From Billiard Balls to Quantum Computing

Thursday 14 November 2013, 6.00pm - 8.00pm

The Davidson Building, 5 Southampton Street, London WC2E 7HA. The nearest underground stations are Covent Garden and Charing Cross.

Geoff Sharman


Could you build a computer from billiard balls? Surprisingly, the answer is "yes" although there would be serious practical problems with such a computer. But analysing its operation enables us to understand reversible computing and the link between entropy and information, and answer the question "What is the least amount energy required for a computational step?". We know that miniaturisation is the key to computing speed and power, but what is the smallest physical unit from which you could build a computer? Would that behave classically or according to the laws of Quantum Mechanics? And what do these laws say about the possibly of building a quantum computer that exceeds the power of any classical computer? How might this affect the cryptographic systems on which our secure communication depends?

I will seek to answer these questions and show that quantum computing is real, how it differs from classical computing, and what impact it may (or may  not) have on practical applications of computing in the next decade.


Free. To gain admission please email your name to our Membership Secretary, Algirdas Pakstas, at in advance of the meeting. Attendance lists will normally be finalised on the Monday preceding each meeting but late admission may be accepted by signing in to the Davison Building as a visitor.


View the slides for this event (PDF)