The 24th Carnival is here! This edition is hosted by Ars Mathematica, a blog that is about mathematics and all of the fields (physics, economics, etc.) that use it. I was looking for a description of the site, and found one on its first ever post, back in May 2005, and then got all distracted reading about octonions on its second ever post. Cool stuff! And speaking of cool stuff, there is a lot of it in the Carnival, so head on over!