, spacecraft, guided missiles, motor vehicles, weather formations, and terrain. The radar dish or antenna transmits pulses of radio...
and basic electronics
Electronics
Electronics is the branch of science, engineering and technology that deals with electrical circuits involving active electrical components such as vacuum tubes, transistors, diodes and integrated circuits, and associated passive interconnection technologies...
. His work in this area was
included in the famous "five foot shelf"--a series of reference books in electronic engineering
Electronic engineering
Electronics engineering, also referred to as electronic engineering, is an engineering discipline where non-linear and active electrical components such as electron tubes, and semiconductor devices, especially transistors, diodes and integrated circuits, are utilized to design electronic...
compiled at MIT that was the circuit designer's bible in the 1950s. He was awarded a Doctor of Science
Doctor of Science
Doctor of Science , usually abbreviated Sc.D., D.Sc., S.D. or Dr.Sc., is an academic research degree awarded in a number of countries throughout the world. In some countries Doctor of Science is the name used for the standard doctorate in the sciences, elsewhere the Sc.D...
degree by MIT in 1949.
Twiss went on to help construct the Narrabri Stellar Intensity Interferometer
Narrabri Stellar Intensity Interferometer
The Narrabri Stellar Intensity Interferometer was the first astronomical instrument to measure the diameters of a large number of stars at visible wavelengths. It was designed by Robert Hanbury Brown, who received the Hughes Medal in 1971 for this work...
. Observations with the interferometer began in 1965. Measurements made between 1965 and 1974 were used to establish the temperature scale for star
Star
A star is a massive, luminous sphere of plasma held together by gravity. At the end of its lifetime, a star can also contain a proportion of degenerate matter. The nearest star to Earth is the Sun, which is the source of most of the energy on Earth...
s hotter than the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...
and this scale is still in use.
The intensity interferometer has a very poor signal-to-noise ratio compared to the classical "Michelson
Albert Abraham Michelson
Albert Abraham Michelson was an American physicist known for his work on the measurement of the speed of light and especially for the Michelson-Morley experiment. In 1907 he received the Nobel Prize in Physics...
" stellar interferometer. Twiss decided to pursue the Michelson alternative at the National Physical Laboratory
National Physical Laboratory, UK
The National Physical Laboratory is the national measurement standards laboratory for the United Kingdom, based at Bushy Park in Teddington, London, England. It is the largest applied physics organisation in the UK.-Description:...
at Teddington
Teddington
Teddington is a suburban area in the London Borough of Richmond upon Thames in south west London, on the north bank of the River Thames, between Hampton Wick and Twickenham. It stretches inland from the River Thames to Bushy Park...
in the UK. John Davis worked with him for a short while on this project.
When the Royal Observatory, Edinburgh
Royal Observatory, Edinburgh
The Royal Observatory, Edinburgh is an astronomical institution located on Blackford Hill in Edinburgh, Scotland. The site is owned by the Science and Technology Facilities Council...
established its outstation at Monte Porzio Catone
Monte Porzio Catone
Monte Porzio Catone is a comune in the Province of Rome in the Italian region Latium, located about 20 km southeast of Rome, on the Alban Hills....
just south of Rome
Rome
Rome is the capital of Italy and the country's largest and most populated city and comune, with over 2.7 million residents in . The city is located in the central-western portion of the Italian Peninsula, on the Tiber River within the Lazio region of Italy.Rome's history spans two and a half...
, Twiss decided to move his Michelson interferometer there. Not only was the weather more conducive to astronomy, the food and wine were much superior to what was available in Teddington!
Speckle interferometry
Speckle imaging
Speckle imaging describes a range of high-resolution astronomical imaging techniques based either on the shift-and-add method or on speckle interferometry methods...
was discovered during that period by Antoine Labeyrie
Antoine Émile Henry Labeyrie
Antoine Émile Henry Labeyrie is a French astronomer and holds since 1991 the "Observational Astrophysics" chair at the Collège de France....
. This stimulated a renewed interest around the world in interferometry. In particular, John Davis and Hanbury Brown became convinced that a Michelson interferometer would be cheaper to build and have superior performance to a new intensity interferometer.
In the mid-1970s Twiss's non-scientific interests gradually took over and he effectively retired from active involvement in science.
In the 1970s he made it clear that he regarded Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
as a colonial backwater. His reaction when told that William J. Tango was going to join Davis and Brown in Sydney was typical. "But William," he said, "they eat peas out of tins!"
In spite of that, a few years before his death Twiss visited Australia and fell in love with it. In 2004 he applied for permanent residence. He died on 20 May 2005.
He is mentioned in the book "BOFFIN : A Personal Story of the Early Days of Radar, Radio Astronomy and Quantum Optics" ISBN 0-7503-0130-9, by Hanbury Brown
He was awarded the Albert A. Michelson Medal of the Franklin Institute
Franklin Institute
The Franklin Institute is a museum in Philadelphia, Pennsylvania, and one of the oldest centers of science education and development in the United States, dating to 1824. The Institute also houses the Benjamin Franklin National Memorial.-History:On February 5, 1824, Samuel Vaughn Merrick and...
in 1982, jointly with Robert Hanbury Brown
Robert Hanbury Brown
Robert Hanbury Brown, AC FRS was a British astronomer and physicist born in Aruvankadu, India. He made notable contributions to the development of radar and he later conducted pioneering work in the field of radio astronomy...
.