14 November 2013, 18.30 – 20.00

Mind-Brain Lecture: Giuseppe Longo (ENS Paris)

“Modelling in natural sciences: continua vs discrete or the necessity of contingency”

Host: Maximilien Chaumon

“Modelling in natural sciences: continua vs discrete or the necessity of contingency”

Turing makes an (implicit) distinction in the passage from his “imitation game” (the 1950 paper on a computer imitating a woman) and the “model” paper (his 1952 work on bio-physical morphogenesis). The model tries to spell out a “causal structure”: in the 1952 paper, the continuous mathematical dynamics of a genesis of forms as an “action/reaction/diffusion” system. An imitation only pretends to mimic, or to cheat an observer, without commitment on the causal structure of the intended phenomenon: a discrete state machine (DSM, as Turing calls his Machine in 1950) imitating a brain.
A finer comparison will be hinted by analyzing the way randomness is treated by the imitating/modeling technique.  Are simulations on DSM's just imitations of phenomena? How is randomness handled?
But … what is randomness? Can a purely probabilistic modeling of randomness give sufficient tools for analyzing it? How does randomness depend on unpredictability in the theoretical frame for a model? Does it coincide with “contingency”?
As J.S. Gould, the famous evolutionist, says:
“Science has dealt poorly with the concept of contingency” (S.J. Gould, Wonderful Life, 1989).
Yet, contingency is a necessary component of life dynamics.

Giuseppe Longo, http://www.di.ens.fr/users/longo
Centre Cavaillès, CIRPHLES, CNRS et Ecole Normale Supérieure, Paris

All are welcome!


F. Bailly, G. Longo, Mathematics and the Natural Sciences. The Physical Singularity of Life, Imperial College Press, London, 2011. 

G. Longo, M. Montévil, Perspectives on Organisms: Biological Time, Symmetries and Singularities, Springer, 2013.     

Papers downloadable from  www.di.ens.fr/users/longo :

Giuseppe Longo.  Critique of Computational Reason in the Natural Sciences, In "Fundamental Concepts in Computer Science"   (E. Gelenbe and J.-P. Kahane, eds.), Imperial College Press, pp. 43-70, 2009.

Giuseppe Longo.  Incomputability in Physics and Biology.  Invited Lecture, Proceedings of Computability in Europe, Azores, Pt, June 30 - July 4, LNCS 6158, Springer, 2010. 

Giuseppe Longo, Maël Montévil. Randomness Increases Order in Biological Evolution. Invited paper, conference on ''Computations, Physics and Beyond'', Auckland, New Zealand, February 21-24, 2012; LNCS volume (Dinneen et al. eds), Springer, 2012.

Marcello Buiatti, Giuseppe Longo.  Randomness and Multi-level Interactions in Biology.  to appear in Theory of Biosciences, vol. 132, n. 3:139-158, 2013.



Berlin School of Mind and Brain
Humboldt-Universitäöt zu Berlin
Luisenstra0e 56
FESTSAAL 2nd floor
10117 Berlin