The Conclave

Marco mentioned the question in anther thread, and I thought it was interesting enough to start.

What are Plas Steel and Adamantium?

I always imagined Plas Steel as an advanced polymer, an STC material, which can be made from many different sources of the monomers and with trace elements in it to make it really strong. Quick and Cheap to Fabricate, with the right know how.

I always pictured Adamantium as being an Element as yet undiscovered, that lies in the next Island of Stability, the next Island of stability is the chemical hypothesis that although right now, as we make larger and larger elements, they decay radioactivly very rapidly, at some point further on, these large elements will again be stable.

This would make sense to me, as Adamantium is described as being very expensive and rare, and heavy.

What do you guys think?

With regards to Plasteel, and any other steel used in the 40k universe, I tend to imagine that the techniques used to create the metals are significantly more advanced (and utilise techniques we cannot in their manufacture) - given that 'steel' is a broad term for a variety of iron alloys with carbon content in a specific range, this isn't particularly far-fetched, especially given that the Imperium has easy access to manufacturing conditions that we can only hypothesise about  - high, low and zero gravity being the ones that spring to mind first.

Plasteel in particular I imagine as a contraction of the correct term - Plasma-treated Steel - which refers to the particulars of heat treatment used in its production. Essentially, Plasteel is a steel-based superalloy that has been heat treated using high-intensity plasma furnaces. The specifics are a little beyond me - I only work with metallurgists, I'm not one myself - but it seems appropriate for the stated vagueness of the 40k universe while still sounding somewhat plausible.

Adamantium as a new element sounds appropriate, though I've never really thought about it to be honest.

On a similar note, I've always taken that the substance 'promethium' is actually a specific compound of the element promethium, more properly known as Promethium Fulminate, but at the same time, it's also become a colloquial term for a range of petrochemical substances of similar purpose (mainly because outside of the Mechanicus, the specifics of the difference aren't known, so nobody knows any better). Again, whether or not that's actually possible is unknown to me and not of any particular concern, but it sounds a little more plausible than there being the same name for two very different substances.

Prometheum differs from real-world petrol (or whatever you put in flamethrowers) becuase it ignites on contact with air, thus not needing a starter light at the nozzle.

Quote from: RobSkib on September 02, 2009, 12:22:38 PM
Prometheum differs from real-world petrol (or whatever you put in flamethrowers) becuase it ignites on contact with air, thus not needing a starter light at the nozzle.

Yes, but real-world promethium doesn't do that. At least, not to my knowledge.

Quote from: RobSkib on September 02, 2009, 12:22:38 PM
Prometheum differs from real-world petrol (or whatever you put in flamethrowers) becuase it ignites on contact with air, thus not needing a starter light at the nozzle.

Nope. Volatile as it is, it does need a source of ignition to get it going.

If it did indeed ignite on contact with air then flamers would be more dangerous to handle than plasma weapons.

I would say the most likely explanation is that ¹⁴⁵Pm is used in conjunction with a component that ignites upon bombardment with Beta particles is mixed into the fuel component of Promethium to form the ignition compound.

Under pressure in the storage flask, there's no air to burn, but once exposed to air the beta decay of ¹⁴⁵Pm ignites this other component, which sets off the napalm-like fuel suspension. Once the fuel suspension starts to burn, it'll quickly reach the temperature at which Promethium itself burns (a modest 150 degrees). The sticky, burning, radioactive substance is more than nasty enough to be used as a weapon.

For this to work, Promethium would need to contain:
- Promethium
- some substance that ignites during beta particle bombardment
- a fuel suspension - something that burns long and hot combined with a thickening agent,preferably with something else that breaks down into more oxygen
The name Promethium would then just come from one of the ingredients of this insane mixture, turning a beta-decaying radioactive metallic lethanoid into a gel-like burn-anywhere fuel source

Well, as you say, Adamantium is dense and rare. It's also very durable and hard.

The name does imply that it's an element, but the truth is, if it were an as of yet undiscovered element, it would almost certainly be a lot rarer. What I like to think is that it's something we know of, but under a different name.
All though the name implies that it's an elemental metal, we shouldn't write off the possibility of it being some form of alloy either. Or possibly not a metal at all - after all, Helium's name would imply the same, but it's clearly not.

The closest real world equivalents are probably Elements 73-77: Tantalum, Tungsten, Rhenium, Osmium, and Iridium.
All dense, hard and pricey, these fit the bill pretty well. They vary between ductile (tantalum & rhenium) and brittle (tungsten, osmium and iridium); can be alloyed in various combinations with one another combining properties; have hard and dense carbides; and are highly corrosion resistant.

For that reason, my best guess is that it's one of those elements, an alloy of them, or perhaps even some form of carbide.

Plasteel is a bit harder to work out, and it depends on whether the plas is from "Plasma" or "Plastic"
I would suggest that it's NOT plastic, as Armaplas is already defined as a metal/plastic composite.

Thermoplas... no idea. Some heat resistant plastic? But that doesn't really explain why it would be in Land Raider armour. Although it's possibly some form of dilatant plastic, that hardens under impacts, which would explain why it was in flak armour.

While I'm at this, I'll bring up Ceramite. Little explanation is needed - some form of hard and heat resistant ceramic.

Quote from: RobSkib on September 02, 2009, 12:22:38 PMPrometheum differs from real-world petrol (or whatever you put in flamethrowers) because it ignites on contact with air, thus not needing a starter light at the nozzle.

They're inconsistent about that, and rightly so, as it's explicitly explained that promethium is just a generic term the fuel used in flamer weapons.

Personally, I think it's a bloody stupid idea to use such a self-igniting fuel - very dangerous (I can see obscene numbers of friendly casualties from filling mistakes, ruptured tanks...), and completely unnecessary.

