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George Johnstone Stoney

George Johnstone Stoney is a physics 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 George Johnstone Stoney rather than just read about it. In short: George Johnstone Stoney (15 February 1826 – 5 July 1911) was an Irish physicist and academic who is best known for introducing the term electron as the "fundamental unit quantity of electricity"; he initially named it electrolion in 1881, and later named it electron in 1891. He published around 75 scientific papers during his lifetime, and was the professor of Physics at Queen's College Galway from 1852 to 1857.

George Johnstone Stoney — main illustration
George Johnstone Stoney — illustration

Key takeaways

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

Reference excerpt

George Johnstone Stoney (15 February 1826 – 5 July 1911) was an Irish physicist and academic who is best known for introducing the term electron as the "fundamental unit quantity of electricity"; he initially named it electrolion in 1881, and later named it electron in 1891. He published around 75 scientific papers during his lifetime, and was the professor of Physics at Queen's College Galway from 1852 to 1857.

Biography George Johnstone Stoney was born on 15 February 1826 at Oakley Park in Clareen, Ireland, the son of George Stoney (1792–) and Anne Bindon Blood (1801–1883). The Stoney family is an old-established Anglo-Irish family. Stoney attended Trinity College Dublin, graduating with a B.A. in 1848. From 1848 to 1852, he worked as an astronomy assistant to William Parsons, 3rd Earl of Rosse, at Birr Castle, where Parsons had built the world's largest telescope, the 72-inch Leviathan of Parsonstown. From 1852 to 1857, Stoney was Professor of Physics at Queen's College Galway. From 1857 to 1882, he was Secretary of the Queen's University of Ireland, an administrative job based in Dublin. He continued his independent scientific research throughout his decades of non-scientific employment duties in Dublin. In 1882, he moved to the post of Superintendent of Civil Service Examinations in Ireland, a post he held until his retirement in 1893. Stoney took up residence in London, England. He died at his home in Notting Hill on 5 July 1911 at the age of 85. His cremated ashes were brought back to Ireland to be buried at St. Nahi's Church in Dublin. Stoney also served for decades as Honorary Secretary and then Vice President of the Royal Dublin Society, and after his move to London he served on the council of the Royal Society. Additionally, he intermittently served on scientific review committees of the British Association for the Advancement of Science from the early 1860s on.

Research Stoney published seventy-five scientific papers in a variety of journals, but chiefly in the journals of the Royal Dublin Society. He made significant contributions to cosmic physics and to the theory of gases. He estimated the number of molecules in a cubic millimetre of gas, at room temperature and pressure, from data obtained from the kinetic theory of gases. Stoney's most important scientific work was the conception and calculation of the magnitude of the "atom of electricity". In 1891, he proposed the term "electron" to describe the fundamental unit of electric charge, and his contributions to research in this area laid the foundations for the eventual discovery of the particle by J. J. Thomson in 1897. His scientific work was carried out in his spare time. A heliostat designed by Stoney is in the Science Museum Group collection. Stoney was elected a Fellow of the Royal Society in June 1861 on the basis of being the author of papers on "The Propagation of Waves", "On the Rings seen in Fibrous Specimens of Calc Spar", and Molecular Physics, published in the Transactions of the Royal Irish Academy, et cetera, Distinguished for his acquaintance with the science of Astronomy & General Physics.

Stoney units

Stoney proposed the first system of natural units in 1881. He realized that a fixed amount of charge was transferred per chemical bond affected during electrolysis, the elementary charge e, which could serve as a unit of charge, and that combined with other known universal constants, namely the speed of light c and the Newtonian constant of gravitation G, a complete system of units could be derived. He showed how to derive units of mass, length, time and electric charge as base units. Due to the form in which Coulomb's law was expressed, the constant 4πε0 was implicitly included, ε0 being the vacuum permittivity. Like Stoney, Planck independently derived a system of natural units (of similar scale) some decades after him, using different constants of nature. Hermann Weyl made a notable attempt to construct a unified theory by associating a gravitational unit of charge with the Stoney length. Weyl's theory led to significant mathematical innovations but his theory is generally thought to lack physical significance.

