The other part of the argument to consider here is wattage. Wattage is a
measure of power, where power is energy over time. The lightbulb in your
microwave may emit, for example, 40 watts of a power, mostly as heat, but
some portion as light. A typical microwave oven may emit 1000 watts in
microwaves. By comparison, a mobile phone emits on the order of 250
milliwatts.
The other factor that makes microwave ovens so efficient is the particular
frequency they work at. 2.4ghz interacts well with (excites) water
molecules. The physics and chemistry behind that is fairly complex, but it's
to do with the fact that electromagnetic fields consist of a changing
electric and changing magnetic field. That changing electric field causes
the water molecules to move (to rotate, actually), and through friction this
is converted to heat.
http://howthingswork.virginia.edu/microwave_ovens.html explains much of this
quite clearly, along with other microwave related physics.
There may be a physicist here on the list that can explain this better than
I, a year 12 student, can. Any corrections are welcome, my intention here
was just to make people think a little bit.
Chris
On Jan 10, 2008 9:37 AM, Fredrik Olson <fredrik@fredrikolson.net> wrote:
Hi Chris
Interesting discussion. But I'm not sure I'm buying your argument here.
Microwaves heat up food much faster than the light from the lamp in the
microwave oven would heat the food up. This can't be explained by the e=H*f
formula, as I understand it. Something must be missing? I'm genuinly
interested, so please don't take me wrong.
Best regards,
Fredrik
At 23:20 2008-01-09, you wrote:
Indeed. Thank you for stating it so succinctly, or I might have posted
something rather more irate.
I'm always scared by how easily people are deceived by things that are
easily shown to be impossible by an understanding of very basic
physics. Unfortunately, it seems that what I consider "basic physics"
wasn't taught 30 years ago, and so many people carry irrational fears
about (particularly) electricity, computers, microwaves and mobile phones.
In this case, I suspect that the "plausibility" of the story comes
from a misunderstanding. The inclusion of having to answer the phone
reminds me of the (true) stores about people being killed by lightning
strikes being conducted by their phone lines.
If you value your time, there's no need to read further.
While I'm at it, I'd just like to take a commonsense approach to the
fears of "mobile phone radiation". Yes, I'm well and truly hijacking a
soapbox here, but this forum is pretty quiet these days anyhow.
Many here may know that mobile phones operate using so-called
"microwave radiation". The simplified electromagnetic spectrum looks
as such:
Low Frequency High Frequency
Radio - Microwave - Infrared - Visible Light - UV - Xray - Gamma
Now for the part that isn't taught until elective physics:
e = hf. That is, Energy of a wave is equal to Planck's constant
multiplied by the frequency. Since Planck's constant is a constant, we
can say that energy is directly proportional to frequency.
Thus, we can see why high frequency x-rays and UV light are harmful -
they carry a large amount of energy. Microwaves, on the other hand,
being of a low frequency carry less energy than visible light, and
even than infrared (heat energy). So if you're worried about mobile
phones cooking your brain, I suggest you don't go outside. The risks
are far greater.
Sorry about your time!
Chris
--- In powderworks@yahoogroups.com.au <powderworks%40yahoogroups.com.au>,
RM <m2k7@...> wrote:
email warnings about technology, crime, viruses etc are generally all
fakes and should be rebutted promptly to stop their travel.
if you get any warning, especially any that say "FORWARD THIS TO
[everyone in your mail list]", first google a key phrase out of the
mail
(in quotes might help too) and see if it shows up on the regular hoax
monitoring sites:
eg:
I googled : "ever answer a cell phone while it is being RECHARGED"
and found:
http://urbanlegends.about.com/library/bl_cell_phone_electrocuted.htm
http://www.hoax-slayer.com/cell-phone-charging.html
http://www.snopes.com/horrors/techno/cellcharge.asp
as the top 3 listings. These 3 sites are the regular hoax-busters.
most people have seen enough of these to have already built up a sense
of loathing for both the mails and those who pass them on, but most
people also have to first send one to learn this, so don't feel too
embarrassed, we've all been caught.
Cheers
RM
[Non-text portions of this message have been removed]
