EDWIN McMILLAN (1907- 90) GLENN SEABORG (1912- 99)

1940 – USA

‘Elements heavier than uranium in the periodic table (transuranium elements) are made artificially. Uranium (U, atomic number 92) is the heaviest element known to exist naturally in detectable amounts on the Earth’

Photograph of SEABORG & McMILLAN together ©


In 1933 ENRICO FERMI showed that the nucleus of most elements would absorb a neutron.
In 1940 McMillan, a nuclear physicist, produced and identified the first artificial element, neptunium (Np, 93). In 1943 Seaborg, a chemist, succeeded in creating plutonium (Pu, 94).

So far more than 20 synthetic elements have been created. All are unstable, decaying with half-lives ranging from a year to a few milliseconds.
At least thirteen transuranium elements have been named after scientists:-
curium (Cm, 96: Marie and Pierre Curie [1944]), einsteinium (Es, 99: Albert Einstein [1952]), fermium (Fm, 100: Enrico Fermi [1952]), mendelevium (Md, 101: Dmitri Mendeleev [1955]), nobelium (No, 102: Swedish chemist Alfred Nobel (1833-96), known for his bequest for the foundation of the Nobel Prizes [1956]), lawrencium (Lr, 103: Ernest O. Lawrence, a physicist best known for development of the cyclotron [1961]), rutherfordium (Rf, 104: Ernest Rutherford [1968]), seaborgium (Sg, 106: Glenn Seaborg [1974]), bohrium (Bh, 107: Niels Bohr [1981]), meitnerium (Mt, 109: Lise Meitner [1982]); roentgenium (Rg, 111: Wilhelm Conrad Röntgen was first created in 1994 by the GSI Helmholtz Centre for Heavy Ion Research near Darmstadt in Germany [1994]), copernicium (Cn, 112: named after astronomer Nicolaus Copernicus [1996]), flerovium (Fl, 114 named after Soviet physicist Georgy Flyorov [2012]).

picture of the Nobel medal - link to nobelprize.org

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GEORGE GAMOW (1904- 68)

1948 – USA

‘The universe began when a single point of infinitely dense and infinitely hot matter exploded spontaneously. The debris of this explosion began to fly away from the explosion point and is still flying and will keep on flying indefinitely. All the galaxies, stars and planets were formed from this debris’

Photograph of GEORGE GAMOW ©


In 1927 the Belgian astronomer Georges Lemaitre (1894-1966) suggested that at some time in the remote past all the matter in the universe was concentrated at one point. The universe began when this ‘primeval atom’ exploded. This idea was further developed by Gamow, who predicted that leftover warmth from this explosion would still fill the universe. The name Big Bang was given to this theory by Fred Hoyle, who believed in the opposing steady-state theory. It was meant to be a put-down when Hoyle first used it scornfully on a radio talk show in 1950.

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