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13:15 - 13:55 28 February 2012

Lunch Hour Lecture: From Euclid to modern geometry: Do the angles of a triangle really add up to 180??


Darwin Lecture Theatre - accessed via Malet Place | Darwin Building (link Map)
access via Malet Place | London | WC1E 6BT | United Kingdom

Open to: Academic | Alumni | Public | Student
Admission: Free and open to anyone on a first-come first-served basis. Lectures are also streamed live online or can be downloaded after the event.
Ticketing: Open

Speaker information

Professor Mark Ronan, UCL Mathematics

More than two thousand years ago, Euclid of Alexandria wrote the most successful textbook of all time. Starting with a few simple assumptions (often called axioms), he proved one result after another — for example that the angles of a triangle add up to 180?. Scholars wondered whether the last of his five axioms — which referred to parallel lines, and sounded more like a theorem than an assumption — wasn't simply a necessary consequence of the other four. Many tried to prove this, and some false proofs were published. I shall give a very convincing one before outlining the history of geometry up to the nineteenth century. That's when three people independently discovered a perfectly consistent geometry in which the Euclid's fifth axiom is not true, and where the angles of a triangle no longer add up to 180?. This new work inspired others and led eventually to the sort of geometry Einstein needed for his theory of gravity.


Cath Dean
+44 (0)20 3108 3838 | c.dean@ucl.ac.uk


Click here to watch this lecture streamed live online at 1.15pm on the day