mathematics

John T. Lewis

John T. Lewis is a mathematics 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 John T. Lewis rather than just read about it. In short: John Trevor Lewis (15 April 1932 – 21 January 2004) was a Welsh mathematical physicist who made contributions to areas including quantum measurement, Bose–Einstein condensation and large deviations theory. He was a senior professor at the Dublin Institute for Advanced Studies (DIAS) in Ireland from 1972, serving as the director of the School of Theoretical Physics from 1975 until his retirement in 2001.

Key takeaways

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

Reference excerpt

John Trevor Lewis (15 April 1932 – 21 January 2004) was a Welsh mathematical physicist who made contributions to areas including quantum measurement, Bose–Einstein condensation and large deviations theory. He was a senior professor at the Dublin Institute for Advanced Studies (DIAS) in Ireland from 1972, serving as the director of the School of Theoretical Physics from 1975 until his retirement in 2001. He also founded the Communications Networks Research Institute at Dublin Institute of Technology.

Academic career Lewis was born in Swansea, Wales, and was educated at Cardiff High School and then the Royal Belfast Academical Institution. He then studied at Queen's University Belfast, earning BSc in 1952 and PhD in 1955, the latter for a thesis on "Quantal Calculations Relating to Certain Rate Processes" done with Alexander Dalgarno and David Bates. He moved to Oxford in 1956, initially at Christ Church and later at Brasenose where he acted as Dean. In 1969 he spent a year visiting Rockefeller University and the Institute for Advanced Study. In 1972, he moved to the Dublin Institute for Advanced Studies on the retirement of John L. Synge, where he served as director of the School of Theoretical Physics. He was an honorary professor at Swansea, Cardiff and Trinity College, Dublin. He was a member of the Royal Irish Academy and was its senior vice-president in 1988. He received one of the first honorary doctorates from Dublin Institute of Technology in 1999. In 1971, he helped to found the Irish branch of Pugwash. With D McQuillan and T West he drew up the draft constitution of the Irish Mathematical Society after the DIAS Christmas Symposium in 1975. From 1985 to 1987 he was president of the Irish Federation of University Teachers. Lewis was also a founder of, and chief scientist at, Corvil, a company specialising in measurement and performance of Internet traffic.

References

External links John T. Lewis at the Mathematics Genealogy Project Death notice for John Trevor Lewis in London Mathematical Society Newsletter Issue 325 International Association of Mathematical Physics News Bulletin March 2004 - John T. Lewis 1932-2004 History of the DIAS School of Theoretical Physics O'Connor, John J.; Robertson, Edmund F., "John T. Lewis", MacTutor History of Mathematics Archive, University of St Andrews

Illustrations

Worked examples

Example 1 — a first encounter with John T. Lewis

Start with the simplest possible case. Write down what John T. Lewis claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In mathematics, 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 John T. Lewis 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 John T. Lewis 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 John T. Lewis

In research: John T. Lewis appears in mathematics 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 John T. Lewis 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: John T. Lewis is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1932 births, 2004 deaths, 20th-century Irish mathematicians, so understanding it makes those chapters shorter.
In everyday life: Look for John T. Lewis 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 John T. Lewis in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what John T. Lewis 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 John T. Lewis out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is John T. Lewis in simple terms?

Why does John T. Lewis matter?

Because it connects several mathematics 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 John T. Lewis?

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 John T. Lewis.