astronomy

William McCrea (astronomer)

William McCrea (astronomer) is a astronomy topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand William McCrea (astronomer) rather than just read about it. In short: Sir William Hunter McCrea (13 December 1904 – 25 April 1999) was an English astronomer and mathematician. Biography He was born in Dublin in Ireland on 13 December 1904.

Key takeaways

William McCrea (astronomer) belongs to astronomy; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect William McCrea (astronomer) to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of William McCrea (astronomer) from memory before moving on to harder problems.

Reference excerpt

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

Biography He was born in Dublin in Ireland on 13 December 1904. His family moved to Kent in 1906 and then to Derbyshire where he attended Chesterfield Grammar School. His father was a school master at Netherthorpe Grammar School in Staveley. He went to Trinity College, Cambridge in 1923 where he studied Mathematics, and attended the first course on quantum mechanics at St John's College, Cambridge in the Easter term of 1926, by Paul Dirac. He later gained a PhD in 1929 under Ralph H. Fowler. From 1930 he lectured in Mathematics at the University of Edinburgh. During his time in Edinburgh (in 1931) he was elected a Fellow of the Royal Society of Edinburgh. His proposers were Sir Edmund Taylor Whittaker, Sir Charles Galton Darwin, Edward Copson and Charles Glover Barkla. He won the Society's Keith Medal (jointly with Edward Copson) for the period 1939–41. In 1932 he moved to Imperial College London as a Reader. In 1936 he became Professor of Mathematics and head of the mathematics department at the Queen's University of Belfast. In the Second World War he was co-opted onto the Admiralty Operational Research Group. After the war, he joined the mathematics department at Royal Holloway College 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 in 1952. In 1965, McCrea created the astronomy centre of the physics department at the University of Sussex. McCrea died on 25 April 1999 at Lewes in Sussex.

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, and about one quarter is helium, 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 stars.

Awards McCrea was president of the Royal Astronomical Society from 1961 to 1963 and president of Section A of the British Association for the Advancement of Science from 1965 to 1966. He was knighted by Queen Elizabeth II in 1985. He won the Gold Medal of the Royal Astronomical Society in 1976.

See also Accretion (astrophysics) History of Solar System formation and evolution hypotheses

References

Illustrations

William McCrea (astronomer) illustration

Worked examples

Example 1 — a first encounter with William McCrea (astronomer)

Start with the simplest possible case. Write down what William McCrea (astronomer) claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In astronomy, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to William McCrea (astronomer) before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about William McCrea (astronomer) ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of William McCrea (astronomer)

In research: William McCrea (astronomer) appears in astronomy research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses William McCrea (astronomer) in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: William McCrea (astronomer) is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1904 births, 1999 deaths, 20th-century English astronomers, so understanding it makes those chapters shorter.
In everyday life: Look for William McCrea (astronomer) outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study William McCrea (astronomer) in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what William McCrea (astronomer) means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain William McCrea (astronomer) out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is William McCrea (astronomer) in simple terms?

Sir William Hunter McCrea (13 December 1904 – 25 April 1999) was an English astronomer and mathematician. Biography He was born in Dublin in Ireland on 13 December 1904.

Why does William McCrea (astronomer) matter?

Because it connects several astronomy ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study William McCrea (astronomer)?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on William McCrea (astronomer).