Do you know what thermal blooming is TBMR... obviously not from your reply.
http://en.wikipedia.org/wiki/Thermal_lensing

Thermal blooming is when ANY LASER heats the portion of the medium through which it passes (including air). If it's denser in particulate matter, then you'll lose more energy. That energy goes somewhere, if it appears as heat... then you see my point about thermal vision being the most likely to see traces of a laser shot in smoke.

Not only that, it's possible for higher energy photons to produce multiple lower energy photons when freed/excited electrons return to ground. The simplest case is when it bucks it up to one state, then immediately returns producing another photon of the same energy in a different direction. The more complex case, is when it returns to a lower state but not the ground state (possibly more than once) before returning to the ground state. With this method and a proper medium, it is possible for any high energy photon to produce visible photons even though the laser itself isn't visible. This effect doesn't work well in simple atoms like hydrogen.. as the states are very limited and you need precise wavelengths to absorb. But when the spectral absorbtion bands are large, it indicates there's a large number of free energy states. So there is more than just scattering of the lasers wavelength.

Ok so in the grand scheme of things, although it's possible that lasers could be invisible to the naked eye, is it possible to build a weaponized laser that is visible?

Yes but only if
A: It is absurdly bright and inefficient (It ionizes the air in its path causing it to glow)
B: There is dust, mist, or other matter in its path (The particles ether directly scatter the beam, or incandess due to the heat)

If you really want lights and sound, you can create a hybrid laser/electron beam sometimes called an "electro-laser"
In this case the sole purpose of the laser is to sparsely ionize the air, which then acts as a conductor for the electrical discharge.
Still inefficient, still awesome.

Because who doesn't want to shoot lightning?

Most Magical Types it seems ^^

That is probably more due to the fact that most mages don't want to use any indirect combat spell. It's not a problem with lightning. Only having a chance of temporarily disabling technological devices isn't an advantage either.

If i's a high enough power laser, would the air superheating along the beam path make a noise?



You can even use it to block doorways!




-karma

OT-Vaders craft wasn't a Tie-bomber, but a predecessor to the TIE-Interceptor. It als had a hyperdrive, which is usually lacking on most Tie-fighter designs. The tie bomber (as appeaered in empire strikes back has two pods-one for the pilot and engine, the other for the payload.

Ok-I'm bumping my geek factor of N^2.

I don't understand why you would want a visible laser anyway. The best weapons are ones that the enemy doesn't know where you are when you shoot at them. You can't see a bullet fly through the air, why would you want to see a laser fly through the air. Your basically saying "LOOK OVER HERE!!! THIS IS WHERE I AM!!!! COME GET ME!!!" Its LOCO!!!

@Falconer
Yes mother! I know what thermal blooming is. I just don't think the laser would leave that distinctive of a trail through the air to be visible more then a few nano-seconds after it was fired.

I've got a character who's been running an Ares Redline as an underbarrel weapon on a submachinegun for a while... tucking the battery pack into the underside of the stock (or plugging the hip pack in there) seems to work pretty well. The MP Laser 3 is a recent addition to his armory, but it's racked up a couple of kills so far without much trouble. Adds a quieter option to a character who usually runs towards gas vented automatics with every single round in the magazine being a tracer.

Half impact armor has some situations where it becomes very, very handy; anything involving multiple layers of armor (target is inside a car, for example), high-end spirits (yes, stick-n-shock works here too), some critters, SWAT or milspec armor, someone who's thrown on a few PPP components... at closer ranges, at least, you're essentially guaranteed a Physical hit. Damage attenuation can annoying, but the pistol-sized laser uses SMG ranges (it's only at -1 out at 40 meters, and it's the only pistol that can reach 80 meters, much less 150), and the rifle-sized one uses sport rifle ranges (doesn't even take a penalty until after 100 meters, only -1 out to 250). It's not all that big of a deal.

In a Car Wars novel, it described the vehicular lasers as being invisible, but that they were mated to a lightshow laser for visibility, to put on a better show for the audience. One could do that in SR, mounting a laser scope on your gun. Get people used to seeing the beam in a fight, and then turn it off for an unexpected, invisible shot.

Given how lasers actually work, that makes no sense at all.




-karma

Do something else: Use your LASER as your LASER-Pointer if your LASER is an Under-Barrel-Modification of the MAIN-Weapon ^^
Top laser-pointer shows up . . nothing happens . . BOTTOM laser-pointer shows up, carves out a nice big hole in the target.
And THEN comes a full spray of Tracer-Rounds to add Insult to Injury ^^

Hm. Kinda what they did in the Superman comics.

