Has anyone been following the disturbing (to me anyway) news stories
about airliners approaching to land being hit with laser beams aimed
at the cockpits?

One pilot reported having his eyes temporarily damaged.

The FBI appears concerned because the beams are apparently tracking
the airliners, which implies some very expensive equipment. I wonder
if they really are tracking the incoming airliners, or just being
aimed by people using a tripod and crosshairs. Either way, it isn't
just one location, it's happening all across the country and the
incidents appear to be increasing.

Terrorists have been suggested but the FBI is not convinced that is
the case, or at least don't seem to think it's el Qaeda. They
reportedely spoke to a resident on the east coast but did not report
what the discussion was about.

Hasn't anyone else been following this?

Corky Scott

> Hasn't anyone else been following this?

How smart it was for the government to broadcast a bulletin to be on the
alert from these kinds of attacks. Yep, that surely helped.

Fortunately it's not getting a lot of media attention, thereby reducing the
number of copycats.

MORONS!

On Mon, 03 Jan 2005 09:29:42 -0500, Corky Scott
> wrote in
>::

>Has anyone been following the disturbing (to me anyway) news stories
>about airliners approaching to land being hit with laser beams aimed
>at the cockpits?

No I hadn't, but there do seem to be several incidents:
http://www.rense.com/general61/eeed.htm
http://cayankee.blogs.com/cayankee/2004/09/laser_injures_a.html
http://washingtontimes.com/upi-breaking/20040929-113221-3952r.htm
http://www.wcpo.com/news/2004/local/12/29/laserbeams.html

Two incidents in Colorado Springs, Colo., and one each in Cleveland,
Washington, Houston, Teterboro, N.J., and Medford, Ore.:
http://repairfaq.ece.drexel.edu/sam/laserhen.htm

This incident was apparently an accident:
http://www.dailyrecord.com/news/articles/news2-laser.htm

Discussion:
http://www.jihadwatch.org/archives/004479.php
http://www.metafilter.com/mefi/38220

Laser FAQ here: http://repairfaq.ece.drexel.edu/sam/laserhen.htm

Does anyone know if these are industrial strength lasers, or the green
laser pens that amateur astronomy buffs use for pointing out stars?
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because I fly, I envy no one.

Does anyone know if these are industrial strength lasers, or the green
laser pens that amateur astronomy buffs use for pointing out stars?
--
Gene Seibel
Gene & Sue's Aeroplanes - http://pad39a.com/gene/planes.html
Because I fly, I envy no one.

That's just what I was wondering, Gene, when I read some of the news
reports......

--
--
=-----
Good Flights!

Cecil
PP-ASEL-IA
Student - CP-ASEL

Check out my personal flying adventures from my first flight to the
checkride AND the continuing adventures beyond!
Complete with pictures and text at: www.bayareapilot.com

"I fly because it releases my mind from the tyranny of petty things."
- Antoine de Saint-Exupery -

"We who fly, do so for the love of flying. We are alive in the air with
this miracle that lies in our hands and beneath our feet"
- Cecil Day Lewis -

"Gene Seibel" > wrote:

>Does anyone know if these are industrial strength lasers, or the
>green laser pens that amateur astronomy buffs use for pointing out
>stars?

And blinding the man on the moon.

"Gene Seibel" > wrote in message
ups.com...
> Does anyone know if these are industrial strength lasers, or the green
> laser pens that amateur astronomy buffs use for pointing out stars?
> --
According to a radio show last night, the lasers have been all "green"
except one. Sounds like it might be the laser pens, but do those have enough
strength to light up a target several thousand feet away?


Matt -- still using a wooden pointer (you can't scratch your own back with a
laser pointer).
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

"Matt Barrow" > wrote in message
...

> According to a radio show last night, the lasers have been all "green"
> except one. Sounds like it might be the laser pens, but do those have
> enough
> strength to light up a target several thousand feet away?

I have a bunch of high power visible lasers. All except one are Argon or
Argon / Krypton Gas Ion lasers. Argon produces a mixture of blue and green
colours and Krypton generally produces red. They range in output from 3 to
13 watts. The largest is a mixed gas Argon / Krypton. The same laser with
an Argon tube can produce over 20 watts. But they're *big*. The power
supply is the size of a small refrigerator. The head is over 7 feet long
and weighs about 200 lbs. They require 480V AC service and draw about 50
amps. They also require water cooling at a rate of about 3 US gallons per
minute. Hardly portable. And, they cost at least 25K for a decent used
one. A high level of technical expertise is required to operate them. Go
here and look for "Ion Lasers".

http://www.cohr.com/

There are portable systems that can produce power in these ranges though.
More later. I used to have one near the top of the CN Tower in Toronto. It
was a large frame Argon laser and produced about 20 watts. It was focused
on the ground about 3 miles away. I can't remember what the power level was
at the ground. But it was well below 2.5 mw/cm (the safety limit for brief
exposure). However, even at that level it's still bright enough to
temporarily affect night vision after a brief exposure.

The reports indicate a green beam. There are a few types of solid state
lasers that produce green at high power. Here's one of the largest:

http://www.laserfantasy.com/products_i2000.asp

Again, it requires a fair bit of power and water but I've seen portable
versions of them. They're expensive (~50K US) and require technical
expertise to operate. So I don't think they're practical for covert
terrorist activities.

On the small scale, there is a device (I happen to have one) that could be
used as a turbocharged pointer. Go to
http://lasers.mellesgriot.com/default.asp and look at "Diode Pumped Solid
State Lasers". These produce about three watts of green and only draw about
150 watts. They could easily be powered by a small Inverter in an
automobile. Cost is about 12K US new.

Now for a reality check. To actually blind someone at a distance of several
miles is practically impossible. It would require a very high power laser
and sophisticated tracking equipment. Even then, one would have to
intentionally stare at the offending beam for permanent damage to occur.
The same tracking system with a smaller (~2 watt) laser could be used to
make it impossible to carry out the visual portion of an approach. But, and
anyone experience with laser shows will tell you, holding a beam steady at a
distance of miles is really tricky stuff. However, I think that an amateur,
armed with a 3 watt DPSS laser could cause some serious problems just by
sitting in a vehicle at the end of a runway and eyeballing shots at incoming
planes.

Now, in anticipation of the question, here's what it feels like to get
zapped by one of these things at a distance. (It's happened to me many
times.) You will be momentarily blinded. It won't incapacitate your vision
for more than a few seconds, assuming that you blink. You will want to
abort the approach, not because you won't be able to land, but because the
same thing might happen again. Obviously you'll want to alert the police
and FSS or Tower. If the idiot shining the beam leaves it on, you should be
able to see their location. The colour produced by these devices is an odd
sort of green that doesn't occur in nature an is unmistakeable.

Here's some links on laser safety.

http://www.laserist.org/Laserist/Safety.html
http://www.laserfx.com/Science/Science4.html

moo

Yes, they do, the green lasers especially. In fact, there are several
varieties of emergency signallers which are *designed* to reach search
aircraft. They're obviously not designed to blind the searchers, however,
and this review makes it seem like it would be pretty difficult to keep a
laser trained on a cockpit long enough to cause any eye damage.

http://www.equipped.com/rescuelaser.htm


"Matt Barrow" > wrote in message
...
>
> "Gene Seibel" > wrote in message
> ups.com...
> > Does anyone know if these are industrial strength lasers, or the green
> > laser pens that amateur astronomy buffs use for pointing out stars?
> > --
> According to a radio show last night, the lasers have been all "green"
> except one. Sounds like it might be the laser pens, but do those have
enough
> strength to light up a target several thousand feet away?
>
>
> Matt -- still using a wooden pointer (you can't scratch your own back with
a
> laser pointer).
> ---------------------
> Matthew W. Barrow
> Site-Fill Homes, LLC.
> Montrose, CO
>
>

"Corky Scott" > wrote in message
...
> Has anyone been following the disturbing (to me anyway) news stories
> about airliners approaching to land being hit with laser beams aimed
> at the cockpits?

There are several possibilities:

1) There are terrorists out there planning to make airliners crash with
laser beams and the government has warned us in the nick of time.

2) Terrorists read the government warning and thought "What a good idea!"
and are conducting tests.

3) The local airport haters read the government warning and thought "Revenge
at last!" and are trying to shut down airports, hopefully with great loss of
life so they can say "See, I told you so! Airplanes are dangerous and a
hazard to the community and should be banned forever!" The only difference,
of course, between an airport hater and a terrorist is that the airport
hater is not generally associated with Islam or extremist political groups.
Other than that, both are willing to resort to violence and intimidation in
order to achieve their idea of paradise. The news media, law enforcement,
and politicians are too cowardly to call a local soccer mom who doesn't like
airplanes a terrorist, even if she has repeatedly threatened life and
property in public hearings.

4) Kids read the government warnings and thought, "Cool, we can make a plane
crash!" and are zapping planes with their laser pointers.

5) Pilots, alert because of government warnings, are over-reacting to
accidental contact with legitimate (but possibly careless) users of lasers,
including folks who got new telescopes for Christmas.

6) Any combination of the above. Heck, there could even be web sites and
Usenet forums devoted to such things.

Personally, I doubt that there is one single conspiracy run by some
mastermind who is coordinating these attacks. I mean, in any population of
nearly 300 million people, there are bound to be some heavily armed random
nuts out there. Sooner or later one of them is going to build a nuke, and we
can forget all about lasers.

> I have a bunch of high power visible lasers.

Well, Happy Dog, I suspect I speak for most everyone here when I ask:

What the heck do you *do* for a living?

:-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"Jay Honeck" > wrote in message
news:TijCd.614532$wV.146573@attbi_s54...
> > I have a bunch of high power visible lasers.
>
> Well, Happy Dog, I suspect I speak for most everyone here when I ask:
>
> What the heck do you *do* for a living?
>

Doesn't involve mutant sea bass, does it?

"Jeremy Lew" > wrote in message
...
> Yes, they do, the green lasers especially. In fact, there are several
> varieties of emergency signallers which are *designed* to reach search
> aircraft. They're obviously not designed to blind the searchers, however,
> and this review makes it seem like it would be pretty difficult to keep a
> laser trained on a cockpit long enough to cause any eye damage.

As I previously said, damaging someone's retina at that distance is
practically impossible. Anyone who's not comatose will shut their eyes well
before any damage is done. In decades of audience scanning with high power
lasers (not legal in the US) I don't think there's ever been a confirmed
case of permanent injury to a spectator. And the levels are much higher
than could be acheived at a distance of several miles.

moo

"Jay Honeck" > wrote in
>> I have a bunch of high power visible lasers.
>
> Well, Happy Dog, I suspect I speak for most everyone here when I ask:
>
> What the heck do you *do* for a living?

www.libertygrand.com
www.eventservices.ca
www.aerobatics.ca
www.bovinesexclub.com

The terrorist thing is just a hobby. :-)

moo

Happy Dog said about all that needs to be said about the topic. These are
unlikely to cause any serious injury. It is just like the mass hysteria
that followed the craze of pointing red LASER pens at people. (a) You are
not going to be blinded by one of these (b) Are you *really* frightened that
somebody is pointing a gun at you? Get over it.

Aviation is cause for a little more concern as even becoming distracted at a
critical moment can lead to or contribute to an accident chain...but will
not likely be the only cause. Sure, perhaps somebody with a military grade
LASER can aim it at you, the light attracts you to look at it (natural
response) and in the few milliseconds that you actually look at it, your eye
balls melt and both you and your co-pilot are blind. Wasn't this also the
topic of a Clancy novel and/or movie?

I also heard a rumor that we tested a weapon like this once. A giant LASER
with a mirror for high speed aiming powered by a huge diesel generator was
driven out onto the battle field and blinded a bunch of the enemy in desert
storm...so the story goes. But this source says they existed and were never
used....

["Laser Weapons. The United States also has developed advanced laser
weapons, which are designed to blind opponents or disable weapons' firing
optics, and are equipped its Army with it.

Rupert Pengelley, technical editor of Jane's Information Group, was quoted
by an Associated Press report as saying that the laser weapons also might
see their first use by US forces in Iraq. The US Army equipped its Bradley
Fighting Vehicles with laser weapons in the 1991 Gulf War, but they were
never used, the report said, quoting sources in the Federation of American
Scientists.

Human Rights Watch urged a ban on laser arms in 1995, calling it
"unnecessarily cruel and injurious." But media quoted Pengelleyas saying
that the US military, which has been developing lasers for roles that
include missile defense and air-ground attacks, believes it "can now use
this in a fitting and legal manner on the battlefield." ]
http://english.people.com.cn/200303/29/eng20030329_114207.shtml


Guess I had a little to say too...

"Slip'er" > wrote in message

> Aviation is cause for a little more concern as even becoming distracted at
> a
> critical moment can lead to or contribute to an accident chain...but will
> not likely be the only cause. Sure, perhaps somebody with a military
> grade
> LASER can aim it at you, the light attracts you to look at it (natural
> response) and in the few milliseconds that you actually look at it, your
> eye
> balls melt and both you and your co-pilot are blind. Wasn't this also the
> topic of a Clancy novel and/or movie?
>
> I also heard a rumor that we tested a weapon like this once. A giant
> LASER
> with a mirror for high speed aiming powered by a huge diesel generator was
> driven out onto the battle field and blinded a bunch of the enemy in
> desert
> storm...so the story goes. But this source says they existed and were
> never
> used....

