Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

I suppose they mine the water of water worlds or mine the hydrogen and oxygen of gas giants then combine it to make water.

And then the recycle and chem treat the water the have to within an inch of it's life.

Melissia wrote:

KamikazeCanuck wrote:But an army can't be supplied indefinitely from the fleet's recycling abilities. Law of conservation of mass and all that.

Law of conservation of mass says that it basically can. What goes in a person will eventually come out after all. Matter doesn't just disappear.

I think you're confused. That would run the fleet dry. The planetside army doesn't go back onto their ships to pee.

KamikazeCanuck wrote:

Melissia wrote:

KamikazeCanuck wrote:But an army can't be supplied indefinitely from the fleet's recycling abilities. Law of conservation of mass and all that.

Law of conservation of mass says that it basically can. What goes in a person will eventually come out after all. Matter doesn't just disappear.

I think you're confused. That would run the fleet dry. The planetside army doesn't go back onto their ships to pee.

No, that just means there's a limit to their capability without resupply. If they never touch down, it's really just dependent on their ability to create energy, which is essentially limitless in 40k.

It doesn't but it is turned into energy for movement, sweat, body temperature, talking, etc. The only way to get it all back would be to have a 100% efficient collection system that managed to grab all the energy expended by a person and reform it into water without expending energy during the process.

So, probably not happening. You need resupply in some form.

-cgmckenzie

The water is not being turned into energy.

It is combined with other chemicals to form what we call sweat, yes, and it's released in the form of humidity from the mouth due to us needing to keep our lungs moist to breathe, yes, and of course it is a component in urine due to its nature as a solvent, yes, hell, even feces has some moisture to an extent. But all of these can be recycled. Humidity can be taken out of the air with current technology, so doing it with futuristic technology and collecting the moisture for recycling isn't unbelievable.

But it is not being turned into energy. It is still water, but either mixed into other stuff (in the case of feces), evaporated (in the case of breath humidity), and or has other stuff mixed into it (in the case of urine and sweat), and so on.

The chemical reaction for digestion, the process of turning food into energy, includes water. So yeah, it is being turned into energy in some amounts. Not overwhelming but still happening. It has been years since I took chemistry, so I won't even try to get the formula up here, just know that it does happen.

-cgmckenzie

cgmckenzie wrote:The chemical reaction for digestion, the process of turning food into energy, includes water.

You reaaaaaally don't understand chemistry very well, do you?

No, I do. The release of energy from the reaction is similar to combustion, where a small amount of the original material will be converted to energy. A large part of that converted matter is foodstuffs but small portions of water are converted as well.

Keep to the topic and don't be attacking other posters.

cgmckenzie wrote:No, I do.

No you do not. I am not attacking you, merely correcting your mistake. And a mistake it is. This is basic first-semester non-majors college chemistry stuff here.

Or hell, even non-majors biology. In cellular respiration-- the most important method of the body for obtaining energy from food-- the overall chemical reaction is something along the lines of C6H12O6 (glucose, which as a side note is why diabetes is so dangerous) + 6 O2 (oxygen gas, which is why we need to breathe) → 6 CO2 + 6 H2O + energy (in the form of ATP after the breaking of bonds). This is almost a reverse of the reaction in photosynthesis (not exactly mind, but the concepts are quite similar). Matter is neither created nor destroyed-- nor is energy created or destroyed. Matter is not turned into energy in this reaction. It merely changes forms due to the changing of various molecular bonds. This energy is produced from the breaking of bonds, not from turning matter into energy. The majority of the water we require is "lost" (IE, it leaves the system) through moisture in our breath, urine, and sweat-- not through metabolism. Water isn't broken down or "used up" in metabolism. Water leaves the body not through being "turned into energy", a nuclear reaction, but through waste (urine and feces), evaporation from skin, moisture from breathing, and moisture from every pore in the body.


WATER IS NOT TURNED INTO ENERGY. I mean for feth's sake, at least look up the damn things on wikipedia, it might not be a scholarly source but even IT tells you you're wrong. I'm not insulting you, I'm just saying you're wrong. If you think someone saying you're wrong is insulting, then you should stop trying to argue with people.

Mellisia is right here... at least from what my teacher said.
At any rate is is sort of on-topic since we need to decide whether it is viable or even possible to do what you suggested.

It seems the Guard get most of their water on site with resupply only being needed when they are in arid environments.

Ok, I looked it up again in my ancient encyclopedia(circa 1945, seriously) and it is different than wikipedia, so I'll admit my mistake. BTW, I have no problem being told I am wrong, happens often actually, but I read the long 'really' as insulting. If that was a mistake on my side, again my bad. If you meant it, well

I still find it hard to imagine that water is shipped in large quantities, simply because of its massive weight. Small stores are probably carried and most will be acquired on site. Or they could be breaking down atoms to neutrons and gak then rebuilding water from it?

