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Sir William Thomson, Lord Kelvin (1824 - 1907)

Kelvin was a Scottish mathematician and physicist who developed the Kelvin scale of temperature measurement.

William Thomson was born on 26 June 1824 in Belfast. He was taught by his father, a professor of mathematics. In 1832, the family moved to Glasgow where Thomson attended university from the age of 10, subsequently studying at Cambridge and Paris universities. In 1846 he became professor of natural philosophy in Glasgow, a post he would hold for more than 50 years.

In Glasgow, Thomson created the first physics laboratory in Britain. He was a pioneer in many different fields, particularly electromagnetism and thermodynamics. Together with Faraday, he was responsible for the introduction of the concept of an electromagnetic field. In thermodynamics, Thomson assimilated and developed the work of the pioneers of the subject, Nicolas Carnot and James Joule. One of the most important results of his work was his idea of an absolute zero of temperature - the scale based on this is named after him.

Throughout his work Thomson's overriding goal was the practical utilisation of science. He achieved fame through his work on submarine telegraphy, a major practical problem of the day. Kelvin was employed as a scientific adviser in the laying of the Atlantic telegraph cables in 1857-1858 and 1865-1866, for which he was knighted in 1866. His interest in marine issues also inspired him to develop a mariners' compass and invent a tide machine and depth-measuring equipment. He invented many electrical instruments and his house in Glasgow was the first to be lit by electric light.

Thomson was raised to the peerage with the title of Baron Kelvin of Largs in 1892 (the Kelvin was a small river that flowed near Glasgow University) and was president of the Royal Society from 1890 to 1895. He died on 17 December 1907 in Ayrshire, Scotland and was buried in Westminster Abbey.

James Watt (1736 - 1819)

Watt was a Scottish inventor and mechanical engineer, renowned for his improvements in steam engine technology.

James Watt was born in Greenock on 18 January 1736. His father was a prosperous shipwright. Watt initially worked as a maker of mathematical instruments, but soon became interested in steam engines.

The first working steam engine had been patented in 1698 and by the time of Watt's birth, Newcomen engines were pumping water from mines all over the country. In around 1764, Watt was given a model Newcomen engine to repair. He realised that it was hopelessly inefficient and began to work to improve the design. He designed a separate condensing chamber for the steam engine that prevented enormous losses of steam. His first patent in 1769 covered this device and other improvements on Newcomen's engine.

Watt's partner and backer was the inventor John Roebuck. In 1775, Roebuck's interest was taken over by Matthew Boulton who owned an engineering works in Birmingham. Together he and Watt began to manufacture steam engines. Boulton & Watt became the most important engineering firm in the country, meeting considerable demand. Initially this came from Cornish mine owners, but extended to paper, flour, cotton and iron mills, as well as distilleries, canals and waterworks. In 1785, Watt and Boulton were elected fellows of the Royal Society.

By 1790, Watt was a wealthy man and in 1800 he retired and devoted himself entirely to research work. He patented several other important inventions including the rotary engine, the double-action engine and the steam indicator, which records the steam pressure inside the engine.

Watt died on 19 August 1819. A unit of measurement of electrical and mechanical power - the watt - is named in his honour.

Isaac Newton (1643 - 1727)

Newton, Sir Isaac (1642-1727), mathematician and physicist, one of the foremost scientific intellects of all time. Born at Woolsthorpe, near Grantham in Lincolnshire, where he attended school, he entered Cambridge University in 1661; he was elected a Fellow of Trinity College in 1667, and Lucasian Professor of Mathematics in 1669. He remained at the university, lecturing in most years, until 1696. Of these Cambridge years, in which Newton was at the height of his creative power, he singled out 1665-1666 (spent largely in Lincolnshire because of plague in Cambridge) as "the prime of my age for invention". During two to three years of intense mental effort he prepared Philosophiae Naturalis Principia Mathematica (Mathematical Principles of Natural Philosophy) commonly known as the Principia, although this was not published until 1687.

