William Thomson - Lord Kelvin (1824-1907)

Team Webpage Report by Tom Woolman, Terri Nicholson, Marco Allain

History of Geology - GO521
Spring Semester, 2013

"There cannot be a greater mistake than that of looking superciliously upon the practical applications of science. The life and soul of science is its practical application; and just as the great advances in mathematics have been made through the desire of discovering the solution of problems which were of a highly practical kind in mathematical science, so in physical science many of the greatest advances that have been made from the beginning of the world to the present time have been made in earnest desire to turn the knowledge of the properties of matter to some purpose useful to mankind."
Lord Kelvin (Thompson, 1910)

William Thomson, Baron Kelvin, in full William Thomson, Baron Kelvin of Largs, also called (1866–92) Sir William Thomson (born June 26, 1824, Belfast, County Antrim, Ireland [now in Northern Ireland]—died Dec. 17, 1907, Netherhall, near Largs, Ayrshire, Scotland), was an engineer, mathematician, and physicist who profoundly influenced the scientific thought of his generation (Brittanica, 2013). This paper will examine Lord Kelvin's biographical background, his contributions set within the historical context of his period, and his major contributions to the geological sciences.

Public domain (due to age) photograph of Lord Kelvin, circa 1900.
Taken from the Smithsonian Institution Libraries Digital Collection (Smithsonian Institute Portraits from the Dibner Library of the History of Science and Technology).

Biographical Information on Kelvin
Historical Context of Kelvin's Scientific Contributions
Major Contributions to Geological Science
Closing Remarks

Biographical Information

Lord William Thomson Kelvin was born in Belfast Ireland on June 26th, 1824 and died in the United Kingdom on December 17th, 1907. His mother died while he was a small boy in 1830. His father was a professor of engineering and math at the university (Scottish Science Hall of Fame). In 1833 William’s father accepted a position at Glasgow University, thus moving the entire family to Scotland. After the move William began his formal educational training at the Glasgow University’s elementary feeder school. Only students which showed exceptional ability were invited to attend these schools. While in attendance William excelled in literature, music, math, and science. One of the awards he earned was on a translation of the “A Dialogues of the God’s” from Latin to English. He also won a class prize for an astronomy project (The Famous People Biographies).

Image of William Thomson, Age 20. Reference: Archive.org
Lord Kelvin, Baltimore Lectures, 1884, Reference: School of Chemistry, University of Glasgow

When William was around nine years of age he developed a heart problem which nearly cost him his life. While his father was teaching at Glasgow the family took summer vacations. For each location visited the children were required to learn the language for each country. These trips included trips to Germany and the Netherlands.

In 1845 William graduated from Peterhouse College (now called St. Peters College) with honors (as cited University of Glasgow History). After graduation he was appointed to a fellowship at St. Peters, where he worked with Henri Victor Renault. When he was appointed the Chair of the Natural Philosophy department at Peterhouse College after the fellowship was completed, a position which he held for 53 years (Scottish Science Hall of Fame).

In 1847 William attended the BAAS (British Association for the Advancement of Science), where he became interested in the work done by Joule. He quickly began working on the mathematical proof for Joule’s theories. George Stokes wrote to Lord Kelvin in 1854 to ask about information regarding Faraday’s Theories as applied to the transatlantic cable (BBC history). William quickly became an active participant in the transatlantic cable’s assembly and the problems which arose from the process. In 1857 Lord Kelvin switched from his scientific research to the process of engineering. He made advancements in the existing compass to allow adjustments to be made. William also designed a delivery mechanism which made laying the cable easier and reduced the stress on the cable (Scottish Science Hall of Fame).

Image of Peterhouse College, Cambridge (now called St. Peters College), Reference: UKStudentLife.com
Image of the Transatlantic Cable Map circa 1857 Reference: Atlantic-Cable.com

From 1869 to 1893 Lord Kelvin consulted on or advised in the French Atlantic cable, Para to Pernambuco section in Brazil, and the design of the power station at Niagara Falls (The Famous People Biographies). William began to question the geologic time scale currently accepted by several Uniformitarianism geologist. He suggested that the energy form the sun was responsible for all geologic changes which take place on Earth (Faul, 1983). This idea was not well received within the geologists of the time. He worked long hours to calculate the energy being produced by the sun and how this related to the changes on Earth. (Faul, 1983) During this time frame he was knighted in 1892 and became the first Baron Kelvin, of Largs in 1892.

