Re: Not sure
Hi David & Frank,
It's fascinating how Science can contradict itself. In the case of vortices the configuration and dynamics determine whether they are a help or a hinderance.
I was unaware of that phenomenon. Who said that you can't teach an old dog new tricks? How do bumblebees fly? What about hummingbirds? I watched 3 fly around flowers yesterday. It's amazing that they are able to maintain the wind speed that they do.
Thanks for the contributions.