Thomas Young (1773-1829)
Dr Thomas Young, physician, physicist and Egyptologistm of the Royal Institution
Polymath responsible for the wave theory of light, Young's modulus, colour theory, understanding of capillary action, and many other phenomena.
1807 Featured in William Walker et al’s painting of "Men of science living in 1807-8"[1]
From The Engineer 1869/01/08
.... Dr. Thomas Young, a man who made many grand scientific discoveries, but whose works are not so well known by the public as they ought to be. Dr. Young, for instance, first established upon a firm basis the undulatory theory of light, but was obliged to succumb, for a time, to Newton, who upheld the emission theory. Dr. Young was born at Milverton, in Somersetshire, on the 17th of June, 1773. His father was a merchant Quaker. Most of the early part of his life was spent at Minehead, in Somersetshire. In March, 1780, when not quite seven years of age, be was sent to school - first at Stapleton, near Bristol, and afterwards at Downend, near Kingswood. From March, 1782, till the early part of 1786, he was at school at Compton, in Dorsetshire; and at the end of that period had acquired a good education, principally in classical subjects. He next res1ded for a time at home, giving attention to scientific subject11, as well as languages, and spent much of his time in learning the use of the lathe, and in making telescopes. He next studied for five years - from 1787 to 1792 - at the residence of distant relatives at Youngsbury, in Hertfordsbire. He then came to London as a medical student, and afterwards went through a course of further medical studies at Edinburgh, Gottingen, and Cambridge.
In the year 1801 Young received the appointment of
Professor of Natural Philosophy at the Royal Institution,
where he worked in the laboratory with his colleague
Davy. Dr. Young only held office in the Institution for
two years, but in that time he delivered ninety-one lectures,
including subjects in nearly every branch of physics.
He had not the "art of expounding" in perfection, so was
not an attractive lecturer, and he had not the faculty of
making his own ideas flow clearly and brightly into the
heads of his bearers. His discovering of the principle of
the interference of light took place in May, 1801, and is
one of the greatest truths at the basis of the undulatory
theory.
....
One of the earliest and most satisfactory applications
which Young made of this theory was to the colours of
striated surfaces - a class of phenomena inexplicable by
any theory of light previously proposed. He next applied
the theory to the explanation of the colours of Newton's
rings, and of thick and thin plates. He afterwards produced
interference bands by placing a hair or thin wire
across the path of a narrow beam of sunlight, and, by
cutting off the rays from one side of the wire only, the
bands disappeared entirely, thus proving crucially that the
interference of rays of light from both sides of the object
is necessary to their formation. Not only did Young find
a strong opponent to the undulatory theory of heat in
Newton, but he was vigorously attacked by Lord Brougham
in the "Edinburgh Review," as well as by lesser foes. The
consequence was that Young's discoveries sank for a time
into oblivion, and were completely unnoticed by men of
science for many years. He finally triumphed, however,
and left behind him a name for ever memorable and for ever
honoured in science.
The subjects of the cohesion of fluids and the ultimate
constitution of matter also occupied much of the attention
of Dr. Young during his term of office at the Royal
Institution. His speculations on the latter subject were
much in advance of his time, and at the present day - as
we have previously recorded in an article upon the Wirbul Bewegung theory of Professor Thomson - the leading philosophers in Europe differ in their opinions as to whether atoms are infinitely hard and rigid particles, or
whether there are such things as atoms at all. Dr. Young
seems to have inclined towards the hypothesis of the
infinite divisibility of matter.
.....
After Young's two years' tenure of office at the Royal Institution he resigned the appointment, in order to devote his whole time to the medical profession. On the 14th June, 1804, he married Miss Eliza Maxwell, of Trippendence, near Farnborough, Kent. About the year 1814 he gave much time to the study of Egyptian hieroglyphics, and was, we believe, the first to decipher them. In 1816 he recommenced his optical researches, and discovered several of the laws which govern the passage of rays of light through doubly-refracting crystals; and after explaining the causes of several of the phenomena of polarised light, his discoveries - together with those of Fresnel, Biot, and Arago - finally established the undulatory theory of light upon its present basis. Later in life he brought his mathematical intelligence to bear upon the value of fire and life assurance. He finally died on the l0th of May, 1829, at Farnborough, after a lingering illness of an asthmatical character. His age at death was fifty-six, and his remains were interred in Farnborough Church, Kent.