Family

Stoney married his cousin, Margaret Sophia Stoney, with whom he had two sons and three daughters. One of Stoney's sons, George Gerald Stoney, was a scientist. His daughter Florence was a radiologist, while his daughter Edith is considered to be the first woman medical physicist. His most scientifically notable relative was his nephew, the Dublin-based physicist George Francis FitzGerald. His brother was the engineer Bindon Blood Stoney. He was second cousin of the grandfather of Ethel Sara Turing, the mother of Alan Turing.

Awards and honours In 1899, Stoney became the first recipient of the Boyle Medal of the Royal Dublin Society. Stoney received an honorary Doctor of Science (D.Sc.) from the University of Dublin in June 1902. In 1902, Stoney was elected a Member of the American Philosophical Society. Craters on Mars and the Moon are named in his honour.

See also Basic concepts of quantum mechanics Planck units Stoney units

References

Bibliography The Infancy of Atomic Physics. Hercules in His Cradle, by Alex Keller. Oxford University 1983. ISBN 0-19-853904-5 2013 reprint. Dover. 9 October 2013. ISBN 9780486149950. O'Hara, J. G. (1975). "George Johnstone Stoney, F.R.S., and the Concept of the Electron". Notes and Records of the Royal Society of London. 29 (2): 265–276. doi:10.1098/rsnr.1975.0018. JSTOR 531468. S2CID 145353314. Stoney, G. J. (1894). "Of the "Electron", or Atom of Electricity". Philosophical Magazine. Series 5. 38: 418–420. Barrow, J. D. (1983). "Natural Units Before Planck". Quarterly Journal of the Royal Astronomical Society. 24: 24. Bibcode:1983QJRAS..24...24B. "The Constants of Nature, by John D. Barrow, Jonathan Cape, London 2002.

Illustrations

George Johnstone Stoney illustration
George Johnstone Stoney: Edith, Florence and George Stoney, c. 1910
Edith, Florence and George Stoney, c. 1910

Worked examples

Example 1 — a first encounter with George Johnstone Stoney

Start with the simplest possible case. Write down what George Johnstone Stoney claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, 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 George Johnstone Stoney 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 George Johnstone Stoney 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 George Johnstone Stoney

In research
George Johnstone Stoney appears in physics 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 George Johnstone Stoney 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
George Johnstone Stoney is common in secondary-school and first-year university syllabi. It links to neighbouring topics 1826 births, 1911 deaths, Academics of the University of Galway, so understanding it makes those chapters shorter.
In everyday life
Look for George Johnstone Stoney 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 George Johnstone Stoney in 20 minutes

  1. Read the reference excerpt below once, without taking notes.
  2. Close the page and write down what George Johnstone Stoney means in your own words.
  3. Compare your version with the excerpt and mark what you missed.
  4. Work through the three examples above with pen and paper.
  5. Explain George Johnstone Stoney out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is George Johnstone Stoney in simple terms?

George Johnstone Stoney (15 February 1826 – 5 July 1911) was an Irish physicist and academic who is best known for introducing the term electron as the "fundamental unit quantity of electricity"; he initially named it electrolion in 1881, and later named it electron in 1891. He published around 75…

Why does George Johnstone Stoney matter?

Because it connects several physics 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 George Johnstone Stoney?

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 George Johnstone Stoney.

Tags

  • 1826 births
  • 1911 deaths
  • Academics of the University of Galway
  • Alumni of Trinity College Dublin
  • Fellows of the Royal Society
  • Irish physicists
  • Members of the American Philosophical Society
  • People from Birr, County Offaly
  • People from Dundrum, Dublin
  • Scientists from County Offaly

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