In 1862 A scientist and inventor who was not rigidly tied to one field, William Thomson also known as Lord Kelvin was willing to try his hand at just about anything that peeked his curiosity, from the study of electromagnetism to developing a calculator to predict oceanic tides. With the debate simmering about the age of the Earth, Thomson set about using his knowledge of physics, and thermodynamics in particular, to determine the age of the Earth. Working before the advent of radiocarbon dating and before a solid understanding of the make-up of the Earth had been obtained; Thomson determined that the Earth was only 20 – 400 million years old. This number is not only different from what we now believe is a more accurate figure of 4.5 billion years old, but it also differed greatly with the age estimations that were provided by geologists, Darwinists, and other groups, including astronomers. Thomson, a respected and admired scientist and educator in Britain, Europe, and the United States, obtained an age for the Earth that differed from that proffered by other researchers and further complicated and enlivened an already raucous debate.
Geologists had trouble accepting such a short age for Earth. Biologists could accept that Earth might have a finite age, but even 100 million years seemed much too short to be plausible. Charles Darwin, who had studied Lyell's work, had proposed his theory of the evolution of organisms by natural selection, a process whose combination of random heritable variation and cumulative selection implies great expanses of time. The German physicist Hermann von Helmholtz (in 1856) and the