[CoLoCo] [OT] there is one thing about microwaves (was Re: ubuntu and science fairs)

[Paul Schwartz]

----- Original Message ----
> From: Kevin Fries <kfries at cctus.com>
> To: Ubuntu Colorado Local Community Team <ubuntu-us-co at lists.ubuntu.com>
> Sent: Tuesday, February 5, 2008 9:07:40 AM
> Subject: Re: [CoLoCo] [OT] there is one thing about microwaves (was Re: ubuntu and science fairs)
> 
> 
> On
> 
Tue,
> 
2008-02-05
> 
at
> 
10:27
> 
-0500,
> 
TheZorch
> 
wrote:
> >
> 
It> 
has> 
to> 
do> 
a> 
lot> 
with> 
"how"> 
microwaves> 
heat> 
things. > 
Usually> 
when> >> 
you>put> 
a> 
cup> 
in> 
the> 
microwave> 
it> 
heats> 
the> 
cup> 
and> 
in> 
the> 
turn> 
the> >>water> 
gets> 
hot,> 
but> 
not> 
all> 
types> 
of> 
cups> 
absorb> 
microwaves.> 
> Actually> 
you>have> 
that> 
backwards.> > Microwave> 
ovens> 
cook> 
by> 
manipulating> 
the> 
orientation> 
of> 
water> 
molecules.> At> 
certain> 
radio> 
frequencies,> 
the> 
molecules> 
in> 
water>with> 
all> 
orient> 
the> same> 
way. > 
when> 
the> 
frequency> 
is> 
discontinued,> 
the>molecules> 
reorient> themselves> 
back> 
to> 
their> 
original> 
orientation.> > By> 
pulsing> 
this> 
frequency> 
on> 
and> 
off,> 
the> 
water> 
molecules> 
"vibrate"> 
and> the> 
friction> 
of> 
the>molecules> 
as> 
they> 
keep> 
moving> 
causes> 
heat> 
(rub> 
your> hands> 
together> 
and>you> 
will> 
get> 
the> 
idea).> 

I get your idea, but I don't think you're correct. The microwave field doesn't couple with the orientational dipole moments of the water molecules. They couple to energy levels within the molecular bonds. The excited molecules decay and transfer the energy into thermal energy [more rapid translational movement]. I haven't studied the molecular spectroscopy in detail, but my gut reaction is this.

Whatever :-)

Paul

> Ideal
> 
containers
> 
will
> 
not
> 
block
> 
the
> 
radio
> 
waves,
> 
and
> 
have
> 
a
> 
low
> 
water
> content
> 
(so
> 
they
> 
do
> 
not
> 
heat
> 
up
> 
themselves
> 
stealing
> 
energy
> 
from
> 
the
> cooking
> 
process). 
> 
Foods
> 
dry
> 
out
> 
because
> 
the
> 
water
> 
in
> 
them
> 
boils,
> 
and
> evaporates. 
> 
Again,
> 
ideal
> 
cooking
> 
vessels
> 
will
> 
trap
> 
as
> 
much
> 
of
> 
the
> moisture
> 
as
> 
possible
> 
and
> 
return
> 
it
> 
to
> 
the
> 
food. 
> 
Kinda
> 
explains
> 
why
> plastics
> 
are
> 
used
> 
so
> 
often.
> 
> -- 
> Kevin
> 
Fries
> Senior
> 
Linux
> 
Engineer
> Computer
> 
and
> 
Communications
> 
Technology,
> 
Inc
> A
> 
Division
> 
of
> 
Japan
> 
Communications
> 
Inc.
> 
> -- 
> Ubuntu-us-co
> 
mailing
> 
list
> Ubuntu-us-co at lists.ubuntu.com
> Modify
> 
settings
> 
or
> 
unsubscribe
> 
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> 
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> 




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