Hi! Slightly oddball request. A nice, but mistaken guy has produced this website-http://www.dynamic-soaring-for-birds.co.uk/ and further written about his ideas here-http://www.bou.org.uk/dynamic-soaring/ He contends that Dynamic Soaring is possible utilising a constant horizontal wind. This is, of course, a clear violation of C of E and the error is using the Earths surface as an absolute frame of reference. It is beyond my limited physics skills to clearly explain this. Could someone with a little more formal training write a brief synopsis of the errors in his logic and, with your pemission, I will direct the Gentleman here?