Visible light lasers wouldn't work since the targets can just close their
eyes or look away. UV would be more effective since it would fry retinas
before the victims could react. Also, UV lasers are available in extremely
high power ratings.

moo

"C J Campbell" > writes:

>"Corky Scott" > wrote:

>> Has anyone been following the disturbing (to me anyway) news stories
>> about airliners approaching to land being hit with laser beams aimed
>> at the cockpits?

>There are several possibilities:
[snip]

>5) Pilots, alert because of government warnings, are over-reacting to
>accidental contact with legitimate (but possibly careless) users of lasers,
>including folks who got new telescopes for Christmas.

An argument against the idea that it's a new telescope owner is that
the green laser pens are typically over $100 (vs. maybe $10-15 for
a typical red laser pointer). Also, the green pointers are mostly
used in amateur astronomy by someone knowledgable about the sky,
who (hopefully) has a bit of common sense. (Of course, this doesn't
in any way say that it isn't a newbie; there are people with lots
of money who think an Astro-Physics 8" refractor is just right as a
first telescope, just like people who do their student training in
a Baron because they think a Cessna 150 is for the hoi polloi...)

I do hope that this doesn't lead to DHS outlawing the green laser
pens. I use one in an astronomy program I run with the National Park
Service inside the District of Columbia (in Rock Creek park, under
the flight path that choppers follow to and from the VP's residence
on the Naval Observatory grounds). And yes, I *am* careful to avoid
pointing it anywhere near anyone overflying the area; the program's
been running for over 50 years and I would hate to have it shut down.

Joe Morris

"Joe Morris" > wrote in message
...
>
> I do hope that this doesn't lead to DHS outlawing the green laser
> pens. I use one in an astronomy program I run with the National Park
> Service inside the District of Columbia (in Rock Creek park, under
> the flight path that choppers follow to and from the VP's residence
> on the Naval Observatory grounds). And yes, I *am* careful to avoid
> pointing it anywhere near anyone overflying the area; the program's
> been running for over 50 years and I would hate to have it shut down.

I am sure most of us would hate that, too. You never know what the
Department of Homeland Fear will come up with next, though.

Joe Morris wrote:
>
> An argument against the idea that it's a new telescope owner is that
> the green laser pens are typically over $100 (vs. maybe $10-15 for
> a typical red laser pointer).

Another argument against this is the location of some of these incidents. You
aren't going to see much of the night sky anywhere close to Teterboro, for
example.

George Patterson
The desire for safety stands against every great and noble enterprise.

I think the whole subject and associated hysteria is ridiculous to the point
of being suspicious. Is somebody OTHER than terrorists trying to scare us?

I mean, if I was Joe Terrorist, I wouldn't dink around with lasers that cost
tens of thousands of dollars and really only **** pilots off. I'd use a
semiautomatic or automatic machine gun or three.

Wanna -really- scare Americans? Punch a few bullet holes in the nose or
wing of a jetliner that's landing or taking off. I know a couple of
locations that would be perfect, and escape without detection would be
trivial. (I ain't tellin', Osama!)

All the lasers would accomplish is distraction, which, it may turn out, is
EXACTLY what's happening.

-gatt
PP-ASEL-IA

On Tue, 4 Jan 2005 09:48:13 -0800, "gatt" >
wrote in >::

>Punch a few bullet holes in the nose or
>wing of a jetliner that's landing or taking off. I know a couple of
>locations that would be perfect, and escape without detection would be
>trivial.

These days, in the metropolitan areas there are microphones on every
traffic-controlled intersection that can be used to triangulate the
report of the weapon to determine its location. Lasers don't make a
sound.

"Larry Dighera" > wrote in message
> On Tue, 4 Jan 2005 09:48:13 -0800, "gatt" >
> wrote in >::
>
>>Punch a few bullet holes in the nose or
>>wing of a jetliner that's landing or taking off. I know a couple of
>>locations that would be perfect, and escape without detection would be
>>trivial.
>
> These days, in the metropolitan areas there are microphones on every
> traffic-controlled intersection that can be used to triangulate the
> report of the weapon to determine its location. Lasers don't make a
> sound.

Cite? Tens of thousands of microphones connected to a central processing
facility? A gunshot going off a mile away from a controlled intersection
won't be heard over the traffic noise in most cases. Not to mention jet
aircraft noise. Response time will be forever.

moo

> www.bovinesexclub.com

Dude. You've got to update your current events...

The "Kick Ass Karaoke" is, like, so over!

;-)
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

"gatt" > wrote

I know a couple of
> locations that would be perfect, and escape without detection would be
> trivial. (I ain't tellin', *****>
> -gatt

Congratulations. You have just won a file on yourself in the FBI's watch
list, with the previous post.
--
Jim in NC

"Nomen Nescio" ]> wrote in message
...
> -----BEGIN PGP SIGNED MESSAGE-----
>
> From: "Happy Dog" >
>
> >Cite? Tens of thousands of microphones connected to a central processing
> >facility? A gunshot going off a mile away from a controlled intersection
> >won't be heard over the traffic noise in most cases. Not to mention jet
> >aircraft noise. Response time will be forever.
>
> Fourier analysis?
> Admittedly, it would take some rather fast processors.

A system of this type is already in use in some places. It only needs a
few strategically placed mikes, though.
--
Jim in NC

A man has been arrested and charged for the recent laser beam being
aimed into a landing airplane's cockpit in New Jersey.

See:
http://www.nj.com/news/ledger/jersey/index.ssf?/base/news-8/1104906903307830.xml

After reading the article, a couple of things are of interest: The
laser is called a "Jasper Laser" and was bought from a company in
Oregon over the internet. The laser was described as cigar sized and
had a range of up to 25,000 feet.

Second, the man in my opinion seems immature. He initially blamed his
7 year old daughter for the incidents. After the initial incident in
which a landing Cessna Citation reported having the laser beamed into
their cockpit while approaching Teterboro at 3,000 feet, a police
helicopter was sent to the likely area to look around. The man, David
Banach, 38, beamed it too. Not a smart move.

The police helicopter responded by targeting the house with it's
floodlight, whereupon local police surrounded the house in large
numbers.

His lawyer denied that there was any willful misconduct, although it's
difficult for me to understand how else one might interpret his
actions. She also criticized the government for prosecuting her
client under the Patriot Act. Think about it for a moment though, who
in his or her right mind would intentionally beam something known to
cause temporary blindness at anyone, let alone the cockpit of a
landing airplane regardless the size?

US District Attorney Christopher J. Christie is quoted as saying:"We
have to send a clear message to the public that there is no harmless
mischief when it comes to airplanes, Mr. Banach's actions as alleged
in the criminal complaint put innocent lives at risk. That is illegal
and unacceptable." I agree with Mr. Christie.

The manufacturer of the laser pointer expressed regret that his
product had been used in such a manner.

Corky Scott

Larry Dighera wrote:

> On Tue, 4 Jan 2005 09:48:13 -0800, "gatt" >
> wrote in >::
>
>>Punch a few bullet holes in the nose or
>>wing of a jetliner that's landing or taking off. I know a couple of
>>locations that would be perfect, and escape without detection would be
>>trivial.
>
> These days, in the metropolitan areas there are microphones on every
> traffic-controlled intersection that can be used to triangulate the
> report of the weapon to determine its location. Lasers don't make a
> sound.

And now this from CNN:
http://tinyurl.com/497uv

Of course I'm glad they caught this guy but this part is troubling:

"Federal authorities Tuesday used the Patriot Act to charge a man with
pointing a laser beam at an airplane overhead and temporarily blinding the
pilot and co-pilot......

.....[he] admitted to federal agents that he pointed the light beam at a jet
and a helicopter over his home near Teterboro Airport last week.......

......According to the FBI, the Patriot Act does not describe helicopters as
``mass transportation vehicles.'' As for why Banach was not charged with
some other offense over the helicopter incident, Michael Drewniak, a
spokesman for the U.S. attorney's office, did not immediately return calls
for comment.....

.......But federal officials have said there is no evidence any the current
incidents represent a terrorist plot."


So they don't have anything else about interfering with air traffic besides
the "Patriot" Act?

And why would I believe anyone who claims the "Patriot" Act won't be abused,
just go ahead and renew it?

--
Frank....H

"Frank" > wrote in message ...
> Larry Dighera wrote:
>
> And now this from CNN:
> http://tinyurl.com/497uv
>
> Of course I'm glad they caught this guy but this part is troubling:
>
>
>
> So they don't have anything else about interfering with air traffic
besides
> the "Patriot" Act?

No. But they are going to throw the book at him and charge him with every
crime that he has violated. Are you suggesting that this dope should not be
prosecuted?

> Larry Dighera wrote:
>
>
> These days, in the metropolitan areas there are microphones on every
> traffic-controlled intersection that can be used to triangulate the
> report of the weapon to determine its location. Lasers don't make a
> sound.

Do have a cite for that "fact"?


--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

On Wed, 5 Jan 2005 09:55:15 -0700, "Matt Barrow" >
wrote in >::

>> Larry Dighera wrote:
>>
> >
> > These days, in the metropolitan areas there are microphones on every
>> traffic-controlled intersection that can be used to triangulate the
>> report of the weapon to determine its location. Lasers don't make a
>> sound.
>
>Do have a cite for that "fact"?

To which fact are you referring? If you're referring to the silent
operation of lasers, just click your laser pointer and listen.

If you are referring to the sonic location of gun shots in urban
locations, here's a clue:
http://www1.coe.neu.edu/~jferraro/guard/centerFrames/proposal_ver2_0.pdf

525 more clues here:
http://search.yahoo.com/search?_adv_prop=web&x=op&ei=UTF-8&prev_vm=p&fr=fp-top&va=microphone+%22gun+shot%22+location&va_vt=any&vp=&vp_vt=any&vo=&vo_vt=any&ve=&ve_vt=any&vd=all&vst=0&vs=&vf=all&vm=p&vc=&fl=0&n=10

It seems that he was simply stupid and thoughtless. It's doubtful that
he knew that it would "flood the cockpit" with light. People think
lasers will just show a tiny dot even at a great distance.

Previous to his arrest I was thinking that the FBI should put out a
warning that shining lasers into cockpits would result in being charged
with the intent to murder x people (x = however many souls are on
board). But now I'm just shaking my head at his immaturity. He didn't
have the intent to hurt anyone, he was just showing off, not knowing it
was a really bad idea. Something any kid would probably do as well.

"Larry Dighera" > wrote in message
...
> On Wed, 5 Jan 2005 09:55:15 -0700, "Matt Barrow" >
> wrote in >::
>
>>> Larry Dighera wrote:
>>>
>> >
>> > These days, in the metropolitan areas there are microphones on every
>>> traffic-controlled intersection that can be used to triangulate the
>>> report of the weapon to determine its location. Lasers don't make a
>>> sound.
>>
>>Do have a cite for that "fact"?
>
> To which fact are you referring? If you're referring to the silent
> operation of lasers, just click your laser pointer and listen.
>
> If you are referring to the sonic location of gun shots in urban
> locations, here's a clue:
> http://www1.coe.neu.edu/~jferraro/guard/centerFrames/proposal_ver2_0.pdf
>
> 525 more clues here:
> http://search.yahoo.com/search?_adv_prop=web&x=op&ei=UTF-8&prev_vm=p&fr=fp-top&va=microphone+%22gun+shot%22+location&va_vt=any&vp=&vp_vt=any&vo=&vo_vt=any&ve=&ve_vt=any&vd=all&vst=0&vs=&vf=all&vm=p&vc=&fl=0&n=10


The first link is hardly a cite for your statement "These days, in the
metropolitan areas there are microphones on every traffic-controlled
intersection that can be used to triangulate the report of the weapon to
determine its location." It is a proposal written in 2001 for such a system
but quotes a DOJ report that pretty much says it would only be useful for
statistical and planning purposes. (See Below)

As for the other 524 other links via that search #2 has not a damn thing to
do with gunshot location and #3 has to do with the JFK shooting. So i
stopped looking.

So the request is still out there. Do you have any cite for your theory that
there are microphones scattered over metro areas to triangulate gunshots?

3.2 Reviews/Criticism of Gun Shot Detection

There are many reviews that analyze the benefits and handicaps produced by a
gun shot

detection system. In a report issued by the U.S. Department of Justice, the
pros and cons

of gun shot detection were evaluated. The following points were presented
against gun

shot detection systems.[2]


The technology is likely to increase the workloads of police officers,

particularly if departments dispatch a patrol unit to every gunfire incident

detected by a technological system.


Gunshot detection systems are not likely to lead to more arrests of people

firing weapons in urban settings because it is highly unlikely that
offenders

will stay at a gunshot location long enough for the police to arrive.

