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Creating Water from Thin Air

Iphtashu Fitz writes "In order to provide the U.S. Military with water in places like Iraq, the Defense Advanced Research Projects Agency gave millions of dollars in research funding to companies like LexCarb and Sciperio to try to extract water from the air. Amazingly, a company that DARPA didn't fund, Aqua Sciences, beat them all to the punch by developing a machine that can extract up to 600 gallons of water a day from thin air even in locations like arid deserts. The 20 foot machine does this without using or producing toxic materials or byproducts. The CEO of Aqua Sciences declined to elaborate on how the machine works, but said it is based on the natural process by which salt absorbs water."

71 of 348 comments (clear)

  1. They did this in ancient times in the middle east by spun · · Score: 5, Informative

    I recall reading an article about ancient rock mounds, where the rocks were loosely lumped with plenty of space in between. Air filtered through and encountered the cool rock faces of the interior of the mound. Water condensed on the interior rock faces and trickled out the bottom. I'll see if I can find a link.

    --
    - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
  2. We already have one of these... by phekno · · Score: 5, Funny

    at my seitch.

    Sincerely,
    Muad'Dib

  3. Someone contact the Fremen by Verteiron · · Score: 3, Funny

    I'm sure they'll be interested.

    --
    End of lesson. You may press the button.
  4. It should work... by ShadowBlasko · · Score: 4, Funny

    Just as long as the superconductors you use on your condensors are not vulnerable to a puppeteer plague.

    If that happens its going to take a long time before Louis shows up.

    --
    There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order- Ed Howdershelt Via Tass
    1. Re:It should work... by illegalcortex · · Score: 2, Informative

      That might have been the cover story, but I seem to remember at some point it being revealed to be a puppeteer machination.

  5. Invented a long time ago, in a galaxy far away... by bbk · · Score: 4, Funny

    Anyone heard of Tatooine's moisture farmers?

    I thought so.

    (sorry, it was just too obivious)

  6. Why the surprise? by Syncerus · · Score: 3, Insightful

    What, you're shocked that all the government funded plodders were out done by a Capitalist independent? Government is very poor at creation and is typically very poor at selecting future winners in the technology race. That's why government should be a consumer of technology rather than a producer of the same.

    --
    "Man is nothing without the works of man" -- Helvetius
    1. Re:Why the surprise? by geekoid · · Score: 2, Insightful

      thats simply not true.
      Historically the government has been a great catalyst of techology inovation and improvements.

      Considering that this company that has allegedly done this claims no byproducts and won't let anyone know how they did it.
      color me Sceptical.

      --
      The Kruger Dunning explains most post on /. http://en.wikipedia.org/wiki/Dunning%E2%80%93Kruger_effect
  7. Good! by thefirelane · · Score: 4, Interesting

    So the government failed to fund a company who promised unbelievable results with no byproducts while not supplying any details? I must say, I'm actually proud of them. Glad to see tax dollars aren't being wasted on Vaporware

    1. Re:Good! by Random+Utinni · · Score: 5, Funny
      Glad to see tax dollars aren't being wasted on Vaporware


      I thought Vaporware was the desired result here, no?
    2. Re:Good! by Kpt+Kill · · Score: 3, Informative

      Did you read the article at all? The company was awarded the contract. The machine works. DARPA just never funded their research.

  8. Water is great by Anonymous Coward · · Score: 4, Funny

    Is there a button to switch it from 'water' to 'beer?'

    1. Re:Water is great by Rik+Sweeney · · Score: 2, Funny

      Is there a button to switch it from 'water' to 'beer?'

      I called Jesus, he said that he can do water into wine... will that do?

    2. Re:Water is great by Gryle · · Score: 5, Funny

      If it's American beer, there's really not a difference.

      --
      Only two things are infinite, the universe and human stupidity, and I'm not entirely sure about the universe - Einstein
  9. Re:Windtraps by Amouth · · Score: 2, Funny

    who wants to bet it is a water tank? that has to be "serviced" to keep running :)

    --
    '...if only "Jumping to a Conclusion" was an event in the Olympics.'
  10. Frank Herbert was prescient by CRCulver · · Score: 3, Interesting

    I was thinking of Dune myself. Frank Herbert's notion that man could survive with such limited water supplies apparently wasn't entirely fantastical. However, IIRC no such device was used in the series. Instead, the Fremen relied on farming the naturally forming dew of the planet. Personally, after reading Kim Stanley Robinson's Mars trilogy, I wonder why Herbert never thought of having some Fremen just crash a few comets into the planet to at least provide some selected portion of it with water. Of course, that would have killed off all the sandworms.

