Evaluate an approximate value of sqrt(2), using a sneaker and a stopwatch only.
Source: Mark Levi's "Why Cats Land On Their Feet?"
On a flat field mark a spot on the ground. Then walk at a normal, sustainable and consistent rate in a straight line for 100 seconds. Make a rightangle turn (make sure the sneaker is in view either directly left or directly right). Restart timing and start walking at the same time, walking at the same consistent rate as before, and again for 100 seconds.
When you've finished that phase, time a walk at that same rate toward the sneaker. The number of seconds divided by 100 will be the square root of 2.

Posted by Charlie
on 20160719 10:42:59 