A friend of mine said that lasers make a sound because they are vaporizing the air. at first i had no reason to say no to this. how ever i keep seeing more and more stuff about lasers and they never do. so for the record do lasers make noise, in real life and in SR? Second dose SR have Laser satellites if so who has em i know that Aris has the Thor rail gun. Any information would be wonderful. If you have any sights that show that lasers make noise in real life it would be grate.

the noise they make is not the gun but the beam dose it make noise or is it just the gun?

P.S. this is because the gun peaty much has to make noise

I hope you know that you have just thrown a can of worms at a hornet's nest.

Well here is what a quick search turned up...
http://answers.yahoo.com/question/index?qi...09103729AAJAKy7
That should make it clear as mud. Well actually, it would seem the beam of light makes no noise or none you could hear unaided. However, its super heated passage through air would make a noise as air rushed back into the space created by the beam as would the actually impact.
Ares doesn't have a rail gun in space. The Thor shot is actually a bunch rocket powered super flechettes, think of it as crowbars or something of similar mass with small rockets attached. These things do their damage by falling from a hella high height much like a meteor does and moving at crazy speeds. I imagine there is some shielding or something on them too, to prevent them from simply melting from friction during re entry.
I would imagine any mega corp with a space presence has/could have orbital laser weapons of some kind as would any national government that still maintains a space program. Off the top of my head, I think S-K, Ares, Aztechnology and Evo all have space based weapons. As I don't feel like going through all the books to figure out who exactly has what weapons, just assume any of them could have anything. Its your game after all.
Anyone else want to fill in the blanks on this?

The Sci-fi genre would have collapsed log ago if lasers didn't make awesome noises.
Now lasers in space on the other hand should not make discernible noise despite what Hollywood thinks.

I have worked with some high power lasers, strong enough to burn through wood, and the only noise I ever heard was the sound of the transformers buzzing and a little crackling coming from the wood. So if looking for RL data, then I would say the electronics pushing power to the laser make more noise than the laser itself.

Incorrect....

Thor Shots are mass drivers and mass drivers utilize the same method of acceleration as a rail gun. So while they are two devices for distinct purposes, interchanging them is acceptable.

From the DumpShock wiki.

IRL, lasers do not make the noises you describe, but, as in some other games I know of, the company that makes said lasers can add a 'effects-sound generator' at no extra cost to get the cool sounds you want to hear.

And yes, I know that "at no extra cost" are taboo words in the corporate structures in SR.

I wager the pew-pew or pzZoooom noise lasers are standard issue.
You will have to pay extra to de-activate the sounds or pay extra for the silent killer version.

The new and improved Ares Infantry Stealth Laser, now only 45% more than the pew pew non-stealth version. Yes, it actually costs us less to make the silent version, but we don't care because we know our customers will pay for what they want.

Regarding the "noise" of a weapon-grade laser firing:

The amount of sound resulting from displaced air is going to be relational to the diameter of the lensing aperture/beam itself as well as the power of the beam. The artwork all show very narrow apertures, but consider that the lasers most people are familiar with are even smaller, at most a couple millimeters in width. The ones in the artwork appear to be closer to 1-2 centimeters on the man-portable version and perhaps as much as 3-5 centimeters on the vehicle mounted version. That's actually a significant amount of air, depending on the power of the beam, and by definition, a "weapons-grade" beam is a LOT of power. If you superheat a significant quantity of air then suddenly remove the heat, the surrounding air is going to rush to fill the volume, not unlike thunder. The question is, are we talking "pop" or "boom"? Having never heard a "weapons-grade" laser fire at sea-level, I can't say, and we're working with unknowns here.