-cgmckenzie

It probably isn't a very high tech solution.
More likely they ship it or find it on site.

Besides, they ship large quantities of promethium (promethium ships whose lengths are measured in the half-dozen kilometer range), so I hardly think shipping water would be that much more difficult.

Those ships must make such a massive explosion when they get hit.

promethium is a scarce resource, though. Water is available on mostly any world people live on/invade, so it would be far less reasonable to ship water than it is to ship promethium.

-cgmckenzie

cgmckenzie wrote:promethium is a scarce resource, though.

Not really.

They can harvest promethium out of a wide variety of resources-- for example, in Caves of Ice, they were refining glacial ice into promethium.

Even Feral Worlds can produce promethium, though it will be considered extremely "low grade". Still, you can put it in a flamer and set mofos on fire with it.

It would also require some form of refinement to be able to be used, not like finding a pond of water that needs to be filtered.

And by 'scarce' I mean relatively so; there is a vastly larger supply of water than promethium in the galaxy, so it might be worth the extra shipping costs.

-cgmckenzie

Nope...
Unrefined promethium is good to burn. It isn't as good for flamers and vehicles but it works.

purplefood wrote:Those ships must make such a massive explosion when they get hit.

Unless promethium contains sufficient oxygen to react with itself if sufficient energy is applied (like the aluminum/rust reaction in thermite), that's unlikely, as there'd be nothing for it to react with in a vacuum.

Melissia wrote:

cgmckenzie wrote:promethium is a scarce resource, though.

Not really.

They can harvest promethium out of a wide variety of resources-- for example, in Caves of Ice, they were refining glacial ice into promethium.

That was either not water-ice or was water-ice with hydrocarbons either sequestered inside it or below it. I distinctly recall promethium being considered too valuable to be used as fuel, instead being used exclusively in weapons, but I don't know how consistent that restriction is throughout the fluff.

It wasn't ice. The glacier was on top of the deposit of promethium...
Not sure what form it was in but go figure...
That made a big boom...

Wrong, it was the ice itself.

Promethium itself can be produced in a variety of ways, and from an astonishing number of sources. Among the most common are the atmospheres of gas giant planets, subterranean deposits of ancient organic materials, and certain kinds of rare ices found only on the coldest of worlds

From Caves of Ice. The three would be the most abundant sources and probably produce the largest quantity of promethium, but as noted, there's an astonishing variety of other sources as well.

Really?
Okay then i'm good with that.
Exploding ice sounds way more fun that normal ice.

Sounds like a fun movie...

Frosty the Snowman part two: Burning Ice!!
*thumpity thump thump

-cgmckenzie

So how much water does it take to keep 1 army going for 1 month? Hopefully a mathematician is reading this...

Under normal conditions a human requires roughly half a gallon/two liters a day, though it's higher for particularly active humans, especially in dry/hot environments. So, I don't know, fifteen to thirty gallons times the number of soldiers, including any water that's in food they're eating, though they'd probably be adding drinking water to dried food, so that's unlikely to be a source of water beyond rations under normal conditions. I believe they have water purification devices/pills, and they're already bringing fuel, food, and ammo for the guns that require constant resupply, so throwing a bit of water into the mix probably wouldn't be a significant burden in most cases.

In the current theatre of war(hot, dry, annoyingly sandy) we drink A LOT of water, something along the lines of 2 full camelbaks and 2-4 canteens. The variability comes from resupply/manliness in carrying a lot of canteens. So a gallon and a half usually(I have a big camelbak).

The water we get from the MRE's. we are told, is has just enough to help with the digestion and only digestion.(see above formula) This cuts down on weight, water is heavy, and ensures that we drink more than the minimum to keep us fighting fit. Of course, that could be army brass lying to us but I am sure there is some modicum of truth in there.

The human metabolism shouldn't have changed too much so the water consumption will probably be around equal to that.

-cgmckenzie

Or less, really, because most fights don't take place in deserts (there's rarely anything to fight over there).

And keep in mind, that MREs aren't soylens viridians. They're tastier (the SV is described as having a sort of taste that you thankfully can't put your finger on) but less nutritious.

Kasrkai wrote:

loner wrote:What about recycling urine? I believe they do such things in space. Why can't they do it in their new ships?
(No Bear Gyllis jokes, please...).

Tryanid on Space hulk?
Better drink my own Peeess.

On topic:
If the Guards get into the space ship, don't they bring water with them?
I mean, inside their bodies as well as in bottles, flasks or something?

Anyways, this started because my friend was telling me about his 7 year campaign that was fought entirely over water. Sounded strange to me at first but after thinking about it I do think water is a strategic resource worth warring over.