What's a gravity wave ? !

RonB
"Dawlish" wrote in message
...
On Aug 25, 7:06 pm, "Les Hemmings" wrote:
... from the ground Iowa 6 May 2007.

http://www.youtube.com/watch?v=yXnkzeCU3bE

Impressive!

Wow! Reminds me of the Rissaga that many captured on their mobile
phones in Menorca 3 years ago and that my next-door neighbour
experienced!