To balance the negative results obtained from the experimenting with gun
shot detection,

the department credited that the systems would be beneficial for the
following reasons.


Gunshot detection systems are likely to reveal important statistics of
rather high

citizen under-reporting rates of random gunfire problems.


Gunshot detection systems seem to offer the most potential as a

problem-solving tool and would fit nicely within the emerging problem
oriented

policing paradigm. The technology can help police identify random gunfire
hot spots and

develop strategies to address the problem.

C J Campbell wrote:

>
> "Frank" > wrote in message ...
>> Larry Dighera wrote:
>>
>> And now this from CNN:
>> http://tinyurl.com/497uv
>>
>> Of course I'm glad they caught this guy but this part is troubling:
>>
>>
>>
>> So they don't have anything else about interfering with air traffic
> besides
>> the "Patriot" Act?
>
> No. But they are going to throw the book at him and charge him with every
> crime that he has violated. Are you suggesting that this dope should not
> be prosecuted?

Not at all. Wherever did you get that impression? Since they didn't
(couldn't?) charge him for the helicopter incident I'm left with the
impression that the only thing they had was the "Patriot" act. Seems like
interfering with airplanes, trains, buses, freeways etc would be covered
under laws that precede Sept. 11.

And I do find it troubling that in one breath they say there is no evidence
of terrorist activity and in the next they, in effect, charge him with that
very thing. Considering all the rhetoric attempting to allay fears about
potential abuses of power inherent in the "Patriot" act this doesn't do
much for their credibility.


--
Frank....H

Frank wrote:
>
> And I do find it troubling that in one breath they say there is no evidence
> of terrorist activity and in the next they, in effect, charge him with that
> very thing. Considering all the rhetoric attempting to allay fears about
> potential abuses of power inherent in the "Patriot" act this doesn't do
> much for their credibility.

Normal procedure in criminal cases is to charge the suspect with any and all
statutes they can think of, whether they apply or not. After consideration by
the prosecuting attorneys, inapplicable charges are typically dropped, but some
may be pressed just to give the DA bargaining power. Credibility usually doesn't
enter into the picture - it's simply not important until the case gets before a
jury.

Based on the statements made so far, they can certainly bring charges of
assault, including assaulting a police officer in the performance of his duty.
That wouldn't get them the publicity they want, and they probably feel that the
penalties for that are too light to serve as a deterrent to others.

George Patterson
The desire for safety stands against every great and noble enterprise.

On Wed, 5 Jan 2005 12:05:22 -0600, "Gig Giacona"
> wrote in
>::

>
>So the request is still out there. Do you have any cite for your theory that
>there are microphones scattered over metro areas to triangulate gunshots?
>

http://student-voices.org/news/index.php3?NewsID=10195
April 7, 2004
Police cams to add gunshot detectors

by Fran Spielman, City Hall Reporter
Chicago Sun-Times

Chicago - Big Brother isn't just watching the bad guys in Chicago. By
late summer, he'll be listening as well -- for the sound of gunshots.

Gunshot detection technology -- capable of "triangulating within 20
feet" the location of a shooting -- is being added to 30 surveillance
cameras already in place on high-crime corners and to 50 new cameras
expected to be installed by late summer at undisclosed locations.
....

-----------------------------------------

http://www.usc.edu/uscnews/stories/10810.html
11/30/04
Waiting for the Gun
A USC engineer uses his expertise with nerve cells to create a
surveillance system that can recognize the sound of a nearby gunshot -
and identify the shooter. In a unique pilot program, L.A. and Chicago
will deploy test units in high-crime areas.

-----------------------------------------

http://www.nlectc.org/techbeat/winter2001/EarshotWinter01.pdf
Until recently, the Los Angeles Sheriff’s Department
(LASD) had no idea how many incidents of actual
gunfire occurred near its Century Station, one of the highest
crime areas in Los Angeles County. Some were random
shots fired into the air; others were drive-by shootings.
Some were nothing more than firecrackers or backfiring
cars. Either way, the majority went unreported.
But a new technology may make this lack of reporting a
thing of the past. Although still in the experimental phase,
gunshot detection technologies are showing promise as a
new way to detect and pinpoint the location of gunfire.
Based on acoustic sensing technology, these location
systems consist of sensors or microphones that detect
the sound of gunfire, transmitters that send a “location
message” to the dispatch center, and a computer that
receives and displays the message. When the message
arrives at the police station, the dispatcher can have a
patrol unit respond to the call.
LASD installed a trial system just days before the millennium
New Year’s Eve. The department inundated citizens
with information, staging a press conference to brief
everyone from the local weekly newspapers to the major
television networks, national news agencies, and even
the foreign media. Department officials made it clear that
if a citizen fired a weapon, the system would detect it,
and deputies would not hesitate to arrest the shooter. On
December 31, 1999, in a brief 3-hour period, the Century
Station system detected 1,100 incidents of gunfire. ...

------------------------------------------------

http://www.ncjrs.org/txtfiles1/nij/179274.txt
Discussed in this Brief: The findings of two field studies of acoustic
sensing systems designed to detect the sound of a muzzle blast from a
gun and, within seconds of the shot being fired, triangulate within
some margin of error the location from which the shot was fired,
before alerting the police about the gunshot. The research team
examined the effectiveness of Trilon Technology's ShotSpotter
[trademark) system, which the local police department has operated in
Redwood City, California, since early 1996, and the Alliant
Techsystems Inc.'s SECURES [trademark] system, which police instlled
for 2 months in a neighborhood with high levels of random gunfire in
Dallas, Texas, in 1996. ...

-----------------------------------------------

More:
http://www.shotspotter.com/inthenews.shtml
http://viterbi.usc.edu/news/news/2004/2004_11_22_gunshot.htm
http://www.maximumpda.com/comments.php?id=311_0_1_0_C

On Wed, 05 Jan 2005 09:11:02 -0500, Corky Scott wrote:

>US District Attorney Christopher J. Christie is quoted as saying:"We
>have to send a clear message to the public that there is no harmless
>mischief when it comes to airplanes, Mr. Banach's actions as alleged
>in the criminal complaint put innocent lives at risk. That is illegal
>and unacceptable." I agree with Mr. Christie.

yeah. sending out a message. like the one who was sentences to 55 years in
prison for dealing Marijuhana. yeah. sure.

>The manufacturer of the laser pointer expressed regret that his
>product had been used in such a manner.

in times like these, and for the security of the Homeland, the manufacturer
should stop the production of the laser immediately and offer huge payments
to everybody involved.

#m

--
Oh. God. What have we done.

"Martin Hotze" > wrote in message
...
> On Wed, 05 Jan 2005 09:11:02 -0500, Corky Scott wrote:
>
> >US District Attorney Christopher J. Christie is quoted as saying:"We
> >have to send a clear message to the public that there is no harmless
> >mischief when it comes to airplanes, Mr. Banach's actions as alleged
> >in the criminal complaint put innocent lives at risk. That is illegal
> >and unacceptable." I agree with Mr. Christie.
>
> yeah. sending out a message. like the one who was sentences to 55 years in
> prison for dealing Marijuhana. yeah. sure.
>
> >The manufacturer of the laser pointer expressed regret that his
> >product had been used in such a manner.
>
> in times like these, and for the security of the Homeland, the
manufacturer
> should stop the production of the laser immediately and offer huge
payments
> to everybody involved.

I suppose the same goes for automobile and truck manufacturers throughout
the world. Sheesh.

>
> #m
>
> --
> Oh. God. What have we done.

"Larry Dighera" > wrote
> On Wed, 5 Jan 2005 09:55:15 -0700, "Matt Barrow"

>> > Lasers don't make a
>>> sound.
>>
>>Do have a cite for that "fact"?
>
> To which fact are you referring?

This:

"These days, in the metropolitan areas there are microphones on every
traffic-controlled intersection that can be used to triangulate the
report of the weapon to determine its location."

> If you are referring to the sonic location of gun shots in urban
> locations, here's a clue:
> http://www1.coe.neu.edu/~jferraro/guard/centerFrames/proposal_ver2_0.pdf

Nope.
>
> 525 more clues here:
> http://search.yahoo.com/search?_adv_prop=web&x=op&ei=UTF-8&prev_vm=p&fr=fp-top&va=microphone+%22gun+shot%22+location&va_vt=any&vp=&vp_vt=any&vo=&vo_vt=any&ve=&ve_vt=any&vd=all&vst=0&vs=&vf=all&vm=p&vc=&fl=0&n=10

Nope.

moo

Sorry for the top post. But I think you might want to revise your initial
claim. The point the original poster made was that it would be easy to
shoot at planes and remain undetected. Your claim of a system to foil such
attempts existing at every major controlled intersection isn't true. And,
even if it did exist, somebody shooting at planes from a field near an
airport (gee, are there many of these?) is not going to be threatened by
such a system.

moo


"Larry Dighera" > wrote in message
...
> On Wed, 5 Jan 2005 12:05:22 -0600, "Gig Giacona"
> > wrote in
> >::
>
>>
>>So the request is still out there. Do you have any cite for your theory
>>that
>>there are microphones scattered over metro areas to triangulate gunshots?
>>
>
> http://student-voices.org/news/index.php3?NewsID=10195
> April 7, 2004
> Police cams to add gunshot detectors
>
> by Fran Spielman, City Hall Reporter
> Chicago Sun-Times
>
> Chicago - Big Brother isn't just watching the bad guys in Chicago. By
> late summer, he'll be listening as well -- for the sound of gunshots.
>
> Gunshot detection technology -- capable of "triangulating within 20
> feet" the location of a shooting -- is being added to 30 surveillance
> cameras already in place on high-crime corners and to 50 new cameras
> expected to be installed by late summer at undisclosed locations.
> ...
>
> -----------------------------------------
>
> http://www.usc.edu/uscnews/stories/10810.html
> 11/30/04
> Waiting for the Gun
> A USC engineer uses his expertise with nerve cells to create a
> surveillance system that can recognize the sound of a nearby gunshot -
> and identify the shooter. In a unique pilot program, L.A. and Chicago
> will deploy test units in high-crime areas.
>
> -----------------------------------------
>
> http://www.nlectc.org/techbeat/winter2001/EarshotWinter01.pdf
> Until recently, the Los Angeles Sheriff's Department
> (LASD) had no idea how many incidents of actual
> gunfire occurred near its Century Station, one of the highest
> crime areas in Los Angeles County. Some were random
> shots fired into the air; others were drive-by shootings.
> Some were nothing more than firecrackers or backfiring
> cars. Either way, the majority went unreported.
> But a new technology may make this lack of reporting a
> thing of the past. Although still in the experimental phase,
> gunshot detection technologies are showing promise as a
> new way to detect and pinpoint the location of gunfire.
> Based on acoustic sensing technology, these location
> systems consist of sensors or microphones that detect
> the sound of gunfire, transmitters that send a "location
> message" to the dispatch center, and a computer that
> receives and displays the message. When the message
> arrives at the police station, the dispatcher can have a
> patrol unit respond to the call.
> LASD installed a trial system just days before the millennium
> New Year's Eve. The department inundated citizens
> with information, staging a press conference to brief
> everyone from the local weekly newspapers to the major
> television networks, national news agencies, and even
> the foreign media. Department officials made it clear that
> if a citizen fired a weapon, the system would detect it,
> and deputies would not hesitate to arrest the shooter. On
> December 31, 1999, in a brief 3-hour period, the Century
> Station system detected 1,100 incidents of gunfire. ...
>
> ------------------------------------------------
>
> http://www.ncjrs.org/txtfiles1/nij/179274.txt
> Discussed in this Brief: The findings of two field studies of acoustic
> sensing systems designed to detect the sound of a muzzle blast from a
> gun and, within seconds of the shot being fired, triangulate within
> some margin of error the location from which the shot was fired,
> before alerting the police about the gunshot. The research team
> examined the effectiveness of Trilon Technology's ShotSpotter
> [trademark) system, which the local police department has operated in
> Redwood City, California, since early 1996, and the Alliant
> Techsystems Inc.'s SECURES [trademark] system, which police instlled
> for 2 months in a neighborhood with high levels of random gunfire in
> Dallas, Texas, in 1996. ...
>
> -----------------------------------------------
>
> More:
> http://www.shotspotter.com/inthenews.shtml
> http://viterbi.usc.edu/news/news/2004/2004_11_22_gunshot.htm
> http://www.maximumpda.com/comments.php?id=311_0_1_0_C

"Corky Scott" >
>A man has been arrested and charged for the recent laser beam being
> aimed into a landing airplane's cockpit in New Jersey.
>
> See:
> http://www.nj.com/news/ledger/jersey/index.ssf?/base/news-8/1104906903307830.xml
>
> After reading the article, a couple of things are of interest: The
> laser is called a "Jasper Laser" and was bought from a company in
> Oregon over the internet. The laser was described as cigar sized and
> had a range of up to 25,000 feet.