    1. Re:Frank Herbert was prescient by pete-classic · · Score: 2, Informative

      You recall incorrectly. Windtraps.

      -Peter

    2. Re:Frank Herbert was prescient by vistic · · Score: 3, Funny

      Please don't tell me you have a prototype stillsuit in the works, to recycle your urine and feces.

      That's one thing I would not want to beta test.

      Just make sure that the processing parts of it still work when you're walking without rhythm.

    3. Re:Frank Herbert was prescient by Julian+Morrison · · Score: 2, Insightful

      Why not? Well (1) they were hiding their numbers from the Padishah emperor and the Harkonnens (2) they needed all their money to bribe the spacing guild to hide their numbers (3) it was unthinkable to imperil spice production (4) waterbombing Arrakis would quickly kill off the spice and the worms (5) the guild navigators would see this quite clearly in advance, and turn against them (6) they'd lose the addictive spice, worms as transport, Shai-hulud, and the impenetrable defensive wall of the desert. Plus they were, when it came down to it, tribal semi-savages, and more used to persistence than immediacy.

  11. Re:I have one of these in my car... by Verteiron · · Score: 2

    The difference is that this will operate down to 14% humidity. So in other words, you could stick it in the desert and keep the troops watered.

    You could distribute it to villages with bad water sources.

    In fact... this thing could be a pretty big deal if it's cheap enough to produce.

    --
    End of lesson. You may press the button.
  12. hm by inKubus · · Score: 5, Informative

    Sounds like they probably use a hydroscopic compound such as calcium chloride and then you some type of ion replacement to recover the water (precipitate calcium metal and some other non-soluable salt, such as Fe(III)Cl.

    --
    Cool! Amazing Toys.
    1. Re:hm by hchaos · · Score: 3, Funny
      Sounds like they probably use a hydroscopic compound such as calcium chloride and then you some type of ion replacement to recover the water (precipitate calcium metal and some other non-soluable salt, such as Fe(III)Cl.
      Quick! To the Patent Office! That'll teach them to keep their methods secret.
    2. Re:hm by c4miles · · Score: 5, Informative
      The word you're looking for is Hygroscopic. From the article you linked to:

      The similar sounding but unrelated word hydroscopic is sometimes used in error for hygroscopic. A hydroscope is an optical device used for making observations deep under water.

      A related word, deliquescent, refers to substances so hygroscopic they will dissolve themselves using water absorbed from the air.
    3. Re:hm by Big+Bob+the+Finder · · Score: 5, Informative
      Calcium bromide (CaBr2) is slightly more hygroscopic, absorbing moisture down to 16% RH (Handbook of Chemistry and Physics); it's also a hexahydrate- it sponges up a lot of moisture. Right below that is lithium chloride, which continues to absorb down to 11% RH.

      Most likely it's a system where prilled or powdered salt is tumbled through dry air to absorb moisture; it's then roasted to release the moisture, captured under reduced pressure to reduce the amount of energy required, and returned to its anhydrous state. It'll be clumpy and chunky, so it'll have to be re-ground into a fine powder before reuse.

      The $.30 a gallon is probably largely from the amount required in the removal of the water from the hydrate; distillation of water runs ~$.25 a gallon (assuming no recycling of the waste heat from condensation to pre-heat water going into the boiler) at $.10/kwh. Using gasoline or diesel would be considerably more expensive- thus the reduced pressure.

      Distilled water from air- not too shabby. I've thought about trying the same here in the desert (where it's routinely ~10% RH in Phoenix), but it's just not worth it.

    4. Re:hm by merphant · · Score: 2, Informative

      I worked for a place that was working on this too. They used lithium bromide to suck the water out of the air, and then extracted the water by reverse osmosis. Presumably you could do power the RO unit with solar panels.

  13. Uncle Owen! by norminator · · Score: 4, Funny

    What I really need is a droid that understands the binary language of moisture vaporators.

  14. Just add water! by quarrel · · Score: 5, Funny

    Asked to clarify how it worked, the CEO noted- "Just add water, and in a few minutes it'll be ready!".

    --Q

  15. The world needs fresh water. by cowscows · · Score: 2, Insightful

    If this technology really works as well as is advertised, how bout the government does something with it a bit more productive than sending a bunch to the army? Like maybe buying thousands of these things and shipping them to many of the different places in the world where a lack access to fresh water is one of the most pressing health concerns of millions of people.

