reply to post by Merriman Weir
I've worked in HVAC before and currently work as a contractor on a military installation. Most buildings have a natural overpressure inside and in
some cases the HVAC is so poorly designed and engineered that the building can be highly overpressured or underpressured. Both can have very bad
effects on a building. It is possible that if a structure is overpressurized enough people MIGHT begin to have some kind of phyisological symptoms
but most buildings have open windows, open doors, and if the building is actually overpressurized, people are gonna know. The air will be forced out
at every opening and whenever you open a door it can swing so violently outward it can knock people and children down (which can injure people pretty
badly). Not to mention, people's ears would be popping if the overpressure is bad enough.
I heard of one case on a military base where the overpressure was so bad that the actual PDM layer that sealed the flat roof of one building actually
filled up like a giant balloon to a point where the top of the PDM layer was like 12 feet above the actual roof..
It happens.. But people would know about it.
However, IMO, it is possible that poor HVAC combined with traffic, industrial actitivites, construction, or other factors could (in theory) combine to
create a very specific audible hum which could be amplified by the structure itself just depending on the aspects of the resulting hum and the overall
architecture and condition of the building. But people would realize that link normally.. I work on a military installation in a small building that
literally vibrates and hums when a helicopter flies over... If the building's hum is being caused by some kind of external factors though, people
are not going to experience it ALL the time unless there are permanent structures or activities nearby that are the true source of the hum. And if it
only lasts for a few seconds at a time, people will know that the source is something quite normal.
These hums we have been talking about last for extremely long periods of time with no known source, with continuous audible attributes, and people
hear the hum for miles and miles around whether they are inside a building or out.. Low frequency noise is, in my mind, very mysterious and not well
understood. It has recently been theorized that ELF noise from the auroras in the upper atmosphere (for example) can actually become amplified by
certain kinds of rocks in the earth's crust making the auroras audible.. Again, this is NOT well understood but many people have claimed to have
actually "heard" the auroras and many scientists now believe that so many people have come forward with similar stories about this that there must
be something to it. My stepdad claims he once could hear high pitched squealing, hissing, and popping directly correllating with changes in the
extremely active auroras he saw on one specific evening a few years ago..
Much I've read about ELF, VLF and other frequency ranges associated with sound too low-frequency to be audible by humans is extremely interesting and
in some cases very bizarre.. People are constantly recording noises within this low-frequency range that are amplified by the earth, which seem to
NOT be associated with any man-made activity, yet the sounds themselves have structure.. Some people actally construct antennaes that stick right in
the ground and then wire the antennaes to computers and other equipment to record their data. Many of the man-made sources of ELF/VLF have very
specific kinds of structure within the signal and occur on very specific frequencies and wavelengths.
I found a link a few years ago about unknown sources of ELF/VLF noise that really blew me away but I couldn't find it for a very long time. I
recently found it and thought I would share with you guys.. It's a gem.. I might have posted this earlier on in the thread, I'm not sure.. I know
I've posted it somewhere on ATS I just don't remember where.. Enjoy.
www.vlf.it...
For galleries of unexplained, unknown ELF signals you can also go here:
www.vlf.it...
On the right-hand side are the links to the unexplained signal galleries.
-ChriS
[edit on 5-10-2008 by BlasteR]
[edit on 5-10-2008 by BlasteR]