dke3591 > wrote:
> forum about cell phones and being exposed to different type of
> radiation. According to this poster, green light can be pretty nasty,
> here's the relevant snippet:

> >400,000 GHz = ~ green light
> > 2.45 GHz = microwave oven frequency.

> At 1 m with 100W radiation exposure to 2.45 Ghz you'd get cooked but
> might
> survive for a while. If that were 'green light' you'd be badly burnt
> and
> very quickly too - microwave will spread out for more then green light
> amoung other factors.

Someone is confusing frequency with power. The frequency of light is
very different from that of microwaves, yes, but just because they are
much higher frequency does not make them any more dangerous or powerful.
Radiation danger can, and does, vary with frequency but light frequencies
in general are not too harmful until you get into the ultraviolet ranges.

> Even a 1 watt green light source is considered dangerous - notice the
> warnings on lasers of only a few milliwatts

Lasers are a different thing than just plain light. The warnings
are usually concerned with eye damage and that is at least partly because
the eye is specifically sensitive to those frequencies. For example staring
at the Sun will damage your eyes very quickly, but sunlight on you skin does
not burn right away, and that is due to ultraviolet components of the light.
The green part of sunlight won't hurt a bit.

Bill Ranck
Blacksburg, Va.