Tag: youtube

Interview With John Nash and his Schizophrenic Son

Posted on by S. Abbas Raza

Video length: 7:10

Some time ago I came upon a recommendation letter written by a professor of mathematics and physics at Carnegie Mellon for John Nash, who was applying for admission to Princeton for grad school. Nash, of course, went on to win a Nobel prize and is the subject of the movie A Beautiful Mind, which you may have seen. His invention of what is now called the Nash Equilibrium is one of the foundational concepts of game theoretic economics. Anyway, here is the letter:

SMqfqU6

Scientists have found the speed limit of vision with an illusion in which nothing moves at all

Posted on by S. Abbas Raza

Stephen L. Macknik in Scientific American:

An entry from The Best Illusion of the Year Contest started off as a representation of the Loch Ness monster, but has grown to become one of the most intriguing, and potentially most important, illusions. The effect stems from a jumping ring: line-segments arranged randomly in an annulus rotate smoothly, and periodically rescramble into a new pattern of randomly arranged line-segments. Bizarrely, the rescrambling appears to viewers as a rapid backward jump in rotation, despite that there is no real motion (or direction of motion) during the rescrambling. Pretty cool.

Mark Wexler of the University of Paris V in France, who discovered the original Loch Ness effect, took third-prize in the contest. He named it the Loch Ness aftereffect after a classic illusion known to ancient Greeks, which Robert Addams later rediscovered in 1834 at the Falls of Foyers (the waterfalls that feed Loch Ness in Scotland). If you stare at the waterfalls for a while, the stationary rocks near the falling water will appear to drift upward. But unlike in the waterfall effect, Wexler’s illusory motion aftereffect is 100 times faster than the inducing movement! So this is not your parent’s waterfall effect: something new is happening.

More here.