Is This Serious?

[INRM]

URL: http://www.noahshachtman.com/archives/002187.html

Laser weapons have a serious shortcoming, in the minds of some Pentagon thinkers. No, it's not the fact that it takes giant vats of chemicals or a gazillion watts of power to get the beam machines to work. Or that a fair-sized rainstorm pretty much renders them useless. It's that lasers can only zap as far as the eye can see. The beams don't curve, so ray guns can't reach over the horizon.

The Defense Department's Office of Force Transformation wants to change that, however, with a world-wide ring of giant mirrors, that would bounce laser light to wherever the Pentagon saw fit.

The transformation shop has been talking about this Tactical Relay Mirror System, or TRMS, for several years. Now, they may be ready to start some early-stage testing, Inside Defense reports.


If so, is this really a good idea? This technology doesn't sound like something a country would use for a war of defense but for global domination...


INRM
BTW: This sounds like it would have surveillance applications too which is quite disturbing...

[Yuri Nalyssus]

URL: http://www.noahshachtman.com/archives/002187.html
If so, is this really a good idea? This technology doesn't sound like something a country would use for a war of defense but for global domination...
Intercontinental ray guns - cool!

But what about the attenuating effect of the inverse square law - what are the military trying to achieve here - making people in terrorist camps "a bit hot" so they take their balaclavas off and we can see who they are or perhaps giving enemy forces a nasty rash but only if they stand in the same place, naked and out doors for 30 minutes or so?

Oooh, scary.

Yuri (probably about to disappear in a puff of ash as the CIA take action after monitoring this post).

[Yuri Nalyssus]

:flamed:

[Piscivore]

Someone at the Pentagon has been masturbating to "Real Genius" again.

[Floyt]

Might work outside the atmopshere, but they seem to be talking of blimps and modified 747's *shrug*

Is atmospheric attenuation an issue for x-ray lasers?

[Hokulele]

How the heck did they get "world-wide ring of giant mirrors" out of the original article?

http://www.globalsecurity.org/military/systems/aircraft/systems/trms.htm

[Cavemonster]

Someone at the Pentagon has been masturbating to "Real Genius" again.

I told you, I was hot and I was hungry!

[Shrinker]

Hmm... aiming a laser at a small mirror attached to the bottom of a blimp. What could possibly go wrong?

[Prometheus]

Heck, they gotta come up with some story the dimwits in Congress can't understand, in order to keep the money rolling in.

[rocketdodger]

But what about the attenuating effect of the inverse square law -

Does not apply to lasers.

[Yuri Nalyssus]

Does not apply to lasers.
Can you explain why not (as if to an imbecile please - not me you understand, it's for a friend :blush:).

Yuri

[Thabiguy]

Can you explain why not (as if to an imbecile please - not me you understand, it's for a friend :blush:).

Well, more accurately, the inverse square law applies to everything - light, EM radiation in general, gravity, sound, you name it - but only as long as it travels straight outwards from a point source. Then it will attenuate proportionally to the inverse square of the distance from the point source.

When the beam diverges slowly, the hypothetical "point source" is effectively very far away, so it takes a great distance for the things to attenuate. The limit case is of course when the radiated things travel in parallel lines - then the hypothetical "point source" is infinitely far away and the beam doesn't get attenuated by inverse square law at all.

And photons emitted by lasers often travel close to parallel paths.

[Wauthan]

If that article has some kind of truth to it I'm all for it. While it would be a hilariously inefficient weapon I'm sure it would be good for the global economy. An arms race for laser bouncing blimps. What could possibla go wrong? ;)

[Ashles]

This makes Bond supervillain schemes sound suddenly sensible.

[BigAl]

Given that a Hamas home-made missile costs a few hundred bucks to make and the missile Israel could use to shoot it down can cost a million bucks, there is lots of room for what is called "area defense" and lasers that cost a few hundred bucks per shot for the chemicals make perfect sense and we are close to making them.

This is a 2006 promotional video of the state of the art. It's optimistic but not fiction.

5 minutes.
http://www.youtube.com/watch?v=nVxZ9IHTH2E

A continental defense anti-ballistic-missile missile costs about $4 million bucks a shot. The problems using beams for continental defense are serious, as stated.

