On Thu, Mar 16, 2017 at 9:19 AM, MRAB <pyt...@mrabarnett.plus.com> wrote: > On 2017-03-15 22:03, Gregory Ewing wrote: >> >> Steve D'Aprano wrote: >>> >>> You probably can't make a whale fly just by changing the class to bird. >>> It >>> will need wings, and feathers, at the very least. >> >> >> Some things succeed in flying with neither wings nor feathers. >> Helicopters, for example. >> > Could you argue that the blades were a kind of wing? After all, they rely on > the same principle of moving through the air to produce lift. > > Balloons, on the other hand, ... :-)
Certainly not. If they were, you'd move (or spin) them faster to go up, and slower to go down. But you don't. So it's all about the ugliness. You twist the blades up a bit to make the helicopter uglier. ChrisA -- https://mail.python.org/mailman/listinfo/python-list