The second sound producer is the impact of the laser on a target. For a laser weapon to be useful, the energy transfer has to be two things: massive and instantaneous. For those people wanting to point at the ABL or earlier ground-based anti-ballistic laser tests, they were all still trying to heat up the target to failure and don't trully represent what a battlefield laser is going to need to do it's job. Specifically, even the ABL in testing requires seconds of coninuous power on-target to have te desired result, which in this case is failure of the (thin and realatively fragile) rocket casing. What most people don't realize is that many liquid-fueled rockets, to save weight, have the outer skin of the missile serve AS the fuel tank itself, and if not pressurized, the tanks have as much inherent structural strength as an empty beer can. Essentially, if you can keep the beam mostly on the same place for a couple seconds, you can rupture the tank or casing (in the case of a solid rocket). If the casing is ruptured by heat, you either a) may ignite the un-fired portion of solid fuel or b) lose containment of expanding gasses dramatically altering your thrust vector and essentially crashing the thing. Here's the problem: on a ground battlefield or in a dogfight in the skies, you're going to need a laser PULSE not a continuous BEAM. You need to deliver all the energy of that several second beam in a fraction of a second, comparable to the time needed for a bullet to transfer all of it's energy to a target. With a pulse that powerful, you're not going to see "melting" or "cutting" like you would on lower-powered beams; You're going to see some rather impressive results as all that energy is transfered into the target. Think of it this way: what would happen if you super-heated the 60%+ of water in the (meta)human body to beyond, oh, say, 500 degrees F? Instant flash vaporization, and the other 40%- of the body's material isn't designed to contain those kinds of pressure. Can you say "explosion of gore"? Around the outer edges of the wound, you're going to see cauterization/burning of tissue possibly, but I don't think you're going to get neat little pin-holes; those would be as useless as punching a tiny hole neatly through somebody with a bullet (unless you hit something really vital on the way through). Against harder targets, the result is going to be different but similarly impressive and you dramatically exceed the tolerances of the materials from differential expansion. Some of the material may just vaporize (aluminum comes to mind with the very low heat-capacity) with related-results to the bdy as micro-imperfections channel the energy and shatter the object. At least that's some of the theory, once the energy levels get high enough and instantaneous enough. THAT's going to result in a sound, if only of bits ane pieces flying in every direction.

So depending on the aperture, power and target, a small laser being fired MIGHT result in the sound of a sledgehammer hitting a watermellon... and the sound of stew meat flying through the air and spattering back onto the ground, of it could result in a thunder-like boom and a sount of catastrophically rending and shattering metal. IF the energy transfer is sudden enough and large enough. Like what you'd expect a man-portable infantry weapon to be able to do against a running, dodging rather fleeting target rushing between bits of cover.

Snap crackle fizz.

I would imagine that the laser would have a sound, but most people would no associate that sound with gunfire unless they are very well trained.

Justified. Trope.

Actually, as everyone knows, one of the many difficulties of using lasers is venting off excess heat. One of the most popular ways of doing this in space is to surround the laser aparatus in a conductive (but invisible) gas, surrounded in turn by insulative material. After each shot, the gas is super-heated and immediately ejected through tiny vents in every direction (so as to not exert any significant force on the ship). While the gas is ejecting, it can still be heard inside of the cabin, and the sound of high-pressure gas undergoing controlled release into space happens to sound like 'phheeww'.

The sound of explosions and background music are just simulators to intuitively represent the situation outside, especially regarding events that may not be immediately visible.

I've worked with lasers and even built my own once. Kerenshara, said most of what i could think of.
The only sounds that a laser will make are the humming and buzzing of the lasing device int self. gas tubes being louder that diodes. This noise is not very loud though, Even a lager 10Kw laser is not too loud to drowned out a conversation right beside it, though it's close.
when the laser fires some air in it's path will be turned to plasma. Also some of the material vaporized off the target will be turned into plasma. only the later will be violent enough to be noticeably audible it smaller lasers. Even the 40w cosmetic/surgical lasers make a pretty good pop when they hit.
On the really big guys i think the discharge would sound like thunder. As the air along the path ionized and expanded.

On a tangent note:
i once say a blerp in a laser weapon that used a very specific power and frequency. i think they also emitted a low power microwave beam along the path.
the result was then the laser hit a human target a small amount of fine material(dead skin, cloth fibers, hair) was turned into plasma. This plasma gave off a EM field that stimulated pain receptor nerves.