Anyway, I personally see it as (usually, with regard to the original caveat) petrol that's modified or in some other way not suitable for vehicle use. But not all of it is - some may be self igniting, some may just be straight petrol, some may be modified petrol, some may be like napalm... lots of options.

~~~~~

In general, I work on the principle that the 40k periodic table is the same as ours in most respects, but that some elements have different names. It would be somewhat absurd for Einsteinium & Nobelium to got by those names in their universe for example.

So for example, the element we call Promethium (#61), wouldn't go by that name in their universe.

Quote from: MarcoSkoll on September 02, 2009, 01:40:44 PM
The name does imply that it's an element, but the truth is, if it were an as of yet undiscovered element, it would almost certainly be a lot rarer.

Rarity is subjective; when dealing with a civilisation willing to mine planets hollow in under a millennium, material rarity seems like somewhat less of a concern than it is for us. Beyond that, the relative rarity of elements as we understand them today are a subjective matter due to our relatively limited viewpoint - we can only say what is rare on earth, which may or may not have any bearing on such things on other worlds elsewhere in the galaxy.

It may even be an artificial element - while the Imperium may be in technological decline, the technology they do have (quite aside from the applications that technology is used for - the disparity between the advancement of Imperial technology and the ways that technology is used seems to be quite a deliberate anachronism) is quite a bit more advanced than we are, even if knowledge of its function is limited to only a few. Just because we can't do it doesn't mean it's impossible...

Quote from: N01H3r3 on September 02, 2009, 01:53:47 PMBeyond that, the relative rarity of elements as we understand them today are a subjective matter due to our relatively limited viewpoint...

I'm no expert on nuclear science, but as I understand it...

As far as natural abundance, we know that the heaviest element that can be formed by exothermic nuclear fusion is Mass 56 (Essentially, Iron, or a rare Nickel nuclide). And between 28 (essentially Silicon) and 56 is only formed in the largest of stars anyway.
Anything heavier can only be formed by the slow-neutron-capture-process in specific stars, or supernova. Whatever it is, if it's of natural origin, if it's "heavier" than 56, it was formed in a supernova.

The S-process can create up to mass 209 (Bismuth), and supernovas are capable of producing anything up to Atomic mass 254 (Californium, although it's only seen synthetically on Earth)
Anything beyond that is synthetic only. If Adamantium IS an element, and one that's not yet been discovered, it does not exist naturally.

Anyway, I'll be the first to admit that my theoretical chemistry is poor, but although "Islands of Stability" may exist, there is no great evidence that I know of that suggests that any of those chemicals will be a wonder metal as mentioned.

That's why I favour a theory that says it's something we already know of by a different name, or some specialised alloy (of known elements) that may well be manufactured and treated by techniques we don't yet know of.

Admittedly I didn't keep up my inorganic chemistry much further than Marco did, so I'm still no expert, but Marco's right about the relative abundances of the heavy elements - it's ridiculously unlikely that any metal as heavy as Adamantium should be would be available in significant amounts.

Having briefly brushed up on the subject:
I expect that any Adamantium-like that was found in the next 'stability island' would be used in a way similar to depleted uranium is now.
Since it would probably be a heavier, higher density metal, I suppose it would be used in cases of 'larger scale' applications - titans, superheavies, possibly ships [though that may be too big]. A second possibility is, since DU is currently extensively used as shielding, adamantium could be used for high-stress machinery like plasma/melta technology, Gellar field generators, ship drives and such.
High velocity penetrating shells/rounds, hard armour plating and perhaps shielding/blades for plasma/power/force weapons seem the likely military uses in the forty-first millennium, much as they are now.
Marco, if I've got the wrong end of the DU business, by all means challenge and correct it.

Quote from: TheNephew on September 02, 2009, 04:01:13 PMMarco, if I've got the wrong end of the DU business, by all means challenge and correct it.

No, you're largely on the money. But it should be said that DU (Uranium 238) is still nasty stuff.
Although its half life is roughly the same as the current age of the earth (so it's pretty much stable), it's always found mixed with U-235, which is more radioactive, and it's hard to completely free the two.

It's also (unless I'm getting it wrong) somewhat toxic. So it's a good idea not to have it around too much.

Other than the less pleasant parts of DU, there's something to be said for Adamantium actually being U-238. However, my best guess remains that it's a special alloy of some of the five metals I listed earlier. The fact that it's called adamantium may well simply be a ploy by the AdMech to keep the actual details of such a special metal to themselves - which would also play a large part in its rarity.

EDIT: Minor correction

Quote from: MarcoSkoll on September 02, 2009, 04:27:04 PM

Quote from: TheNephew on September 02, 2009, 04:01:13 PMMarco, if I've got the wrong end of the DU business, by all means challenge and correct it.

No, you're largely on the money. But it should be said that DU (Uranium 238) is still nasty stuff.
Although its half life is roughly the same as the current age of the earth (so it's pretty much stable), it's always found mixed with U-235, which is more reactive, and it's hard to completely free the two.

It's also (unless I'm getting it wrong) somewhat toxic. So it's a good idea not to have it around too much.

The radiation hazard of DU isn't small enough to entirely ignore, but it's worth noting that the risk from DU is far more because it's toxic, and pyrophoric in swarf and powder form (the latter making it extremely dirty and time consuming to cut, because you have to pour mineral oil over the stuff and cut it at extremely low speeds to avoid a stray spark causing a fire), than because it's radioactive.

If memory serves [since I was last on Wikipedia...] depleted uranium gives out about half the radiation that raw stuff of similar mass/size etc. does - so it's still pretty nasty.
As far as toxicity goes, I'd have assumed it was toxic in the way most heavy metals are - so as long as you don't spend too much time breathing dust [that being more an issue when crafting rather than using it] in or licking it, it shouldn't be a huge issue. [Or ritually stroking the surface reverentially for hours a day, I guess..]
I guess I'd have to agree that it's probably a heavy metal alloy. I was initially unconvinced due to some of the more insane sounding properties of adamantium, but then I'm not all that well educated on the properties of tailored heavy metal alloys either, so I've no reference point really.

Quote from: TheNephew on September 02, 2009, 04:49:33 PM
If memory serves [since I was last on Wikipedia...] depleted uranium gives out about half the radiation that raw stuff of similar mass/size etc. does - so it's still pretty nasty.

Oddly, not as much as you'd think. Due to its composition, most of the radiation that DU does put out is alpha, which is essentially harmless to humans so long as it stays outside the body, given that it can't get through human skin, paper, and similarly thin materials and only travels a short distance (it's extremely dangerous once it gets in, however, for much the same reason - it can't get through your skin, so it bounces around your insides. It's the type of radiation that killed Alexander Litvinenko back in 2006).

That's not to say that it's not dangerous, but between the quantity of radiation (about 60% of natural Uranium) and the type (alpha being easy enough to deal with in controlled conditions, compared to beta or gamma), it's relatively low-risk as radioactive metals go.

Trust me on this. I'd get more of a dose on a week's holiday in Cornwall than I would from spending a week at work dealing with DU. Though that's probably more because the ground in Cornwall produces a lot of Radon gas.

Quote from: N01H3r3 on September 02, 2009, 04:59:32 PMI'd get more of a dose on a week's holiday in Cornwall than I would from spending a week at work dealing with DU. Though that's probably more because the ground in Cornwall produces a lot of Radon gas.

Yup - stay out of the basement and you'll be fine though.

I can't help but think that this has got a little sidetracked though.

Quote from: TheNephew on September 02, 2009, 06:55:43 PMI can't help but think that this has got a little sidetracked though.

It has a little, but then again, this is a discussion on materials.

Depleted Uranium, apart from the toxicity and radiation, shares a lot of traits with adamantium. I imagine Admantium would be somewhat less brittle (and probably not pyrophoric either!) though.

Maybe it is some alloy of Uranium then. I like Marco's idea, it being an alloy. If it's main mixture is Uranium though, that wouldn't explain, it's rarity, Uranium is about 40 times more abundant than silver.

Also, The Admech talking about Adamantium mines, if it's an alloy. Unless of course, they don't let those outside the machine cult know that it's an alloy.

Quote from: Adlan on September 03, 2009, 11:12:02 AM
Maybe it is some alloy of Uranium then. I like Marco's idea, it being an alloy. If it's main mixture is Uranium though, that wouldn't explain, it's rarity, Uranium is about 40 times more abundant than silver.

Also, The Admech talking about Adamantium mines, if it's an alloy. Unless of course, they don't let those outside the machine cult know that it's an alloy.

Perhaps they're speaking more of the other materials specifically required to produce Adamantium, and those materials are sufficiently rare compared to Uranium to account for the overall rarity of Adamantium.

Y'know what... next week, when I'm back at work, I'm going to speak to one of my colleagues, who happens to be a 40k-playing metallurgist, about this topic. See what someone with a professional knowledge of the subject has to say about these metals...

A point to consider is that promethium would have to have an oxidising agent (oxygen) mixed in (like in TNT, which has oxygen atoms bound into the molecule, thus can provide its own oxygen giving the dramatic explosions that occur) or sprayed out at the same time otherwise it would not burn (think combustion 101; fuel, oxygen, heat). It is also daft for GW to suggest that it bursts into flame once sprayed as there may not be any oxygen in the atmosphere (e.g. Space Marines in a Space Hulk).

Also Promethium is said to be used in Imp Guard tanks and cookers, which means it can not have a massive octane rating due to engines needing a a slower (in commparsion to other fuels) more powerful burn to produce touque (which is why lorries and tanks use desiel).

My guess is that the metals that are used are alloy combinations, which at the moment we do not know about. In addition some of the metals could be isotopes that have not be discovered yet.

Quote from: Kasthan on September 03, 2009, 12:36:11 PMA point to consider is that promethium would have to have an oxidising agent (oxygen) mixed in  or sprayed out at the same time otherwise it would not burn (think combustion 101; fuel, oxygen, heat).

Not at all. I think you'll find petrol burns fine in air without adding further oxygen. Given that the operators of these things need oxygen to survive, it's safe to say that if the user is still alive to use it, then it will be capable of burning.

Actually, a big part of flamethrowers is that they DON'T mix in an oxidiser.

If you mix in an oxidiser, you'd get a very hot blue flame... but one that would have a very short range, because of the high rate of combustion.
If you don't mix in an oxidiser - you get the characteristic orange/yellow flame, which can travel over longer distances.

QuoteIt is also daft for GW to suggest that it bursts into flame once sprayed as there may not be any oxygen in the atmosphere (e.g. Space Marines in a Space Hulk).

Space Hulks have an atmosphere. If they didn't, nothing would live in them, and thus, nothing would need to be cleared out of them. Simple.

QuoteAlso Promethium is said to be used in Imp Guard tanks and cookers, which means it can not have a massive octane rating due to engines needing a a slower more powerful burn to produce torque.

Promethium is merely a generic term for a wide range of combustible fluids - think of it as a form of slang for the word "Fuel".

QuoteIn addition some of the metals could be isotopes that have not be discovered yet.

But that would still be the element in question, just a specific nuclide of it.

QuoteLike in TNT, which has oxygen atoms bound into the molecule, thus can provide its own oxygen giving the dramatic explosions that occur.

Not really... Trinitrotoluene decomposes exothermically (breaks down into smaller molecules giving off energy in the process), but the process has a high activation energy.

That is to say, it doesn't combust. Instead, it breaks apart explosively after it's conferred enough energy to start the reaction. (Similar thing with Nitroglycerine, but it has a very low activation energy, thus allowing knocks or minor heat to set it off.)

There's a difference between low explosives that are a mixture of compounds where some are fuel and some are oxidiser and thus combust... and high explosives which are simply one compound that decomposes exothermically.

I should admit that I know more about explosives than most of the people I know would like me to.

Plasteel is common across sci-fi settings, it is simply a plastic with most of the structural qualities of steels.
The concept probably arose during the 70s when polymer technologies were advancing at a significant rate and these new materials were particularly fashionable. A Plastic's very low cost plus the versatile applications of steel was an appealing concept.

I would suggest that Plasteel would be a thermoset plastic (akin to epoxy, Tuffnel, Bakerlite...etc). Once cured Thermoset plastics behave much more like metals than Thermoplastics and therefore are more suitable for construction applications...etc.
I would suggest that in most properties it is equal to or better than steel and that it is (in keeping with the ideas of the 70s) both significantly lighter and significantly cheaper. Other than cost one might suggest that Carbon fibre reinforced plastics offer an appropriate analogue.


Adamantium however is a mythic material - in some cases an alloy of known materials, in others a metal reserved for the gods themselves.
It is, without exception, incredibly tough. Treated appropriately it has exhibited ductility, hardness, strength, plasticity... It is implied that it is also reasonably elastic but never actually stated.
Put simply it is a reasonably rare, and therefore expensive, metallic material with exceptional qualities. Dense enough to function well as a penetrator (in the way Tungsten might be used in the real world), Hard and strong enough to defeat attempts to penetrate it.
Quite simply it is the best material for almost any task - except for its prohibative costs.

It's worth bearing in mind that adamantium is not something that the GW staffers came up with. It's a ficticious material that's been getting thrown around in popular fiction for decades.

If I recall correctly, the material was first mentioned in marvel comics as being a top secret alloy made from iron which was made as an attempt by some scientist to recreate the material used to produce Captain America's shield. Since then, it has featured in dozens of different universes, usually as some nigh-indestructable super-hard doomsday material. And once again, I prove myself to be, beyond reasonable doubt, a complete nerd.

