Posts Tagged ‘Quantum magnetism’

A few links: Medieval Africa, College Quidditch and Unparticles

November 28, 2007
  1. Philobiblon reviews a book about medieval African kingdoms:

    The Royal Kingdoms of Ghana, Mali, and Songhay: Life in Medieval Africa is one of those books that does just what it says in the title: this introductory text by Patricia and Frederick McKissack sets out a brief history, a short outline of the life and economies of the kingdoms, and describes the sources on which this information is based – and their contradictions.

    That’s great, and is probably all most readers are going to want, since I suspect most will, like I did, come to the subject from the starting point of almost total ignorance.

    Sounds very interesting, isn’t it? After reading Amitav Ghosh, I always wanted to know more about medieval Africa; this looks like the book I should try first.

  2. Grrslscientist has a must-read post on College Quidditch teams and their (earth-bound) Quidditch games (with a video to boot — just don’t miss it):

    To play earth-bound Quidditch, brooms are required, leaving only one hand available, making the game harder as you chase the game ball, a slightly deflated volleyball.

    Each team has seven cape-clad players, consisting of three chasers who throw the ball among them as they work down the field. If they get it through one of three circular goals (hula hoops on poles), the team scores 10 points.

    At the same time, two other team members fling around dark balls called bludgers in an attempt to distract and knock over opposing players. When a player is hit with a bludger, s/he must drop any ball s/he is holding and run around to her/his goal zone before s/he can make any more plays.

    Seekers try to catch the most elusive ball, the Golden Snitch (pictured, right). In the Rowling books, the Golden Snitch is a small ball that flies about independently. In real life, it hangs in a sock from the shorts of a player selected for fleetness and agility. As in the books, the Snitch disappears for periods of time, reappearing on the field to shrieks of the crowd. The Snitch player has a much larger boundary than the others, often covering a large part of campus. Seekers are the only players who can follow the Snitch. Catching the Snitch is worth 50 points and, as in the Harry Potter books, once the Snitch is caught, the game ends.

    By the way, making a remote driven mechanical snitch should not be too difficult, right? I am getting ideas!

  3. Doug at Nanoscale views points to a nice, pedagogical review on quantum magentism and criticality, which sounds very interesting (and, manages to sneak-in a link to a critique of Garrett Lisi’s paper along the way).