Lasers make whatever cool sound you know from your favoourite show employing them

That's one of my favorite things in any Rifts supplement ever.

Here's a related thread from a while back....
http://forums.dumpshock.com/index.php?show...27147&st=65


Reference thread... post referenced has elementary physics math for amount of energy in a weaponized beam. (assumed 5cm x 5cm x 20cm hole cut, w/ estimates far lower than they should be, but serves to illustrate that even being very generous that a weaponized laser of SR power should be in the megajoule range.

That much said, I wouldn't expect much of a sound from the beam. If your wavelengths are such that you're not in the gasses spectral lines, it's going to be hard to ionize the gas (now since the atmosphere isn't 100% one gas... I'd expect some bits of it to get heated and that to heat surrounding gas slightly leading to thermal bloom). Now if you get some kind of 'smoke', I have no problem w/ that incandescing and showing the laser, but even there I don't think you'll get much of a sound. I'd believe most of the sound would be from the steam explosion at the target from the sudden flash vaporization of target matter.

Also, since SR lasers are SA... w/ 4 passes. 8 shots over 3 seconds... so roughly .3s per shot... we can quickly ballpark them in around 1megajoule over say a quarter second. Or 4 megawatt at least.

What Kerenshara, Straight Razor, and Falconer said.

The other thing is that the way you attack armor with a high-powered pulse laser is lot like how a HEP or HESH round penetrates armor. It superheats the armor into gas and the superheated armor explosively expands, compressing the armor towards the inside. On the inside a chunk of the armor tears off the inside face (spalling) and shreds everything inside.

I suspect this is not quiet.

Why are people so frigging hung up on realism concerning such awesome stuff like frigging LASER CANNONS?
Realism has to go to the corner and wear the doofus hat while fun with lasers is being had <.<

I think that it's just the hard sci-fi side of Shadowrun's appeal. I'm all for realism in the more scientific aspects of Shadowrun, since where the setting really diverges from things that are possible is the introduction of magic and its repercussions. Hard sci-fi needs to stay hard sci-fi so that the fantasy can have a realistic grounding point.

Also, I'd imagine it'd make a difference if you were trying to be all sneaky-like and fire a laser gun...

You can add a voice activation on your laser gun to have only fire when you make the pew pew sound with your mouth.

Staying with the Hard Sci-Fi you defend in your posting:
You don't see anything wrong with taking laser guns that fire lacnes of fire and heat up pretty much everything around them and up to the target on a sneaky run? O.o

Staying with hard sci-fi, the beam of the laser itself would be invisible, unless passing through some sort of particulate (dust, mist, etc...) in the air (which would also, in all likelihood, scatter the beam sufficiently to make it a pointless exercise to fire through such obstructions).

A slightly different, and more amusing question,
In Street Magic, there's a single-target light-element spell called 'laser'. What the hell does that do? Does it make noise? Is it ANYTHING like a normal laser? Or is it just a normal bolt of light without any coolness involved...

Didn't we JUST have this thread like 2 weeks ago?

I distinctly recall talking about flash vaporization of flesh. And while I do that somewhat often, rarely is it in a Shadowrun context.

Space is Noisy

You'll get ionization of the air at high beam power, which is supposed to produce a visible effect.

But in the end, the game is a game and it is bound to be interpreted and operated by various people. As long as the people playing are happy with the sound their lasers make, and feel comfortable reproducing that sound any time their characters shoot a Yak enforcer with their portable laser system, that is all that matters. Can my lasers go 'oink'?

No they can't. If they do, Catalyst ninja-lawyers™ will rapel into your house and sue you faster than you can say Dunkelzahn's Will, you may try though.

I rest my case.

OK, this gets points for style. I can just see some 3 meter tall troll taking a stand and vaporizing badguys while yelling "Pew! Pew! Zap! Pow!"

Though on mature consideration I think I'd rather "zorch!" myself...