My point is that Adamantium was not made by the GW brain-trust. It's an alien element that was brought in for convenience simply so that when people see the name, they think "uber-hard metal". If they had called it "Emperorium" or something, we wouldn't know any of it's properties, but since they've used the familiar name of Adamantium, we all know that it's a super-hard, high-melting point, very rare material, just because that's the way it's always portrayed in other forms of fiction.

Just my two cents on that little matter.

Adamantium, or rather adamantine or simply Adamant, has also been used in fiction since Classical times. It's hardly as if Marvel came up with something totally original.

Adamantine is also an archaic name for diamond, if it's of any use.

Quote from: MarcoSkoll on September 03, 2009, 01:06:00 PM
Space Hulks have an atmosphere. If they didn't, nothing would live in them, and thus, nothing would need to be cleared out of them. Simple.

Usually some bits of a hulk will have an atmosphere and some bits won't - and 'stealers are capable of surviving in a vacuum for some time, so it's entirely possible marines would want to use flamers somewhere where there's no oxygen.

Quote from: Kaled on September 03, 2009, 06:26:51 PM...so it's entirely possible marines would want to use flamers somewhere where there's no oxygen.

In such a case, you'd need a specialised flamer. The Imperium might be daft at times, but I can't see them creating and equipping all flamers so they have the capacity to work in vacuum. (So in this case, if there are "vacuum flamers" then the fuel they use is yet another different thing lumped under the term Promethium.)

Alternately, if they're in an area of a hulk without an atmosphere, the Marines might simply have to do without the flamer and use bolters instead - which would work in vacuum, because firearm propellants contain oxidisers.

Actually, on that note, that's one of the few things that irritated me about Firefly, the fact that Vera was supposed to need air to fire. (Science Fail)
But in their defence, although they don't need air to fire, guns do need air to cool them, so sustained fire with them in vacuum is pretty ill advised, as the gun will rapidly overheat and damage itself. So actually, you'd probably need specialised bolt weapons as well for using in a vacuum, made of more durable materials, and with a cooling system that could work in a vacuum*

And before anyone says "Space is cold" - yes, it is. However, that's useless without any air to act as a conductor to the heat.

*These do exist. The one NASA uses works by using the fact that boiling points drop as pressure goes down, and that boiling something absorbs energy. Basically, they slowly vent water into the vacuum, which boils off, taking heat with it.

Adamantium is a very ancient material - as I've previously stated "- in some cases an alloy of known materials, in others a metal reserved for the gods themselves."
Hephaestus' forges are the first incidence on the material which I can call to mind - so that's 3000 odd years in existance before it appeared in the 40k universe.

However...
While we do know that it's strong because it forms the exoskeletal framework of a suit of Tactical Dreadnaught Armour and we know that it's both hard and tough from its other applications we cannot accurately predict its properties otherwise.
Marvel's use of Adamantium differs from the original, almost all uses differ in some way from the original... In some worlds it can only be forged by magic, in some it is alchemical, in others still it is indestructable once solid...

No outside references can be used to predict the properties of Adamantium in the 40k universe simply because the adamantium of the 40k universe is different to all other instances of the fictional material.
The best guess we could make would be to call it elemental. The quintescance of metal. To say that any property one associates with metal is expressed most perfectly in Adamantium.
It would be heavy then. Aluminium is a metal and it is light but it is aluminium's lightness which makes it remarkable and therefore lightness is not a usual property of metal.
It would be strong, hard...etc. It will melt but like the one ring a blacksmith's forge won't even soften it.


On the branch topic of flamers and O2.
I would suggest that equipping Space Marines with Flamers/Heavy Flamers which do not contain either a bound source of oxygen (nitrous oxide for example) for combustion or a fuel which produces heat and flame without need for oxygen would be rather silly considering that they are all equipped as standard with a space suit.
The application of hard vacuum is not the only reason to fuel them in that manner, doing so makes the target difficult to extinguish, even by immersion for example.
There are means by which this could be done without making the flamers particularly risky - we aren't talking about a substance which needs to be self igniting for example like White Phos. The fuel could be made to have a low volitility for a start, give it a high enough ignition temperature and the risks, even on a battlefield where laser weapons are in frequent use, could be mitigated with a little refractory material... And by keeping the fuel tanks small to limit the damage when one does go up.

As to weapon overheating, Air cooled weapons do, as implied require air to conduct heat away from (particularly) the barrel but air cooling is not the only option. Water cooled weapons would be unimpeded by operation in that environment and many weapons could easily operate within normal usage parameters indefinitely because their barrels are sufficient heatsink to allow radiant heat dispersion. Bolters (given the minimal access air has to the barrel) would seem to come in that last category... particularly as the primary heat generation on such a weapon is after the round exits the weapon's barrel.

Quote from: InquisitorHeidfeld on September 04, 2009, 01:32:24 PMI would suggest that equipping Space Marines with Flamers/Heavy Flamers which do not contain either a bound source of oxygen for combustion or a fuel which produces heat and flame without need for oxygen would be rather silly...

And I argue that it's silly on the basis that a flame weapon that carried its own oxidiser would result in a hot, but very short flame.
Think of a bunsenburner - if the air valve is shut, you get a normal yellow flame, like you see in most flame throwers. If you open the air valve, you get a hotter, but shorter blue flame.

Mixing in an oxidiser more efficient than air would only continue this trend. If doing such a thing, you'd need to find a way of heavily slowing the burn rate.

Quote...considering that they are all equipped as standard with a space suit.

Power armour is better thought of as an environment suit. It can survive a vacuum, but it's not a feature you'd use by choice.

QuoteWater cooled weapons would be unimpeded by operation in that environment

Depends what you mean by water cooling.
Any water cooling that would work in a terrestrial environment wouldn't in a vacuum, because closed circuit water cooling is almost invariably air cooled itself. The heat that goes into the water has to go somewhere.
If you're talking about vacuum water cooling (which won't work under pressure), that's a different matter.

But in either case, bolters aren't normally water cooled. It would still involve modification.

Quoteand many weapons could easily operate within normal usage parameters indefinitely because their barrels are sufficient heatsink to allow radiant heat dispersion.

That's not actually the case. By the time radiant heat dispersion became particularly effective, you'd already have the barrel hot enough to be doing it serious damage.
And given that the barrel absorbs about as much heat as the kinetic energy of the shot, that would happen after only a few magazines from most weapons.

QuoteBolters (given the minimal access air has to the barrel) would seem to come in that last category...

The air has a lot of access to the barrel. We're not talking about just the air that can reach the outside of the barrel, but a lot of cooling comes from air being able to flow into and through the barrel, which given the dynamics of the gas flow around barrels is actually pretty effective.

Quote...particularly as the primary heat generation on such a weapon is after the round exits the weapon's barrel.

But they still have a basic propellant charge, which generates a lot of heat. Although bolts are self propelled, the operation of the firearm is pretty similar to any other.

Quote from: MarcoSkoll on September 04, 2009, 03:33:23 PMMixing in an oxidiser more efficient than air would only continue this trend. If doing such a thing, you'd need to find a way of heavily slowing the burn rate.

Not necessarily.

Astartes doctrine is short-duration rapid-strikes that presumably are organised with the benefit of as much prior information as possible. It stands to reason that the Astartes would have access to a variety of different flamer fuels, configurations of bolter shells and so forth, along with particular alterations to the environmental systems of their armour as appropriate for the ambient conditions to allow them to operate at peak efficiency in any situation.

Thusly, they'd have promethium for low or zero-oxygen environments, and ones for higher-oxygen environments, with the appropriate one chosen as necessary. That aside, if you're fighting something capable of functioning effectively in a vacuum, you'll probably want as hot a flame as possible if you intend to incinerate it...

It may be worth noting at this point that Imperial Armour 4 actually gives us some numbers for Astartes Heavy Flamer performance. Apparently, they contain sufficient fuel for 9 seconds of continuous fire, and "generates heats in excess of 900 [degrees] C" (enough to melt aluminium or boil sodium), suggesting a fuel which burns quickly and at high-temperature.

QuoteIt can survive a vacuum, but it's not a feature you'd use by choice.

Given the nature of boarding actions and space hulk missions, I can imagine they utilise the vacuum-proof qualities of their armour quite frequently. If you've got a self-contained heavily-armoured suit that can support the wearer in almost any conditions including vacuum, then why not use it for that? Certainly, it makes boarding actions against enemy vessels easier, as you are far less concerned about loss of atmosphere than those whose ship you're boarding.

Quote from: N01H3r3 on September 04, 2009, 06:35:03 PMThusly, they'd have promethium for low or zero-oxygen environments, and ones for higher-oxygen environments, with the appropriate one chosen as necessary.

No. If it's being done, the oxidiser and fuel HAVE to be separate, requiring separate tanks of each, and a more complex design.
Else, you'll end up with the entire tank exploding. It's very important that in flame throwers that there is no oxidiser in the fuel tank, to prevent any risk of such an incident. With an oxidiser in the fuel, then the flame can (and will) trace back through the system into the main tank, even if a flame arrester is present.

Also, can we just emphasise the point that using a flamer in a vacuum, even if it CAN work in a vacuum, is immediately less useful, because nothing but the fuel can combust (and as I've already said, it will burn very fast), thus removing any secondary sources of fire - much of the damage from a flame is through prolonged application of heat, not the application of high heat for a relatively short time.

QuoteGiven the nature of boarding actions and space hulk missions, I can imagine they utilise the vacuum-proof qualities of their armour quite frequently.

Use, maybe. Choose to use, much less so, because at that point, if there are any damaged seals in the suit (highly likely, if you've taken fire), it would no longer function as such.

It's a safety measure. It's like the gear I use when working with something that has the potential to produce shrapnel. The gear may well get used (as in stopping said shrapnel from making a mess of me), but I wouldn't choose to use it (i.e. deliberately inducing a situation where it would have to stop the shrapnel).

Quoteyou are far less concerned about loss of atmosphere than those whose ship you're boarding.

Under those circumstances, why worry about needing a flamer that can work in vacuum? If it can't work, odds on, everything you wanted to use it on is dead as well.

Survivors will be few, and I take it that any flamer armed marine will carry some form of sidearm.

Quotegenerates heats in excess of 900 [degrees] C

That's actually pretty low, and is certainly not an oxidised flame. Even a yellow bunsen flame is about 1000 degrees C. In oxidised conditions, a blue flamed bunsen is about 1300-1500 C, and I've got a blowtorch which is capable of hitting temperatures of 1500-1600 C with the right gas mixture, which is enough to melt steel without too much bother.

Quote from: MarcoSkoll on September 04, 2009, 10:23:38 PMUse, maybe. Choose to use, much less so, because at that point, if there are any damaged seals in the suit (highly likely, if you've taken fire), it would no longer function as such.

Assuming no means of quickly patching damage to the armour (which seems unlikely, really), or that the Astartes themselves are engineered to be able to endure in vacuum for a time without their armour (required standard mucranoid activation treatment before any mission which contains risk of vacuum exposure).

It's an acknowledged function of the Adeptus Astartes. Whether or not it's convenient isn't a consideration - it's still something they do better than essentially everyone else in the Imperium.

Quote

Quoteyou are far less concerned about loss of atmosphere than those whose ship you're boarding.

Under those circumstances, why worry about needing a flamer that can work in vacuum? If it can't work, odds on, everything you wanted to use it on is dead as well.

Survivors will be few, and I take it that any flamer armed marine will carry some form of sidearm.

The remaining survivors (like, say, Genestealers, who aren't exactly the most normal of creatures when it comes to their innate capabilities - if so engineered, a Tyranid species need never eat nor breathe so long as it has sufficient internal food and energy reserves to last as long as it needs to in order to fulfil it's biological imperative, and the other considerations of vacuum exposure are known to be within the capabilities of the Hive Mind to overcome) are the ones you need to worry about.

And, when considering flamer-armed marines, Terminators with Heavy Flamers need to be considered - they physically can't carry a sidearm. It's the heavy flamer (which, it should be noted, has been depicted for the last decade at least as having a multitude of feed pipes and nozzles... why must all of those be for the fuel itself) and a powerfist.

I hate to be an ill-educated arse, but Index Astartes explicitly refers to the huge amount of molten adamantium that naturally occoured within Nostramo. This would suggest to me that it's a at least a naturally occouring fictional metal

Tullio

The suggestion that all flamers, even Marine flamers, are equipped for use in vacuum is still laughable, as is the suggestion that the fuel itself contains oxidisers, which would be stupidity taken to epic levels.

Flamers might exist that can be used in a vacuum, but not all flamers would be, and even if such weapons exist, they would be dramatically limited.

QuoteThe remaining survivors are the ones you need to worry about.

Then deal with them with a weapon that will work in a vacuum. If you haven't got another weapon, then you'll have to do without.
If I had to cross water, I wouldn't faff around with creating an amphibious car, I'd use a boat. If no boat were available, I'd swim.

Even if they have no sidearm, a Terminator still has a power fist if their flamer goes south. They've got to be used to making do, because the promethium would run out every now and again.
And on that note, what happens when a Storm bolter armed Terminator uses up their magazine? You're not going to be reloading ANY weapon with a power fist for your second hand. Anyone familiar with Tactical Dreadnought armour has got to be familiar with being reduced to just a close combat weapon.

