Two mathematicians have proved that a straightforward question—how hard is it to untie a knot?—has a complicated answer.
NPR's Scott Simon talks to John Hogan, professor of applied mathematics at the University of Bristol, about his research on the "Golfer's Curse" - when a ball looks like it's been sunk, but spins back ...
Some results have been hidden because they may be inaccessible to you
Show inaccessible results
Feedback