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What would happen if you fired a lasgun through glass, such as a window?

Would it melt, shatter, weaken the shot, none of the above? Would it pass straight through?

Are there any surfaces that a lasgun shot could ricochet off? Would a hall of mirrors just feth up your day?

EDIT: Feel free to query more uses and features of the Imperium's faithful pew pew gun, Whilst we're here.

Depends -- glass is a composite material, Its melting point is dependent on the materials used.

We have nothing solid to compare to to determine the power output of a lasgun. But due to the transparent property of most untinted glass types means it doesn't absorb heat very well. The majority of the heat would pass through the glass and arrive at whatever destination it was heading. Therefore it's much harder to heat up untinted, clear glass via radiation, like light.

Like I said, glass is a composite material, which means different types of glass has different melting points. It seems to be around 1500 degree Celsius, but there are ones with much lower melting points.

While it takes much more energy to melt steel (as steel has a higher melting point), it's worthy noting that iron is very well at absorbing heat, whereas untinted glass allow most of the heat from light to pass through it. So it'd take far more energy to melt glass with lasgun lights, because much of that energy ends up not contributing to heating the glass material. Can it though? Maybe. At a high enough output ratio anything can be melted, or even vaporized. The problems is if one can get there.

Depends on thermal shock as well. I've seen glass tabletops shatter when hot pots were put on them. It doesn't take sudden temperature changes well, either.

Given that the wounds tend to be described in some of the novels as not unlike serious burns (like a point contact oxy-spanner) then it would seem to indicate that the energy flash-heats the water in the tissues and this sudden expansion causes the wounding.

(different writers handle it differently, I don't even think there IS a consensus on how they work in BL, let alone the whys)

It would melt a hole in the glass and pass right through. The real question is what happens when you shoot a lasgun at a mirror.

Depending on the quality of the glass and the energy of the laser, it will either melt the glass down or shatter it.

I have to wonder, seeing as a lasgun super-heats blood to boiling point and the force of it escaping casuses body parts to detach and fall off, surely the victims blood is now boiling and spreading around its body.

Say for example you get shot in the foot or hand and it doesn't kill you, the wound will be caterised but the blood should still be pumped around the body. It would burn you up from the inside wouldn't it? Like pins and needles but on fire.

....That's not how lasguns work. They don't cause limbs to fall off, they explode them.

"fall off"was a poor choice of wording. I know how they work, the laser super boils the water in the blood, the blood forces its way out of the body and this causes limbs to fly off.

No, the arms are blown off because humans are mostly composed of water throughout their body, not just the blood. Water molecules get excited before detonation, no different than a microwave in theory.

 Wyzilla wrote:
No, the arms are blown off because humans are mostly composed of water throughout their body, not just the blood. Water molecules get excited before detonation, no different than a microwave in theory.

This seems like an interesting discussion for a different thread, maybe one titled "how do lasguns work?"

In response to OP, the energy from the laser would likely just pass straight through the glass and hit its target, though a small amount of thermal energy would dissipate into the glass.

Thanks so much for the replies, guys! Though I didn't expect the different answers. I realise it's all fictional science, but thank you for taking time to reply.

The point about suddenly heated glass shattering does make me wonder. But also, I wonder if the gun might have a focusing lens or something? I don't have an exploded diagram, or know if there was one.

How about other clear surfaces like still water?

Do feel free to turn this into a "Fething Lasguns: How do they work?" (thank you ICP) topic, I can update the title when I am not using a phone screen.

I know this forum has covered recoil and sounds in the past, in quite some depth, so I was rolling this thought around for a while...

Is it cinematically appropriate for the glass to shatter? Is it cooler to pass through it? Forge that narrative! If it sounds cool, run with it. And if it would be better the other way later, don’t feel beholden to consistency. You can always blame Chaos meddling.

From a real world POV, you don’t get perfect efficiency ever. The glass is going to absorb some if the energy passing through it, the mirror as it bounces. When talking about high energy lasers, that small fraction that gets absorbed might be enough to melt/shatter it.

Lasguns are sometimes described as being "thermokinetic", which means it is a combination of heat and "punch". The window and the mirror would likely shatter.

True enough, Nevelon! The idea of a sniper being able to use a mirror or curve a shot using a piece of glass could be quite cool as well.
I'm not writing anything about lasguns (well, not at the moment) it was just an idle thought. The more I puzzled about it, the more I could see both sides.

I'm now intrigued as to what firing one into water would do...

 Psienesis wrote:
Lasguns are sometimes described as being "thermokinetic", which means it is a combination of heat and "punch". The window and the mirror would likely shatter.

This is what I'd go with, too. A las "bolt" or "shot" is made of energy. Some kinetic, some heat, some light, etc. In all likely hood, a pane of glass would simply shatter/be blown out by the force of the laser before the heat has chance to melt it.

How would you add kinetic force to photons..