Totally different principle. The thing you have to understand is that unlike a plasma jet from a detonating HEAT round (very very fast) or an incoming APDS round (very fast) or the propagating detonation shock-wave of a HESH shell, the laser is vaporizing and blowing off pieces at the speed of light. This is truly instantaneous. In fact, the pulse will have dissipated by the time the actual surface detonation are tearing the material appart from internal stresses. There wouldn't be TIME for a HESH style shockwave to form, and the shattering of the material would actually disrupt the smooth propogation that HESH depends on in the first place. If the total energy was sufficent to breach into the interior of the vehicle, there would certainly be quite a bit of secondary spalling effects, as well as plasma wash and secondary effects of any remaining energy against unprotected components, but that's not the same thing at all.

And with all respect to Falconer, I think that .3 second beam window is going to be a litte long. Keep in mind, you need to charge the final capacitor, pulse the lasing diode, wait for the material to jump states and emit, lens the resultant light, focus and travel all as the initial firing step. That's all going to happen VERY fast, but even light speed means there is a time component to the beam traveling to the target. Then you have SOME cooling and cycle time between shots, if nothing else, to make sure your diode is fully returned to pre-fire energy state. Probably a quick self-test diagnostic between shots, too. Then you're charging secondary capacitors again prior to final release of energy into a final capacitor (call it a condenser) on pulling the trigger. I'd say, since I long ago stipulated super-conducting super-capacitors, the times are all going to be really short. Getting rid of heat is going to be a bigger problem with continuous firing... think a BattleTech heat gague in your HUD right next to the Charge readout. I figure actual energy pulse to be not more than .2 seconds. I expect there to be a LOT more time between shots... ok, we're talking tenths of seconds, but still.

With all due respect I really don't think you understand the damage mechanism of a pulse laser.

See
http://www.dtic.mil/ndia/smallarms/Moore.pdf
In particular, page 5, step 4.

What it does is convert a chunk of the surface of the target and the air into extremely energetic plasma, which expands with great force, imparting significant mechanical energy to the remaining surface, which propagates into the target as a shock wave. Sort of like placing a chunk of high explosive directly on the target. Like a HESH or HEP round. If the target is not sufficiently strong this will tear a hole in the target. If is is strong enough you'll get a similar spallation effect on the inside. If the target is very strong you'll just get a loud noise and a small crater on the surface, though you can eventually chew your way through if you can continue to accurately strike this point.

The focus of this presentation is on anti-personal use, but it works just the same for anti-material use. This effect is one of the reason why people who think that lasers are going to produce nice, clean and cauterized wounds are wrong. They are going to be extremely ugly and traumatic blast wounds.

Respectfully, you're talking about a pulse laser, and I'm talking about a single laser PULSE. Not the same thing at all. Here, they're pulsing rapidly with lower energy levels than I was talking about... by a long chalk. This is a way to use existing technologies to achieve a result on target, and I'm talking about three levels of technology further ahead. They are talking about 1.2kJ where I'm talking about 10+MJ. Really BIG energy delivery. That concept is a great way to get bigger bang out a lot smaller buck, considering they were hoping to make a go with as little as 100J in an anti-personnel model. I've seen it before a long time ago, but it's worth mentioning anyhow, and explains why you were looking for a HESH style blast wave propagation. But like I have said in other threads, that kind of weapon depends for success on homogeneous plate armor; Modern laminate armor packages are damaged and weakened possibly to compromization (see: Striker) by attacks like this, but their primary effect is mitigated by the heterogeneous armor layers.

But it's an excellent description of the kind if thing we ARE going to see against flesh from megajoule class lasers whenever they show up, like I mentioned above. The plasma may cautarize the flesh against bleeding, but you're cautarizing a huge gaping cavity.

Okay, time for some physics and engineering.

Laser beams do not make any appreciable noise_ even for metal-vaporizing energy levels. Yes, it ionizes air but so does my ionic breeze air purifier. Ionized air means it has a charge imbalance. Go scuff your feet across a carpet: when the hairs on your arm stand up they've been ionized. What makes noise is air that has been excited to the point of flourescence. Touch a doorknob and the spark you see is the air flourescing and the sound is from the rapid expansion (flourescing gasses are hot, and the Ideal Gas Law says a given mass of gas will expand an amount equal to the ratio of the before and after temps. Since the air goes from anbient 370K to a flourescing 28000K, you get an expansion factor of around 70. Lightning is this writ large.