    It's good that our soldiers are out in the middle east doing their jobs, and they deserve fresh water too. But seeing the general anger towards the US that's prevelant in so much of the world right now, actually helping people with something like this would generate tremendous good will. It'd probably be a lot cheaper than our wars are as well.

    --

    One time I threw a brick at a duck.

    1. Re:The world needs fresh water. by synth7 · · Score: 4, Insightful

      Who is going to provide the guards for these condensers, because you know that the local warlords and privileged will abscond with them as another source of wealth and power. There's more than just buying the equipment, there is maintenance and policing, just to name the obvious manpower needs.

    2. Re:The world needs fresh water. by couchslug · · Score: 2, Insightful

      Giving people free stuff does not address ideological conflict.
      If an ideological opponent gave ME free stuff in hope that I could be bribed, I'd thank the nice man and then use it against him.
      If someone to whom I was indifferent gave me free stuff, I would thank the nice man and then question their motive.

      --
      "This post is an artistic work of fiction and falsehood. Only a fool would take anything posted here as fact."
    3. Re:The world needs fresh water. by cowscows · · Score: 3, Insightful

      Meh, I also do not think we should have gone to war in Iraq. It is, however, not correct or productive to place the blame on the troops, and since they're over there following orders as best they can, they deserve our respect and the best logistics/support that we can manage to give them.

      --

      One time I threw a brick at a duck.

    4. Re:The world needs fresh water. by Blacklantern · · Score: 2, Insightful

      Who is going to provide the guards for these condensers....

      The equipment would not need any extra protection. They would most likely be kept along with the other supplies (chow, parts, and medical suppllies). The normal guard details should be able to handle protecting this equiment just by adding a few feet to their patrol routes (if the camp has to expand to encompass them).

      --


      "There is only a one in six billion chance that you actually exist"
  16. Linky link by spun · · Score: 5, Informative

    Here we are, as promised. About a third of the way down the page. Ignore the Reichian weirdness, the wells were built near the ancient Byzantine city of Feodosiya. There were 13 large conical tumuli of stones, each about 10,000 feet square and 30-40 feet tall, on hilltops. Russian engineer Friedrich Zibold calculated they would each produce more than 500 gallons daily. These theories have been disputed by some archeologists (who don't seem to like it when engineers discover cool archeological stuff and make up theories about it) but the mounds do all have numerous terra-cotta pipes around the base, presumeably to collect the run off

    --
    - None can love freedom heartily, but good men; the rest love not freedom, but license. -- John Milton
    1. Re:Linky link by asolipsist · · Score: 2, Interesting

      This sounds like a good mythbusters experiment. Do adam and jamie read slashdot?

  17. Finally... by Mantrid42 · · Score: 4, Funny

    Some good Vaporware!

  18. Reusable Jokes by zulater · · Score: 2, Insightful

    Now I just need a droid that understands the binary language of moisture vaporators. Oh sorry, I thought every comment was supposed to have that joke in it.

  19. not surprising by z3d4r · · Score: 2, Informative

    this is coming from an australian company, seeing as australia is both the most arid continent and largest desert island in the world.

    --
    You shall know him by his Sig
    1. Re:not surprising by MostAwesomeDude · · Score: 2, Informative

      Actually, if we're going by humidity as an indicator of available water, Antartica's far more desert-like. It's also bigger.

      --
      ~ C.
  20. Re:I have one of these in my car... by Yartrebo · · Score: 2, Informative

    It's pretty much a reusable desiccant - and in the best case (probably using reverse osmosis) the energy cost will be about an order of magnitude worse than desalinization plants. It even says in the article that the cost is 30 cents a gallon (which is probably highly optimistic and certainly cannot be verified without full disclosure from the company). At 30 cents a gallon (or perhaps 3 dollars a gallon when you're operating it in field conditions) you could forget about serving any sort of civilian market, and even for military use it would be quite expensive.

  21. Re:And remember kids... by kfg · · Score: 2, Insightful

    sucking all the moisture out of the environment will have no impact on the eco system, right?

    Pretty much, since you pretty much put it right back in. That's why you need so much of it in the desert. And why there's so little eco system there to damage.

    How much water gets used up when you flush a toilet? That's right. None. There's no water shortage, it's a question of purity and distribution, not quantity.

    KFG

  22. Some points to consider... by Rockinsockindune · · Score: 2, Interesting
    To make this work and be cost effective in reality these things have to continue to be cheap to run. A few things the article doesn't mention are:
    1. Does it require electricity, if so how much?
    2. Do the chemicals used in the condensation need to be replenished? If so, how often, how much potable water can be generated per load of chemicals, what is the cost of the chemicals?
    --
    I abuse commas, I cannot help myself.
  23. Serious questions ... by Shadowlore · · Score: 5, Insightful
    Question1 L How inept are the congressional people in Washington DC?