While addressing the conference of BAAS in 1900 Lord Kelvin was quoted saying “There is nothing new to be discovered in Physics now. All that remains is more precise measurements.” (Weisten). In 1905 William was the first international award for the John Fritz medal. This is the highest award given in the engineering profession in the development or improvement of equipment. Upon his death on December 17, 1907 he was buried at Westminster Abby. (BBC history)

PICTURE POST CARD SIGNED 07/17/1906 Lord Kelvin,
Reference: Amazon.com

Historical Context of Kelvin's Scientific Contributions

William Thomson (1824–1907) was among the most eminent scientists of his day in the British Isles. Lord Kelvin was largely responsible for the rise of engineering in the 19th century. The Cambridge network of the 18th century had a progressive view of the Earth and the solar system and a separation of the geometry of physical motions from their causes or kinematics from dynamics. Kelvin adopted this ideology after doing his undergraduate work at Cambridge. While at Cambridge, Kelvin worked closely with mathematics professor Hugh Blackburn in his research on electricity (Smith and Wise, 1989).

Lord Kelvin began work on the kinematics of field theory and the nature of electricity. His work focused on electrostatics as an analogy to heat flow. His work found that geometrical analogies allowed mathematical theorems about electrostatic force to be proved from physical reasoning about the motion of heat (Smith and Wise, 1989).

Kelvin was responsible for the mathematical analysis of electricity and formulation of the first and second laws of thermodynamics (Britannica, 2013). Kelvin and his colleagues defined the dynamics of electromagnetic fields by using an analogy to the fluid-flow nature of magnetism. Thermodynamics provided Lord Kelvin with a challenge and years of uncertainty. He struggled with Carnot’s theory of the motive of power and heat and eventually explored the dynamics of field theory in terms of work, ponder-motive force (such as what makes an electrified body move) and extreme conditions (Smith and Wise, 1989). After extensively studying thermodynamics, Kelvin predicted the heat related future death of the universe.

Kelvin was a renowned inventor which thrust him into the public spotlight and earned him considerable wealth and public honor. Kelvin greatly improved the mariner's compass, making it a reliable tool for sailors. Kelvin also supervised the first successful transatlantic cable (Buchwald, 1977). This cable brought instantaneous communication across the ocean for the first time. The cable succeeded only with his invention of signal amplifiers and sensitive receivers. Along with James Joule, he discovered the Joule-Thomson effect that ushered in the invention of refrigerators.

His most ubiquitous honor is the Kelvin temperature scale, that begins at absolute zero (a concept he originated), which is widely used in physics, chemistry and astronomy. He was dissatisfied by the gas thermometer and began doing studies on temperature. Lord Kelvin determined the correct value of absolute zero as approximately -273.15 Celsius. France’s Sadi Carnot incorrectly presumed that the value was -267. Kelvin personally predicted that the melting point of ice must fall with pressure; otherwise its expansion on freezing could be exploited (Smith and Wise, 1989). After testing this hypothesis, Kelvin proved his theory. Because Kelvin made the correction, temperatures are stated in units of ‘kelvin’ in his honor.

Kelvin assumed that the Earth was once hot and had cooled to about 300K by radiation into space. Kelvin then calculated a radiative cooling time for the Earth to prove his theory. If the hot temperature is more than three times the final temperature, then the contribution of the high temperature term is less than one percent. For example, for the 300K ambient on the Earth, an original temperature higher than 1000K would make the second temperature in the expression above negligible. If we take only the term involving the current Earth temperature, the cooling time can be estimated as:

Kelvin's physics equations for estimating the age of the Earth-based on radiative cooling. Reference: Smith and Wise 1989

This estimates the Kelvin cooling time for the Earth to be about 30,000 years. The cooling time can be modeled more simply by the formula:

Kelvin's simplified equation for estimating the age of the Earth-based on radiative cooling. Reference: Smith and Wise 1989

This cooling time is much shorter than what was previously thought. Kelvin's calculation suggested the existence of an internal heat supply which has kept the Earth warm long after the radiative cooling time. Today we understand that natural radioactive decay provides a source of heat to the Earth. But, Kelvin’s calculation was done before the discovery of radioactivity (Smith and Wise 1989).