Lasers won't cause air to flouresce because it wastes energy with all that glowing, crackling, and heating. Lasers will use frequencies that have minimal interaction with atmospheric gases. So treat it like subsonic ammo, essentially inaudible unless you are a very near miss.

The noise of the target depends on details of the beam type and the material hit. Given the low time-on-target from a firefight, We know its gonna dump a lot of joules in a short period of time. But then, so does a bullet. For simplicity, assume a 4 box laser wound sounds like a 4 box bullet wound. It might be hissier, or cracklier, or growlier but waste energy is waste energy.

Having heard the hum of transformers and high voltage poer lines, I'd say that laser weapons make noise equvalent to a silenced weapon with electronic firing system. It won't sound like a gunshot but it won't sound like anything else normal people hear either.

Kerenshara:
I chose the numbers arbitrarily to keep them nice and round... don't really care to get down into the weeds. The point was the energy required to flash vaporize a half liter of water already at 100deg centigrade is way up there. (not including energy needed to actually heat the material).

I also, chose the numbers so that they're arguably too long, too low, so that the counterargument of you're being too generous couldn't be used. As obviously some of the assumptions are overly generous. But the scale of the resulting numbers show best case is still way up there.


Stahlseele:
If you haven't noticed... a lot of the time in magic threads I turn around and argue. It's magic, I don't need an explanation. I just want the resulting rules to be reasonably balanced to both awakened and non-awakened.

But in this case, this is hard sci-fi... and it's fun to discuss/argue :). (and to a more limited degree educate)

This is where my thinking was going, primarily if the energy levels were getting high enough.


I hadn't considered that as a possibility and I should have.


I can live with this. I was allowing for things like the vehicle scale weapon, but if it HITS like an assault cannon... Yeah, I can live with that.


I'm trying to remember if that sound is a result of ineffeciency or another effect. If it's ineffeciency, then using super-conducting material would get rid of most of it. If it's another effect, then I would say you're probably right. Actually, a good analogy would probably be a high-power cameral flash where you hear the high-pitched and rising sound of the capacitors charging to peak and the pop of the instantaneous discharge (again, if super-conductors wouldn't remediate that entirely). Again, I can live with this as a rough-and-ready rule-of-thumb/mechanic.

Ah, ok. Not a problem then. It actually took me a second to figure out what you were referring back to, and then I remembered the last bit about actual lasing pulse duration. *shrug* I just took it as an excuse to detail some of the "steps" that would be needed to actually fire a weapon laser; I don't think most people really understand just how many "steps" and how much "time" is required to fire and ready to re-fire a semi- or fully automatic firearm, either. *grin*

From the sound of it, the best laser wouldn't make any noise, heat the weapon or air, or show any light; because all of these things would be a waste of energy at the point of impact. This is of course assuming the perfect laser, so you would probably have anything in the spectrum from 'worse than a gun' to 'the hypothetical perfect laser gun'.

That might explain the Imperial Stormtrooper Marksmanship Academy. It doesn't matter if they hit, their SOUND PRODUCING and LIGHT SHOW GIVING laser pistols are wasting so much energy that even if they did hit it wouldn't do any damage.

laser pop
even louder laser
i really don't think the sound would be devastating, but there would a unique POP for a weapons grade laser hitting the target.

as for the air path to target? maybe, maybe-not. lots of variables. i would default to a good solid humm. But that's just my minds' eye.

When I was a kid I came up with a raygun stunner that used a laser to ionize the atmosphere in its path to the target thus allowing a bolt of electricity to be conducted along the charged gases and into the target.

That's a cool little toy called an roElectrolaser.

IIRC, one of the older shadowrun books mentioned that Ares was working on for the nonleathal weapon compition in Dunkie's Will, but gave up on it due to how it interacted with cyberware.

Hmm, I don't remember Big D's will that well, but I wonder if SnS or the Pain Inducer would qualify for the reward...