On Fri, 3 Mar 2006 at 15:21:11 in message
, "00:00:00Hg"
wrote:
On Fri, 03 Mar 2006 01:27:46 +0000, David CL Francis wrote:

Above
Mach one the air does not detect the approaching aircraft! :-)

If it did, what would happen?

The whole point is that disturbances in the air are propagated at or
near the velocity of sound. It follows that at supersonic speeds
nothing happens to the air until it reaches the supersonic aircraft, or
vice versa.
--
David CL Francis