Despite a liberal academic career at Cambridge, Kelvin was a staunch opponent of Charles Darwin’s theory of evolution. However, he remained on good personal terms with his academic rivals. Lord Kelvin was respected even by “Darwin’s bulldog” Thomas Huxley as a gentleman, a scholar, and a formidable opponent. Huxley called Kelvin “the most perfect knight who ever broke a lance,” out of respect. Under the name of William Thomson, Lord Kelvin published over 600 research papers. He eventually served as president of the British Royal Society: England’s premier scientific organization. Kelvin was awarded with 21 honorary doctorates from universities around the world. Kelvin was a renowned professor who mentored James Prescott Joule, James Clerk Maxwell, Peter Tait and other eminent scientists (Britannica, 2013). As a scientist, engineer, professor and Scottish gentleman, Lord Kelvin had a long and successful career.

Major Contributions to Geological Science

Kelvin's Application of 19th-century Physics to Geology

Lord Kelvin's arguement with the then-current geologic dating methodologies was that measurements of the rates of geologic processes were highly uncertain by his accustomed level of physics-based precision, and he disputed if it was possible to even accurately measure them at all (Hallam, 1989). Lord Kelvin sought to apply his knowledge of his era's physics to the issue. With the knowledge that temperature generally increases the further one descends below the Earth's surface, Lord Kelvin concluded that Earth must be slowly cooling from the outside (crust), with heat dissipating outward from the core and the mantle.

He set out to calculate the time required for the Earth to cool, and thereby solidify, from an initially molten state. The idea that Earth had begun as an incredibly hot sphere of liquid dates back to Descartes and Leibnitz. This assumed initial condition was the linchpin for Kelvin's entire method (Hallam, 1989). Bits of material at the surface would sink before solidifying, creating convection currents that kept the Earth at a uniform temperature until solidification began at the core (Hallam, 1989). Kelvin needed to know: (1) the temperature at Earth's core, (2) the temperature gradient with regard to depth below the surface, and (3) the thermal conductivity of rocks. The gradient was established to be around one degree Fahrenheit for every fifty feet. Kelvin made his own measurements of conductivity. The problem was determining the temperature at the core. This is where Kelvin's theory of solidification enters the picture. Because the core was thought to be solid rock, its temperature could not exceed the melting point of rocks (Hallam, 1989). In 1862, Kelvin arrived at a likely age of 100 million years. Because of uncertainties in the data, the lower and upper limits were stated as between 20 million and 400 million years (Dalyrmple, 2004; Hallam, 1989).

Kelvin's Erroneous Assumptions and Intimidation of Potential Critics

The result of Kelvin's assumptions about the deep interior of the Earth, without any sound evidence, was unfortunately quite significant. Because the timeframe he provided was far too brief to allow for known geological processes to produce the current topographical features of the Earth. Even worse, Kelvin then made significant attacks on the science of geology and it's practitioners, but most of the geologists in that era were intimidated by Kelvin's stature within the overall scientific community (Lewis, 2000). Kelvin was regarded as possibly the most well regarded and imposing scientific figure of the day (Lewis, 2000).

Kelvin began his attack in an address in 1868 where he stated "There have been feeble attempts to reason away the argument from under-ground heat. The geologists, to whose theory I object, do at the same time, I believe, admit that the temperature increases downwards, wherever observations have been made. They have hitherto taken a somewhat supine view of the subject. Admitting that there is in many places evidence of an increase of temperature downwards, they say they have not evidence enough to show that there is increase of temperature downwards in all parts of the Earth, of enough of evidence to allow us to say that the theory that accounts for underground heat, by local chemical action, may not be true. This being the state of the case as regards underground heat, where must we apply to get evidence?" (Kelvin, 1868).

