Charles Glover Barkla FRS FRSE (7 June 1877 – 23 October 1944) was a British

physicist A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate cau ...

, and the winner of the

Nobel Prize in Physics ) , image = Nobel Prize.png , alt = A golden medallion with an embossed image of a bearded man facing left in profile. To the left of the man is the text "ALFR•" then "NOBEL", and on the right, the text (smaller) "NAT•" then " ...

in 1917 for his work in

X-ray spectroscopy X-ray spectroscopy is a general term for several spectroscopic techniques for characterization of materials by using x-ray radiation. Characteristic X-ray spectroscopy When an electron from the inner shell of an atom is excited by the energy o ...

and related areas in the study of

X-ray An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30&nb ...

s (

Roentgen rays An X-ray, or, much less commonly, X-radiation, is a penetrating form of high-energy electromagnetic radiation. Most X-rays have a wavelength ranging from 10 picometers to 10 nanometers, corresponding to frequencies in the range 30 ...

Life

Barkla was born in

Widnes Widnes ( ) is an industrial town in the Borough of Halton, Cheshire, England, which at the 2011 census had a population of 61,464. Historically in Lancashire, it is on the northern bank of the River Mersey where the estuary narrows to form th ...

, England, to John Martin Barkla, a secretary for the Atlas Chemical Company, and Sarah Glover, daughter of a watchmaker. Barkla studied at the Liverpool Institute and proceeded to

Liverpool University , mottoeng = These days of peace foster learning , established = 1881 – University College Liverpool1884 – affiliated to the federal Victoria Universityhttp://www.legislation.gov.uk/ukla/2004/4 University of Manchester Act 200 ...

with a County Council Scholarship and a Bibby Scholarship. Barkla initially studied Mathematics but later specialised in Physics under Sir

Oliver Lodge Sir Oliver Joseph Lodge, (12 June 1851 – 22 August 1940) was a British physicist and writer involved in the development of, and holder of key patents for, radio. He identified electromagnetic radiation independent of Hertz's proof and at his ...

. During the absence of Oliver Lodge due to ill health, Barkla replaced him in lectures. In 1899 Barkla was admitted to

Trinity College, Cambridge Trinity College is a constituent college of the University of Cambridge. Founded in 1546 by King Henry VIII, Trinity is one of the largest Cambridge colleges, with the largest financial endowment of any college at either Cambridge or Oxford. ...

, with an

1851 Research Fellowship The 1851 Research Fellowship is a scheme conducted by the Royal Commission for the Exhibition of 1851 to annually award a three-year research scholarship to approximately eight "young scientists or engineers of exceptional promise". The fellowship ...

from the

Royal Commission for the Exhibition of 1851 The Royal Commission for the Exhibition of 1851 is an institution founded in 1850 to administer the international exhibition of 1851, officially called the Great Exhibition of the Works of Industry of all Nations. The Great Exhibition was held ...

, to work in the Cavendish Laboratory under the physicist

J. J. Thomson Sir Joseph John Thomson (18 December 1856 – 30 August 1940) was a British physicist and Nobel Laureate in Physics, credited with the discovery of the electron, the first subatomic particle to be discovered. In 1897, Thomson showed that ...

(discoverer of the electron). During his first two years at Cambridge, under the directions of Thomson, Barkla studied the velocity of electromagnetic waves along wires of different widths and materials. After a year and a half at Trinity College, Cambridge, his love of music led him to transfer to

King's College, Cambridge King's College is a constituent college of the University of Cambridge. Formally The King's College of Our Lady and Saint Nicholas in Cambridge, the college lies beside the River Cam and faces out onto King's Parade in the centre of the cit ...