    "I was pretty blown away by the things it's able to do," Rowe said. "The fact that this technology is not tied to humidity like others are makes it an attractive alternative for military bases in the Mideast where humidity is not really an option.


    Yet further down ...
    Aqua Sciences' machines only require 14 percent humidity,


    Anybody with half a brain knows that there has to be some humidity in the air in order to extract water. Wait, that explains it. ;) Moving on.

    While it is an accomplishment to reduce the humidity requirement, it doe not eliminate it. Indeed given their claim of up to 600 gal/day I'd say that at the minimum required humidity of 14%, it is possible that they may require far more of them than is talked about. A key factor is how rapidly that output drops when the humidity levels drop. if it porduces 600 gal/day at optimum humidity levels, it may only put out say 10 gal/day. If that were the case you could not rely on this for troop support in such areas. A supplemental, sure.

    Depending on the size and maintenance requirements, as well as the phsyical inputs other than air, it may not be cost effective to use these in more arid regions. Now, places like the southern US they would be quite useful.

    What I'd like to know is the size and power requirements. Something like this could be quite useful in high-rise buildings. Pumping water to the upper levels requires a significant amount of power. If instead we could put a few of these on tops of buildings and use them to bring water down, we might see a net win in terms of supply and energy usage. Imagine places like Phoenix or Las Vegas.

    Pheonix has an average daily humidity of about 55% IIRC. Thus it would stand to reason that these units could pump out their maximum output. Depending on their size and power requirements, several of these atop an office building in Phoenix could produce several thousand gallons per building. As office buildings their water requirements might be low enough to satisfy with these units. They would have the further advantage of dehumidifying the hot air of Phoenix, thus possibly resulting in a slight cooling load reduction.

    Even small residential units could be tremendously benefited. The average person requires 125 gal/day. Thus one of these could supply the water needs (not counting grass lawns) of a family of four in Phoenix. If the house is designed with greywater and systems for landscaping purposes it is possible that one of these could fully supply the average water requirement of a family of four in Phoenix. Which leads to the question .. how much are they to acquire and operate?

    Anyone from Phoneix care to share how much you pay for water? If you've got a spouse and a pair of kids, and this unit eliminated your water usage bill (there would still be sewage), how much would it save you per year?

    40,000 of these units in Phoenix would drop the summer daily demand for water by 24Mgal/day, or 5-12% depending on the season (Summer to Winter).

    Essentially, if this proved cost effective then the more arid parts of the country might be able to make large savings on their infrastructure and supply costs. Which would be yet another miltary requested technology applied to positive civilian use.

    The next question is: does it scale up and down? Can it be scaled down to be an effective one-person supply? Do larger units demonstrate a better-than-linear increase in water production?

    Combine this with greywater systems, solar thermal heating (water and home), and appropriate landscaping and we would be a long ways toward a more sustainable system - without major changes and reductions to our standard of living.

    --
    My Suburban burns less gasoline than your Prius.
    1. Re:Serious questions ... by sm62704 · · Score: 2, Informative

      Pheonix has an average daily humidity of about 55% IIRC

      You don't RC, it's more like 3%. Its 20% right now and they're predicting rain, which they usually don't get a whole lot of.

      The humidity is so low they don't use standard air conditioners there; they have "swamp coolers" which work by evaporating a stream of water. Very cheap and efficient where there's practically no humidity at all. At 50% humidity one wouldn't work.

      --
      mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
    2. Re:Serious questions ... by Shadowlore · · Score: 2, Insightful

      In an attemot to answer some of my questions ...here is the company's site and product listing.

      http://www.aquasciences.com/

      Apparently they have container models that can produce 1200 gal/day. 20'x8'x8'. So a couple of these on office buildings would do niceley.

      They seem a bit on the large side for single-family home use. Bummer. Perhaps that would improve. These seem to have a built-in generator. If attached to grid I wonder how much smaller these would be. Perhaps multi-family structures could work out well with these, depending on electrical needs. At a target price of 25 cents per gallon, I suspect many places would, for now, be cheaper to use "city water". The question however then becomes: for how long?

      Even Phoenix has cheaper water than this. Much cheaper.

      However, for "off the grid" types, this is the last piece of the puzzle.

