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Democritus
Democritus was born in Abdera, Thrace around 460 BC, although, some thought it was 490 BC. His exact contributions are difficult to disentangle from those of his mentor Leucippus, as they are often mentioned together in texts. Their speculation on atoms, taken from Leucippus, bears a passing and partial resemblance to the nineteenth-century understanding of atomic structure that has led some to regard Democritus as more of a scientist than other Greek philosophers; however, their ideas rested -
John Dalton
He was an English chemist, physicist, and meteorologist. He is best known for his pioneering work in the development of modern atomic theory; and his research into colour blindness, sometimes referred to as Daltonism, in his honour. -
JJ Thomson
In 1897, Thomson showed that cathode rays were composed of previously unknown negatively charged particles, which he calculated must have bodies much smaller than atoms and a very large value for their charge-to-mass ratio. -
Philipp Lenard
Philipp Eduard Anton von Lenard (7 June 1862 – 20 May 1947) was a German physicist and the winner of the Nobel Prize for Physics in 1905 for his research on cathode rays and the discovery of many of their properties. He was a nationalist and anti-Semite; as an active proponent of the Nazi ideology, he had supported Adolf Hitler in the 1920s -
Ernest Rutherford
In early work he discovered the concept of radioactive half-life, proved that radioactivity involved the nuclear transmutation of one chemical element to another, and also differentiated and named alpha and beta radiation. -
Niels Bohr
Niels Henrik David Bohr was born in Copenhagen on October 7, 1885, as the son of Christian Bohr, Professor of Physiology at Copenhagen University, and his wife Ellen, née Adler. Niels, together with his younger brother Harald (the future Professor in Mathematics), grew up in an atmosphere most favourable to the development of his genius - his father was an eminent physiologist and was largely responsible for awakening his interest in physics while still at school. -
James Chadwick
In 1930, when Herbert Becker and Walter Bothe sent alfa particles (helium nuclei) against beryllium, strong penetrating radiation was emitted, there was a hypothesis that this could be electromagnetic radiation of high energy. -
Leucippus
Leucippus reported in some ancient sources to have been a philosopher who was the earliest Greek to develop the theory of atomism the idea that everything is composed entirely of various imperishable, indivisible elements called atoms. The name Leucippus is often associated as master to pupil with that of Democritus, the philosopher who was also touted as the originator of the atomic theory