I dunno about that. This guy was a few miles from the plane. The light may
have been distracting but I really doubt it temporarily blinded the pilots.
Really doubt it. It's a weird colour of green though. Reminds me of the
tube used in old photocopiers. I remember people warning me about leaving
the cover open to copy a book. Like it was some kind of death ray. So
maybe they were spooked. It's a L A S E R, after all. Gotta be very
dangerous... At three miles, you could see the light from this thing. But,
unless it could be held steady, which it can't, it wouldn't represent a
threat. It's going to be *way* less bright than a hit from the popular 4K
Xenon publicity searchlights. Sounds like hype. (Like the pilot who claims
to have permanent retina damage from a laser show system.)

le moo

And these are your cites for to back up the statement that there are systems
in place in all metro areas to triangulate gunshots? THey are, on the other
hand, pretty damn good cites to prove you were wrong since they all are
talking about a pilot program taking place in a few high crime locations in
a couple of cities.



"Larry Dighera" > wrote in message
...
> On Wed, 5 Jan 2005 12:05:22 -0600, "Gig Giacona"
> > wrote in
> >::
>
>>
>>So the request is still out there. Do you have any cite for your theory
>>that
>>there are microphones scattered over metro areas to triangulate gunshots?
>>
>
> http://student-voices.org/news/index.php3?NewsID=10195
> April 7, 2004
> Police cams to add gunshot detectors
>
> by Fran Spielman, City Hall Reporter
> Chicago Sun-Times
>
> Chicago - Big Brother isn't just watching the bad guys in Chicago. By
> late summer, he'll be listening as well -- for the sound of gunshots.
>
> Gunshot detection technology -- capable of "triangulating within 20
> feet" the location of a shooting -- is being added to 30 surveillance
> cameras already in place on high-crime corners and to 50 new cameras
> expected to be installed by late summer at undisclosed locations.
> ...
>
> -----------------------------------------
>
> http://www.usc.edu/uscnews/stories/10810.html
> 11/30/04
> Waiting for the Gun
> A USC engineer uses his expertise with nerve cells to create a
> surveillance system that can recognize the sound of a nearby gunshot -
> and identify the shooter. In a unique pilot program, L.A. and Chicago
> will deploy test units in high-crime areas.
>
> -----------------------------------------
>
> http://www.nlectc.org/techbeat/winter2001/EarshotWinter01.pdf
> Until recently, the Los Angeles Sheriff's Department
> (LASD) had no idea how many incidents of actual
> gunfire occurred near its Century Station, one of the highest
> crime areas in Los Angeles County. Some were random
> shots fired into the air; others were drive-by shootings.
> Some were nothing more than firecrackers or backfiring
> cars. Either way, the majority went unreported.
> But a new technology may make this lack of reporting a
> thing of the past. Although still in the experimental phase,
> gunshot detection technologies are showing promise as a
> new way to detect and pinpoint the location of gunfire.
> Based on acoustic sensing technology, these location
> systems consist of sensors or microphones that detect
> the sound of gunfire, transmitters that send a "location
> message" to the dispatch center, and a computer that
> receives and displays the message. When the message
> arrives at the police station, the dispatcher can have a
> patrol unit respond to the call.
> LASD installed a trial system just days before the millennium
> New Year's Eve. The department inundated citizens
> with information, staging a press conference to brief
> everyone from the local weekly newspapers to the major
> television networks, national news agencies, and even
> the foreign media. Department officials made it clear that
> if a citizen fired a weapon, the system would detect it,
> and deputies would not hesitate to arrest the shooter. On
> December 31, 1999, in a brief 3-hour period, the Century
> Station system detected 1,100 incidents of gunfire. ...
>
> ------------------------------------------------
>
> http://www.ncjrs.org/txtfiles1/nij/179274.txt
> Discussed in this Brief: The findings of two field studies of acoustic
> sensing systems designed to detect the sound of a muzzle blast from a
> gun and, within seconds of the shot being fired, triangulate within
> some margin of error the location from which the shot was fired,
> before alerting the police about the gunshot. The research team
> examined the effectiveness of Trilon Technology's ShotSpotter
> [trademark) system, which the local police department has operated in
> Redwood City, California, since early 1996, and the Alliant
> Techsystems Inc.'s SECURES [trademark] system, which police instlled
> for 2 months in a neighborhood with high levels of random gunfire in
> Dallas, Texas, in 1996. ...
>
> -----------------------------------------------
>
> More:
> http://www.shotspotter.com/inthenews.shtml
> http://viterbi.usc.edu/news/news/2004/2004_11_22_gunshot.htm
> http://www.maximumpda.com/comments.php?id=311_0_1_0_C

In article om>, > wrote:

> It seems that he was simply stupid and thoughtless. It's doubtful that
> he knew that it would "flood the cockpit" with light. People think
> lasers will just show a tiny dot even at a great distance.
>
> Previous to his arrest I was thinking that the FBI should put out a
> warning that shining lasers into cockpits would result in being charged
> with the intent to murder x people (x = however many souls are on
> board). But now I'm just shaking my head at his immaturity. He didn't
> have the intent to hurt anyone, he was just showing off, not knowing it
> was a really bad idea. Something any kid would probably do as well.

I don't believe it "flooded" anything with light. It's 5 mW. That's
0.005 Watt. So it will "flood" your cockpit with a lot less light than
your LED headlight. Which is not to mention the difficulty of hitting
a moving target from thousands of feet away with a hand-held pointer.
Any "flooding" would be very brief. The major problem would be
distraction, and if we're going after everyone distracting someone
operating a vehicle, I think we should lock up the people responsible
for those obnoxious animated roadside signs. Now *there's* an
anti-terrorism action I could endorse without reservation.

I think this is the typical incredible overreaction because "we have to
look like we're protecting the public." You might as well arrest some kids
that were throwing rocks in the river because an ocean liner might go
past.

Note that there's no way to tell whether this guy was involved in the
Citation incident, by the way. But "flooding the cockpit with light"
from a slant range of over a mile away seems like it would require
something with a much higher output. Maybe there's someone out
there with an industrial laser (or more likely, a spotlight).

Mike Beede

I've seen pictures of Humvees with lasers mounted on top- seems the idea was
to use them to detonate unexploded ordnance (by heating it up) at a distance
and that sort of thing. Since UXO doesn't move it wasn't a big deal if it
needed a few seconds to reach critical temperature.

I also saw somewhere that there was some design work done to mount a
tactical laser weapon in a turret on the Joint Strike Fighter. The big issue
was what to do with the excess heat. Seems the types of lasers they were
looking at were about 10% efficient, so for every 1,000 watts of light
output, you'd have 9,000 watts of heat. Given the size lasers they were
talking about, they needed a way to pull that heat off or the laser would
melt itself. So of course the engineers thought to use the airplane's fuel
supply as a heat sink. I sure would have loved to been in the room when they
suggested that to the test pilots. "Sure, we'll just cool the 100,000 watt
laser by pouring jet fuel all over it."

-cwk.

"Happy Dog" > wrote in message
. ..
> "Slip'er" > wrote in message
>
> >
> > I also heard a rumor that we tested a weapon like this once. A giant
> > LASER
> > with a mirror for high speed aiming powered by a huge diesel generator
was
> > driven out onto the battle field and blinded a bunch of the enemy in
> > desert
> > storm...so the story goes. But this source says they existed and were
> > never
> > used....
>
> Visible light lasers wouldn't work since the targets can just close their
> eyes or look away. UV would be more effective since it would fry retinas
> before the victims could react. Also, UV lasers are available in
extremely
> high power ratings.
>
> moo
>
>

> That's
> 0.005 Watt. So it will "flood" your cockpit with a lot less light than
> your LED headlight.

This may be true but a laser straight out of the box is pretty
focused, and put a simple lens in front of it and you can keep the
beam even tighter. There may not be that many photons involved, but
they are all coming from the same direction, and that does count for
something. (somebody posted about a five digree divergence, the
lasers I've seen are all much tighter than that.)

I don't know whether it counts for the alleged problems, but there is
a nontrivial difference betweem laser light and the diode in your
headband.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
wrote in >::

>There may not be that many photons involved, but
>they are all coming from the same direction, and that does count for
>something.

If I'm not mistaken, coherent laser light is all in phase. Doesn't
that cause it to have more energy?

"Jose" > wrote in message

>> 0.005 Watt. So it will "flood" your cockpit with a lot less light than
>> your LED headlight.
>
> This may be true but a laser straight out of the box is pretty focused,
> and put a simple lens in front of it and you can keep the beam even
> tighter.

Not really. You can use a beam telescope to help a bit. But the problem is
more one of diffusion by the atmosphere than divergence.

> There may not be that many photons involved, but they are all coming from
> the same direction, and that does count for something.

I assume you mean directed at the same point. In this case, light is acting
like a bunch of particles. It would be the same from a flashlight though.

> (somebody posted about a five digree divergence, the lasers I've seen are
> all much tighter than that.)

Much. <1 millirad
>

moo

"Larry Dighera" > wrote in message
...
> On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
> wrote in >::
>
>>There may not be that many photons involved, but
>>they are all coming from the same direction, and that does count for
>>something.
>
> If I'm not mistaken, coherent laser light is all in phase. Doesn't
> that cause it to have more energy?

No. The energy is measured in watts like any other kind of power source.
In the case of a laser, it's all concentrated into narrow part(s) of the EM
spectrum. An incandescent lamp, for example, creates more IR than visible
light.

moo

"Colin W Kingsbury" > wrote

> I've seen pictures of Humvees with lasers mounted on top- seems the idea
> was
> to use them to detonate unexploded ordnance (by heating it up) at a
> distance
> and that sort of thing. Since UXO doesn't move it wasn't a big deal if it
> needed a few seconds to reach critical temperature.
>
> I also saw somewhere that there was some design work done to mount a
> tactical laser weapon in a turret on the Joint Strike Fighter. The big
> issue
> was what to do with the excess heat. Seems the types of lasers they were
> looking at were about 10% efficient, so for every 1,000 watts of light
> output, you'd have 9,000 watts of heat. Given the size lasers they were
> talking about, they needed a way to pull that heat off or the laser would
> melt itself. So of course the engineers thought to use the airplane's fuel
> supply as a heat sink. I sure would have loved to been in the room when
> they
> suggested that to the test pilots. "Sure, we'll just cool the 100,000 watt
> laser by pouring jet fuel all over it."

A 1 Kw laser is tremendously powerful. 10% efficency is pretty good. 9 Kw
of heat to sink is no big deal. Several times that would be feasible since
it's only used for very short periods of time. Not sure what it would be
good for though.

moo



>
> -cwk.
>
> "Happy Dog" > wrote in message
> . ..
>> "Slip'er" > wrote in message
>>
>> >
>> > I also heard a rumor that we tested a weapon like this once. A giant
>> > LASER
>> > with a mirror for high speed aiming powered by a huge diesel generator
> was
>> > driven out onto the battle field and blinded a bunch of the enemy in
>> > desert
>> > storm...so the story goes. But this source says they existed and were
>> > never
>> > used....
>>
>> Visible light lasers wouldn't work since the targets can just close their
>> eyes or look away. UV would be more effective since it would fry retinas
>> before the victims could react. Also, UV lasers are available in
> extremely
>> high power ratings.
>>
>> moo
>>
>>
>
>

"Happy Dog" > wrote in message
...
> I dunno about that. This guy was a few miles from the plane. The light
may
> have been distracting but I really doubt it temporarily blinded the
pilots.
> Really doubt it. It's a weird colour of green though. Reminds me of the
> tube used in old photocopiers. I remember people warning me about leaving
> the cover open to copy a book. Like it was some kind of death ray. So
> maybe they were spooked. It's a L A S E R, after all. Gotta be very
> dangerous...

It didn't bother us when many of us photocopied our faces...or more
importantly, our buttocks.


Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

> "Larry Dighera" > wrote in message
> ...
> > On Wed, 5 Jan 2005 12:05:22 -0600, "Gig Giacona"
> > > wrote in
> > >::
> >
> >>
> >>So the request is still out there. Do you have any cite for your theory
> >>that
> >>there are microphones scattered over metro areas to triangulate
gunshots?
> >>
> >
> > http://student-voices.org/news/index.php3?NewsID=10195
> > April 7, 2004
> > Police cams to add gunshot detectors
> >
> > by Fran Spielman, City Hall Reporter
> > Chicago Sun-Times
> >
> > Chicago - Big Brother isn't just watching the bad guys in Chicago. By
> > late summer, he'll be listening as well -- for the sound of gunshots.
> >
> > Gunshot detection technology -- capable of "triangulating within 20
> > feet" the location of a shooting -- is being added to 30 surveillance
> > cameras already in place on high-crime corners and to 50 new cameras
> > expected to be installed by late summer at undisclosed locations.

WOW!!! 30 camera in the city of Chicago is "microphones scattered over metro
areas".

Larry is a salesman's delight!!
--
Matt
---------------------
Matthew W. Barrow
Site-Fill Homes, LLC.
Montrose, CO

>>There may not be that many photons involved, but they are all coming from
>> the same direction, and that does count for something.
>
> I assume you mean directed at the same point. In this case, light is acting
> like a bunch of particles. It would be the same from a flashlight though.

