The 17th Ockham Lecture - 'Physics in the World of Ideas: Complexity as Energy'

Date: Thursday 5 March 2015
Time: 17:00 - 19:00
Venue
TS Eliot Theatre, Merton College

Given by Professor Yuri Manin, Professor Emeritus, Max Planck Institute for Mathematics, Bonn, Germany; Professor Emeritus, Northwestern University, Evanston, USA; Principal Researcher, Steklov Mathematical Institute, Russian Academy of Sciences, Moscow, Russia.

The lecture was introduced by Professor Minhyong Kim and was followed by a Q&A session.

Watch the lecture

Abstract

In the 1930s, George Kingsley Zipf discovered an empirical statistical law that later proved to be remarkably universal. Consider a corpus of texts in a given language, make the list of all words that occur in them and the number of occurences. Range the words in the order of diminishing frequencies. Define the Zipf rank of the word as its number in this ordering. Then Zipf's Law says:

"Frequency is inversely proportional to the rank".

Zipf himself suggested that this law must follow from the principle of 'minimisation of effort' by the brain. However, the nature of this effort and its measure remained mysterious. In my lecture, I will argue that Zipf's effort needed to produce a word (say, name of the number) must be measured by the celebrated Kolmogorov complexity: the length of the shortest Turing program (input) needed to produce this word/name/combinatorial object/etc. as its output. I will describe basic properties of the complexity (some of them rather counterintuitive) and one more situation from the theory of error-correcting codes, where Kolmogorov complexity again plays the role of 'energy in the world of ideas'.

The Ockham Lecture series

The Merton College Physics Lecture (the Ockham, or Occam, Lecture, so named in honour of one of the greatest—if unattested—alumni of the College and of his philosophical principle of intellectual discipline) started in 2009 and is held once a term. It is organised by the physics tutors of the College to promote both intellectual curiosity and social cohesion of the Merton Physics community.

Attendance is by invitation: All Merton physicists (and sympathisers!) belonging to the three Common Rooms (JCR, MCR and SCR) are invited, as are the Old Members. Their guests are also accommodated, space permitting.