Hans Geiger (1882-1945) and Ernest Marsden (1889-1970) discover large angle deflections of alpha particles by thin metal foils. The unexpected results of the experiment demonstrated for the first time the existence of the atomic nucleus.
Editors. "The Geiger–Marsden experiment". The Literary Encyclopedia. First published 01 May 2009
[http://www.litencyc.com/php/stopics.php?rec=true&UID=6419, accessed 28 November 2015.]