~~~~~

To get back to the original topic...

Quote from: Tullio on September 05, 2009, 01:19:07 AMThis would suggest to me that it's a at least a naturally occurring fictional metal

Well, that rules out the artificial element theory.

It does make the alloy theory a little more questionable, but it could still be shorthand for "ores used in the creation of adamantium."

Sorry to be on topic here (I find the off-topic discussion otherwise quite interesting, though!), but I'd like to reinforce the point that plasteel is almost certainly not just polymer- whether a metal-polymer composite (I have no idea if that is possible, I'm no metallurgist) or some kind of treated steel I don't know,  but I tend to imagine it as more metal than plastic, and refer to plastics as 'polymer' in 40k, to be clear about it.

As for adamantium - it is indeed a term that goes back to the classical age, and some classicists have argued that it is just an archaic term for... iron. Yup, plain, boring iron, largely obsolete in its unalloyed form today. Clearly, 40k adamantium isn't that, but I'd go with it being either a re-naming of a dense metal or an alloy of dense metals, which have already been suggested. An undiscovered element would also be possible, but only in as much as science fiction is written with with limited respect for science. Because undiscovered elements would all be fitting at the big and unstable end of the periodic table. And unless human understanding of atoms is completely wrong, there isn't space for any whole elements in between.

Quote from: MarcoSkoll on September 05, 2009, 01:39:49 AM
The suggestion that all flamers, even Marine flamers, are equipped for use in vacuum is still laughable, as is the suggestion that the fuel itself contains oxidisers, which would be stupidity taken to epic levels.

That... would... be... hilarious. Even the Imperium wouldn't be that daft.

-Aidan.

Quote from: MarcoSkoll on September 05, 2009, 01:39:49 AM
It does make the alloy theory a little more questionable, but it could still be shorthand for "ores used in the creation of adamantium."

From my understanding of it, natural alloys do exist, so this should reduce the questionability of adamantium being an alloy.

Quote from: Aidan on September 05, 2009, 03:11:16 AM

Quote from: MarcoSkoll on September 05, 2009, 01:39:49 AM
The suggestion that all flamers, even Marine flamers, are equipped for use in vacuum is still laughable, as is the suggestion that the fuel itself contains oxidisers, which would be stupidity taken to epic levels.

That... would... be... hilarious. Even the Imperium wouldn't be that daft.

[rant]Because shouting "WRONG!" at the background whenever you don't believe it to make sense is the appropriate response...

It's called suspension of disbelief, a requirement when dealing with any form of fiction, particularly fantasy and sci-fi (remembering that 40k shares more in common with the former than the latter - it's fantasy dressed as science fiction). In this case, it's the acknowledgement that our understanding of science, while not inconsiderable, remains incomplete (and gladly so - our scientists would have nothing to do if they knew everything about the way the universe works), and thus what we are limited to doing (such as, our inability to travel and communicate between worlds within a reasonable amount of time) has very little bearing on the capabilities of a culture who are still far more scientifically and technologically advanced than we are, even with all that they've lost.

I'm not saying "just go with it, it's sci-fi, it doesn't matter". What I'm asking is that people try and work from the other direction - starting with the known element of the setting and determining how it is possible, even with a couple of vague assumptions (Star Trek example: the function of the Warp Drive is a relatively easy one to consider, assuming the existence of subspace... the use of subspace is the notional leap upon which logical foundations can be constructed), rather than starting from the modern day and coming to the dismissive conclusion that something is wrong, because frankly, that's not constructive...[/rant]

Quote from: N01H3r3 on September 05, 2009, 11:57:29 AMWhat I'm asking is that people try and work from the other direction - starting with the known element of the setting and determining how it is possible...

