Ask Mr Brain...all will be explained

PUBLISHED : Monday, 20 March, 2000, 12:00am
UPDATED : Monday, 20 March, 2000, 12:00am

Did Atlantis really exist? The Greek philosopher Plato first wrote about the continent of Atlantis.

The story goes that the gods wanted to punish Atlantis because its people were corrupt. There was a huge explosion and it sank into the ocean.

Some believe that Plato was actually writing about the island we now call Santo-rini, or Thera, in the Aegean Sea. Volcanos destroyed the island in about 1500 BC.

Why are feathers asymmetrical? A symmetrical flight feathers act like individual wind foils, giving better lift in flight. It seems from fossil record that feathers have been asymmetrical since the earliest time when birds took to the air.

Birds' wings resemble the wings of an aeroplane, slightly convex above and concave below, with a rounded edge facing forward, and a longer, tapering shape on the trailing side. This shape provides aerodynamic lift. Birds also get lift from individual feathers. One side of a bird's flight feather is smaller than the other. On that side, the flexible 'barbs' that make up the feather's surface are shorter and a bit stiffer.

So, just as the bird's whole wing resembles an aeroplane wing in cross section, so does each flight feather, with a stiffer edge facing forward, and a longer trailing side.