[AT] Waaay OT

[Larry D. Goss]

Thanks, Henry.  There are times that you just "know" when you're being
fed a line.  The whole bit about the farmer and his big brick of cold
hardened copper was just a bit too much to swallow, but the
Nanotechnology site had a reasonable explanation of what they're doing.

"Faraday cage."  It's been a long time -- many years -- since I've come
across that term.  I know what it is, and they had one at the GE Works
Lab that my uncle Claude Summers was the manager of.  I remember touring
through it during one of the open houses at the company shortly after
WWII.  Between he and my Dad, conversations were pretty high-tech when
the family got together.  They were college roommates, both EE majors,
and they finished in a dead heat with a third man (also their apartment
mate) for the head of their class in 1926.  All three men were recruited
to work at GE before the start of their senior year.  Claude and my Dad
married sisters, so they became relatives.  We lived on a farm with
cows, so the families got together twice a week for nearly 30 years --
every Thursday night and Sunday afternoon --- so they could get a supply
of fresh milk, butter, eggs, and homemade cottage cheese.  On Sunday
nights, those two best friends would sit around the bonfire in our
backyard (weiner roasts were a regular occurrence) and discuss motors,
control systems, radios, epoxies, atomic energy, transistors,
refrigeration, and a whole host of other subjects that they had new
ideas about while the sisters compared recipes in the kitchen and the
kids played "hide and seek" and had snipe hunts. 

Listening to them talk about the latest developments in those fields was
an education second to none for me.

Claude put together a Christmas program for employees and their families
that was called "House of Magic".  It was through those that I became
exposed to early strobe lights, RF phenomena, military fire control,
radar, and a whole litany of physics and engineering demonstrations that
mirrored the latest things the company was working on.  When I taught a
physics class one summer that was a survey course that was set up as
"physics without math", I dredged all those demonstrations I had seen as
a kid out of the recesses of my mind and recreated those for the
principle discoveries as part of my lectures.  It was the most work I
ever had to do to prepare for my classes, but it was also the most fun
course I ever taught.

Larry

-----Original Message-----
From: at-bounces at lists.antique-tractor.com
[mailto:at-bounces at lists.antique-tractor.com] On Behalf Of Henry Miller
Sent: Sunday, March 12, 2006 1:35 PM
To: at at lists.antique-tractor.com
Subject: Re: [AT] Waaay OT

On Saturday 11 March 2006 21:24, Larry D. Goss wrote:
> I know just enough about this subject to be REALLY dangerous.  Have
any
> of you heard anything about this?  Or is this simply someone's wishful
> thinking?
>
> SUPPOSEDLY, some "farmer" somewhere discovered that he didn't have
cell
> phone reception when he was in his barn.  He then discovered that the
> lack of reception was associated with a bar of cold hardened copper he
> was using as a door stop (or some similar mundane use).  He has
> discovered a way of putting the cold hardened copper into paint so it
> can be applied to ordinary walls in office buildings, schools,
churches,
> theaters, funeral parlors...  Think of the possibilities! -- to
> automatically keep cell phones from disturbing meetings or events held
> in certain locations simply by covering the walls with a special
paint.
>
> Is there any truth to this?  I'm well aware that the ordinary way of
> hardening copper is to cold work it, so what's with the "cold
hardened"
> emphasis in the story?  And what's the hardening of copper got to do
> with it blocking cell phone signals -- but not pagers?  And why copper
> instead of lead?  Or is the whole thing a shaggy dog story?
>

In physics we call this a Faraday cage.    If a room is made out of
something 
conductive (copper is most common, depending on what you want to stop a 
window screen might work), radio waves will not go through.   I won't
bore 
you will all the equations needed to see what something will stop.  (I
just 
barely passed that class, and it was 10 years ago)

The cold hardened stuff is pure BS.   Doesn't matter if the copper is
hard or 
soft, copper is a good conductor, so it works well for this.

The door stop part is also BS.    What is important is that you have
solid 
metal surrounding the room.  A door stop will not stop radio waves.  It
might 
reflect waves enough that the cell phone can no longer find the signal
in all 
the noise, but only if the signal is week.   Now if the signal is weak,
wood 
conducts enough that it can stop them, but wood is not enough of a
conductor 
that it can stop powerful waves.

The story was a farmer, who typically will live in an area where the
signal is 
weak.   It is no surprise that a cell phone wouldn't work in his barn
(Even 
in the cities cell phones have problems in houses because the signal is
never 
very powerful).

Someone else posted a link to conductive paint that will work.   Been on
the 
market for years.   Most places don't care enough to use it, they just 
pretend to care enough to make those who do think they care.
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