It is not possible to use a fuel with already mixed in oxidisers like that, because it can and will burn inside the tank.

Quote...even with a couple of vague assumptions...

I sort of work on the principle of "why ask for suspension of disbelief if you don't need to", but...

However, let's propose that they have a version of promethium that's very strong acid (of course, one that wouldn't damage the flamer). It wouldn't burn in vacuum, but it would still prove dangerous. But then, you've then got to get around fluids not boiling off in vacuum.

To illustrate the point, take a syringe and fill it with boiled water so there are no air bubbles present. Cover the end, and you can't push the syringe in... but now pull it. It'll move just fine, and you'll end up with a large void, filled with what is actually low temperature steam.
A vacuum causes boiling points to change, and in this case, the minor vacuum you just created was enough to boil water - at least until enough had boiled off to bring the pressure up high enough that no more would. In a vacuum like space, liquids would easily boil off.

To tell the truth, I'm not even sure how a flame would react in a vacuum. Micro gravity is one thing to find out (it burns in a sphere), but there's very little information on how one would act in a vacuum. With the aforementioned caveat on liquids boiling off, I suspect it's an idea of very limited viability on that basis alone, even without worrying about where the oxygen comes from.

EDIT:

Quote from: Aidan on September 05, 2009, 03:11:16 AMa metal-polymer composite (I have no idea if that is possible, I'm no metallurgist)

It's viable on a scale like carbon-fibre. In other words, where you've got a metal weave supported in a plastic base, and indeed, such materials exist. However, that wouldn't match the qualities normally given to plasteel.

Something that came to me a few minutes ago, something I've only just remembered.

The recently-released Central Supply Catalogue for Mongoose Publishing's version of Traveller contains a number of 'flame weapons' which go a step beyond the conventional notion of a device that spews burning fuel over the target.

It starts with the Projection Flamer, which unleashes 'gouts of atomised fuel in a swirling cone' and which have 'a very high damage output but do not continue to burn on a normal target like other flamethrowers', and then continues the trend for "other ways to make people over there burn" with the Gauss Flamer (also known as the Gauss Thermite Superflamer), a weapon that accelerates metallic flechettes at high speed towards a target and ignites them, and then capping off the list with weapons that are more properly plasma weapons used in a manner akin to flamethrowers, projecting jets superheated ionised gas at the target.

Some things to think about, particularly as Promethium seems solely to be a colloquialism for "non-specific fuel".

Quote from: N01H3r3 on September 05, 2009, 05:43:52 PM... weapons that are more properly plasma weapons used in a manner akin to flamethrowers, projecting jets superheated ionised gas at the target.

Actually, I'll admit that I've been writing almost exactly that (although I didn't base the idea on anything specific) into the Revised Armoury over the last week or so.
However, that's a bit of a stretch of the definition of flamethrowers.

Just thinking - could the heavy flamers normally use normal fuel, then have an additional oxidiser supply for vacuum use?  It might explain all the tubes, and makes sense at least on first thought for my admittedly un-chemistry oriented brain.

That was kinda what I've been implying would have to be the option if you really did have to have a flame in vacuum.

But I'm increasingly beginning to doubt how possible a flame in a vacuum is, with or without oxidiser.

I've always assumed that "adamatium" and "promethium" were placeholder names, used by the AdMech to describe a huge range of valuable fuel and metal alloys of entirely different types, concealing their true nature from the uninitiated.  So the naturally occurring adamantium of Nostramo, and the artificial adamatium of Land Raider hulls need not be anything like the same metal.

That way, "I extract natural adamantium" and "I construct artificial adamantium" need not be mutually exclusive claims.  The "adamantium" on Nostramo might simply be a cover word for iron ore, whilst the "adamatium" on a Land Raider's exploded diagram might be a special secret AdMech alloy.

The same applies to promethium.

R.

Quote from: MarcoSkoll on September 03, 2009, 07:15:15 PM
Actually, on that note, that's one of the few things that irritated me about Firefly, the fact that Vera was supposed to need air to fire. (Science Fail)
But in their defence, although they don't need air to fire, guns do need air to cool them, so sustained fire with them in vacuum is pretty ill advised, as the gun will rapidly overheat and damage itself. So actually, you'd probably need specialised bolt weapons as well for using in a vacuum, made of more durable materials, and with a cooling system that could work in a vacuum*

And on that continued side note, because browncoat discussions always are appropriate, it was a case of did the research badly. They asked their gun guy if firearms could fire in a vaccum. He said no, and the writers then assumed it was because they needed oxygen.

Oh well, could just be that Jayne is dumb, and made the same assumption.

Quote from: Adlan on September 06, 2009, 01:52:22 PMOh well, could just be that Jayne is dumb, and made the same assumption.

Ah, the old fall back - It wasn't the writers' mistake, it was the character's...

Quote from: MarcoSkoll on September 06, 2009, 03:33:19 PM

Quote from: Adlan on September 06, 2009, 01:52:22 PMOh well, could just be that Jayne is dumb, and made the same assumption.

Ah, the old fall back - It wasn't the writers' mistake, it was the character's...

Hey, it's a solid excuse - if the writers can screw up like that, why can't the characters do likewise?

Quote from: N01H3r3 on September 06, 2009, 03:40:41 PMHey, it's a solid excuse - if the writers can screw up like that, why can't the characters do likewise?

Perhaps, but it gets more questionable when it's something a character familiar with firearms would probably know - and with the number of characters present at the time (and most similarly familiar, although not obsessed, with firearms) somewhat more so.

But then again, there are other issues with the show. Flat sides on a spaceship wouldn't exactly be a wise engineering choice.

Either way, it's still a good piece of television.

check out X-Men, as in Wolverine, for adamantium
hes had the stuff surgically grafted to his skeleton

kerby

Quotecheck out X-Men, as in Wolverine, for adamantium
hes had the stuff surgically grafted to his skeleton

Yeees, but these are two different sets of intellecutal property. The properties of adamantium in X-Men don't really apply here

Tullio

just spit balling lol, im sitting here watching Xmen with my old man so thats where my answer comes from
kerby

Quote from: MarcoSkoll on September 06, 2009, 08:05:01 PMEither way, it's still a good piece of television.

And, to be fair, the whole show is an exercise in not caring about the technical details...

Fuel burning in tanks...

1, A mix of fuel and oxidising agent does not immediately burst into flame.
In its simplest form let's consider an Oxy-Acetylene torch. The mixture of Oxygen and Acetylene coming out of the nozzle is stable. It is an explosive mixture but without external influence it will do very little.
The mix of fuel and Oxidising agent can be "safe" if it is tailored to have a high enough ignition temperature to limit risk. If the fuel mix has an ignition temperature around its 900° Combustion temperature and a high enough specific heat capacity that small sparks, las blasts...etc are smothered by the fuel before they can ignite it then the risks of tank fires are minimised.

2, Flames cannot pass through small appetures, the plasma boundary simply cannot sustain itself below a certain size - going back to the Oxy-Acetylene torch the fuel is mixed with oxygen well down the torch, but no combustion occurs until the flame boundary at the end of the torch.
If the flame could cross the plasma boundary then Oxy-Acetylene would be impossible to use - the hose and the metal of the oxygen cylinder would be more than sufficient fuel.


Radiant Heat

You (Marko) seem to have a very low opinion of the capacity of radiant heat...
Hold your hand close to the side of your cup of tea/coffee - the heat you're detecting is predominantly radiant. There is some conducted through the air between your hand and the mug but air has a very low specific heat capacity and therefore you need a large amount of it to contain any significant quantity of heat (not temperature but heat). Water (of which I hope your tea/coffee contains a considerable proportion) however has a very large specific heat capacity.
Most of the heat loss from your mug of tea comes in the form of evaporation, energy usage, a state change from liguid to vapour and therefore a conversion of heat energy to kinetic energy plus a mass loss from the system. A significant portion comes from convection, another heat to kinetic energy transfer... but a significant portion, almost a quarter IIRC of the heat loss is through radiation.
Radiation is considered a short ranged method of energy transfer - predominantly because in atmosphere radiated heat quickly transfers to matter and becomes convection or conduction. In hard vacuum however it is more efficient simply because there is so little in the way.

Quote from: InquisitorHeidfeld on September 07, 2009, 01:29:34 PMThe mixture of Oxygen and Acetylene coming out of the nozzle is stable. It is an explosive mixture but without external influence it will do very little.

I'd hardly call something with ignition energies in the microjoules stable. 17 microjoules in air. About 100 times less in an oxy/acetylene mix, with an exceptionally wide explosive limits of 2.5% to 82% in air.

Very bad example.

QuoteThe mix of fuel and Oxidising agent can be "safe" if it is tailored to have a high enough ignition temperature to limit risk.

Which is pretty unlikely. Oxidised mixes, particularly homogeneous ones, have very low ignition energies. Like I said above, acetylene needs 100 times less energy to ignite it in pure oxygen than in air.

QuoteIf the fuel mix has an ignition temperature around its 900° Combustion temperature and a high enough specific heat capacity that small sparks, las blasts...etc are smothered by the fuel before they can ignite it then the risks of tank fires are minimised.

