Asked by: Dave Ford, London
The idea of a budgie flapping through the cosmos in a little space suit is quite splendid but physically impossible. Birds fly by sending a mass of air downward by the flap of their wings, with Newton's law of action and reaction producing a force upwards in response. In the absence of air under the wings, there's no mass to move.
Robert is a science writer and visiting professor of science at Aston University.