By Unknown, Anon, Peter Lafferty; Julian Rowe
By Bass, Thomas A.
By Swain, Harriet
By Fifield, Richard
By Norbert Adolph Lange, John A. Dean
By Peter Atkins
By Frank Close (Professor of Theoretical Physics and Fellow of Exeter College, University of Oxford)
By Stephen Hawking
By Dwight R. Nicholson
By Fred Schuh, F. Gobel
By Brian Cox, Jeff Forshaw
By Kinsler, LE
By Zukav, Gary, Gary Zukav
By School Mathematics Project
By A.M. Arthur (University of York)
By Fred C. Hess, Reginald Care
By Ann Fisher