Firstly, see above statement on the unlikelihood of such a mixture.

Secondly, you should pay more attention to ignition energies than ignition temperatures. The latter is of little relevance when discussing the likelihood of accidental ignition.

Quote2, Flames cannot pass through small apertures.

Only partially true. It can happen under some circumstances - and I know, having done it. The circumstances in a flamer are likely to be one of those, particularly with oxidisers present.
Truth is, we need to talk not just about aperture size, but the ratio involved when talking about flame arrestors.

But anyway, you're confusing "unlikely to explode" with the correct answer of "We have taken every possible precaution to avoid it combusting."

QuoteYou (Marko) seem to have a very low opinion of the capacity of radiant heat...

Firstly, there's a K in Skoll, but there's not one in Marco.

Secondly, I'm an engineering undergraduate. I don't think it would entirely inaccurate to say know a bit about heat transfer.

I don't have a low opinion of radiant heat - the best thermometer I own works solely on radiant heat. However, I do have an accurate one.

Take your cup of tea/coffee (it can't be mine, I don't drink either), and leave it, preferably covered to minimise heat loss from convection. Put it on a heat insulator to help reduce temperature loss to the surface it's on as well.
Five minutes later, it's still going to be pretty hot, so even accounting for the fact that water has a high specific heat capacity, it's not shifting too much energy at 100 degrees.

Now, consider the heat energy generated by a gun. An automatic AR-15 will generate easily 20 kW of heat when firing. Without any heat loss, That's enough to increase the barrel's temperature by 50 degrees per second of firing.

Calculating radiant heat from the barrel means that even if we assume there is no received radiant heat (which would be nonsense, particularly inside a space craft), under constant firing (also nonsense, but whatever), the barrel's equilibrium temperature would be 2000 Kelvin - more than hot enough to melt it.

However, a barrel doesn't need to be hot enough to melt it in order to be doing it damage. Hotter than 600 Kelvin would be starting to push it, and to maintain that as an equilibrium temperature, you only need to be firing for seven rounds (one half second) a minute.
Of course, it takes more than that to reach said temperatures, but let's say that in a combat situation, you're firing 50 rounds each minute (~1 second of firing in every 20). Your barrel would eventually reach equilibrium at 975 Kelvin, way more than enough to be doing it damage.

I'm also even doing the calculations with simplifications that assume the barrel is perfectly thermally conductive. In reality, it is not, and it's only the inside of the barrel that needs to get too hot, and it's the (cooler) outside of the barrel which is responsible for radiant heat loss.
So in reality, the amount of fire you could maintain without damaging a firearm in space is even lower than these figures.

Hence, I maintain my earlier point that radiant heat loss is not nearly enough to allow you to keep using a firearm as you normally would.

Quote from: MarcoSkoll on September 07, 2009, 07:03:30 PM
I'd hardly call something with ignition energies in the microjoules stable. 17 microjoules in air. About 100 times less in an oxy/acetylene mix, with an exceptionally wide explosive limits of 2.5% to 82% in air.

It's stable without outside influences - it does not self combust.

QuoteWhich is pretty unlikely. Oxidised mixes, particularly homogeneous ones, have very low ignition energies. Like I said above, acetylene needs 100 times less energy to ignite it in pure oxygen than in air.

But it's not impossible by any means.
Volatility is the important factor - adding an oxidising agent will increase the effective volatility but with the right tailored mix...

QuoteSecondly, you should pay more attention to ignition energies than ignition temperatures. The latter is of little relevance when discussing the likelihood of accidental ignition.

Ignition temperature is (relatively) constant, Ignition energy significantly less so.

Quote

Quote2, Flames cannot pass through small apertures.

Only partially true. It can happen under some circumstances - and I know, having done it. The circumstances in a flamer are likely to be one of those, particularly with oxidisers present.
Truth is, we need to talk not just about aperture size, but the ratio involved when talking about flame arrestors.

How the vortices form and interact and how conductive the material surrounding the vortex is is even more important... and reasonably predictable.

QuoteBut anyway, you're confusing "unlikely to explode" with the correct answer of "We have taken every possible precaution to avoid it combusting."

Touché.
My riposté:
I think you're confusing "unlikely to explode" (ie less than 50% chance) with "chance to explode compliant with design levels".

Quote

QuoteYou (Marko) seem to have a very low opinion of the capacity of radiant heat...

Firstly, there's a K in Skoll, but there's not one in Marco.

Apologies. My bad.

QuoteSecondly, I'm an engineering undergraduate. I don't think it would entirely inaccurate to say know a bit about heat transfer.

I've been a professional engineer for more than 15 years. I work within a sphere where managing heat loss is incredibly important.

Quote<Snip>
Hence, I maintain my earlier point that radiant heat loss is not nearly enough to allow you to keep using a firearm as you normally would.

Maintaining 600RPM from an open bolt weapon in a hard vacuum I would agree... But then maintaining 600RPM in an air cooled, open bolt weapon will allow barrel creep in atmosphere.
But Bolters are another matter.
The design is, to my mind, neither air nor fluid cooled. The sheer mass of the barrel suggests heat sink - and equipping Space Marines (the clue is in the name) with a weapon which operates at sub-optimal efficiency in a hard vacuum is simply bad design.

Gents,

You're both very, very clever and interesting.  Stop arguing and let the rest of us get on with gawping in awe.

R.

Quote from: InquisitorHeidfeld on September 08, 2009, 01:43:34 PMIt's stable without outside influences - it does not self combust.

It may not self combust, but battlefields are however full of such external influences.
If we take a lasbolt to be very focused and energetic, we can almost certainly guarantee that the heat generated, at least locally, will be sufficient to exceed ignition temperature and ignite the fuel.

If an oxidiser is present, this will then result in combustion (and probably explosion) of the tank's contents. If not, then it will result in a rather impressive gout of flame from the tank. Neither is particularly desirable, but the latter is likely to be less of an issue. And again, the oxidised mixture is still almost certainly going to be more prone to ignition.

QuoteI've been a professional engineer for more than 15 years. I work within a sphere where managing heat loss is incredibly important.

While impressive credentials, they don't mean that my knowledge of the area is in error.

Either way, I have specifically sat down and done maths that told me unambigiously that you could not practically use an M-16 (first weapon for which figures were easily available) in a vacuum for any prolonged time if relying on solely radiant heat loss to cool it, and unless you want to show me other maths to prove otherwise, I stick by the point.

QuoteBut Bolters are another matter. The design is, to my mind, neither air nor fluid cooled.

The 3rd Edition 40K rulebook's picture of a storm bolter (p 60) shows air cooling vents are present on at least some models.
Anyway, simply having a hot weapon in air will result in heat loss to the surrounding air. A weapon may not make special provision to be air cooled, but they will derive at least some cooling from the air around.

QuoteThe sheer mass of the barrel suggests heat sink - and equipping Space Marines (the clue is in the name) with a weapon which operates at sub-optimal efficiency in a hard vacuum is simply bad design.

... and given the fact that the game designers are not gun designers, the design they use being bad (or incapable of what is claimed of it) sounds like a very likely situation.

No liquid cooling, a lack of atmosphere for air cooling and the low power dispersal of radiant heat loss means that unless they've found a way to dramatically reduce heat transferred to the barrel (either by lower heat conductivity or cooler propellants) or some new method of disposing of said heat, bolters could not realistically work in a vacuum as they are depicted.

So, while I accept that bolters can be and are used in vacuums to at least some degree of effectiveness within the fictional universe, I am saying that the same could not be replicated in reality.

QuoteSecondly, I'm an engineering undergraduate. I don't think it would entirely inaccurate to say know a bit about heat transfer.

QuoteI've been a professional engineer for more than 15 years. I work within a sphere where managing heat loss is incredibly important.

QuoteWhile impressive credentials, they don't mean that my knowledge of the area is in error.

I agree with what Robey said, folks, this is turning into a Cigaro scenario. At the very least, get some ground work down and then build up from there so that the uneducated masses (like me) know what the hell you're arguing about.

To be honest, I'm not sure the groundwork will make the heated debate any more relevant.
I expect Marco at least will disagree with me, but I don't think we need to know these things about the bolter or flamer.
Or, at the very least, not in a thread about plasteel and adamantium.

Quote from: TheNephew on September 08, 2009, 06:47:39 PMI expect Marco at least will disagree with me, but I don't think we need to know these things about the bolter or flamer.

Not at all. Having done the maths, I'm convinced it couldn't work in real life, but this is a point that I'm happy to let be. Generally, if I actually had to do anything more than the most basic of mental maths to be entirely sure of something being wrong*, then it's close enough.

*The exception being when I know something is wrong, and I'm doing the maths to find out how ridiculously bad...

I'm a little concerned that there's mathematics to do for bolters when the specifics about dimensions, mass, the propellant in the shells etc. are so elusive...

I reverse engineered a lot of information about bolters a couple of months ago. Enough to do the calculations in question, but for practical reasons, I did the maths with the data of the M16 instead. The information from it is still informative about using guns in a vacuum.