Yes, I meant directed at the same point. With a flashlight the
photons are sprayed all over the place.

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

On Wed, 5 Jan 2005 16:19:06 -0600, "Gig Giacona"
> wrote in
>::

>And these are your cites for to back up the statement that there are systems
>in place in all metro areas to triangulate gunshots?

Here's what I said:

"These days, in the metropolitan areas there are microphones on
every traffic-controlled intersection that can be used to
triangulate the report of the weapon to determine its location."

I didn't say "all metro areas." You inferred that.

My use of the absolute 'every' should have given you a clue, that
there was some hyperbole here.

In English the modifying adjective precedes the noun it modifies
(unlike some other languages). I made no reference to 'all' nor
'every' metro area. The absolute (every) that I used referred to
'intersections'.

But it's obvious you're not concerned that these systems are now in
place around the nation. Your's just looking to make me wrong, or
else you would have addressed the issue of "Big Brother" eavesdropping
on the urban proletariat instead of pressing your point.

>THey are, on the other
>hand, pretty damn good cites to prove you were wrong since they all are
>talking about a pilot program taking place in a few high crime locations in
>a couple of cities.

A 'couple' is usually two. I count more than a couple: Chicago, Los
Angeles, Dallas, San Diego, Redwood City ...

If you had bothered to look here
http://www.shotspotter.com/customers.shtml , you'd have known that one
ShotSpotter has systems currently operating in:

Redwood City, CA
Willowbrook, CA
City of Industry, CA
Glendale, AZ
Charleston, NC

There's more information here:
http://www.safetydynamics.net/recent_press.htm
http://www.informationweek.com/showArticle.jhtml?articleID=6500206

Although this technology may aid law enforcement, I find it a bit too
Orwellian for my taste.

Welcome to the 21st century. :-(

On Wed, 5 Jan 2005 23:30:57 -0500, "Happy Dog" >
wrote in >::

>"Larry Dighera" > wrote in message
...
>> On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
>> wrote in >::
>>
>>>There may not be that many photons involved, but
>>>they are all coming from the same direction, and that does count for
>>>something.
>>
>> If I'm not mistaken, coherent laser light is all in phase. Doesn't
>> that cause it to have more energy?
>
>No. The energy is measured in watts like any other kind of power source.

I was referring to the phenomenon of light coherence. There's an
explanation of it here:
http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.html

And my point was that because the light of a laser is coherent (in
phase), it will provide more energy than an equally bright light
source whose radiation is out of phase. At least this is what I was
told by an EE.

In article >, Jose > wrote:

> I don't know whether it counts for the alleged problems, but there is
> a nontrivial difference betweem laser light and the diode in your
> headband.

Yes, the nontrivial differences are that my headband is around a thousand
times closer and puts out a hundred times as much energy.
We're not talking about a precision instrument here. How big a circle would
be illuminated at 5000 feet? If it spreads even 0.01 degree it's over a foot
in diameter. 5 mW spread over a couple square feet? I'm extremely
skeptical of this. Extremely.

Mike Beede

> Yes, the nontrivial differences are that my headband is around a thousand
> times closer and puts out a hundred times as much energy.
> We're not talking about a precision instrument here. How big a circle would
> be illuminated at 5000 feet? If it spreads even 0.01 degree it's over a foot
> in diameter. 5 mW spread over a couple square feet?

The energy of your diode in the cabin is spread out quickly. (and I
don't know whether the laser in question is 5 mW)

Take an ordinary pocket laser ("cat toy") and aim it at the ground on
a sunny day and you will =still= see the spot. Place it far enough
away so the spot is faint, and focus it with a magnifying glass and it
will be as bright as ever. To do this, the brighness of the light is
rivaling that of the sun (at that point), and winning.

That's bright. You can't cook with it partly because it's all one
wavelength and partly because it only hits one spot. But without
trying an experiment on my eyeballs, I can see how it could
temporarily blind you and may even cause permanent damage (especially
as your pupils probably won't contract).

Jose
--
Money: What you need when you run out of brains.
for Email, make the obvious change in the address.

On Wed, 05 Jan 2005 20:31:28 GMT, Martin Hotze >
wrote:

>>US District Attorney Christopher J. Christie is quoted as saying:"We
>>have to send a clear message to the public that there is no harmless
>>mischief when it comes to airplanes, Mr. Banach's actions as alleged
>>in the criminal complaint put innocent lives at risk. That is illegal
>>and unacceptable." I agree with Mr. Christie.
>
>yeah. sending out a message. like the one who was sentences to 55 years in
>prison for dealing Marijuhana. yeah. sure.

I disagree with your comparison Martin. It's not the same thing.
While I agree that the sentence of 55 year in prison for dealing
Marijuana is wildly excessive for so relatively harmless a drug, it's
very hard to compare that to this case. The marijuana guy was selling
to people who wanted it. No one got inadvertantly high on it while
landing an airplane.

Sure Banach was a really dumb idiot for doing what he did. Does that
excuse him from punishment?

Corky Scott

Larry Dighera wrote:
>
> If I'm not mistaken, coherent laser light is all in phase. Doesn't
> that cause it to have more energy?

No, but it will deliver more energy in the visible spectrum, and it can be tuned
to deliver most of its energy in a very narrow band, which a typical
incandescent light source cannot.

George Patterson
The desire for safety stands against every great and noble enterprise.

On Thu, 06 Jan 2005 12:28:32 -0500, Corky Scott wrote:

>I disagree with your comparison Martin. It's not the same thing.
>While I agree that the sentence of 55 year in prison for dealing
>Marijuana is wildly excessive for so relatively harmless a drug, it's
>very hard to compare that to this case. The marijuana guy was selling
>to people who wanted it. No one got inadvertantly high on it while
>landing an airplane.
>
>Sure Banach was a really dumb idiot for doing what he did. Does that
>excuse him from punishment?

it depends. a punishment might be on order. but making a point by making an
example .. this seems that they will use the PATRIOT Act etc ...

#m
--
Oh. God. What have we done.

On Thu, 06 Jan 2005 17:32:43 GMT, "G.R. Patterson III"
> wrote in >::

>Larry Dighera wrote:
>>
>> If I'm not mistaken, coherent laser light is all in phase. Doesn't
>> that cause it to have more energy?
>
>No, but it will deliver more energy in the visible spectrum, and it can be tuned
>to deliver most of its energy in a very narrow band, which a typical
>incandescent light source cannot.

I'm way out of my depth on this subject, but this is the way I
understand the physics of coherent light verses light that is not
coherent.

Because the photons of coherent light arrive at the target at the same
time, they "pound" harder against the surface upon which they impinge
than they would if they arrived at varying times. I imagine the
physics to be similar to sonic resonance. So perhaps the photons
don't have more energy, but they have a greater effect than light that
is not coherent.



[sci.physics,sci.physics.electromag added]

"Larry Dighera" > wrote in

>>No. The energy is measured in watts like any other kind of power source.
>
> I was referring to the phenomenon of light coherence. There's an
> explanation of it here:
> http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.html
>
> And my point was that because the light of a laser is coherent (in
> phase), it will provide more energy than an equally bright light
> source whose radiation is out of phase.

No.

moo

"Corky Scott" >
> On Wed, 05 Jan 2005 20:31:28 GMT, Martin Hotze >
> wrote:
>
>>>
Mr. Banach's actions as alleged
>>>in the criminal complaint put innocent lives at risk. That is illegal
>>>and unacceptable." I agree with Mr. Christie.
>>
>>yeah. sending out a message. like the one who was sentences to 55 years in
>>prison for dealing Marijuhana. yeah. sure.
>
> I disagree with your comparison Martin. It's not the same thing.
> While I agree that the sentence of 55 year in prison for dealing
> Marijuana is wildly excessive for so relatively harmless a drug, it's
> very hard to compare that to this case. The marijuana guy was selling
> to people who wanted it. No one got inadvertantly high on it while
> landing an airplane.
>
> Sure Banach was a really dumb idiot for doing what he did. Does that
> excuse him from punishment?

How much punishment? What was his intent. How bright is this thing at that
distance? I'll bet that if he was shining a followspot at aircraft there
would be nowhere near the same consequences. And a common theatrical
followspot is brighter.

moo

"Larry Dighera" > wrote in message
> > wrote in:
>
>>And these are your cites for to back up the statement that there are
>>systems
>>in place in all metro areas to triangulate gunshots?
>
> Here's what I said:

Give it up. Your claim was that the technology you misrepresented (if only
a bit) would be a deterrent to, or a means of apprehending, people shooting
at planes. With very rare exception, like nearly zero, it isn't.

moo

"Larry Dighera" > wrote in message
...
> On Thu, 06 Jan 2005 17:32:43 GMT, "G.R. Patterson III"
> > wrote in >::
>
> >Larry Dighera wrote:
> >>
> >> If I'm not mistaken, coherent laser light is all in phase.
Doesn't
> >> that cause it to have more energy?
> >
> >No, but it will deliver more energy in the visible spectrum, and it
can be tuned
> >to deliver most of its energy in a very narrow band, which a
typical
> >incandescent light source cannot.
>
> I'm way out of my depth on this subject, but this is the way I
> understand the physics of coherent light verses light that is not
> coherent.
>
> Because the photons of coherent light arrive at the target at the
same
> time, they "pound" harder against the surface upon which they
impinge
> than they would if they arrived at varying times. I imagine the
> physics to be similar to sonic resonance. So perhaps the photons
> don't have more energy, but they have a greater effect than light
that
> is not coherent.

I am afraid your concept of what constitutes a coherent source of
light is completely wrong. Why don't you read up something on the
topic?
In the meantime, it might be better if you restricted your interests
to aviation.

Franz
>
>
>
> [sci.physics,sci.physics.electromag added]

"Franz Heymann" >
> "Larry Dighera" > wrote in message

>> Because the photons of coherent light arrive at the target at the
> same
>> time, they "pound" harder against the surface upon which they
> impinge
>> than they would if they arrived at varying times. I imagine the
>> physics to be similar to sonic resonance. So perhaps the photons
>> don't have more energy, but they have a greater effect than light
> that is not coherent.
>
> I am afraid your concept of what constitutes a coherent source of
> light is completely wrong. Why don't you read up something on the
> topic?

This guys misunderstanding of basic physics aside, the topic was,
originally, the effect on pilots of exposure to visible light lasers. It's
sort of on-topic for Sci.physics. I have many years of experience scanning
people with visible light lasers (Laser Shows) and it's my opinion that the
claims are hype. Claims of retina damage are almost certainly complete
crap. The current news involves a guy with a 5Mw hand held YAG shining it
at a small jet and a police helicopter.

le moo

"Happy Dog" > wrote in message
...
> "Franz Heymann" >
> > "Larry Dighera" > wrote in message
>
> >> Because the photons of coherent light arrive at the target at the
> > same
> >> time, they "pound" harder against the surface upon which they
> > impinge
> >> than they would if they arrived at varying times. I imagine the
> >> physics to be similar to sonic resonance. So perhaps the photons
> >> don't have more energy, but they have a greater effect than light
> > that is not coherent.
> >
> > I am afraid your concept of what constitutes a coherent source of
> > light is completely wrong. Why don't you read up something on the
> > topic?
>
> This guys misunderstanding of basic physics aside, the topic was,
> originally, the effect on pilots of exposure to visible light
lasers. It's
> sort of on-topic for Sci.physics.

Sorry, none of that ever appeared on my computer.

> I have many years of experience scanning
> people with visible light lasers (Laser Shows) and it's my opinion
that the
> claims are hype. Claims of retina damage are almost certainly
complete
> crap. The current news involves a guy with a 5Mw hand held YAG
shining it
> at a small jet and a police helicopter.

Whilst I think that would only be marginally dangerous, it was a
rather stupid thing to do.
I presume your laser shows are run with widened laser neams.
Do you, at the same time make very loud music which would result in
members of your audience being plagued by tinnitus?