, in order to sing in their chapel choir. Barkla's voice was of remarkable beauty and his solo performances were always fully attended. He completed his

Bachelor of Arts Bachelor of arts (BA or AB; from the Latin ', ', or ') is a bachelor's degree awarded for an undergraduate program in the arts, or, in some cases, other disciplines. A Bachelor of Arts degree course is generally completed in three or four year ...

degree in 1903, and then his

Master of Arts A Master of Arts ( la, Magister Artium or ''Artium Magister''; abbreviated MA, M.A., AM, or A.M.) is the holder of a master's degree awarded by universities in many countries. The degree is usually contrasted with that of Master of Science. Th ...

degree in 1907. He married Mary Esther Cowell in the same year, with whom he had two sons and one daughter. In 1913, after having worked at the Universities of Cambridge, Liverpool, and King's College London, Barkla was appointed as a Professor of

Natural Philosophy Natural philosophy or philosophy of nature (from Latin ''philosophia naturalis'') is the philosophical study of physics, that is, nature and the physical universe. It was dominant before the development of modern science. From the ancient wo ...

at 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 ...

in 1913, a position that he held until his death. Barkla made significant progress in developing and refining the laws of X-ray scattering,

, the principles governing the transmission of X-rays through matter, and especially the principles of the excitation of secondary X-rays. For his discovery of the characteristic X-rays of elements, Barkla was awarded the

in 1917. He was also awarded the

Hughes Medal The Hughes Medal is awarded by the Royal Society of London "in recognition of an original discovery in the physical sciences, particularly electricity and magnetism or their applications". Named after David E. Hughes, the medal is awarded with ...

of the British

Royal Society The Royal Society, formally The Royal Society of London for Improving Natural Knowledge, is a learned society and the United Kingdom's national academy of sciences. The society fulfils a number of roles: promoting science and its benefits, re ...

that same year. Barkla proposed the J-phenomenon as a hypothetical form of

behaviour similar to

X-ray fluorescence X-ray fluorescence (XRF) is the emission of characteristic "secondary" (or fluorescent) X-rays from a material that has been excited by being bombarded with high-energy X-rays or gamma rays. The phenomenon is widely used for elemental analysis ...

but other scientists were not persuaded that this was a different mechanism from other known effects such as

Compton scattering Compton scattering, discovered by Arthur Holly Compton, is the scattering of a high frequency photon after an interaction with a charged particle, usually an electron. If it results in a decrease in energy (increase in wavelength) of the photon ...

and so the theory was not successful. From 1922 to 1938 he lived at Hermitage of Braid in south-west Edinburgh. He died in Edinburgh on 23 October 1944.

Personal life

Plaque to C G Barkla, Hermitage of Braid

A religious man, Barkla was a

Methodist Methodism, also called the Methodist movement, is a group of historically related denominations of Protestant Christianity whose origins, doctrine and practice derive from the life and teachings of John Wesley. George Whitefield and John's ...

and considered his work to be ''"part of the quest for God, the Creator".''

Public recognition

The lunar crater Barkla was named in the honour of Charles Barkla. A plaque exists on Barkla's house at Hermitage of Braid in Edinburgh. A commemorative plaque has been installed in the vicinity of the Canongate, near the Faculty of Education Buildings, at the

. Additionally, a lecture theatre at the

University of Liverpool , mottoeng = These days of peace foster learning , established = 1881 – University College Liverpool1884 – affiliated to the federal Victoria Universityhttp://www.legislation.gov.uk/ukla/2004/4 University of Manchester Act 200 ...

's Physics department, as well as a Biophysics laboratory in the Biological science department, are named after him. In 2012 a gritter in Barkla's home town of

was named in his honour, following a competition run by the local newspaper."A gritter named Barkla"
Physics World Volume 25 Number 02, February 2012

References

External links

* including the Nobel Lecture, June 3, 1920 ''Characteristic Röntgen Radiation''

* ttp://www.encyclopedia.com/topic/Charles_Glover_Barkla.aspx Biography at Encyclopedia.com {{DEFAULTSORT:Barkla, Charles Glover 1877 births 1944 deaths 20th-century British physicists Alumni of Trinity College, Cambridge Alumni of King's College, Cambridge Academics of King's College London Academics of the University of Edinburgh English physicists English Methodists Fellows of the Royal Society Nobel laureates in Physics People from Widnes People educated at Liverpool Institute High School for Boys English Nobel laureates Spectroscopists