## Turning on a Dime

Flies are almost impossible to catch. Anyone who has waved a fly swatter around, desperately hoping to hit one, will agree. Flies are very fast, but perhaps it isn’t the speed that tricks the desperate human, but rather the remarkable capability for a fly to turn 90° in about 50-thousandths of a second.

Already, these disgusting little creatures are overcoming impossible aerodynamic forces, their wings beat over 2000 beats per second just to stay aloft.

Initially, it was believed, flies turned very differently from larger fliers like birds or planes, but in reality, flies use the same speed-up-turn-speed-up sequence. However, unlike planes, flies don’t rely on drag to change course.

Flies fight the inertia of their own bodies along with the drag force of the air, to physically spin themselves about. That is a physiological feat for something with a sesame-seed sized brain. The closets thing humans can come to is making a running jump, spinning 90°, then running again, all in less than a blink of an eye. Throw in some complicated arm movements and you’re half way there.

perhaps the most amazing thing about the flies turn, is its inability to see. The fly turns so fast, it cannot tell where it is in the turn until it has finished turning.

This strange new way of turning, a way that focuses on torque rather than aerodynamic forces, could be revolutionary in the technological field. While Dickinson, the scientist who discovered the flies incredible turning ability, has no specific technological ideas in mind, he is hopeful for the future explaining that, “If you want to understand something, study an animal that does it really well.”

And so far, the fly is one of the best.

Resources

### One Comment

posted on November 3, 2012 at 7:12 pm

There is a misunderstanding here — the flies do not beat their wings at 2000 beats per second.
In fact, the writer for ABC calculated a rate of turn from the information that the fly changes direction by 90º in 50 ms.
90º / (50×10^-3) = 1800º per second … he approximated that to 2000 degrees per second.