You reverse engineered information on a fictional weapon? Crikey. You are clever...  ;)

So you'll be building them next....  ;)

Without the specifics of anything like the production methods, the relative technologies used to construct the weapons, what effect the Warp has on physics in the 40k universe, this is a lovely exercise in academia but since it's based in our physical realm where as far as I'm aware, 8ft tall super soldiers aren't blasting at daemons from another dimension, it's just that - academic rambling demonstrating how much super knowledge you chaps have in your relative fields.

And well done on that, by the way. It's interesting stuff and I'm genuinely impressed, you guys know *alot*.

But, can we be serious for a second - it's a fictional realm.

If I say "They use super duper heating sinks" it has as much credibility as you chaps showing the science in this world works and renders weapons useless / hot / whatever in a fictional realm.

@the OP - I like the idea of plasma treated steel = plasteel and adamantium being an as yet undiscovered super alloy. They sound cool.

-Ben

Quote from: Dosdamt on September 23, 2009, 02:21:58 PMYou reverse engineered information on a fictional weapon?

In a manner of speaking. There's enough numbers about them, as well as pictures to make it possible to estimate dimensions, mass and performance with some accuracy.

QuoteBut, can we be serious for a second - it's a fictional realm.

Of course, but when I originally posed the question in the other thread, I was setting it up to be assessed from the viewpoint of science as it's known today - mostly to avoid just what you talk about... people pulling out the "the canon says it just happens, okay?" arguments in place of the "Actually, if you look at it, it could possibly work like this..." arguments.
In other words, looking it at it from the perspective of science fact, rather than science fiction (or if you prefer, science fantasy).

So strictly, while you can say "Magical heatsinks that use unicorn tears and fairy dust for a heat transfer mechanism", that's outside the spirit of the discussion.

I don't mean to be offensive, and please don't take it that way, but surely that is complete and utter nonsense. The pictures are drawn by artists and the numbers loosely made up to ensure the weapon could be used by an 8ft tall superhuman. If they were proposed technical diagrams drawn by some kind of mish-mash of a technical draftsman / ballistics expert / futurologist, then perhaps there'd be some credence.

Not only that, but if you're making calculations of any kind on this kind of stuff, surely you'd have to throw in a giant variable X, X being the gap between today's scientific knowledge + any general differences in the laws of physics. Accounting in those terms and quantifying the variable i.e. 'For this to feasibly work using what we know today and using our laws of physics, the weapons would have to x y z' is a different statement to 'This won't work according to our science and our laws of physics'.

Where do you draw a line? The ins and outs of warp travel? The Necron FTL engine? The Webway? 'Nid bio-titans? Idle speculation is fine, but surely there comes a point where you have to say 'Ok, that's a bit far fetched, but let's roll with it / 30 000 years of scientific advancement probably accounts for it'.

-Ben

Quote from: Dosdamt on September 23, 2009, 10:59:27 PM
I don't mean to be offensive.

You aren't being. every one is so nice these days... whatever happend to Charax, he's being quite quiet :D I miss it!

I understand where Marco is coming from here. If you have, even a basic, understanding of a certain field of expertise which is then translated into fiction it is often difficult to accept. I like my 40k to be Grimdark and gritty like everyone else (generalising of course, excuse me mr Zoat/ squat fanboy...) but it is Science Fiction, rooted in fact (there are people, lots of war happens which is depressing... yadda yadda) but the Fiction part is important. Alien would have been a less good film without the aliens (hell even starship troopers would have been), we readily(ish) accept las technology and Warp Drive etc in Sci Fi, we can also only speculate on things that exist outside our world in reality.

This forum is about a game. and a game setting. Sometimes we all need to keep sight of that.

Bearing in mind of course we have to make concessions to every body else's interpretation of the game setting.

I wouldn't just say that /30 000 years of scientific advancement probably accounts for it. I'd say the fictional nature of the setting does and the fictional advancement of technology more than accounts for it and pales in comparison to the completely off the wall appearance of a Blood letter bursting through your plasteel wall and raping your warband to death. suddenly nobody cares what its made of....

yours sarcastically and lovingly

Adam

Quote from: Dosdamt on September 23, 2009, 10:59:27 PMI don't mean to be offensive, and please don't take it that way, but surely that is complete and utter nonsense.

Nonsense? Well, if you want to believe that, but while the dimensions I have aren't millimetre perfect, they do at least possess some degree of accuracy. Enough to work with, at least.

QuoteNot only that, but if you're making calculations of any kind on this kind of stuff, surely you'd have to throw in a giant variable X, X being the gap between today's scientific knowledge + any general differences in the laws of physics.

I have to take it that the laws of physics, at least before you throw in the warp, are as near to identical to ours as makes no difference, because any notable deviation from them would result in a universe where the existence of anything we could recognise as similar to our world would be preposterous.

This concept is better known as the anthropic principle. Anyway, for that reason, basic laws of motion, thermodynamics (obviously including the warp as part of the closed system for the 1st law) and whatnot would be things we could recognise. Physical constants might be a mite off, but not enough to throw off any calculations by an amount that would matter.

QuoteIdle speculation is fine, but surely there comes a point where you have to say 'Ok, that's a bit far fetched, but let's roll with it / 30 000 years of scientific advancement probably accounts for it'.

If there's a far-fetched point, personally I'd rather hear "There isn't really an explanation for it" than some attempt to rationalise it with pseudo-science. In other words, more or less what Adam said: "It's not the 'science' that's the answer, it's the fiction".

Obviously though, IMHO, I'd rather sit down and change the situation so that neither solution was necessary - seldom possible, but we can dream.

I'm sorry, I might be backwards, but can you explain how an artistic rendering of anything could be a fundamental basis for a 'scientific reverse engineering' of anything!?! I'm genuinely struggling to get my head around it. It's not even an approximation, it's not based on sound assumptions, because it's a sketch by an artist. It probably doesn't work because it's not a technical drawing! If you believe you can do a sound scientific assessment of anything based on an artist's rendering then knock yourself out, but that doesn't sound like solid science to me.

How do you know the basic laws of physics are the actual laws of physics? Sure, I can prod my pen and it'll move - equal and opposite reaction and all that - but that's based on our current understanding of the universe. 1000 years ago the earth was flat etc etc etc. I'll not labour the point.

What you are doing *is* psuedo-science simply because trying to drag something (a) fictional or if we ignore that (b) we assume it is this universe, 38 000 years in the future, into our current understanding of physics / science is a nonsense simply because you have basically have a story / artistic renderings to go from.

I tell you what, go 38 000 years into the past, I'll explain the concept of a computer / gun / whatever mundane device we take for granted today to you, and let you explain why it simply wouldn't be possible with a rock, the basic ability to make fire and a club and their understanding of the laws of physics / science.

-Ben

If you start from the assumption that something is possible - time travel, say, or teleportation - then you can work backwards using known scientific principles to see how it might be done, even though those things are fictional devices.

Similarly, with the bolter, we know roughly what its effects are, how many rounds it can fire and approximately how large it must be.  If we start from those principles, using modern materials and ballistic technology, it is possible to work backwards from those assumptions to achieve some idea of how the weapon may operate or how it may be constructed.

"Reverse engineering" is, perhaps, not the perfect term as this usually describes taking something that already exists and working out its operating principles from that fact.  "Reverse fictioneering" might be a more appropriate term.  But it's still perfectly feasible.  Most inventions start from the "this should be possible" image before working backwards through the principles to determine how to build said thing.

There is nothing inherently impossible about a bolter.

R.

Plasma treated steel as Plasteel doesn't work...

Plasma treatment of metals is used today to improve surface properties - but while the plasma part of the process allows a very even treatment it offers nothing which would revolutionise the material.
Use Plasma as your heat source and you still get molten steel. Use it to introduce another material and you still get an alloy (to all intents and purposes), use it to heat treat the metal and it will perform in the same way as any other flame.
Either you may as well use steel formed or alloyed by some other method, or if plasma treatments offer cost benefits for example then all steel will use that method except on primative worlds - so it becomes simply steel.

We know from the known properties that Plasteel is cheap - which means that it's not akin to modern plasma treatments, simply because they add cost to components which could easily be simple steel.
The implication from the various other comtemporaneous sources has the prefix "Plas" used to indicate a polymer compound - and the way it is used in those senses tends to follow the same formula:

"Plas" + "Contraction of the material for which the compound substitutes"

This gives us primarily Plascrete - a polymer substitute for concrete & Plasteel - a polymer substitute for steel.
Note that these are both materials used in vast quantities in construction and fashionable materials at the time we're primarily considering.

I still maintain you must include a huge variable in there i.e. the gap in knowledge. Stating that something couldn't realistically work according to our knowledge is a nonsense when you factor in that variable. Saying we don't have the current technology / know-how in that particular area is considerably more accurate.

I agree with the basic premise - start with an idea, state it must be possible, try and make it to that idea using current thinking - but then categorically stating something is not possible because my current knowledge says it isn't possible is silly.

