Icicles

Today's the day ............................ for a scientific explanation

Icicles are one of our strongest symbols of winter - a tapered, hanging spike of ice formed by the freezing of dripping or falling water. But have you ever wondered why they are the shape that they are?

According to physicist Martin Short of the University of Arizona - this shape, which always conforms to a certain mathematical formula, is a result of what happens when the icicle forms.

As water drips on to an icicle and freezes, it releases heat. The warm air rises up the sides of the icicle and acts like an insulating blanket. The blanket is very thin near the tip and thick at the top. That allows the top to grow very slowly and the tip to grow rapidly - creating a long, thin carrot sort of a shape.

Mmmh - not sure - sounds a bit far-fetched to me ................?!