seamus dubhghaill

Promoting Irish Culture and History from Little Rock, Arkansas, USA

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Birth of John Tyndall, Experimental Physicist

File source: // Tyndall, Irish experimental physicist who, during his long residence in England, is an avid promoter of science in the Victorian era, is born on August 2, 1820 in Leighlinbridge, County Carlow.

Tyndall is born into a poor Protestant Irish family. After a thorough basic education he works as a surveyor in Ireland and England from 1839 to 1847. When his ambitions turns from engineering to science, he spends his savings on gaining a Ph.D. from the University of Marburg in Marburg, Hesse, Germany (1848–1850), but then struggles to find employment.

In 1853 Tyndall is appointed Professor of Natural Philosophy at the Royal Institution, London. There he becomes a friend of the much-admired physicist and chemist Michael Faraday, entertains and instructs fashionable audiences with brilliant lecture demonstrations rivaling the biologist Thomas Henry Huxley in his popular reputation and pursuing his research.

An outstanding experimenter, particularly in atmospheric physics, Tyndall examines the transmission of both radiant heat and light through various gases and vapours. He discovers that water vapor and carbon dioxide absorb much more radiant heat than the gases of the atmosphere and argues the consequent importance of those gases in moderating Earth’s climate, that is, in the natural greenhouse effect. He also studies the diffusion of light by large molecules and dust, known as the Tyndall effect, and he performs experiments demonstrating that the sky’s blue color results from the scattering of the Sun’s rays by molecules in the atmosphere.

Tyndall is passionate and sensitive, quick to feel personal slights and to defend underdogs. Physically tough, he is a daring mountaineer. His greatest fame comes from his activities as an advocate and interpreter of science. In collaboration with his scientific friends in the small, private X Club, he urges greater recognition of both the intellectual authority and practical benefits of science.

Tyndall is accused of materialism and atheism after his presidential address at the 1874 meeting of the British Association for the Advancement of Science, when he claims that cosmological theory belongs to science rather than theology and that matter has the power within itself to produce life. In the ensuing notoriety over this “Belfast Address,” his allusions to the limitations of science and to mysteries beyond human understanding are overlooked. He engages in a number of other controversies such as spontaneous generation, the efficacy of prayer and Home Rule for Ireland.

In his last years Tyndall often takes chloral hydrate to treat his insomnia. When bedridden and ailing, he dies from an accidental overdose of this drug on December 4, 1893 at the age of 73 and was buried at Haslemere, Surrey, England.

Tyndall is commemorated by a memorial, the Tyndalldenkmal, erected at an elevation of 7,680 ft. on the mountain slopes above the village of Belalp, where he had his holiday home, and in sight of the Aletsch Glacier, which he had studied.

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Birth of William McCrea, Astronomer & Mathematician

CREATOR: gd-jpeg v1.0 (using IJG JPEG v80), quality = 100Sir William Hunter McCrea, English astronomer and mathematician, is born in Dublin on December 13, 1904.

McCrea’s family moves to Kent in 1906 and then to Derbyshire where he attends Chesterfield Grammar School. His father is a school master at Netherthorpe Grammar School in Staveley. He goes to Trinity College, Cambridge in 1923 where he studies mathematics, later gaining a PhD in 1929 under Ralph H. Fowler.

In 1928, McCrea studies Albrecht Unsöld‘s hypothesis and discovers 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 realise most stars consist of hydrogen.

From 1930 McCrea lectures in mathematics at the University of Edinburgh. In 1931, during his time in Edinburgh, he is elected a Fellow of the Royal Society of Edinburgh. His proposers are Sir Edmund Taylor Whittaker, Sir Charles Galton Darwin, Edward Copson and Charles Glover Barkla. He wins the Society’s Keith Medal, jointly with Edward Copson, for the period 1939-1941.

In 1932 McCrea moves to Imperial College London as a Reader and marries Marian Core the following year. In 1936 he becomes Professor of Mathematics and head of the mathematics department at the Queen’s University Belfast.

During World War II McCrea is co-opted onto the Admiralty Operational Research Group. After the war, he joins the mathematics department at Royal Holloway College in 1944. He is elected a Fellow of the Royal Society of London in 1952.

McCrea is 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 1965–1966.

In 1964 McCrea proposes mass transfer mechanism as an explanation of blue straggler stars. In 1965, he creates the astronomy centre of the physics department at the University of Sussex.

McCrea wins the Gold Medal of the Royal Astronomical Society in 1976 and is knighted by Queen Elizabeth II in 1985.

William McCrea dies on April 25, 1999 at Lewes in Sussex. The McCrea Building on the Royal Holloway College campus is named after him.

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Birth of Physicist John Joly

John Joly, Irish physicist famous for his development of radiation therapy in the treatment of cancer, is born in Bracknagh, County Offaly, on November 1, 1857. He is also known for developing techniques to accurately estimate the age of a geological period, based on radioactive elements present in minerals.

Joly is a second cousin of Charles Jasper Joly, the astronomer. He enters Trinity College, Dublin in 1876, graduating in Engineering in 1882 in first place with various special certificates in branches of engineering, at the same time obtaining a First-Class Honours in modern literature. He works as a demonstrator in Trinity’s Engineering and Physics departments before succeeding William Johnson Sollas in the Chair of Geology and Mineralogy in 1897, a position which he holds until his death in 1933.

Joly joins the Royal Dublin Society in 1881 while still a student, and is a frequent contributor of papers. During his career he writes over 270 books and scientific papers.

