I do believe that any mechanical wave, such as a pressure or shock
wave,
travels at the speed of sound, no more and no less. To travel faster,
it
would have to be an electromagnetic wave.

Also, the deaf person wouldn't hear the mechanical wave. Well,
unless they had "some" hearing still available. If it was proven that
a totally deaf person could hear it, that would pretty much nail it
down as
electromagnetic. If that came out to be true, then Coffmans theory
about the auditory nerve picking it up would probably be true unless
some other nerve was actually involved.
MK

On 18 Dec 2005 08:41:47 -0800, wrote:

I do believe that any mechanical wave, such as a pressure or shock
wave,
travels at the speed of sound, no more and no less. To travel faster,
it
would have to be an electromagnetic wave.

Also, the deaf person wouldn't hear the mechanical wave. Well,
unless they had "some" hearing still available. If it was proven that
a totally deaf person could hear it, that would pretty much nail it
down as
electromagnetic. If that came out to be true, then Coffmans theory
about the auditory nerve picking it up would probably be true unless
some other nerve was actually involved.
MK

Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

R

Russ wrote:

Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

No.

Roy Lewallen, W7EL

The denotation is supersonic, while the flame spread is subsonic.

"Roy Lewallen" wrote in message
...
Russ wrote:

Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

No.

Roy Lewallen, W7EL

On Sun, 18 Dec 2005 12:39:09 -0800, Roy Lewallen
wrote:

Russ wrote:

Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

No.

Roy Lewallen, W7EL

The definition of dentonation includes the flame front moving at
supersonic speeds.

http://www.globalsecurity.org/milita...itions/fae.htm

R

Russ wrote:
On Sun, 18 Dec 2005 12:39:09 -0800, Roy Lewallen
wrote:


Russ wrote:

Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

No.

Roy Lewallen, W7EL


The definition of dentonation includes the flame front moving at
supersonic speeds.

http://www.globalsecurity.org/milita...itions/fae.htm

Yes, I can understand the flame front moving faster than sound, if it's
not a pressure wave. I don't know the mechanism, but presume it's
propagated by radiant heat. That is, a flame occurs, and its heat
radiates and superheats nearby material, causing it to flame. That would
be propagation by electromagnetic wave, i.e., infrared "light". The
radiation would travel at the speed of light, with the apparent speed of
the front being dictated by how fast the material is heated and ignited
by the radiated heat. Propagation by this mechanism and at this speed
would end as soon as the flame front reached the outside of the vapor
cloud, beyond which the resulting pressure wave would travel at the
speed of sound.

I'm not an expert at this, but I'm quite sure that the only way you can
get a mechanical wave to travel faster than sound is if the behavior of
the air becomes nonlinear at some compression level. That could
conceivably happen as a result of an explosion, but I don't think so. If
anyone has any references describing such nonlinear behavior, I'd love
to learn more about it.

Roy Lewallen, W7EL

Roy Lewallen wrote:
I'm not an expert at this, but I'm quite sure that the only way you can
get a mechanical wave to travel faster than sound is if the behavior of
the air becomes nonlinear at some compression level.

Carrier velocity is linear and must be taken into account. Relative
to a measurement point at the center of the earth, sound waves
traveling East in the surface atmosphere are moving faster than
Mach 2. Do the carriers move during an explosion?
--
73, Cecil http://www.qsl.net/w5dxp

This has been an interesting discussion, and prompted me to do a tiny
bit more research.

It seems to me that if there's any nonlinear phenomenon which allows
some pressure waves to travel through air faster than the speed of
sound, surely a nuclear blast would produce enough pressure to excite
it. But it doesn't seem to. From
http://www.globalsecurity.org/wmd/intro/nuke-blast.htm:

"During the time the blast wave is passing through the superheated
atmosphere in the fireball, it travels at supersonic velocities. After
it leaves the vicinity of the fireball, it slows down to the normal
speed of sound in the atmosphere. As long as the blast wave is expanding
radially, its intensity decreases approximately as the square of the
distance. When the expanding blast wave from a nuclear air burst strikes
the surface of the earth, however, it is reflected, and the reflected
wave reinforces and intensifies the primary wave."

Roy Lewallen, W7EL

Russ wrote:
On 18 Dec 2005 08:41:47 -0800, wrote:


I do believe that any mechanical wave, such as a pressure or shock
wave,
travels at the speed of sound, no more and no less. To travel faster,
it
would have to be an electromagnetic wave.

Also, the deaf person wouldn't hear the mechanical wave. Well,
unless they had "some" hearing still available. If it was proven that
a totally deaf person could hear it, that would pretty much nail it
down as
electromagnetic. If that came out to be true, then Coffmans theory
about the auditory nerve picking it up would probably be true unless
some other nerve was actually involved.
MK


Doesn't the delta P of a fuel-air bomb travel at greater than the
speed of sound?

R

Also, the pressure wave INSIDE a rifle barrel travels faster than the
speed of sound. It produces velocities of the projectiles at Mach 3 to
Mach 4. Hmmm...

The air pressure profile on an aircraft wing shows supersonic, transonic
and subsonic reponses. Hmmm..

It raises a physics question. How does the velocity of sound vary in a
compressible medium as the temperature, volume and pressure change?