LooseChanj wrote in message .com...
On or about Sun, 15 Feb 2004 16:51:50 -0800 (PST), ed kyle
made the sensational claim that:
That's because you were roughly 9 miles or more from
SLC 40! It takes sound about 45 seconds or so to go
that distance, depending on temperature and humidity.

Yes, I know all that. :-P But I've lived here almost my whole life, seen
dozens of shuttle launches, (not to mention everything else) and this latency
struck me as extreme. Probably the longest I've yet experienced.

Here is a possibility. A check with Weatherunderground.com
shows that launch time conditions we

T = 26 C
Humidity = 57% (pretty dry by FL standards)
Wind = 22 km/hr from the southwest.

Under these conditions of temperature and humidity,
the speed of sound is 347.9 m/s. You were about
14.8 km from the lauch pad, so it should have taken
about 42.5 seconds for the sound to reach you.

But the wind, blowing pretty much straight away
from you toward the pad, would have subtracted
about 6 m/s from the ideal result, so that the
sound would have taken an extra 0.8 seconds (43.3
seconds), longer if the wind was gusting.

My guess is that the extra beat added by the wind,
coupled with the visual impact of the rocket
disappearing quickly into low clouds before the
sound reached you, were responsible. If, for example,
the launch had happened on a different Florida day
(say 30C/75% humidity, wind blowing toward you) the
sound could have reached you nearly 2 seconds
earlier.

- Ed Kyle