Photons have mass right? (i forget me physics class)

If anything Glass and mirrors still absorb light energy. even if 99.9999% efferent energy should still be absorbed.

If that .0001 energy is strong enough to cause temperature shock then it could shatter it.

Otherwise more likely the surface is dirty and the energy hits that and that heats up and explodes.

probably.

Photons already have mass, you wouldn't need to "add" anything. Light also acts as both a particle and a wave, as we have demonstrated in our own laboratories on modern-day Earth. They have also recently developed holograms that can react to a person's touch, and which themselves provide tactile feedback.

The concept isn't so difficult to consider, really. You have a body of matter (photons), energized to a super-hot level, propelled downrange at extremely high speeds. Force is equal to mass times acceleration... even if the photons are not at all heavy, they're traveling really damn fast.

 Psienesis wrote:
Photons already have mass, you wouldn't need to "add" anything. Light also acts as both a particle and a wave, as we have demonstrated in our own laboratories on modern-day Earth. They have also recently developed holograms that can react to a person's touch, and which themselves provide tactile feedback.

The concept isn't so difficult to consider, really. You have a body of matter (photons), energized to a super-hot level, propelled downrange at extremely high speeds. Force is equal to mass times acceleration... even if the photons are not at all heavy, they're traveling really damn fast.

Well we could always do the fun thing of trying to figure out just how strong a laser needs to be to break glass and mirrors

Edit: Oh right and its possible that some glass doesn't let IR or UV range through ether,.

Well, there is glass that can stop physical bullets, so the concept of "lasproof" glass isn't so far-fetched.

 Psienesis wrote:
Well, there is glass that can stop physical bullets, so the concept of "lasproof" glass isn't so far-fetched.

I mean the glass absorbs the shot if it was say IR range laser, rather than being transparent to it (so the heat can damage the material and shatter the glass is what i mean)

I can see that being a possibility, but I dont think GW has given things like Markerlights or needle guns or even lasguns that much thought to know the spectrum and frequency of the various lasers flying about.

How a lasgun works

i always pictured las guns fireing like a very high powered laser(battle tech style/mech warrior)

then i pictured melta being like a spray of super heated napalm that turns everything molten

flamer well just a flame thrower..

Flamethrowers shoot napalm :p

Meltaguns fire an invisible beam of energy - they've been described as microwave guns on occasion - that leave a slight shimmer in the air accompanied by a roaring sound as the air in the path of the beam superheats.

Lasguns don't shoot lasers. They're liker blasters in Star Wars.

They "fire" some manner of heated blobish shot.

For more trivia, there are no moving parts in a lasgun, even the trigger is a touch pad.

 DarknessEternal wrote:
Lasguns don't shoot lasers. They're liker blasters in Star Wars.

They "fire" some manner of heated blobish shot.

For more trivia, there are no moving parts in a lasgun, even the trigger is a touch pad.

That's how I've always seen it, too. They fire "bolts" of energy (like the future war plasma rifles from The Terminator/T2 but crimson, not purple), rather than continuous beams. It's kind of how you have to remember that, despite the name, lightsabers are not actually made of light - it's an energy beam. Same with lasrifles, I feel. They fire "lasers" that are actually bolts of energy, not beams of light (like real world lasers).

I prefer the DOW interpretation of them as lasers.



Otherwise they should be called blasters.

Huh, I always imagined a meltagun as being somthing like a massive blowtorch.


I looked up some stuff about glass and if a laser can burn them. Most of the energy from a laser will pass through and out the other side, however any imperfection will absorb the light and heat up. Its the same reason you dont touch Halogen lightbulbs, the fingerprints absorb the heat and shatter the glass.

Assuming that a lasgun is powerful enough to microwave a human body instantlly, it's likely that it will have a similar effect on imperfections in glass. A simple bubble in the glass will absorb enough heat to shatter the window, a scratch or smudge will do the same. The lasguns beam will still pass through it with more than 99% of its energy left.

Someone mentioned UV light and that has me wondering... would Guardsmen go blind after constant use of a lasgun?


EDIT: woops, double post. sorted now

 DarknessEternal wrote:
Lasguns don't shoot lasers. They're liker blasters in Star Wars.

They "fire" some manner of heated blobish shot.

For more trivia, there are no moving parts in a lasgun, even the trigger is a touch pad.

No, lasguns have always been explicitly true lasers. Blasters meanwhile are also just plasma weapons.

 DarknessEternal wrote:
Lasguns don't shoot lasers. They're liker blasters in Star Wars.

They "fire" some manner of heated blobish shot.

For more trivia, there are no moving parts in a lasgun, even the trigger is a touch pad.

Except there are, literally, thousands of patterns of lasgun in the Imperium, and some most certainly have triggers. There's a dozen different pieces of studio artwork that depict this. Also, take it for what it's worth, but the lasguns carried by the IG in the DoW series fire beams, not bolts.