[technoextreme]

Well, more accurately, the inverse square law applies to everything - light, EM radiation in general, gravity, sound, you name it - but only as long as it travels straight outwards from a point source. Then it will attenuate proportionally to the inverse square of the distance from the point source.

When the beam diverges slowly, the hypothetical "point source" is effectively very far away, so it takes a great distance for the things to attenuate. The limit case is of course when the radiated things travel in parallel lines - then the hypothetical "point source" is infinitely far away and the beam doesn't get attenuated by inverse square law at all.

And photons emitted by lasers often travel close to parallel paths.
EDIT:Must remember to read posts.
Given that a Hamas home-made missile costs a few hundred bucks to make and the missile Israel could use to shoot it down can cost a million bucks, there is lots of room for what is called "area defense" and lasers that cost a few hundred bucks per shot for the chemicals make perfect sense and we are close to making them.

This is a 2006 promotional video of the state of the art. It's optimistic but not fiction.

5 minutes.
http://www.youtube.com/watch?v=nVxZ9IHTH2E

A continental defense anti-ballistic-missile missile costs about $4 million bucks a shot. The problems using beams for continental defense are serious, as stated.
I have to figure out the absorption spectrum of air because you sure as hell don't want the same thing happening to your laser that causes the sky to turn blue.

[blutoski]

If so, is this really a good idea? This technology doesn't sound like something a country would use for a war of defense but for global domination.

Meh. The big 19th century advancement in naval combat was the ability to shoot over the horizon - you could shoot something before it even saw you. eg: the UK original "Dreadnaught". Same with land-based artillery and ultimately missiles. Lasers unable to do this would sort of be a step backward, since their range appears to be very limited.

Having said that, the Dreadnaughts and missiles were built for world domination... so you may be onto something there.

[3bodyproblem]

Well, more accurately, the inverse square law applies to everything - light, EM radiation in general, gravity, sound, you name it - but only as long as it travels straight outwards from a point source. Then it will attenuate proportionally to the inverse square of the distance from the point source.



That's not entirely correct, but it applies more often than not. It just doesn't apply to "everything".

[INRM]

Wouldn't having all these reflective balloons around make for an excellent recon platform?

INRM

[Gord_in_Toronto]

I think there was a thread on a similar topic here some months ago.

I shall point out once again (since the military didn't listen to me then) -- if you use mirrors, the people you are attacking can use mirrors to reflect the energy back at you. Just a few centimetres different and you get zapped.

I'm envisioning a computer controlled game of laser billiards for some reason. :D

[Soapy Sam]

Let's go the whole hog.
Orbiting solar collecers that beam power by microwave lasers to ground collecting stations.
Turn the planet green.

Except for the black bits, obviously.

Would anyone here trust any government that tried to build such a system?

[Pragmatist]

And when the guy at the other end (the proposed target) whips out a mirror and directs it back to the source...?

(Ooops.. just noticed Gord beat me to it)

[Shrinker]

Wouldn't having all these reflective balloons around make for an excellent recon platform?

INRM

If they were, we'd have them already, no? Instead we spend billions on spy satellites...

[Dave Rogers]

Meh. The big 19th century advancement in naval combat was the ability to shoot over the horizon - you could shoot something before it even saw you. eg: the UK original "Dreadnaught".

That's a bit of a stretch. Even in WW2, ship-to-ship gun combat was restricted to visual (or radar, which is still line-of-sight) ranging and aiming. Indirect fire was used in ship-to-shore bombardment, but that's not what Dreadnoughts were designed for. The advance made by HMS Dreadnought was that it could shoot something at longer range than they could shoot back, and of course it was only a transitory advantage.

Same with land-based artillery and ultimately missiles. Lasers unable to do this would sort of be a step backward, since their range appears to be very limited.

That sounds more like it. Even at relatively short ranges, the ability to fire on targets that aren't line-of-sight is vital because of terrain issues - rather more important on land than at sea, of course. Rather than replacing ICBMs, this reads more like a high-tech 25pdr field gun.

Of course, any weapon, no matter how defensive, has some implications for offense. A secure base of operations is the first requirement for an offensive strategy.