Franz

On Thu, 6 Jan 2005 20:30:00 +0000 (UTC), "Franz Heymann"
> wrote in
>::

>
>"Larry Dighera" > wrote in message
...
>> On Thu, 06 Jan 2005 17:32:43 GMT, "G.R. Patterson III"
>> > wrote in >::
>>
>> >Larry Dighera wrote:
>> >>
>> >> If I'm not mistaken, coherent laser light is all in phase.
>Doesn't
>> >> that cause it to have more energy?
>> >
>> >No, but it will deliver more energy in the visible spectrum, and it
>can be tuned
>> >to deliver most of its energy in a very narrow band, which a
>typical
>> >incandescent light source cannot.
>>
>> I'm way out of my depth on this subject, but this is the way I
>> understand the physics of coherent light verses light that is not
>> coherent.
>>
>> Because the photons of coherent light arrive at the target at the
>same
>> time, they "pound" harder against the surface upon which they
>impinge
>> than they would if they arrived at varying times. I imagine the
>> physics to be similar to sonic resonance. So perhaps the photons
>> don't have more energy, but they have a greater effect than light
>that
>> is not coherent.
>
>I am afraid your concept of what constitutes a coherent source of
>light is completely wrong. Why don't you read up something on the
>topic?
>In the meantime, it might be better if you restricted your interests
>to aviation.
>
>Franz
>>
>>
>> [sci.physics,sci.physics.electromag added]
>

Thank you for your helpful, insightful, and enlightening response,
Franz. I always welcome informative follow up articles such as yours.
Please accept my sincere thanks for your thoughtful deliberation,
astute tutelage, and avuncular assistance. I'm sure scientists
everywhere find your attitude representative of the best they are able
to offer. :-)

"Larry Dighera" > wrote in message
...
> On Thu, 6 Jan 2005 20:30:00 +0000 (UTC), "Franz Heymann"
> > wrote in
> >::
>
> >
> >"Larry Dighera" > wrote in message
> ...
> >> On Thu, 06 Jan 2005 17:32:43 GMT, "G.R. Patterson III"
> >> > wrote in >::
> >>
> >> >Larry Dighera wrote:
> >> >>
> >> >> If I'm not mistaken, coherent laser light is all in phase.
> >Doesn't
> >> >> that cause it to have more energy?
> >> >
> >> >No, but it will deliver more energy in the visible spectrum, and
it
> >can be tuned
> >> >to deliver most of its energy in a very narrow band, which a
> >typical
> >> >incandescent light source cannot.
> >>
> >> I'm way out of my depth on this subject, but this is the way I
> >> understand the physics of coherent light verses light that is not
> >> coherent.
> >>
> >> Because the photons of coherent light arrive at the target at the
> >same
> >> time, they "pound" harder against the surface upon which they
> >impinge
> >> than they would if they arrived at varying times. I imagine the
> >> physics to be similar to sonic resonance. So perhaps the photons
> >> don't have more energy, but they have a greater effect than light
> >that
> >> is not coherent.
> >
> >I am afraid your concept of what constitutes a coherent source of
> >light is completely wrong. Why don't you read up something on the
> >topic?
> >In the meantime, it might be better if you restricted your
interests
> >to aviation.
> >
> >Franz
> >>
> >>
> >> [sci.physics,sci.physics.electromag added]
> >
>
> Thank you for your helpful, insightful, and enlightening response,
> Franz. I always welcome informative follow up articles such as
yours.
> Please accept my sincere thanks for your thoughtful deliberation,
> astute tutelage, and avuncular assistance. I'm sure scientists
> everywhere find your attitude representative of the best they are
able
> to offer. :-)

Always glad to be of service
{:-))

Franz

On Thu, 6 Jan 2005 19:05:37 -0500, "Happy Dog" >
wrote:

>"Franz Heymann" >
>> "Larry Dighera" > wrote in message
>
>>> Because the photons of coherent light arrive at the target at the
>> same
>>> time, they "pound" harder against the surface upon which they
>> impinge
>>> than they would if they arrived at varying times. I imagine the
>>> physics to be similar to sonic resonance. So perhaps the photons
>>> don't have more energy, but they have a greater effect than light
>> that is not coherent.
>>
>> I am afraid your concept of what constitutes a coherent source of
>> light is completely wrong. Why don't you read up something on the
>> topic?
>
>This guys misunderstanding of basic physics aside, the topic was,
>originally, the effect on pilots of exposure to visible light lasers. It's
>sort of on-topic for Sci.physics. I have many years of experience scanning
>people with visible light lasers (Laser Shows) and it's my opinion that the
>claims are hype. Claims of retina damage are almost certainly complete
>crap. The current news involves a guy with a 5Mw hand held YAG shining it
>at a small jet and a police helicopter.

Not exactly the sophisticated tracking scenario they were putting on
the news.

OTH, Although the laser may not cause damage at a distance, it sure
leaves one whale of an after image which can make seeing in a dim
cabin a bit difficult for a minute or two.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>
>le moo
>

Larry Dighera > wrote in
:

> On Wed, 5 Jan 2005 23:30:57 -0500, "Happy Dog" >
> wrote in >::
>
>>"Larry Dighera" > wrote in message
...
>>> On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
>>> wrote in >::
>>>
>>>>There may not be that many photons involved, but
>>>>they are all coming from the same direction, and that does count for
>>>>something.
>>>
>>> If I'm not mistaken, coherent laser light is all in phase. Doesn't
>>> that cause it to have more energy?
>>
>>No. The energy is measured in watts like any other kind of power
>>source.
>
> I was referring to the phenomenon of light coherence. There's an
> explanation of it here:
> http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%
2C00.html
>
> And my point was that because the light of a laser is coherent (in
> phase), it will provide more energy than an equally bright light
> source whose radiation is out of phase. At least this is what I was
> told by an EE.
>
>


Coherence comes in two flavors. Spatial coherence add temporal
coherence. Spatial coherence is a measure of how well we can focus the
light into a small spot. Temporal coherence is a measure of how narrow
the frequency (color) is. Both are responsible for how it can damage the
eye. However, I doubt that a 5mW laser can cause much damage. I work
with these lasers all the time, but I have never looked at the beam
directly.

Franz Heymann wrote:

> I presume your laser shows are run with widened laser neams.
> Do you, at the same time make very loud music which would result in
> members of your audience being plagued by tinnitus?

Very loud music has recently been implicated in collapsed lungs. This
occurs after a small tear in the lung sac allows air into the chest
cavity, which tear can be in turn be caused by gut thumping bass.

"Roger" >

>>originally, the effect on pilots of exposure to visible light lasers.
>>It's
>>sort of on-topic for Sci.physics. I have many years of experience
>>scanning
>>people with visible light lasers (Laser Shows) and it's my opinion that
>>the
>>claims are hype. Claims of retina damage are almost certainly complete
>>crap. The current news involves a guy with a 5Mw hand held YAG shining it
>>at a small jet and a police helicopter.
>
> Not exactly the sophisticated tracking scenario they were putting on
> the news.
>
> OTH, Although the laser may not cause damage at a distance, it sure
> leaves one whale of an after image which can make seeing in a dim
> cabin a bit difficult for a minute or two.

I really doubt a 5 Mw laser would cause a problem at a distance of three
miles. As I said previously, if it had been a theatrical followspot, I
doubt anyone would care much. It's the weird colour of green that makes it
stand out.

m

"Franz Heymann" >

>> I have many years of experience scanning
>> people with visible light lasers (Laser Shows) and it's my opinion
> that the
>> claims are hype. Claims of retina damage are almost certainly
> complete
>> crap. The current news involves a guy with a 5Mw hand held YAG
> shining it
>> at a small jet and a police helicopter.
>
> Whilst I think that would only be marginally dangerous, it was a
> rather stupid thing to do.
> I presume your laser shows are run with widened laser neams.

Not widened. They're scanned at high speed so the potential exposure is at
a safe level.

> Do you, at the same time make very loud music which would result in
> members of your audience being plagued by tinnitus?

Yep.

moo

On 8 Jan 2005 14:19:01 -0600, Andrew Sarangan
> wrote in
>::

>Larry Dighera > wrote in
:
>
>> On Wed, 5 Jan 2005 23:30:57 -0500, "Happy Dog" >
>> wrote in >::
>>
>>>"Larry Dighera" > wrote in message
...
>>>> On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
>>>> wrote in >::
>>>>
>>>>>There may not be that many photons involved, but
>>>>>they are all coming from the same direction, and that does count for
>>>>>something.
>>>>
>>>> If I'm not mistaken, coherent laser light is all in phase. Doesn't
>>>> that cause it to have more energy?
>>>
>>>No. The energy is measured in watts like any other kind of power
>>>source.

Of course, power is measured in watts. That was not what I was
referring to. Without the knowledge of the specific terms involved,
I'm finding it difficult to express my thoughts coherently. The point
I was trying to make was that for a given brightness, coherent (in
phase temporally) light will affect the surface it strikes greater
than light whose waves/particles arrive at random times.

>>
>> I was referring to the phenomenon of light coherence. There's an
>> explanation of it here:
>> http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%
>2C00.html
>>
>> And my point was that because the light of a laser is coherent (in
>> phase), it will provide more energy than an equally bright light
>> source whose radiation is out of phase. At least this is what I was
>> told by an EE.
>>
>
>Coherence comes in two flavors. Spatial coherence add temporal
>coherence. Spatial coherence is a measure of how well we can focus the
>light into a small spot.

That is the first time I have heard coherence used to refer to spot
size.

>Temporal coherence is a measure of how narrow the frequency (color) is.

Yes. But it's more than that. Like it says here
<http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.html>,
"Coherent electromagnetic waves have identical frequency, and are
aligned in phase." I am referring to the _in-phase_ aspect of
coherent light that permits a 0.005 watt light source (laser) to
illuminate its target significantly brighter than a light source whose
electromagnetic waves are not aligned in phase.

>Both are responsible for how it can damage the
>eye. However, I doubt that a 5mW laser can cause much damage. I work
>with these lasers all the time, but I have never looked at the beam
>directly.
>

My guess is that the US military possesses laser weapons for blinding
the enemy, and fears that something similar may be used by terrorists.
So the fellow who was charged under the Patriot Act provided a
convenient vehicle for the government to flex its might publicly in
the vane attempt to impress the populace with its prowess for which we
are paying dearly. Instead, it displays the government's ruthlessness
in dealing with citizens now that it is no longer constrained by
judicial due process. (I suppose much of that went away on January 2,
2005.)

Like you, I would not expect a Class III laser to be capable of
inflicting permanent physical damage. But that doesn't make it a good
idea to aim one at aircraft.

Larry Dighera > wrote in
:

>
>>Temporal coherence is a measure of how narrow the frequency (color)
>>is.
>
> Yes. But it's more than that. Like it says here
> <http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.htm
> l>, "Coherent electromagnetic waves have identical frequency, and are
> aligned in phase." I am referring to the _in-phase_ aspect of
> coherent light that permits a 0.005 watt light source (laser) to
> illuminate its target significantly brighter than a light source whose
> electromagnetic waves are not aligned in phase.
>


The spatial coherence allows the beam to be focused into a tiny spot. Your
eye is a focusing lens. When a tiny spot is imaged on the retina, the power
density is very high and damage can occur. The temporal coherence allows
the same power (5mW) to be packed into a narrow wavelength range. As a
result, even though the total power is low, the power spectral density can
be much brighter than the sun. Eye damage can occur from that too.

In article >, Andrew Sarangan > writes:
>Larry Dighera > wrote in
:
>
>>
>>>Temporal coherence is a measure of how narrow the frequency (color)
>>>is.
>>
>> Yes. But it's more than that. Like it says here
>> <http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.htm
>> l>, "Coherent electromagnetic waves have identical frequency, and are
>> aligned in phase." I am referring to the _in-phase_ aspect of
>> coherent light that permits a 0.005 watt light source (laser) to
>> illuminate its target significantly brighter than a light source whose
>> electromagnetic waves are not aligned in phase.
>>
>
>
>The spatial coherence allows the beam to be focused into a tiny spot. Your
>eye is a focusing lens. When a tiny spot is imaged on the retina, the power
>density is very high and damage can occur. The temporal coherence allows
>the same power (5mW) to be packed into a narrow wavelength range. As a
>result, even though the total power is low, the power spectral density can
>be much brighter than the sun. Eye damage can occur from that too.

Nah. The eye couldn't care less whether the relative bandwidth is 1%
or 10^(-12) %. Once it is significantly smaller than the detection
bandwidth of the cones (and this one is quite broad) then it doesn't
matter how much smaller (especially re damage). So the temporal
coherence is a non-issue in this context. Spatial coherence, on the
other hand, is very much an issue for the reasons you mentioned above.

Mati Meron | "When you argue with a fool,
| chances are he is doing just the same"

On Sat, 8 Jan 2005 15:51:52 -0500, "Happy Dog" >
wrote:

>"Roger" >
>
>>>originally, the effect on pilots of exposure to visible light lasers.
>>>It's
>>>sort of on-topic for Sci.physics. I have many years of experience
>>>scanning
>>>people with visible light lasers (Laser Shows) and it's my opinion that
>>>the
>>>claims are hype. Claims of retina damage are almost certainly complete
>>>crap. The current news involves a guy with a 5Mw hand held YAG shining it
>>>at a small jet and a police helicopter.
>>
>> Not exactly the sophisticated tracking scenario they were putting on
>> the news.
>>
>> OTH, Although the laser may not cause damage at a distance, it sure
>> leaves one whale of an after image which can make seeing in a dim
>> cabin a bit difficult for a minute or two.
>
>I really doubt a 5 Mw laser would cause a problem at a distance of three
>miles. As I said previously, if it had been a theatrical followspot, I
>doubt anyone would care much. It's the weird colour of green that makes it
>stand out.