Physics was regarded as a more mature and noble field than geology (Hallam, 1989), which was still perceived as immature and without the (apparent) certainty provided by the more mathematically-oriented physics and chemistry. Kelvin derived his estimate from quantitative and repeatable measurements, physical principles of the known natural laws of the time, and elegant math (Dalrymple, 2004). That method, combined with his arguments about the uncertainty of geologic data analysis, provided Kelvin with a tremendous amount of swagger over his theory's potential opponents. He was enthusiastic and persuasive, and was perhaps the leading scientific celebrity of his time, and this made him an exceptionally difficult opponent for Lyell and Darwin (Hallam, 1989); Darwin referred to Kelvin as his "sorest trouble" (Dalrymple, 2004; Lewis, 2000). The end result was that most scientists sought agreement rather than conflict with Kelvin (Lewis, 2000). Archibald Geikie (Hallam, 2009), James Croll, Lyell, and Samuel Haughton all adjusted their theories to make allowances for Kelvin. Additionally, P.G. Tait, T. Mellard Reade, Clarence King, and John Joly (Hallam, 1989) all reached conclusions concordant with Kelvin through their own methods. This is unfortunate and could be concluded as an effect of peer pressure biasing the scientific method, and perhaps a little bit of an inferiority complex on the part of the geologists in comparison with their 19th century physics peers.

Criticism Finally Mounts

Finally, criticism started to mount of Kelvin's techniques and Kelvin became increasingly defensive in his assertions. Thomas Huxley began to systematically critique Kelvin's assumptions. Placing incorrect values into a perfect equation will result in bad results, in modern technological terminology, it was "garbage in, garbage out" (Hallam, 1989). Osmond Fisher, a pioneering geophysicist, challenged Kelvin's asumption of a solid Earth. If the interior were plasticine, convection currents would fundamentally undermine Kelvin's entire fundamental model. Geikie and Croll rejected the arrogance of the mathematical physicists and argued that there must be some flaw in Kelvin's reasoning (Hallam, 1989). That uncannily prescient comment foretold the coming of radioactivity and atomic physics. Once it was discovered that radioactive isotopes are abundant in rocks and that radioactive decay releases massive amounts of heat energy, Kelvin's assumption of a closed system and dwindling initial heat proved to be completely false (Dalrymple, 2004; Hallam, 1989; Lewis, 2000).

Faulty Assumptions Proven Incorrect

Kelvin's assumption of a solid Earth and heat transfer only by conduction also proved incorrect; the mantle does flow, and convection is the key method of heat transfer within the Earth. As Burchfield explains, radioactivity undermined the foundations for virtually all of Kelvin's dating work (Dalrymple, 2004). Huxley and Fisher also leveled charges of arrogance. G.H. Darwin (astronomer and mathematician) attacked Kelvin's ideas about tides retarding Earth's rotation; the underlying charge was that Kelvin attributed far too much certainty to speculative findings (Dalrymple, 2004). Kelvin's John Perry, who happened to be Kelvin's former assistant, also attacked Kelvin's assumptions by arguing that the mantle was partly liquid, and therefore conduction was less responsible for heat transfer than was convection (Dalrymple, 2004).

Closing Remarks

There was good reason for Perry to doubt Kelvin's basic assertions, and especially to take a position against Kelvin's use of statements that claimed "certain truth" and "no other possible alternative" (Dalrymple, 2004) which were completely improper both from an etiquette and scientific perspective. Kelvin didn't know what he didn't know, and Kelvin admitted no possibility of having imperfect knowledge. Quite the claim for a mid-19th century physicist! Most importantly, Perry attacked Kelvin's assumption about a closed system of dwindling initial heat by offering the possibility that the then-unknown internal structure of atoms could contain massive amounts of potential energy (Dalyrmple, 2004; Hallam, 1989).

Lord Kelvin initially rejected the idea that radioactivity could emit significant heat, but he publicly abandoned this theory at the British Association Meeting of 1904. In a debate two years later, however, it was clear that he never truly accepted radioactivity as the primary source of Earth's internal heat (Lewis, 2000). Accordingly, Kelvin never published a retraction of his overall theory, though he did privately concede to J.J. Thomson that the discovery of radioactivity rendered several of his assumptions unworkable (Hallam, 1989).

Lord Kelvin exerted profound influence in the debate over the age of the Earth. His theory dominated the scientific debate for over forty years. By applying mathematics and principles of physics to attempts to quantify the date of Earth's formation, he greatly stimulated debate and research into this topic. Although he fundamentally failed at using the heat-loss model of the earth is a form of geological clock, he did inadvertently demonstrate that faith in physics and mathematics alone is insufficient to prove geological phenomenon, as such equations need to be validated by scientific observation and correlate with known geological phenomenon.


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