Dave

[casebro]

Don't the mirrors have to be expendable? I think they only last a blink before they go up in a puff of smoke once enough of the laser's energy soaks in. Regular mirrors are only 95% efficient with visible light, that 5% would add up to a puff of smoke in milliseconds. But then, I suppose there may be something which is more efficient for the wavelength in discussion. Anybody got a clue? Polished Tungsten? or???

[MRC_Hans]

I think the main attraction of a laser gun is that the "projectile" moves (app) at the speed of light, and that it is not perturped by wind. Other than that, it just makes holes in things, which we can do cheaper in other ways.

Somebody mentioned Hamas missiles, and exactly incoming missiles is an interesting target for laser weapons. You see, unless your projectile is significantly faster than your target, aiming and hitting is hairy. But for a laser, it won't matter, as it is always vastly faster than any physical target.

If you use mirrors, you need to be able to aim the mirror, otherwise the position of the laser/mirror will be critical (forming two sides of a triangle), but if you have a fully controllable mirror, then ....

I think the idea is that such a mirror is a cheap, light, fairly simple, and expendable device, which can be carried on an aircraft, blimp, or sattelite, leaving the sensitive, expensive, and complicated laser device safely on the ground (or sea) behind your own lines.

As for the guy at the target whipping out a mirror .... with the beam coming at him at the speed of light, from a direction he cannot foresee, at a time he cannot foresee, he sure has to be fast with that mirror. Better enroll Lucky Luke.

Hans

[MRC_Hans]

Don't the mirrors have to be expendable? I think they only last a blink before they go up in a puff of smoke once enough of the laser's energy soaks in. Regular mirrors are only 95% efficient with visible light, that 5% would add up to a puff of smoke in milliseconds. But then, I suppose there may be something which is more efficient for the wavelength in discussion. Anybody got a clue? Polished Tungsten? or???Well regular mirrors, as in your average bathroom mirror, are not very good, and would get a nice hole in them rather than reflecting much beam, but since a key component in a high-energy laser device is indeed very efficient mirrors, we can make them. They are probably a bit more expensive than a bathroom mirror, tho'.

Hans

[Cuddles]

If so, is this really a good idea? This technology doesn't sound like something a country would use for a war of defense but for global domination...

Please explain exactly how you think this could be used for global domination.

BTW: This sounds like it would have surveillance applications too which is quite disturbing...

If you're disturbed by that you may want to start worrying about the multiple spy satelites already in orbit.

[INRM]

Soapy Sam,

Would anyone here trust any government that tried to build such a system?

No


Shrinker,

If they were, we'd have them already, no? Instead we spend billions on spy satellites...

Not if they just started to develop the idea...


INRM

[Shrinker]

Shrinker,



Not if they just started to develop the idea...


INRM

Mirrors? Balloons? They've been around a while you know...

[Z]

VLF emission weapons (like EMP bursts from space) might have a better effect, from a network of low-flying satellites. Something like what was proposed in Broken Saints.

[jj]

Can you explain why not (as if to an imbecile please - not me you understand, it's for a friend :blush:).

Yuri

Laser light is collimated.

Now, strictly speaking it does apply to lasers, but the apparent source distance for the laser is very, very far away, so the 1/r intensity or 1/r^2 power falloff is very, very small.

I realize this must sound confusing, but since lasers diverge very slowly, they appear to be coming from a point source that is far, far behind the actual laser. This means that their intensity falls off not as 1/(r*r) if "r" is the actual distance to the front end of the laser, but rather as

a*a/( ( r +a)^2) where a is the apparent extra distance.

This isn't an exact law, either, there are other interesting things that happen when you get to the intensities of laser light.

but the point is that the falloff is not nearly as fast as you expect.

[Yuri Nalyssus]

As for the guy at the target whipping out a mirror .... with the beam coming at him at the speed of light, from a direction he cannot foresee, at a time he cannot foresee, he sure has to be fast with that mirror. Better enroll Lucky Luke.

Hans
Bring it on!

http://forums.randi.org/imagehosting/thum_295649b01db4e1c9f.jpg (http://forums.randi.org/vbimghost.php?do=displayimg&imgid=15539)

Yuri