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Re: laser comment(was: Coil ideas for experiments)
I replied to Robert off-list yesterday, since this thread is getting old and
off-topic. However, maybe I should have replied on-list.
A laser travelling through a vacuum will lose no energy. Air is so diffuse
that it is generally treated as a vacuum in the optics community (index of
refraction for air is 1.000276 -at- 15C, 760mmHg). Also, the beam will diverge
(get larger), which will mean that it's power will decrease. The larger the
wavelength, the smaller the beam divergence. Also the larger the beam size,
the smaller the divergence.
One would have to terminate the beam (thick concrete slab, maybe even the
ground). There are *NO* exceptions when power levels reach over about 10
mW/cm^2 (at which point there's serious chance that retinas can be burned).
Contact me off-list if you have more questions.
Mark
Tesla List wrote:
> Original Poster: ANTarchimedes-at-aol-dot-com
>
> In a message dated 4/14/2000 9:53:47 AM US Mountain Standard Time,
> tesla-at-pupman-dot-com writes:
>
> << I do not mean to be a hair splitter but I tend not to agree with
> this comment
> >> snip
> Also a LASER doesn't lose much power over long distances.
> >> snip
> since (I think) power loss will be governed by the inverse square law
> (double the distance 1/4 the power)
> >>
>
> Great! As long as we aim the laser at something far away, the laser will do
> no damage and won't get us with UV light. Thanks for the idea.