Re: Highest Acoustic Atmospheric Frequency?
- From: The Ghost In The Machine <ewill@xxxxxxxxxxxxxxxxxxxxxxx>
- Date: Sat, 31 Mar 2007 14:28:47 -0700
In sci.physics, Sam Wormley
<swormley1@xxxxxxxxx>
wrote
on Sat, 31 Mar 2007 19:04:37 GMT
<9hyPh.20046$oV.5644@attbi_s21>:
The Ghost In The Machine wrote:
In sci.physics, Sam Wormley
<swormley1@xxxxxxxxx>
wrote
on Sat, 31 Mar 2007 18:27:55 GMT
<LKxPh.19946$oV.16203@attbi_s21>:
Radium wrote:
On Mar 30, 10:25 pm, Sam Wormley <sworml...@xxxxxxxxx> wrote:There are practical limits such as sound generation, attenuation, etc.
What makes you think there is a limit?Huh? There is no limit?
But as long as the sound wavelength is >> than the size of the medium
constituents of it is propagating through...
http://www.ndt-ed.org/EducationResources/CommunityCollege/Ultrasonics/cc_ut_index.htm
http://scienceworld.wolfram.com/physics/topics/Acoustics.html
This would make for a practical limit of about 10^-10 m (the size of an
atom). Since sound speed is about 331.4 m/s at 0 degrees Celsius, the
maximum frequency would therefore be on the order of 3.314 teraHertz.
I'd have to look regarding intermolecular distance, which would give
another, lower, limit.
About a factor of a thousand lower.
:-)
Wouldn't surprise me. A cubic meter of air is about 41 moles. That
same cubic meter of air, liquefied, would occupy about 1.2 liters
or 1.2 * 10^-3 m^3. (Maybe not quite that, as I'm assuming the same
density as water.) This suggests that the molecule-to-molecule distance
might be about 10 molecules in width, for a maximum frequency of 331 GHz.
Give or take.
Of course this shouldn't be that difficult to measure directly.
Computers routinely generate signals of more than 3 GHz (if one has
a modern processor) and the overtones shouldn't be too hard to filter
out and drive something along the lines of a speaker coil.
So color me slightly curious. :-)
--
#191, ewill3@xxxxxxxxxxxxx
"Your mother was a hamster and your father smelt of
elderberries!" - Monty Python and the Holy Grail
--
Posted via a free Usenet account from http://www.teranews.com
.
- Prev by Date: Re: The General Relativity gang are circling the wagons.
- Next by Date: Re: Part IV Nothing to see here folk people...
- Previous by thread: Re: The General Relativity gang are circling the wagons.
- Next by thread: Re: Part IV Nothing to see here folk people...
- Index(es):
Relevant Pages
|