Newton has been regarded for almost 300 years as the founding examplar of modern physical science, his achievements in experimental investigation being as innovative as those in mathematical research. With equal, if not greater, energy and originality he also plunged into chemistry, the early history of Western civilization, and theology; among his special studies was an investigation of the form and dimensions, as described in the Bible, of Solomon's Temple in Jerusalem.
In 1664, while still a student, Newton read recent work on optics and light by the English physicists Robert Boyle and Robert Hooke; he also studied both the mathematics and the physics of the French philosopher and scientist René Descartes. He investigated the refraction of light by a glass prism; developing over a few years a series of increasingly elaborate, refined, and exact experiments, Newton discovered measurable, mathematical patterns in the phenomenon of colour. He found white light to be a mixture of infinitely varied coloured rays (manifest in the rainbow and the spectrum), each ray definable by the angle through which it is refracted on entering or leaving a given transparent medium. He correlated this notion with his study of the interference colours of thin films (for example, of oil on water, or soap bubbles), using a simple technique of extreme acuity to measure the thickness of such films. He held that light consisted of streams of minute particles. From his experiments he could infer the magnitudes of the transparent "corpuscles" forming the surfaces of bodies, which, according to their dimensions, so interacted with white light as to reflect, selectively, the different observed colours of those surfaces.
Newton's work on pure mathematics was virtually hidden from all but his correspondents until 1704, when he published, with Opticks, a tract on the quadrature of curves (integration) and another on the classification of the cubic curves. His Cambridge lectures, delivered from about 1673 to 1683, were published in 1707.
Newton published an edition of Geographia generalis by the German geographer Varenius in 1672. His own letters on optics appeared in print from 1672 to 1676. Then he published nothing until the Principia (published in Latin in 1687; revised in 1713 and 1726; and translated into English in 1729). This was followed by Opticks in 1704; a revised edition in Latin appeared in 1706. Posthumously published writings include The Chronology of Ancient Kingdoms Amended (1728), The System of the World (1728), the first draft of Book III of the Principia, and Observations upon the Prophecies of Daniel and the Apocalypse of St John (1733).

BLAISE PASCAL (1623-1662)

Pascal was a child prodigy, who was educated by his father. He was a mathematician of the first order. At 16 he wrote the Essai pour les coniques which was published in 1640. In 1642 he invented a calculating machine to help his father, who served as Royal Tax Commissioner at Rouen. Pascal is often credited with the discovery of the mathematical theory of probability, and he also made serious contributions to number theory and geometry.

In 1646 Pascal learned of Toricelli's experiments with the barometer and the theory of air preassure. These experiments involved placing a tube of mercury upside down in a bowl of mercury. Pascal repeated Toricelli's experiments and did more work which led to the publication of Experiences nouvelles touchant le vide in 1647. Aristotle had argued against the atomists that nature abhors a vacume. This was a view still strongly held in the seventeenth century, even by such anti-Aristotelians as Descartes and Hobbes. In the Experiences Pascal explains the reasons why a genuine vacume could and did exist above the mercury in the barometer. In defending these conclusions against Father Noel, rector of the College de Clermont in Paris, Pascal gave one of the clearest statements of scientific method in the seventeenth century.

Pascal Time Line

1623	June 19, born in Claremont the son of Etienne Pascal a minor noble and government official.
1626	Mother dies.
1631	Etienne moves to Paris and directs his children's education based on the pedagogy of Montaigne. Blaise proves to be exceptional at mathematics.
1638	Etienne goes into hiding after opposing a fiscal measure of Richelieu but leaves the children in Paris.
1639	Blaise's sister, Jacqueline, appears in a play before Richelieu after which he not only pardons Etienne but appoints him tax collector at Rouen.
1642	Blaise begins to work on his calculating machine to assist his father in the computation of taxes.
1646	Etienne is injured and is cared for by two Jansenists who convert the family to this strict form of Christianity.
1647	Visits by Descartes and discussion on atmospheric pressure and the function of the barometer.
1648	Pascal returns to Claremont. Writes treatise on conic sections.
1650	Returns to Paris.
1651	Etienne dies and Jacqueline joins the convent at Port-Royal.
1654	November 23, a two-hour ecstatic vision leads to his conversion. The account of this vision is kept in the lining of his coat at all times.
1655	January 7, takes a retreat to Port-Royal where he defends Arnauld against the Jesuits who sought to expell him.
1656	Appearance of the first of the Provicial Letters.
1658	Lectures on his apologetics to the leaders of Port-Royal.
1659	Comes down with the illness that will lead to his death. Works in brief periods of relief from suffering.
1661	Jacqueline dies. Port-Royal closed after official condemnation of Jansenism.
1662	August 17, Blaise Pascal dies in the house of one of his sisters.
1670	Publication of his Thoughts which he had worked on sporadically the last four years of his life "Man is but a reed, the most feeble thing in nature, but he is a thinking reed. The entire universe need not arm itself to crush him. A vapor, a drop of water suffices to kill him. But, if the universe were to crush him, man would still be more noble than that which killed him, because he knows that he dies and the advantage which the universe has over him, the universe knows nothing of this. All our dignity then, consists in thought. By it we must elevate ourselves, and not by space and time which we cannot fill. Let us endavour then, to think well; this is the principle of morality." --Pascal Pensees 347

The SI units for the five basic dimensions are :

1.The second                    ( for time )

2.The metre                      ( for length )

3.The kilogram                ( for mass )

4.The Kelvin                    ( for temperature )

5.The ampere                 ( for electric current )