Sir William Hunter McCrea (13 December 1904 – 25 April 1999) was an English

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

and

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 ...

Biography

He was born in

Dublin Dublin is the capital and largest city of Republic of Ireland, Ireland. Situated on Dublin Bay at the mouth of the River Liffey, it is in the Provinces of Ireland, province of Leinster, and is bordered on the south by the Dublin Mountains, pa ...

Ireland Ireland (, ; ; Ulster Scots dialect, Ulster-Scots: ) is an island in the North Atlantic Ocean, in Northwestern Europe. Geopolitically, the island is divided between the Republic of Ireland (officially Names of the Irish state, named Irelan ...

on 13 December 1904. His family moved to

Kent Kent is a Ceremonial counties of England, ceremonial county in South East England. It is bordered by Essex across the Thames Estuary to the north, the Strait of Dover to the south-east, East Sussex to the south-west, Surrey to the west, and Gr ...

in 1906 and then to

Derbyshire Derbyshire ( ) is a ceremonial county in the East Midlands of England. It borders Greater Manchester, West Yorkshire, and South Yorkshire to the north, Nottinghamshire to the east, Leicestershire to the south-east, Staffordshire to the south a ...

where he attended

Chesterfield Grammar School Chesterfield may refer to: Places Canada * Rural Municipality of Chesterfield No. 261, Saskatchewan * Chesterfield Inlet, Nunavut United Kingdom *Chesterfield, Derbyshire, a market town in England ** Chesterfield (UK Parliament constituen ...

. His father was a school master at Netherthorpe Grammar School in Staveley. He went to

Trinity College, Cambridge Trinity College is a Colleges of the University of Cambridge, 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 ...

in 1923 where he studied Mathematics, later gaining a PhD in 1929 under

Ralph H. Fowler Sir Ralph Howard Fowler (17 January 1889 – 28 July 1944) was an English physicist, physical chemist, and astronomer. Education Ralph H. Fowler was born at Roydon, Essex, Roydon, Essex, on 17 January 1889 to Howard Fowler, from Burnham-on-Sea, ...

. From 1930 he lectured in Mathematics 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 ...

. During his time in Edinburgh (in 1931) he was elected a Fellow of the

Royal Society of Edinburgh The Royal Society of Edinburgh (RSE) is Scotland's national academy of science and letters. It is a registered charity that operates on a wholly independent and non-partisan basis and provides public benefit throughout Scotland. It was establis ...

. His proposers were Sir Edmund Taylor Whittaker, Sir Charles Galton Darwin, Edward Copson and

Charles Glover Barkla Charles Glover Barkla (7 June 1877 – 23 October 1944) was an English physicist who received the Nobel Prize in Physics in 1917 for his discovery of characteristic X-rays. Life Barkla was born in Widnes, England, to John Martin Barkla, a sec ...

. He won the Society's

Keith Medal The Keith Medal was a prize awarded by the Royal Society of Edinburgh, Scotland's national academy, for a scientific paper published in the society's scientific journals, preference being given to a paper containing a discovery, either in mathema ...

(jointly with Edward Copson) for the period 1939–41. In 1932 he moved to

Imperial College London Imperial College London, also known as Imperial, is a Public university, public research university in London, England. Its history began with Prince Albert of Saxe-Coburg and Gotha, Prince Albert, husband of Queen Victoria, who envisioned a Al ...

as a Reader. In 1936 he became Professor of Mathematics and head of the mathematics department at the

Queen's University of Belfast The Queen's University of Belfast, commonly known as Queen's University Belfast (; abbreviated Queen's or QUB), is a public research university in Belfast, Northern Ireland, United Kingdom. The university received its charter in 1845 as part of ...

