This past weekend I was watching a show on TLC, (The Learning Channel)
called "The World's Biggest Explosions." In one of the segments a hiker
takes a video of a rocket fuel storage depot exploding. The hiker is looking
down at the depot from a mountain top. I'm guessing he was recording the
event from a mile away. Here is the part I'm trying to make sense of -and
I'm sure someone out there will have an answer. ASSUMING TLC DID NOT DOCTOR
THE VIDEO, when the fuel depot explodes (a mile away) you can hear a BOOM
ALMOST at the instant the flash is seen. The BOOM sounds like it contains no
high frequencies. The BOOM is following by a low volume rumbling. At the
moment of the flash you also see the shock sweep across a valley below the
hiker doing the filming. After about 5 seconds you hear the sound of an
incoming rocket (like in a cartoon) followed by the tremendously louder boom
of the shock wave as it hits the camera's location.
QUESTIONS:
To accomplish this, is the initial BOOM traveling through the ground to the
camera that fast to almost be instantaneous from a mile away?
Is the rumbling between the flash of the explosion and the shock wave caused
by sound being carried through the ground to the camera?
Does the shock wave caused by the explosion travel through the air at the
speed of sound for air ?
-Tony
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Tony Wayne Those that can, do.
wayne@pen.k12.va.us Those that understand, teach.
This posting is the position of the writer, not that of SUNY-BSC, NAU or the AAPT.