That is what I assume scientists do you in your situation Robey - start with a problem i.e. faster than light travel, next step what do we know in the area i.e. laws of relativity and all that, what don't we know enough about i.e. generation of the huge amounts of energy etc etc required to make it work, next step advance knowledge in that area. They don't simply stop at 'it's not feasible because my laws of physics / knowledge of manufacture state they're not possible'.

This debate about a debate has reached a point of vicious circle so I'll poke my nose elsewhere.

-Ben

Quote from: InquisitorHeidfeld on September 24, 2009, 01:14:04 PM
Plasma treated steel as Plasteel doesn't work...

Plasma treatment of metals is used today to improve surface properties

Which assumes that a hypothetical form of plasma heat treatment (or the processes it is used to enable) is identical to a real contemporary one, and ignores the fact that the Imperium demonstrably are far more able at utilising the practical applications of various plasma technologies than we are.

One particular desirable grain structure, from one particular alloy, most easily achievable by a specific (but undefined and hypothetical) process... that's all it would need to be.

The ever-present problem with treating 40k as if it were science fiction, rather than fantasy that happens to include starships and lasers alongside its swords, magic and orcs, is that it isn't intended for such scrutiny - 40k has about as much to do with science as the banana flavouring in milkshakes has with real bananas...

Quote from: Dosdamt on September 24, 2009, 11:21:05 AM...but can you explain how an artistic rendering of anything could be a fundamental basis for a 'scientific reverse engineering' of anything!?!

I never said "scientific reverse engineering" - it's you who is adding the word "scientific". The words I used were more along the lines of "approximate".

If we take an image, and work from known dimensions, it is still possible to estimate the dimensions of at least that particular bolter within the image. If that doesn't agree with another bolter in another image... well, it's already set out in the canon that bolters are repaired for as long as it is feasible to do so. Hence, all bolters are actually unique anyway, so as I've already said, I'm not pretending the measurements are millimetre perfect.

I still maintain the numbers are enough to do some rough calculations by, at least.

Anyway, I think you're misunderstanding why I did the "reverse engineering". It was all part of a discussion on the last 'clave about bolter practicality and the issues related to normal humans lugging them around.
The point is nicely illustrated by the mock-up I did of a 20 round bolter magazine (http://i210.photobucket.com/albums/bb122/RagnarokEOTW/IMG_1705copy.jpg). For reference, the modern 20 and 30 round STANAG magazines are on the same scale. The bullets are 7.62x39mm (top) and 5.56x45mm (bottom), used in the AK47 and the AR15 (as well as most other modern assault rifles) respectively.

QuoteHow do you know the basic laws of physics are the actual laws of physics?

Lack of any evidence to the contrary, in the simplest form.

There are some things we know aren't quite right (parts of quantum physics for example), but given nothing has proven the "basics" wrong, they're considered to be the genuine article.

Quote from: N01H3r3 on September 24, 2009, 11:31:04 PM40k has about as much to do with science as the banana flavouring in milkshakes has with real bananas...

Banana flavouring and real bananas have at least one shared attribute - either makes me somewhat queasy. It's an odd but unfortunate situation - the thing is, other than that, I quite like bananas.

On the bolters debate, because quite frankly I didn't want to see this rise to the top of the bowl again:

If there's reason to suggest that it might work this way or [/i]that[/i] way, then we can just apply some general physics-y guff and leave it at that, surely. Same for things like meltaguns and other directed-energy weapons in the 40Kverse. We don't need exact specifics, because there are none (Marco, I'm sorry, but your numbers don't count, because you're still working from assumptions rather than hard data which still isn't available), so the best we can get -- and incidentally all we need -- is from just a casual and general application of physical laws as opposed to getting technical with diagrams and whatnot. The amount of time between now and the age of the Imperium will just iron out any problems.

Remember, the idea of mobile telephones was absolutely laughable less than half a century ago, and now we get things that I could quite easily break in my hands, because technology is better understood (and arguably a lot more fragile).

tl;dr version: just let it rest

Quote from: Koval on September 25, 2009, 08:18:27 AMMarco, I'm sorry, but your numbers don't count, because you're still working from assumptions rather than hard data which still isn't available.

Again, when originally I did the numbers I didn't intend for them to be used in this fashion, and I never said they were any more than approximations.

I can't see why everyone is up in arms about the use of estimated numbers (in fact, only the suggestion of estimated numbers - I did the calculations with genuine AR15 data). There are, after all, such things as "rough calculations".

QuoteRemember, the idea of mobile telephones was absolutely laughable less than half a century ago, and now we get things that I could quite easily break in my hands, because technology is better understood (and arguably a lot more fragile)

I'd argue otherwise. While the technology to make a portable phone wasn't around yet, the science behind them was. The concept of "spread spectrum communication" (the core principle behind mobile phones) was first patented in 1942, although Nikola Tesla alluded to the the idea back in patents he filed in 1900 and 1903.

In many cases, the concept behind things very frequently proceeds the technology with which to do it by some dramatic amount of time. In other words "It's possible - it just isn't possible yet" is a very frequent answer.

Quote from: N01H3r3 on September 24, 2009, 11:31:04 PM

Quote from: InquisitorHeidfeld on September 24, 2009, 01:14:04 PM
Plasma treated steel as Plasteel doesn't work...

Plasma treatment of metals is used today to improve surface properties

Which assumes that a hypothetical form of plasma heat treatment (or the processes it is used to enable) is identical to a real contemporary one, and ignores the fact that the Imperium demonstrably are far more able at utilising the practical applications of various plasma technologies than we are.

One particular desirable grain structure, from one particular alloy, most easily achievable by a specific (but undefined and hypothetical) process... that's all it would need to be.

Except that it is the grain structure or the alloying which is important in these examples.
We talk about Manganese steel or cast iron - how the alloy is arrived at or what fuel was used to heat the metal to its pouring point is not a concern.
We make no distinction between coal, gas or electric arc furnaces when dealing with the final product and it is counter intuative that the Imperium (or more specifically the Mechanicus) would in this way.
And if they do, where are the references to Costeel, Gasteel, Arsteel, Solasteel...etc.

In general terms a process would be referred to as an uncontracted prefix (cast, wrought, Drop forged, Plasma Nitrided).
The "corruption" here suggests something rather more like a trade name...

Before I get people telling me that trade names don't fit into the Mechanicus or something similar...
Kevlar is not a name descriptive of the polymer it represents - but even if you eliminate the DuPont corporation (who trademarked it) from your universe it is much easier to use the word Kelvar to describe similar materials than to either invent a new word which you would have to explain to the reader or (worse yet) to describe the chemical formulation or structure of the substance and completely confuse everyone.

Quote from: InquisitorHeidfeld on September 25, 2009, 04:52:20 PMWe make no distinction between coal, gas or electric arc furnaces when dealing with the final product and it is counter intuative that the Imperium (or more specifically the Mechanicus) would in this way.
And if they do, where are the references to Costeel, Gasteel, Arsteel, Solasteel...etc.

And? I'm willing to accept inconsistency in fiction, given how inconsistent real life so frequently ends up being (as the saying goes, "truth is stranger than fiction, because fiction has to make sense"). Considering that there's not only thirty millennia of technological development and decline, but also a similar amount of linguistic drift and cultural evolution, terms we might consider strange to describe something we would describe differently are not exactly an issue I find myself getting flustered about.

Just to add some confusion, remember that "plasteel" would presumably be the translation from High Gothic, in which language it would hopefully be clear whether the prefix referred to plasma or plastic.

Simply because of the existence of plascrete, I'd go with the polymer explanation.

I'm more prepared to accept linguistic and social explanations for both materials, personally. Adamantium in contemporary langauge is more or less synonymous with "super-hard-mega-metal", even though it is indeed derived from Latin. Same goes for Plasteel - I think we're all in agreement that whoever invented the metal had no intention of creating a name that alluded to any industrial process in particular - thus I'm prepared to let the name go as a 40K linguisitic anomaly.

The social development and regression of a people is routinely overlooked in science fiction and fantasy alike - mostly, I suppose, because people would rather believe that the spear creates the society rather than the other way around - and in this case is probably more relevant to our discussion than anything else, as Dosdamt pointed out. Philosophically speaking, we can only guess at how such weapons as the Bolter, Flamer etc might work, given that the definition of knowledge as "justified true belief" forces one to accept that knowledge today might not be knowlegde tomorrow.

Blimey, that was a mouthful


Tullio

Oh, JTB... how you irritate me. :) Just because I have to deal with Gettier...

When it comes to terminology, I do wonder why people are bothered by oddities in terminology, as if all of our words are totally consistent - there are loads of conflicts of differing usage or multiple words, often from the approach being different now to how it was then. "Random" has a particular meaning in mathematics - but in the case of "Rowntree's Randoms", the word is now a synonym for "arbitrary" or "unexpected". This much annoys the mathematicians of my aquaintance. Or "Hag". Would any of you call a lovely young woman a hag? Shakespeare would have. Word use and naming has more to do with social or political influence than logic. So of course in the 10000 year old, 1000000 world empire of the Imperium "plasteel" or "Adamantium" may refer to a variety of things.