Editorial

The word ‘bumble’ is centuries old and is thought to be a mix of the words ‘bungle’ and ‘stumble’. Mostly today we associate the word with the bumblebee, that rotund insect that, according to popular legend, shouldn’t really be able to fly. The fluid dynamics behind bumblebees’ flight are different from those that allow a plane to fly. An airplane’s wing forces air down, which in turn pushes the wing (and the plane it’s attached to) upward. For bugs, the wing sweeping is a bit like a partial spin of a somewhat crappy helicopter propeller, but the angle to the wing also creates vortices in the air like small hurricanes. The eyes of those mini-hurricanes have lower pressure than the surrounding air, so, keeping those eddies of air above its wings helps the bee stay aloft. Take your arm and put it out to your side, parallel to the ground with your palm facing down. Now sweep your arm forward. When you reach in front of you, pull your thumb up, so that you flip your arm over and your palm is upwards. Now, with your palm up, sweep your arm back. When you reach behind you, flip your hand over again, palm down for the forward stroke. Repeat. If you gave your hand a slight tilt (so that it’s not completely parallel to the ground) you’d be doing something similar to a bug flap and now, gentle reader, you are airborne. Thank you Michael Dickinson - professor of biology and insect flight expert at the University of Washington.