You do have to be careful though. We sometimes use 30Mw lasers for
astronomical pointers on clear nights and you definitely do not want
to look into one of those. They cost a tad more (between $200 and
$300 USD) than the typical little one used for pointing as screens and
are a whole lot brighter. The green light also carries a bit more
energy than the red ones. But even at three miles it'd light up most
of the cockpit and wouldn't show as a moving spot inside.
I don't think the 30 Mw would do permanent damage at 3 miles, but
you'd need to turn up the cockpit lighting to read the instruments if
you looked directly at it.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>
>m
>

"Edward Green" > wrote in message
oups.com...
>
> Very loud music has recently been implicated in collapsed lungs. This
> occurs after a small tear in the lung sac allows air into the chest
> cavity, which tear can be in turn be caused by gut thumping bass.
>

Sounds like a job for Myth Busters

As a sound tech, I have had the opportunity to stand in front of some very
large sub cabinets. These buggers would blow your clothes similar to having
your back to a 40mph+ wind.
They have left welts on my legs from my jeans snapping on my skin, but I
never lost a lung tho.

Marty

"Roger" >
>>I really doubt a 5 Mw laser would cause a problem at a distance of three
>>miles. As I said previously, if it had been a theatrical followspot, I
>>doubt anyone would care much. It's the weird colour of green that makes
>>it
>>stand out.
>
> You do have to be careful though. We sometimes use 30Mw lasers for
> astronomical pointers on clear nights and you definitely do not want
> to look into one of those. They cost a tad more (between $200 and
> $300 USD) than the typical little one used for pointing as screens and
> are a whole lot brighter. The green light also carries a bit more
> energy than the red ones. But even at three miles it'd light up most
> of the cockpit and wouldn't show as a moving spot inside.
> I don't think the 30 Mw would do permanent damage at 3 miles, but
> you'd need to turn up the cockpit lighting to read the instruments if
> you looked directly at it.

You *might* see a bright flash. But it wouldn't likely have much effect on
vision. You need to get over 5Mw/cm before the eye can't react quickly
enough to avoid temporary blindness.

moo

"Marty" > wrote in message
...
>
> "Edward Green" > wrote in message
> oups.com...
>>
>> Very loud music has recently been implicated in collapsed lungs. This
>> occurs after a small tear in the lung sac allows air into the chest
>> cavity, which tear can be in turn be caused by gut thumping bass.
>>
>
> Sounds like a job for Myth Busters
>
> As a sound tech, I have had the opportunity to stand in front of some very
> large sub cabinets. These buggers would blow your clothes similar to
> having your back to a 40mph+ wind.
> They have left welts on my legs from my jeans snapping on my skin, but I
> never lost a lung tho.

I wonder at what level this could occur. Meyer, for instance, build a sub
cabinet capable of 146 db at 1m

moo

Recently, Happy Dog > posted:

> "Roger" >
>>> I really doubt a 5 Mw laser would cause a problem at a distance of
>>> three miles. As I said previously, if it had been a theatrical
>>> followspot, I doubt anyone would care much. It's the weird colour
>>> of green that makes it
>>> stand out.
>>
>> You do have to be careful though. We sometimes use 30Mw lasers for
>> astronomical pointers on clear nights and you definitely do not want
>> to look into one of those. They cost a tad more (between $200 and
>> $300 USD) than the typical little one used for pointing as screens
>> and are a whole lot brighter. The green light also carries a bit
>> more energy than the red ones. But even at three miles it'd light
>> up most of the cockpit and wouldn't show as a moving spot inside.
>> I don't think the 30 Mw would do permanent damage at 3 miles, but
>> you'd need to turn up the cockpit lighting to read the instruments if
>> you looked directly at it.
>
> You *might* see a bright flash. But it wouldn't likely have much
> effect on vision. You need to get over 5Mw/cm before the eye can't
> react quickly enough to avoid temporary blindness.
>
The difficulty that I'm having with this thread is that I haven't seen
mention of the windscreen. These are not optically transparent, and I
suspect that most would be sufficiently micro-scratched so that the laser
beam would be imaged on their surface and therefore diffused to the point
that retinal damage would be highly unlikely. However, I can imagine that
night vision may be affected by the glow, and that is not something one
would want to have happen on short final. I agree with Happy Dog's point
that someone using a follow spot would be far more detrimental, yet not
cause all this ruckus.

Regards,

Neil

Roger opined

>On Sat, 8 Jan 2005 15:51:52 -0500, "Happy Dog" >
>wrote:


>You do have to be careful though. We sometimes use 30Mw lasers for
>astronomical pointers on clear nights and you definitely do not want
>to look into one of those. They cost a tad more (between $200 and
>$300 USD) than the typical little one used for pointing as screens and
>are a whole lot brighter. The green light also carries a bit more
>energy than the red ones. But even at three miles it'd light up most
>of the cockpit and wouldn't show as a moving spot inside.
>I don't think the 30 Mw would do permanent damage at 3 miles, but
>you'd need to turn up the cockpit lighting to read the instruments if
>you looked directly at it.

I hope you are talking about milliwatt, not Megawatt lasers.


-ash
Cthulhu in 2005!
Why wait for nature?

Marty wrote:

> "Edward Green" > wrote in message
> oups.com...
> >
> > Very loud music has recently been implicated in collapsed lungs.
This
> > occurs after a small tear in the lung sac allows air into the chest
> > cavity, which tear can be in turn be caused by gut thumping bass.
> >
>
> Sounds like a job for Myth Busters

Well, the evidence in fact seems to be anecdotal, but not entirely
mythological, and was published in a peer reviewed journal:

http://www.wired.com/news/medtech/0,1286,64829,00.html?tw=wn_tophead_8

I do retract my "mechanism" though. That's pure speculation.

> As a sound tech, I have had the opportunity to stand in front of some
very
> large sub cabinets. These buggers would blow your clothes similar to
having
> your back to a 40mph+ wind.
> They have left welts on my legs from my jeans snapping on my skin,
but I
> never lost a lung tho.

> wrote in message
oups.com...
> Marty wrote:
>
>> "Edward Green" > wrote in message
>> oups.com...
>> >
>> > Very loud music has recently been implicated in collapsed lungs.
> This
>> > occurs after a small tear in the lung sac allows air into the chest
>> > cavity, which tear can be in turn be caused by gut thumping bass.
>> >
>>
>> Sounds like a job for Myth Busters
>
> Well, the evidence in fact seems to be anecdotal, but not entirely
> mythological, and was published in a peer reviewed journal:
>
> http://www.wired.com/news/medtech/0,1286,64829,00.html?tw=wn_tophead_8
>

The four cases cited were all indoor or in a car. That may be the difference
as I have only done outdoor venues. They don't say but I would speculate
that there were additional strains on the lungs like yelling/screaming and
toxicology issues at the time. Again, thats only speculation.

Marty wrote:

> > wrote in message
> oups.com...
> > Marty wrote:
> >
> >> "Edward Green" > wrote

> >> > Very loud music has recently been implicated in collapsed lungs.

> >> Sounds like a job for Myth Busters
> >
> > Well, the evidence in fact seems to be anecdotal, but not entirely
> > mythological, and was published in a peer reviewed journal:
> >
> >
http://www.wired.com/news/medtech/0,1286,64829,00.html?tw=wn_tophead_8
> >
>
> The four cases cited were all indoor or in a car. That may be the
difference
> as I have only done outdoor venues. They don't say but I would
speculate
> that there were additional strains on the lungs like
yelling/screaming and
> toxicology issues at the time. Again, thats only speculation.

Yes, but its very well-informed speculation. ;-)

Until we are able to run a controlled experiment randomly assigning a
test group to two cohorts, one required to become high and scream, and
the other distributed in a similar fashion in the sonic field at
selected entertainment venues but restricted to sober foot taping,
we'll never know.

Larry Dighera wrote:
> On Wed, 5 Jan 2005 23:30:57 -0500, "Happy Dog"
>
> wrote in >::
>
> >"Larry Dighera" > wrote in message
> ...
> >> On Thu, 06 Jan 2005 03:52:02 GMT, Jose >
> >> wrote in >::
> >>
> >>>There may not be that many photons involved, but
> >>>they are all coming from the same direction, and that does count
for
> >>>something.
> >>
> >> If I'm not mistaken, coherent laser light is all in phase.
Doesn't
> >> that cause it to have more energy?
> >
> >No. The energy is measured in watts like any other kind of power
source.
>
> I was referring to the phenomenon of light coherence. There's an
> explanation of it here:
>
http://whatis.techtarget.com/definition/0%2C%2Csid9_gci214527%2C00.html
>
> And my point was that because the light of a laser is coherent (in
> phase), it will provide more energy than an equally bright light
> source whose radiation is out of phase. At least this is what I was
> told by an EE.

No, the differrence is in power vs power/area. A given power laser or
other light source will put out that same power level. But, at the
target, the laser will result in a higher received power density,
measured in watts/meter squared.

Some targets that may resonate with the laser light frequency would
absorb more power, but that's a separate issue as well.

-Malcolm Teas

On Sun, 9 Jan 2005 01:34:10 -0600, "Marty" >
wrote:

>
>"Edward Green" > wrote in message
oups.com...
>>
>> Very loud music has recently been implicated in collapsed lungs. This
>> occurs after a small tear in the lung sac allows air into the chest
>> cavity, which tear can be in turn be caused by gut thumping bass.
>>
>
>Sounds like a job for Myth Busters
>
>As a sound tech, I have had the opportunity to stand in front of some very
>large sub cabinets. These buggers would blow your clothes similar to having
>your back to a 40mph+ wind.

I have an old Fender Super Twin Reverb concert amp with 395 watts of
peak music power out. 195 watts RMS. (6, 6L6s) I can guarantee when
it's cranked it'll snap your pant legs like a blast out of an air hose
when you pop a low E string.

No collapsed lungs after this many years, but it will give you an
upset stomach with too many low notes. At that power level I used to
wear headphones.

>They have left welts on my legs from my jeans snapping on my skin, but I
>never lost a lung tho.

What say?? Speak up.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

>
>Marty
>
>

On 9 Jan 2005 8:45:26 -0500, "Ash Wyllie" > wrote:

>Roger opined
>
>>On Sat, 8 Jan 2005 15:51:52 -0500, "Happy Dog" >
>>wrote:
>
>
>>You do have to be careful though. We sometimes use 30Mw lasers for
>>astronomical pointers on clear nights and you definitely do not want
>>to look into one of those. They cost a tad more (between $200 and
>>$300 USD) than the typical little one used for pointing as screens and
>>are a whole lot brighter. The green light also carries a bit more
>>energy than the red ones. But even at three miles it'd light up most
>>of the cockpit and wouldn't show as a moving spot inside.
>>I don't think the 30 Mw would do permanent damage at 3 miles, but
>>you'd need to turn up the cockpit lighting to read the instruments if
>>you looked directly at it.
>
>I hope you are talking about milliwatt, not Megawatt lasers.

Don't know, but we lost three telescopes last week.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>
>
> -ash
> Cthulhu in 2005!
> Why wait for nature?

Marty wrote:
> "Edward Green" > wrote in message
> oups.com...
>
>>Very loud music has recently been implicated in collapsed lungs. This
>>occurs after a small tear in the lung sac allows air into the chest
>>cavity, which tear can be in turn be caused by gut thumping bass.

I vaguely remember hearing that one too. Got any cites?

> Sounds like a job for Myth Busters

Buster isn't equipped for that sort of test; they'd have
to go to pig parts again (remember the cola-pop rocks ep?).

> As a sound tech, I have had the opportunity to stand in front of some very
> large sub cabinets. These buggers would blow your clothes similar to having
> your back to a 40mph+ wind.
> They have left welts on my legs from my jeans snapping on my skin, but I
> never lost a lung tho.

So blowing a lung may be dependent on a "convenient"
resonance inside the chest cavity, requiring the subject to
prestress everything by yelling etc. Gonna be hard to
model with pig parts...

Mark L. Fergerson

"Mark Fergerson" > wrote in message
news:DQwEd.4$bX4.2@fed1read03...
> Marty wrote:
>> "Edward Green" > wrote in message
>> oups.com...
>> SNIP
>> Sounds like a job for Myth Busters
>
> Buster isn't equipped for that sort of test; they'd have to go to pig
> parts again (remember the cola-pop rocks ep?).
>
Oh yea, I remember.
They don't always "recreate" accurately either. The other nite saw them
testing the "thawed vs frozen chickens" thing. Thru an airplanes windscreen
it may have been OK, but there would be (I think) a considerable difference
in a jet engine test just from the frozen bird being solid.
I have heard the "Myth" as the jet engine not a windscreen. That test may
have been cost prohibitive.
I still find them entertaining and thats probably their main goal.
Marty

"Roger" > wrote in message
...
> On Sun, 9 Jan 2005 01:34:10 -0600, "Marty" >
> wrote:
>
>>
--SNIP---
>>As a sound tech, I have had the opportunity to stand in front of some very
>>large sub cabinets. These buggers would blow your clothes similar to
>>having
>>your back to a 40mph+ wind.
>
> I have an old Fender Super Twin Reverb concert amp with 395 watts of
> peak music power out. 195 watts RMS. (6, 6L6s) I can guarantee when
> it's cranked it'll snap your pant legs like a blast out of an air hose
> when you pop a low E string.

You bet!
What I left out was that it wasn't a constant "wind". As you know it's the
back and forth of the subs that make your pants snap. The subs I routinely
use are 8 cabinets (Peavy UDHs if your into it) w/4 16" black widows
ea.,using a 2kw Crown amp to drive each cabinet.

