Laser beams being aimed at airliners?

"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 he
http://whatis.techtarget.com/definit...4527%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 he
http://whatis.techtarget.com/definit...id9_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.