The November conference was the 31st outgoing session of the Students' Mathematical Society US. This time we've decided to concentrate on the motivations, intuitions and constructions - during our courses we often take theorems or ideas for granted, not considering where did they come from; we've thought that learning about them from the historical or intuitionistic point of view may be an interesting experience.

The conference "Motivations, intuitions, constructions" took place on 10-13th November 2011, traditionally in Szczyrk. Our presentation day was opened by Szymon Draga, who constructed the Hausdorff measure, gave its most significant properties and showed its connections with the Lebesgue measure. Our next speaker was Piotr Idzik, who, during a two-part talk "Possible worlds", introduced his listeners to the world of advanced logic, in particular touching upon the notions of, among others, Boolean algebras. Adam Wrzesiński told us about the Euler triangles, Catalan numbers, binary trees and the drama of a cash receptionist. Our last speaker before the break was the Society's tutor, dr Tomasz Kochanek, who showed us the idea of the spectral theorem. This topic interested some of our members so much that dr Kochanek decided to lead a cycle of meetings about Banach algebras and spectral theory during this academic year. After lunch the session was opened by Magdalena Nowak and Konrad Jałowiecki, who told us about the Poisson theorem, learned reluctantly on our courses. Tomasz Kania, a doctoral student of the Lancaster University and a former student of US, told us about Banach algebras, C*-algebras and showed us how to construct the Gelfand transform; Michał Łasica told us about the Navier-Stokes equation. Doctor Rafał Kucharski showed us a geometrical solution of a certain variational problem, while Marek Biedrzycki tried to introduce his listeners to the difficult world of intuitionistic logic (which proved to be not intuitive at all!). The last talk of the session was given by Daria Morys, who told us about the Wada lakes, i. e. about constructing irreducible continua.

Szymon's Draga "On Hausdorff measure" talk was chosen as the best student talk of the session - we can say with all confidence that it was a model example of a good mathematical talk and we would like to congratulate Szymon very much. We have also chosen the topic of our next, May session - "Algorithms". Traditionally, pictures and recordings of the talks may be found on Society's website.