> No collapsed lungs after this many years, but it will give you an
> upset stomach with too many low notes.

Ah Ha! So that's what it was! ;-)

>>They have left welts on my legs from my jeans snapping on my skin, but I
>>never lost a lung tho.
>
> What say?? Speak up.

<g>
Marty

> Roger Halstead (K8RI & ARRL life member)
> (N833R, S# CD-2 Worlds oldest Debonair)
> www.rogerhalstead.com
>

Marty wrote:
> "Mark Fergerson" > wrote in message
> news:DQwEd.4$bX4.2@fed1read03...
>
>>Marty wrote:
>>
>>>"Edward Green" > wrote in message
oups.com...
>>>SNIP
>>>Sounds like a job for Myth Busters
>>
>> Buster isn't equipped for that sort of test; they'd have to go to pig
>>parts again (remember the cola-pop rocks ep?).

> Oh yea, I remember.
> They don't always "recreate" accurately either. The other nite saw them
> testing the "thawed vs frozen chickens" thing. Thru an airplanes windscreen
> it may have been OK, but there would be (I think) a considerable difference
> in a jet engine test just from the frozen bird being solid.

I've never heard a chicken-gun/engine version.

> I have heard the "Myth" as the jet engine not a windscreen. That test may
> have been cost prohibitive.

Uh, yeah, considering that pretty much anything bigger
than a cockroach inhaled into a turbine _will_ destroy it
catastrophically. Obviously even a thawed chicken will too,
so no point.

As for acuracy, they never did test actual bird-rated
"military" canopies, but they ain't cheap. But in their
defense, for my money the final test with multiple sheets of
glass pretty much proves that frozen birds have more
penetrating power.

> I still find them entertaining and thats probably their main goal.

Well yeah. They're a real example of "infotainment" or
"edutainment". I'm considering getting their DVD's for my
grandkids.

Mark L. Fergerson

"Mark Fergerson" > wrote in message
news:9gREd.1988$bX4.999@fed1read03...
>> I have heard the "Myth" as the jet engine not a windscreen. That test may
>> have been cost prohibitive.
--SNIP--
> Uh, yeah, considering that pretty much anything bigger than a cockroach
> inhaled into a turbine _will_ destroy it catastrophically. Obviously even
> a thawed chicken will too, so no point.

Hmmm, I thought they could take a hit from a bird.

> As for acuracy, they never did test actual bird-rated "military"
> canopies, but they ain't cheap. But in their defense, for my money the
> final test with multiple sheets of glass pretty much proves that frozen
> birds have more penetrating power.

It was interesting tho, that where a thawed bird went thru, there was more
physical damage. Largely due to the flattening of mass prior to penetration.
The frozen bird went farther into the fuse'. Standard ballistics really.
Solid vs semi solid, blah, blah.

>> I still find them entertaining and thats probably their main goal.
>
> Well yeah. They're a real example of "infotainment" or "edutainment".
> I'm considering getting their DVD's for my grandkids.
>
> Mark L. Fergerson

You and I have heard a great many of these myths. The Chevy with a JATO is a
good one. They could easily have disproved that one with basic physics but
it wasn't entertaining that way. It was, IMHO, entertaining to see it
attempted. I mainly watched it to see how they mounted it so that it would
drive the car rather than "gut" it on it's way thru. ;-)
If I had kids (or grandkids) I'd probably ruin the entertainment for them.
My anal, nit-pick narrative would most likely **** 'em off.
Hee Hee

Marty

On Mon, 10 Jan 2005 20:24:31 -0600, "Marty" >
wrote:

>
>"Roger" > wrote in message
...
>> On Sun, 9 Jan 2005 01:34:10 -0600, "Marty" >
>> wrote:
>>
>>>
>--SNIP---
>>>As a sound tech, I have had the opportunity to stand in front of some very
>>>large sub cabinets. These buggers would blow your clothes similar to
>>>having
>>>your back to a 40mph+ wind.
>>
>> I have an old Fender Super Twin Reverb concert amp with 395 watts of
>> peak music power out. 195 watts RMS. (6, 6L6s) I can guarantee when
>> it's cranked it'll snap your pant legs like a blast out of an air hose
>> when you pop a low E string.
>
>You bet!
>What I left out was that it wasn't a constant "wind". As you know it's the
>back and forth of the subs that make your pants snap. The subs I routinely
>use are 8 cabinets (Peavy UDHs if your into it) w/4 16" black widows
>ea.,using a 2kw Crown amp to drive each cabinet.

You are setting the volume for the back of the crowd so they can
*feel* the low notes and hear them over all the racket made by the
crowd.

I can't imagine how there can be any musicians left who have played an
outdoor concert that can still hear.

I just played for fun, although my guitar teacher played the circuit
and called me up on stage to play a few times, but these were night
clubs not open air concerts.

When I was a lot younger and on the road going to computer schools for
the company I worked for, I used to hunt up the music stores that
mainly catered to the small groups that might end up playing open air
concerts.

I'd go in, try out a few guitars, start a few blues cord progressions
and it wouldn't be long at all before we'd have a combo going. The
store owners liked it as they'd get a pretty good crowd that way and I
got to play a lot of guitars I couldn't afford to own. <:-))

I was setting there by myself one day just running through some
progressions and riffs (kinda trading 8's by myself) when the store
owner walked over. I thought he was going to turn the amp off, but he
*cranked* that sucker. <:-)) That was in a store just north of
Philadelphia and a bit south of Willow Grove. Nuther story but I
managed to spend an afternoon loose on the base with my cameras.
Yes there were areas I was told to stay well away from, but I managed
to get a guided tour trough some of those (without cameras).

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
>
>> No collapsed lungs after this many years, but it will give you an
>> upset stomach with too many low notes.
>
>Ah Ha! So that's what it was! ;-)
>
>>>They have left welts on my legs from my jeans snapping on my skin, but I
>>>never lost a lung tho.
>>
>> What say?? Speak up.
>
><g>
> Marty
>
>> Roger Halstead (K8RI & ARRL life member)
>> (N833R, S# CD-2 Worlds oldest Debonair)
>> www.rogerhalstead.com
>>
>
>
>

"Joe Morris" > wrote in message
...
>
> An argument against the idea that it's a new telescope owner is that
> the green laser pens are typically over $100 (vs. maybe $10-15 for
> a typical red laser pointer). Also, the green pointers are mostly
> used in amateur astronomy by someone knowledgable about the sky,
> who (hopefully) has a bit of common sense.

Apparently David Banach of New Jersey didn't have any.


>
> the program's
> been running for over 50 years and I would hate to have it shut down.
>

On the bright side, they didn't need lasers 50 years ago. :-(

Marty wrote:
> "Mark Fergerson" > wrote in message
> news:9gREd.1988$bX4.999@fed1read03...
>
>>>I have heard the "Myth" as the jet engine not a windscreen. That test may
>>>have been cost prohibitive.
>
> --SNIP--
>
>> Uh, yeah, considering that pretty much anything bigger than a cockroach
>>inhaled into a turbine _will_ destroy it catastrophically. Obviously even
>>a thawed chicken will too, so no point.

> Hmmm, I thought they could take a hit from a bird.

Apparently my info is a tad out of date, frinst:

http://www.aphis.usda.gov/ws/nwrc/field/sandusky/significant_strikes.html

Note that "uncontained failure" means bits of the engine
departing the nacelle at right angles to the engine axis
(usually at high velocities). But few complete destruction
events are seen; apparently repaired turbines are now
considered trustworthy. Back in my military days, the whole
thing would be replaced if even a single blade showed a nick
or crack, just in case something could cause later failure
at a "Murphy moment", per:

http://www.testdevices.com/lcf_page.htm

If you're not on dial-up, watch the next one. In the
"make it fail" spirit of Mythbusters, Rolls-Royce uses a
"small explosive charge" to blow a blade loose from one of
their engines in a static test and it _doesn't_ blow itself
all over the place:

http://www.msm.cam.ac.uk/phase-trans/2002/1510.mpg

Some other fun stuff:

http://www.elchineroconcepts.com/el_chinero_aircraft_action.htm

>> As for acuracy, they never did test actual bird-rated "military"
>>canopies, but they ain't cheap. But in their defense, for my money the
>>final test with multiple sheets of glass pretty much proves that frozen
>>birds have more penetrating power.

> It was interesting tho, that where a thawed bird went thru, there was more
> physical damage. Largely due to the flattening of mass prior to penetration.

Also the test fixture couldn't have been what I'd
consider solid enough; I mean, the first and _fourth_ (IIRC)
plates broke, but not the second etc? WTF?

> The frozen bird went farther into the fuse'. Standard ballistics really.
> Solid vs semi solid, blah, blah.

Yep, but not obvious in the earlier tests where
frozen/thawed birds did much the same damage.

>>>I still find them entertaining and thats probably their main goal.
>>
>> Well yeah. They're a real example of "infotainment" or "edutainment".
>>I'm considering getting their DVD's for my grandkids.

> You and I have heard a great many of these myths. The Chevy with a JATO is a
> good one. They could easily have disproved that one with basic physics but
> it wasn't entertaining that way. It was, IMHO, entertaining to see it
> attempted. I mainly watched it to see how they mounted it so that it would
> drive the car rather than "gut" it on it's way thru. ;-)

Also, in the version I most often hear the rocket from a
Sidewinder is bolted _under_ the car, making it go airborne
at the first bump in the pavement. But where's the fun in
that? ;>)

> If I had kids (or grandkids) I'd probably ruin the entertainment for them.
> My anal, nit-pick narrative would most likely **** 'em off.

I plan on trying to keep my commentary to asking them if
what they see is "reasonable". ;>)

Mark L. Fergerson

On Mon, 03 Jan 2005 09:29:42 -0500, Corky Scott
> wrote in
>::

>
>Hasn't anyone else been following this?

The FAA has issued a new Advisory Circular addressing this subject:
http://www.faa.gov/newsroom/AC_70-2.pdf

>I'm just shaking my head at his immaturity. He didn't
>have the intent to hurt anyone, he was just showing off, not knowing it
>was a really bad idea.

I know it's an old post, but I disagree and I'm glad they threw the book at
that weenie. He tried to blame it on his kid, he'd seen the stories about
concerns for safety, and he did konw it was a bad idea but he still did it,
deliberately. Numerous copycats since have started doing the same thing.

Sure, it's a prank for most, just like dropping rocks off the bridge over the
freeway. But it's stupid, and malicious, and there's no useful or positive
purpose for doing it. A woman died last year in Council Bluffs when teens were
dropping landscaping bricks off a bridge and one went through the window of a
van driving by underneath and caught her in the head. They didn't intend to
hurt anyone either.

"StellaStar" > wrote in message
> >I'm just shaking my head at his immaturity. He didn't
>>have the intent to hurt anyone, he was just showing off, not knowing it
>>was a really bad idea.
>
> I know it's an old post, but I disagree and I'm glad they threw the book
> at
> that weenie. He tried to blame it on his kid, he'd seen the stories about
> concerns for safety, and he did konw it was a bad idea but he still did
> it,
> deliberately.

He'll be lots of use to his kid when he's in prison. He didn't pose a
threat to anyone. Don't believe the hype.

moo

>
>He'll be lots of use to his kid when he's in prison. He didn't pose a
>threat to anyone. Don't believe the hype.
>
>moo
>

He did pose a threat, would have posed a greater one if he had access to a more
powerful laser without any qualms, and his kid's better off without that kind
of example. I don't read hype.

On 22 Jan 2005 03:59:59 GMT, (StellaStar) wrote:

>>
>>He'll be lots of use to his kid when he's in prison. He didn't pose a
>>threat to anyone. Don't believe the hype.
>>
>>moo
>>
>
>He did pose a threat, would have posed a greater one if he had access to a more
>powerful laser without any qualms, and his kid's better off without that kind
>of example. I don't read hype.

Those hand held pointers do startle you when pointed in, but beyond a
few hundred yards they do nothing more than leave an after image if
you look directly at it. Beyond a 1000 feet you'd have to stare at
one.

I think his biggest threat is lack of smarts.

To say, what if he had a bigger laser is a ridiculous what if.

Do I want something pointed at me? No I don't. I don't know if it's
hooked to anything or not, but to say what if puts us in the same boat
as the public being afraid of small aircraft.

We have a strictly uncontrolled airport, but they are going to badges
and limited access. Something I understood was to be for airports
with scheduled flights. They say it's what homeland security says
they should do and the airport manager sounds almost paranoid.
(second hand). I'm going to try to get a chance to talk with him to
find out why they are taking the approach they are talking about.

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com

"StellaStar" > wrote in message
>>He'll be lots of use to his kid when he's in prison. He didn't pose a
>>threat to anyone. Don't believe the hype.
>
> He did pose a threat,

Wrong. You're stupid or uneducated. Pick one.

> would have posed a greater one if he had access to a more
> powerful laser without any qualms,

Idiot.

moo

.. I don't read hype.