Posted by on Tuesday, October 4, 2011,
In :
News
The Nobel prize committee have just announced that the 2011 prize for physics will go to the two teams that inadvertently discovered dark energy (or at least their leaders).
For those who haven't followed this story, here is a brief review.
Back in 1915 Einstein published his General Theory of Relativity which describes the properties of space, time and gravity. One of its predictions was that the size of the Universe is changing - but Einstein didn't like that so he added an extra term called ... Continue reading ...
The Four Colour Theorem
Posted by on Monday, October 3, 2011,
A couple of days ago I was discussing the four-colour theorem with one of my mathematics students, and I realized that there is some misunderstanding of it even among bright young (amateur) mathematicians. (Not to imply that even older or professional mathematicians don't sometimes misunderstand it as well)
And so I thought I would take this opportunity to give a brief review of some of the overlooked details...
Suppose you take a two-dimensional map (by which I mean a bunch of lines separating... Continue reading ...