The phenomenal Young
Stories from Physics for 11-14 14-16
Thomas Young was born in 1773. He is reported to have begun reading at the age of two and to have read the bible twice by the time he was four years old. He had a prodigious talent for languages and an anecdote relates that as a boy he was set the task of copying a sentence out of a book to test his writing skills. As his response took some time, his challenger investigated and found that Young had written the sentence out in four or five (some sources claim it was as many as 14) languages.
Because of his talents, Young was given the nickname ‘phenomenon Young’ at Cambridge and he has been described as the last man who knew everything. On leaving university, he trained and practised as a physician but his interests switched to physics. A contemporary surgeon described traits that explained why Young failed to thrive in a medical career, but helped him become an excellent scientist:
[Young] was not a popular physician. He wanted that confidence or assurance which is so necessary to the successful exercise of his profession. He was perhaps too deeply informed, and therefore too sensible of the difficulty of arriving at true knowledge in the profession of medicine, hastily to form a judgment; and his great love of and adherence to truth made him often hesitate where others felt no difficulty whatever in the expression of their opinion.
Despite his scientific genius, Young struggled to describe his ideas clearly. He stated the definition of his eponymous modulus as:
The modulus of the elasticity of any substance is a column of the same substance, capable of producing a pressure on its base which is to the weight causing a certain degree of compression, as the length of the substance is to the diminution of its length.
Unsurprisingly, when the idea of the Young’s modulus was explained to the Admiralty, a clerk replied: “Though science is much respected by their Lordships and your paper is much esteemed, it is too learned ... in short it is not understood.” Young’s biographer observed that Young’s research on fluids was: “…amongst the most original and important he made to physical science; but being conducted without the aid of figures or symbolical reasoning, are extremely obscure.”
As well as lacking clarity, Young’s work was pre-empted by Giordano Riccati who worked on the elastic modulus of brass and steel a quarter of a century before Young. The familiar, and more comprehensible, definition of Young’s modulus as the ratio of stress to strain was not given by Young, but published by Claude-Louis Navier, a French engineer and physicist, three years before Young’s death.
At the age of 29, Young was appointed to the chair of Natural Philosophy at the Royal Institution. Though considered a prodigy, he nevertheless encountered some stiff scientific competition. At the Institution, Young met Humphry Davy who had just been appointed Professor of Chemistry at the age of 24. His rival’s more engaging style attracted larger audiences, according to a contemporary, a Dr Paris, who wrote that Young “adopted too severe and didactic a style”.
Sacrificing time to experiment
Young was a theoretical scientist and not fond of carrying out experimental work. His friend and biographer, Hudson Gurney, reported that:
…he was afterwards accustomed to say, that at no period of his life was he particularly fond of repeating experiments, or even of very frequently attempting to originate new ones; considering that, however necessary to the advancement of science, they demanded a great sacrifice of time, and that when the fact was once established, that time was better employed in considering the purposes to which it might be applied, or the principles which it might tend to elucidate.
Not just a modulus man
Young was a polymath and made contributions to a wide range of fields:
- he discovered the phenomenon of astigmatism and proposed the threecolour theory of vision
- he played a significant role in deciphering Egyptian hieroglyphics
- he was a scholar of ancient Greek and coined the term ‘Indo-European’ to refer to a family of languages
- he contributed articles to the Encyclopaedia Britannica on topics including the alphabet, dew, friction, Egypt, tides, and ‘anything of a medical nature’
- he acted as an advisor to the Admiralty on shipbuilding.