How do birds stay in the sky?
PHYSICAL WORLD: Students from South Wellington Intermediate asked this question
Birds rely on the same effect as airplanes to stay in the sky. In fact, we can say that airplane wings copy birds wings.
It is a little complicated to explain and requires mathematics and physics to fully understand why it works.
In essence, the speed of the air flowing over the top of the wing is faster than that along the bottom as a consequence of the shape of the wing. Because of this the pressure pushing down on the top of the wing is less than the pressure pushing up on the bottom of the wing so the wing is lifted. This then lifts the bird (cancelling out its weight) so it stays aloft.
See http://aviationknowledge.wikidot.com/aviation:aerofoil
Our expert
Professor John Harvey anwered this question. He is a Fellow of Royal Society Te Apārangi, which means he’s one of the top experts in his field of photonics and optics. John started the University of Auckland Laser Lab in the early 80′s and has been CEO of Southern Photonics since its inception in 2001.
For more information visit: http://www.southernphotonics.com/about-us/prof-john-harvey/