They're back ...

http://news.yahoo.com/s/nm/20080421/tc_nm/australia_lasers_dc

High-powered hand lasers, including so-called "star pointers"
used by astronomers, would be listed as prohibited weapons in
New South Wales state with jail terms of up to 14 years for
anyone carrying them without a permit.

Bert Hyman wrote:
They're back ...

http://news.yahoo.com/s/nm/20080421/tc_nm/australia_lasers_dc

High-powered hand lasers, including so-called "star pointers"
used by astronomers, would be listed as prohibited weapons in
New South Wales state with jail terms of up to 14 years for
anyone carrying them without a permit.

No society that calls itself "free"

should be able to get away with
banning something simply because it could potentially be used as a
weapon. Criminal behavior is an act, not an object. Criminalizing a
possession is tantamount to presuming guilt by association, race,
gender, nationality, etc. The standard should be that no crime is
committed until a criminal act occurs and mere possession of an
otherwise useful tool should not count as a criminal act, since no harm
has been done. If we continue to allow the standard of criminality to
to drift toward a mere potential rather than an actual crime then we
will eventually all live in police states.

In sci.astro.amateur message <90vr0417n42v549c191oqgtb5deuq8kn68@4ax.com
, Tue, 22 Apr 2008 08:59:28, Chris L Peterson <clp@alumni.caltech.edu
posted:

Regulations on class 3a and lower lasers in the U.S. are generally very
light, regardless of application, simply because there's no evidence and
no history of harm or damage.

Devices readily available to the general public,

especially but not only
when designed to be used in the manner of a pointer, should not be
capable of doing permanent harm or damage; and that should include the
harm or damage that can be caused by malicious or thoughtless dazzling.

In sci.astro.amateur message <90vr0417n42v549c191oqgtb5deuq8kn68@4ax.com
, Tue, 22 Apr 2008 08:59:28, Chris L Peterson <clp@alumni.caltech.edu
posted:
Regulations on class 3a and lower lasers in the U.S. are generally very
light, regardless of application, simply because there's no evidence and
no history of harm or damage.

Devices readily available to the general public, especially but not only
when designed to be used in the manner of a pointer, should not be
capable of doing permanent harm or damage; and that should include the
harm or damage that can be caused by malicious or thoughtless dazzling.

Consider what might happen if, at night, you were driving down a
mountain road or landing a light aircraft, and a group of vandals ahead
decided to try the effect of one or more of there laser pointers on you.

You can aim to hit a pupil at 300 yards distance????????

Dr J R Stockton wrote:
[snip]

Consider what might happen if, at night, you were driving down a
mountain road or landing a light aircraft, and a group of vandals
ahead decided to try the effect of one or more of there laser
pointers on you.

You can aim to hit a pupil at 300 yards distance????????

Devices readily available to the general public, especially but not only
when designed to be used in the manner of a pointer, should not be
capable of doing permanent harm or damage; and that should include the
harm or damage that can be caused by malicious or thoughtless dazzling.

Consider what might happen if, at night, you were driving down a
mountain road or landing a light aircraft, and a group of vandals ahead
decided to try the effect of one or more of there laser pointers on you.

I'd consider that pretty harmless. A 5mW laser is a stupid choice for
vandals with this intent, because (a) it isn't very bright, and (b)
it's damn hard to actually hit somebody in the eyes, and impossible
to hold it there. For the same price as a green laser pointer I can
go down to Walmart and buy a million candlepower spotlight, and have
a much more effective "dazzle weapon".

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
--

within a solid angle of around 2*Pi/3 to Pi degrees...

Devices readily available to the general public, especially but not
only when designed to be used in the manner of a pointer, should not
be capable of doing permanent harm or damage;

Chris, I respectfully disagree. Have you had a simple 2-3mW red laser hit you in
the eye?

I've had mine accidentally hit me in the eye long time ago from a distance of
about 50m and I'd guestimate that the brilliance I saw was not only completely
dazzling in terms of obscuring my vision within a solid angle of around 2*Pi/3
to Pi degrees, that is, pretty much obscuring my entire field of vision, but
also later checked with some net reference (which unfortunately I don't have
handy right now), and it said that the eye's perceived luminance of the red
laser spot on the retina was around 10,000 times that of looking directly at the
sun.

I don't think the brightness of a one million candela spotlight can achieve
such luminances upon hitting the retina, but I will gladly be corrected if I am
wrong.

I've had a simple spotlight of around a million candelas built around 20 years
ago, using an arc welder with the then famous copper sheathing carbon electrodes
which were used for cinema projection and housing the arc exactly at the focal
point of a car headlight reflector. The beam was visible without any astro gear
to around 3-4 km's. Going to a friend's house at 1km, I checked the beam from
there. The beam was bright, but small and it did not obscure my field of vision.

The spotlight was bright, but not "blindingly" bright, in the sense that it did
not obscure my vision. It was simply a bright point in the horizon. The red
laser was "blindingly" bright, because it also completely obscured my vision
sideways to a large solid angle, even from a large distance.

This is way off the mark. It's very simple to test. Go outside and
glance at the Sun, and at the same time shine a 3mW red laser at your
eye. You will see that the Sun both appears brighter, and stimulates a
stronger aversion reflex.

I don't really follow that. From a long distance (100s of meters or
more) both a spotlight and a laser appear as a point source. There may
be some dazzle, but that's all.

Chris L Peterson
Cloudbait Observatory
http://www.cloudbait.com
--

Just wondering. Rather than wasting all that time and money banning
laser pointers and issuing licenses (can a telescope license be far
behind ?), why not catch the laser lunatics and jail them ? Just
thought I would ask...

Just wondering. Rather than wasting all that time and money banning
laser pointers and issuing licenses (can a telescope license be far
behind ?), why not catch the laser lunatics and jail them ? Just
thought I would ask...

Even more, provided you are equipped with the proper astro gear.