. In the

Second World War World War II or the Second World War (1 September 1939 – 2 September 1945) was a World war, global conflict between two coalitions: the Allies of World War II, Allies and the Axis powers. World War II by country, Nearly all of the wo ...

he was co-opted onto the Admiralty Operational Research Group. After the war, he joined the mathematics department at

Royal Holloway College Royal Holloway, University of London (RH), formally incorporated as Royal Holloway and Bedford New College, is a public research university and a member institution of the federal University of London. It has six schools, 21 academic departmen ...

where he remained a professor for twenty years. The McCrea Building on Royal Holloway's campus is named after him. He was elected a Fellow of the

Royal Society of London 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, r ...

in 1952. In 1965, McCrea created the astronomy centre of the physics department at the

University of Sussex The University of Sussex is a public university, public research university, research university located in Falmer, East Sussex, England. It lies mostly within the city boundaries of Brighton and Hove. Its large campus site is surrounded by the ...

. McCrea died on 25 April 1999 at

Lewes Lewes () is the county town of East Sussex, England. The town is the administrative centre of the wider Lewes (district), district of the same name. It lies on the River Ouse, Sussex, River Ouse at the point where the river cuts through the Sou ...

Sussex Sussex (Help:IPA/English, /ˈsʌsɪks/; from the Old English ''Sūþseaxe''; lit. 'South Saxons'; 'Sussex') is an area within South East England that was historically a kingdom of Sussex, kingdom and, later, a Historic counties of England, ...

Family

In 1933 he married Marian Core (d. 1995) and had three children.

Discoveries

In 1928, he studied Albrecht Unsöld's hypothesis, and discovered that three-quarters of the Sun is made of

hydrogen Hydrogen is a chemical element; it has chemical symbol, symbol H and atomic number 1. It is the lightest and abundance of the chemical elements, most abundant chemical element in the universe, constituting about 75% of all baryon, normal matter ...

, and about one quarter is

helium Helium (from ) is a chemical element; it has chemical symbol, symbol He and atomic number 2. It is a colorless, odorless, non-toxic, inert gas, inert, monatomic gas and the first in the noble gas group in the periodic table. Its boiling point is ...

, with 1% being other elements. Previous to this many people thought the Sun consisted mostly of iron. After this, people realised most stars consist of hydrogen. In 1964 he proposed mass transfer mechanism as an explanation of

blue straggler A blue straggler is a type of star that is more luminous and bluer than expected. Typically identified in a stellar cluster, they have a higher effective temperature than the main sequence turnoff point for the cluster, where ordinary stars b ...

stars.

Awards

McCrea was president of the

Royal Astronomical Society The Royal Astronomical Society (RAS) is a learned society and charitable organisation, charity that encourages and promotes the study of astronomy, planetary science, solar-system science, geophysics and closely related branches of science. Its ...

from 1961 to 1963 and president of Section A of the

British Association for the Advancement of Science The British Science Association (BSA) is a Charitable organization, charity and learned society founded in 1831 to aid in the promotion and development of science. Until 2009 it was known as the British Association for the Advancement of Scienc ...

from 1965 to 1966. He was knighted by Queen

Elizabeth II Elizabeth II (Elizabeth Alexandra Mary; 21 April 19268 September 2022) was Queen of the United Kingdom and other Commonwealth realms from 6 February 1952 until Death and state funeral of Elizabeth II, her death in 2022. ...

in 1985. He won the

Gold Medal of the Royal Astronomical Society The Gold Medal of the Royal Astronomical Society is the highest award given by the Royal Astronomical Society (RAS). The RAS Council have "complete freedom as to the grounds on which it is awarded" and it can be awarded for any reason. Past awar ...

in 1976.

References

{{DEFAULTSORT:McCrea, William 20th-century English astronomers People from Chesterfield, Derbyshire Alumni of Trinity College, Cambridge Academics of the University of Edinburgh Academics of Imperial College London Academics of Queen's University Belfast Academics of Royal Holloway, University of London 1904 births 1999 deaths Scientists from County Dublin Recipients of the Gold Medal of the Royal Astronomical Society People educated at Chesterfield Grammar School Fellows of the Royal Society Knights Bachelor 20th-century English mathematicians Presidents of the Royal Astronomical Society Fellows of the Royal Society of Edinburgh

Biography

Family

Discoveries

Awards

See also

References