🚀 go-pugleaf

In article <D9M34K.Cx6@mv.mv.com>, Andy Borsa <andy@moose.mv.com> wrote:
>In article <3qg5sf$4gh@nyx10.cs.du.edu>, pwayne@aol.com says...
>>
>> Can anyone explain me what is ELF? How does it work? What are its
>>advantages?  Please post, we have a size limit on our mailfolder.
>>
>ELF means extremely-low-frequency-electromagnetic waves, about the range of 
>audio freq's to ultra-sonic freq's.  

Careful - some take this and run with it.  There is a difference
between electromagnetic waves and acoustic (audible compressional)
waves; a fact Hollywood more often than not ignores... Just because 
the EM ELF wave is at say 10 kHz does not mean it can be heard thru your
ear. You need an antenna and some means of demodulating the EM transmission
before you can drive a speaker that emits sound that you can hear.
However, beacuse of it's frequency being in the audible range
frequency wise it's extremely easy to build a suitable receiver (I did
at age 10).  Also, do not confuse ELF with microwaves... they are 
basically as far away from each other as you can get, frequency- and 
technology-wise. Both both obey standard laws of physics, tho.
The effect of microwaves (ULF and higher) on the human body is under debate
(at least make sure you understand who finances any given survey/study).

>sea water, etc.  Used to comm with submarines by the navy, WWV for time 
>standard transmission, Loran for navigation (currently displaced by GPS).

WWV on ELF? Bizarre. Reference, please.

>
>BTW - this is a subject you will get more response on from one of the 
>sci.physics... groups.
>

Yep, nothing paranormal about it. :-)

>-- 
>    Andy Borsa -- !!!The universe is discretely analog!!!
>


-- 
Trond Steinar Trondsen                             VE6NOR/LA1OEA
_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/
                        opinions packed by volume  University of Calgary/Physics
trond@phys.ucalgary.ca  not by weight, etc.        Institute  for Space Research