They reasoned that red sun energy sapped a Kryptonian's power temporarily. So they made a gun that fired a high powered red sun laser at the same time it fired an armor-piercing round. The red sun energy would weaken the invulnerability for moment, long enough for the bullet to penetrate.

But that's kinda off-topic. As you were!



-karma

Nuh Hu! I wasn't! *bllllll*
There's several LASER in that Posting and one Weapon.
Perfectly On Target < = Pun very much intended.
Basically, Laser-Weapons are usefull for the surprise-effect.
And imagine what it would do to certain things out there that have the LIGHT Allergy.

I think I can offer a rule here: Lasers are invisible and inaudible, except when they aren't.

In my opinion lasers are worth it if you really like them. I do. I think I'm gonna make a laser gunslinger. I think his name will be Jim, though most people call him... Jim.

No you don't and didn't until I pointed it out, as evidenced by the manner you chose to criticize.

Here's my problem w/ your position... If there is enough energy in the beam to vaporize steel and damage the target, then there is easily enough energy to ionize water/smoke particulates into plasma or at the very least incandesce them. (I'm talking in terms of joules which would measure the integral of power over time watts... I don't care how short the pulse duration is... there is hard physics, you need X amount of energy to take a few grams of matter and change it from solid to gas vapor and that's well known basic physics).

Lets put this another way... you claim that the flash on the target would be visible so there's enough energy to incandesce the material in the target... so lets say you cut out a 5cm hole 20cm deep in a person. 1000cm3 == 1liter of water (body is mostly water). So that's .5 liter (5*5*20). .5l of water weights .5kg. Just to speed things up... you're talking about something over 1 megajoule of energy to vaporize that much water (flash boil blow a hole through an unarmored target 20cm deep and 5cm across). For those w/o a science background... I'm talking about the amount of energy it takes to vaporize 1 pound of water/meat. (which seems reasonable for a weapon grade laser in SR).


Do I agree, normal clear blue sky, nothing but basic nitrogen/oxygen... invisible... yeah probably if we're talking IR laser like CO2. However, every laser I've ever heard about powerful enough to be a weapon has a problem w/ thermal lensing once you start trying to get any range. Shorter wavelengths going to UV or Xray have a bigger problem in that they interact more w/ gas particles and scatter more (why is the sky blue...).


Now a pulse like that you claim, won't interact w/ fog (which is liquid particulate water molecules suspended in air) and produce a noticable effect. Or if someone had the presence of mind to throw a smoke grenade to try and locate where the shots are coming from (and give cover/reduce incoming damage). At the very least, it would 'burn' a hole through the fog which would be visible. If it doesn't incandesce the material by heating it to red hot let alone white hot. (since thermal vision sees longer wavelengths... this would be more visible to them than people w/ just normal vision... thermal > low-light > normal in this case).

On the other hand, if you build a metal vapor laser based on orichalcum and the knowledge of lucifer lamps...

What have you brewed up in your twisted mind this time?
Laser-Weapon-Focus?

Astral laser.

EDIT: Dual Natured Laser, even.

EDIT2: The beams, that is. Dual Natured light formed into a Laser beam.

Ow! my head is hurting on how bad an idea that is.

Incredibly bad idea...

Or an incredibly AWESOME one?

Let's find out!


...Actually, I can see a rampaging great spirit getting taken out by a massive secret government astral laser. It'd be very cinematic.



-karma

Yeah, but spirits vulnerable to mundane-carried-weapons would kill a lot of fluff-feeling from SR, don´t you think?

Meanwhile, I'm going to create a suspension of dual-natured biomass in liquid - big tanks of the stuff. Voila! Astral water-cannon for spirit crowd control.

And for my next trick, I get a number of magicians to craft foci in the form of various components - wheels, a body, a harness. I bond the lot of them, Astrally project and assemble into ASTRAL CHARIOT! You just need a couple of spirits to pull it and you're good to go!

Only if building-sized clones disguised as mecha count as "mundane".

If by mundane, you mean biomodified supersoldiers in heavy military armor, though - then the Thunderstruck is still the way to go.

You just need those Ghostbusters slime blowers.



I want a dual natured muscle car. Preferably something classic.



-karma

Shooting a spirit with an assault cannon kills it pretty well. Heck, a revolver and a steady hand can do pretty well in a pinch. I'd say your "fluff" is already dead in that case.

How about a Possession tradition magician? Conjure a spirit and have it possess you car...


Yepper. Ruger Super Warhawk + APDS rounds (6P/-6AP) will wreck most spirits if you're a good shooter.

-paws

Been there,done That.. Ares Alpha,EX-Explosive rounds,3-round burst and distance 5 ft, 17 dies and 16 success.. POOF!!!