"Thomas Borchert" wrote in message
...
AliR,

Is either one of us right?


Your friend, partly. There are atmospheric conditions when the pressure
change over the wing or at a wing tip is enough to make the water in
the air visible. But they are rare and don't make long contrails. The
long contrails from jets you see are because the exhaust contains small
particles (soot and other stuff) which cause the water vapor in the air
to condense on them where it wouldn't condense without them.

--
Thomas Borchert (EDDH)



How dare you promote the cover story that contrails are just water vapor and
exhaust. It is an operation by the CIA, FBI, NSA and Disney to poison us
all. You must be one of them.

OK I made up the Disney part, but you can read the TRUTH at the link below.


http://www.carnicom.com/contrails.htm