Tying a tie

Someone posted this video of them tying a four-in-hand knot.

In response to this video, someone uploaded a how-to here.

The how-to concludes, "An interesting thing to note here is that, as we can see from this process, the four-in-hand is not a true "knot" in the mathematical sense, since it can be tied without access to either of the free ends!"

Mathematician Claims Proof of Connection between Prime Numbers

From Yahoo

A Japanese mathematician claims to have the proof for the ABC conjecture, a statement about the relationship between prime numbers that has been called the most important unsolved problem in number theory.

Border Collie meets Alan Turing

Full episode here.

Don't you love the New York Times?

And now, the mathematics of pasta shapes

“I play around with Mathematica a lot,” he said. “We were eating pasta, and I was wondering how easy these shapes would be recreated” with the software.

So that evening after dinner, Mr. Huisman figured out the five lines or so of Mathematica computer code that would generate the shape of the pasta he had been eating — gemelli, a helixlike twist — and a dozen others. “Most shapes are very easy to create indeed,” he said.

(NYTimes via io9)

Henrik Ehrsson uses mannequins, rubber arms and virtual reality to create body illusions, all in the name of neuroscience.

"It is not every day that you are separated from your body and then stabbed in the chest with a kitchen knife. But such experiences are routine in the lab of Henrik Ehrsson, a neuroscientist at the Karolinska Institute in Stockholm, who uses illusions to probe, stretch and displace people's sense of self."




(via Nature)

How coral snakes cause excruciating pain

(via Not Exactly Rocket Science)



"MitTx is a toxin of two halves, neither of which do anything alone. When they unite, the two subunits – MitTX-a and MitTx-b – activate proteins called acid-sensing ion channels, or ASICs. These act as gates that sit on the surface of neurons. When they detect an acidic environment, they open up and let ions into the cells, causing them to fire.

ASICs can be triggered by tissue injuries, inflammation or build-ups of lactic acid, and they tell our bodies that something is wrong. The coral snake hijacks this early warning system, by producing chemicals that turbo-charge it. Bohlen and Chesler found that when MitTx is around, acidic environments trigger a much stronger response from the ASICs. As a result, some sensory neurons fire over a thousand times more strongly than they normally would, and they take far longer to return to normal."