      --
      My Suburban burns less gasoline than your Prius.
    3. Re:Serious questions ... by hankwang · · Score: 2, Insightful
      Even small residential units could be tremendously benefited. The average person requires 125 gal/day.

      What?? Here in the Netherlands, which does not exactly have a water shortage, the water consumption for residential use is about 125 liters per day per person.[1] That is about 4 times less! What do you do with all that water?

  24. Re:Wait... by boarder · · Score: 2, Informative

    The water will be consumed by soldiers who will breathe it out, sweat it out and urinate it out. The breath, sweat and urine will all evaporate the water back into the air. This is essentially a closed system with some losses which are overcome by adding energy into they system.

    --
    IANAL, but I play one on /.
  25. Lithium [Chloride|Bromide], probably by comingstorm · · Score: 3, Interesting

    It sucks the moisture out of the air, then you heat it up and evaporate the water, leaving the salts behind to be reused.

    The great thing about is, all you need is a heat source. You can either burn fuel, or use waste heat coming off a turbine, or even use solar energy -- you need temperatures above boiling, but not too much higher.

    This is the same stuff they use for solar-powered heat pumps, except there they use a closed loop system, and evaporate the water at low pressure to get air conditioning.

  26. Today's Irony Moment by sterno · · Score: 5, Insightful

    Government is very poor at creation and is typically very poor at selecting future winners in the technology race.

    See also the Internet you're using to post your comment. Oh wait, DARPA created that, nevermind.

    --
    This sig has been temporarily disconnected or is no longer in service
  27. I know a SERE instructor... by rampant+mac · · Score: 5, Informative
    I hang out with a SERE instructor and do a lot of camping / hiking / ORV riding where I'm sometimes far away from reliable potable water. He gave me some pretty cool information about how to obtain water from your surroundings:

    1) Water from plants is always drinkable. I'm talking about water from the root system, not some stagnant water you could slurp out of a recess between branches. The easiest way is to take a large trash bag, grab a cluster of branches and put the bag around them (make sure the open end of the trash bag is tightly sealed to prevent air from going into the enclosed bunch). It forces the tree to "sweat" water from its root system. After about 24 hours you can slit the bottom of the bag and drain it into a nalgene bottle. You can only do one group of branches per 24 hour period, so you need to use different trees to gather water. I tried it out when I was in Eastern Oregon (which, for all intents and purposes, is an inland desert) and averaged about 1 liter of water per 24 hours. I had 6 trash bags that I normally have in my hiking ruck, so I could feasibly harvest 6 liters per day if I was SOL somewhere.

    2) A cluster of birch trees usually means there's water underground.

    3) Any multi-celled berry (ie: raspberry) is edible.

    Anyway, I thought it was pretty cool shit, and informative. :)

    --
    I like big butts and I cannot lie.
    1. Re:I know a SERE instructor... by exp(pi*sqrt(163)) · · Score: 2, Funny
      Maybe you're also unaware that in the rest of the world we don't eat wichetty grubs, we have no idea how to wrestle with crocodiles and we don't drink Fosters.

      A little while back I asked an Australian friend of mine about the 'Crocodile Hunter'. He told me that he was unheard of in Australia and he was just some Australian stereotype promulgated by American TV. But when Irwin died I read comments like that of the Australian Prime Minister saying that he represented the real Australia. So now I assume that all Australian stereotypes are accurate :-)

      --
      Doesn't it make you feel good to know that our freedoms are protected by politicans, lawyers and journalists.
  28. Solar Still by David+Off · · Score: 4, Informative

    A solar still produces water in the desert and uses no external energy source other than sunlight (there is plent of that in the desert)

    1. Re:Solar Still by jamesh · · Score: 2, Informative

      In central Victoria (South Eastern Australia), we're having a bit of a drought at the moment. I was listening to talkback radio show where a woman was talking about a fairly simple device to collect dew (basically just some fine mesh with a collector down the bottom) and how it could be used to keep a few plants alive without actively watering them.

      This got me thinking though, what is the effect going to be if this sort of thing is deployed in a really large scale? Does it reduce the moisture content of the air by any measurable amount? I guess in suburban areas if you just used the collected water to run evaporative air conditioning then it might even things out...

      On the other hand, one of the feared run-away effects of global warming is that higher temperatures will speed up evaporation, and the increased moisture content acts as a greenhouse gas. Maybe we should be sucking the moisture out of the air a bit more :)

  29. Re:these vaporators you speak of... by sm62704 · · Score: 2, Funny

    Obi Wan: "These aren't the vaporators you're lookong for."

    Dumb soldier: "These aren't the vaporators we're lookong for. