New Horizons

Beautiful movie of Venus passing in front of the Sun at various optical wavelengths. May be you know that observing at a given wavelength is like watching the Sun at a given depth. Not just optical depth, but it's really like seeing inside the Sun peeled.  A must watch ! I love gamma rays, uhhh. Source APOD

For our greatest delight (at least mine), Andrew Lipson is a crazy guy. He's building many funny things in Lego. Like topological surfaces, Klein bottle, from the in/out-side ! Escher pictures, waterfall Or scultpures, like Rodin's thinker However, lego construction may be a way to counter-act the financial crisis which has the inconvenient to cut funding in research laboratory. For instance, Daniel strange (I don't invent anything !) built and programmed a crane that moves in a set path, raising and lowering the sample between beakers containing solutions using a Lego Mindstorms NXT kit. Neat.

You can get very interesting result when plotting different linear combination of eigenfunctions of the Laplacian on a given (convex) shape. Here I use a square plate [0,1] by [0,1] and show the zero iso-value of the some of such linear combination. As time evolves, the linear combination changes. Since the Eigenfunctions are symmetric, I only plot them on the [0, 0.5] interval.  In that case, the eigenfunction are of the form With (n1,n2) such that The associated eigenvalue l= 340*pi^2 is of multiplicity 4 (12,14) (18,4) (14,12) (4,18). Below, same thing with l = 5525 which is of multiplicity 12. Those isocontours are called nodal lines. By the unique continuation property, those nodal lives consist of curves in the interior of the domain (her a square, but the result is valid for any convex shape) which are infinetly differentiable. You may also note, but that is a well known theorem, that when nodal lines interesect a boundary (except may be at corner points...

This magnifical (I had english lessons with Sarkozy) sculpture is the artwork of one of my co-worker, Alexandre. He got the blueprint from here: http://www.youtube.com/watch?v=vjOOhemquss Think it's better than post-it war! http://www.postitwar.com/page/2

Bertrand Russel used humour to show that whatever is logical is not necessary true. He was saying the following Do you pretend that if 2+2=5, then Bertrand Russel is the pope ? Suppose that 2+2=5 Let's substract 2 from each side, then 2=3 By symmetry we have 3=2 If you substract 1 on both sides, 2=1 Now the pope and I are two distinct people, since 2=1 the Pope and Russel are one.