🚀 go-pugleaf

On Wed, 14 Aug 1996, Thorsten Franz wrote:

> Hello,
> 
> when I was sitting in my living room tonight, a spot of red light (at
> most one inch in diameter) appeared on the wall and wandered over it,
> coming to rest on the back of the head of my girlfriend. I wasn't able
> to determine the exact size because it was obviously steered by a
> shaking hand.
> 
> I thought it might have to do with a construction site across the
> street and went downstairs to check, but found noone. From down there
> it was clear that the angle wasn't right anyway and that the beam must
> have come from one of the dark windows in a nearby administration
> building, probably 5th or 6th floor.
> 
> A laser pointer, as used for presentations on blackboards, would have
> been too unprecise over the estimated distance of 100 meters. I don't
> know of lab lasers with in-built magnifying glasses, and when you play
> with measuring devices you don't aim them at people's head because you
> are probably professional enough to know about the danger of blinding.
> You would also use a stand.
> 
> So I figure someone might have been playing with the aiming device of
> a rifle, especially considering how restless the spot was. I will go
> to the police tomorrow and report the scary incident. If anyone can
> give me information that might be useful, confirm my suspicion (so I
> have something at hand when talking to a lazy officer), or calm me
> down, I will certainly appreciate it. :-)
> 
> Maybe a physicist can draw conclusions from the estimated distance and
> approximate diameter of the beam, or you know what else portable,
> aimable lasers without a stand/tripod are made for.
> 
> Thank you very much,
> kind regards
> 
> -- 
> uzsd78@uni-bonn.de
 
Dear Thorsten,

I sympathize with you, it does sound scarey.  But I am skeptical.

You cannot conclude that it was "obviously steered by a shaking hand". 
The change in position of any light beam over a distance, is very great
in realation to slight changes in angle.  Over large distances, a
shaking hand could not be steady enough to hold a spot steady enough to
be noticed.  If it was from a tripod mounted device, it would still
"shake", especially in a location with large buildings as you describe. 
I see no evidence that it was a laser, or that it was not a reflection
off something in your room from your own light.  So I will ask some more
questions-- I am interested in helping, but I need to know more: 

1.  Exactly what time of day was it?

2.  Was there direct sunlight outdoors anywhere in the vicinity of your
neighborhood at the time? (ie, daytime, and not overcast skys?)

3.  Were there any artificial light sources in your "abode" at the time?
And again, I mean ANY?

4.  Was there any traffic, or even a parked vehicle visible from your
window at the time?

5.  Were there any artificial sources of light outside, such as street
lamps, commercial lighting, etc?

6.  Were there any exposed reflective surfaces in your "abode" at the
time--
such as a mirror, tv screen, silverware, cd-rom disks, jewelry (even on
your girlfriend), brass knobs, furniture hardware, shiney book cover,
plastic buttons, anything?

And do me this favor:  recall the exact physical locations of where the
spot of light occurred.  Go to those locations and place your right
eyball as closely as possible in those locations.  Look at the world
around you from those locations and tell me if you see any reflective
surfaces (they don't have to be reflecting anything at you at the time).
Also note exactly what can be seen out of the window from those
locations.

Fulfill these needs for details, and I will try to be of more help!

Bill Bailer

\\\  William Bailer ("Bill")
\\\  Rochester, NY, USA;  Phone (voice): 716-473-9556
\\\  wbailer@concentric.net (same mailbox as wbailer@cris.com)
\\\  Some interests: acoustics, JS Bach, anthropology, & education.