On May 17, 1899 Joly reads his paper “An Estimate of the Geological Age of the Earth” to the Royal Dublin Society. In it, he proposes to calculate the age of the earth from the accumulation of sodium in the waters of the oceans. He calculates the rate at which the oceans should have accumulated sodium from erosion processes, and determines that the oceans are about 80 to 100 million years old. The paper is quickly published, appearing four months later in the Society’s Scientific Transactions. Although this method is later considered inaccurate and is consequently superseded, it radically modifies the results of other methods in use at the time.

In 1903 he publishes an article in Nature in which he discusses the possibility of using radium to date the Earth and goes on to study the radioactive content of the Earth’s crust to formulate a theory of thermal cycles, and examines the radioactive constituents of certain rocks as a means of calculating their age. Working in collaboration with Sir Ernest Rutherford, he uses radioactive decay in minerals to estimate, in 1913, that the beginning of the Devonian period could not be less than 400 million years ago, an estimate which is in line with modern calculations.

Joly serves as President of Section C (Geology) when the British Association for the Advancement of Science meets in Dublin in 1908, during which he presents his paper “Uranium and Geology” in an address to the society. This work describes radioactive materials in rocks and their part in the generation of the Earth’s internal heat.

Along with his friend Henry Horatio Dixon, Joly also puts forward the cohesion-tension theory which is now thought to be the main mechanism for the upward movement of water in plants.

In 1914 Joly develops a method of extracting radium and applies it in the treatment of cancer. As a Governor of Dr. Steevens’ Hospital in Dublin, in collaboration with Walter Stevenson, he devises radiation therapy methods and promotes the establishment by the Royal Dublin Society of the Irish Radium Institute where they pioneer the “Dublin method” of using a hollow needle for deep radiation therapy, a technique that later enters worldwide use. The Radium Institute also supplies capillary tubes containing radon to hospitals for some years for use in the treatment of tumours.

Joly is elected a Fellow of the Royal Society of London in 1892, is awarded the Boyle Medal of the Royal Dublin Society in 1911, the Royal Medal of the Royal Society of London in 1910, and the Murchison Medal of the Geological Society of London in 1923. He is also conferred honorary degrees by the National University of Ireland, the University of Cambridge, and the University of Michigan. After his death in 1933, his friends subscribe the sum of £1,700 to set up a memorial fund which is still used to promote the annual Joly Memorial Lectures at the University of Dublin, which were inaugurated by Sir Ernest Rutherford in 1935. He is also remembered by the Joly Geological Society, a student geological association established in 1960.

In 1973 a crater on Mars is named in Joly’s honour.

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Death of Robert Mallet, the Father of Seismology

robert-malletRobert Mallet, geophysicist, civil engineer, and inventor who distinguishes himself in research on earthquakes and is sometimes called the Father of Seismology, dies on November 5, 1881.

Mallet is born in Dublin on June 3, 1810, the son of factory owner John Mallet. He is educated at Trinity College, Dublin, entering it at the age of 16 and graduating in science and mathematics in 1830 at the age of 20.

Following his graduation, he joins his father’s iron foundry business and helps build the firm into one of the most important engineering works in Ireland, supplying ironwork for railway companies, the Fastnet Rock lighthouse, and a swing bridge over the River Shannon at Athlone. He also helps manufacture the characteristic iron railings that surround Trinity College and which bear his family name at the base.

Mallet is elected to the Royal Irish Academy in 1832 at the early age of 22. He also enrolls in the British Association for the Advancement of Science in 1835 which helps finance much of his research in seismology.

In 1838 he becomes a life member of the Royal Geological Society of Ireland, and serves as its President from 1846–1848. From 1848–1849 he constructs the Fastnet Rock lighthouse, southwest of Cape Clear.

On February 9, 1846 he presents to the Royal Irish Academy his paper On the Dynamics of Earthquakes, which is considered to be one of the foundations of modern seismology. He is also credited with coining the word “seismology” and other related words which he uses in his research. He also coins the term epicentre.

From 1852 to 1858, he is engaged in the preparation of his work, The Earthquake Catalogue of the British Association (1858), and carries out blasting experiments to determine the speed of seismic propagation in sand and solid rock.

On December 16, 1857, the area around Padula, Italy is devastated by the Great Neapolitan earthquake which causes 11,000 deaths. At the time it is the third largest known earthquake in the world and has been estimated to have been of magnitude 6.9 on the Richter Scale. Mallet, with letters of support from Charles Lyell and Charles Darwin, petitions the Royal Society of London and receives a grant of £150 to go to Padula and record at first hand the devastation. The resulting report is presented to the Royal Society as the Report on the Great Neapolitan Earthquake of 1857. It is a major scientific work and makes great use of the then new research tool of photography to record the devastation caused by the earthquake. In 1862, he publishes the Great Neapolitan Earthquake of 1857: The First Principles of Observational Seismology in two volumes. He brings forward evidence to show that the depth below the Earth’s surface, from where the impulse of the Neapolitan earthquake originated, is about 8–9 geographical miles.

One of Mallet’s papers is Volcanic Energy: an Attempt to develop its True Origin and Cosmical Relations, in which he seeks to show that volcanic heat may be attributed to the effects of crushing, contortion, and other disturbances in the crust of the earth. The disturbances leading to the formation of lines of fracture, more or less vertical, down which water would find its way, and if the temperature generated be sufficient volcanic eruptions of steam or lava would follow.

Mallet is elected Fellow of the Royal Society in 1854, and in 1861 moves to London, where he becomes a consulting engineer and edits The Practical Mechanic’s Journal. He is awarded the Telford Medal by the Institution of Civil Engineers in 1859, followed by the Cunningham Medal of the Royal Irish Academy for his research into the theory of earthquakes in 1862, and the Wollaston Medal of the Geological Society of London in 1877, the Geological Society’s highest award.

Blind for the last seven years of his life, Robert Mallet dies at Stockwell, London, on November 5, 1881 and is buried at West Norwood Cemetery.