[geeks] One for Dave McGuire ...

[David Cantrell]

On Wed, Aug 15, 2001 at 12:50:51PM -0400, joshua d boyd wrote:
> On Wed, Aug 15, 2001 at 04:25:15PM +0100, David Cantrell wrote:
> > http://www.theregister.co.uk/content/6/21037.html
> > 
> > Yeah yeah, I know, atmospheric scattering, absorption in the atmosphere,
> > hazard to air traffic ...
> 
> Oh.  Painting the moon red with laser pointers.  All we need is a few
> people to get those industrial lasers off of ebay to use.  

Let's use some nice round numbers.  We'll assume a 100W laser with a beam
1mm across.  We'll assume that by the time it reaches the moon it is a
meter across.  So each square millimeter of the moon's surface will get,
assuming only one laser and no attenuation at all, 0.0001W.  That's not
enough to see even if it's being shone directly into your eye whilst you
stand on the moon.  It's not even worth bothering with the numbers for
the light's return journey.

Now, if 100 million people all have one of those lasers, and they all
shine them *precisely* at the right spot so there's no overlap, then we
cover a grand total of 100 sq km.  100 sq km features may just about be
visible with the naked eye if well lit, but this won't be.  We will see
nothing, and what few photons do reach our eyes will be drowned out by
mere starlight.

Bleah.  Artists.

-- 
David Cantrell | david at cantrell.org.uk | http://www.cantrell.org.uk/david

   Educating this luser would be something to frustrate even the
   unflappable Yoda and make him jam a lightsaber up his arse
   while screaming "praise evil, the Dark Side is your friend!".
                              -- Derek Balling, in the Monastery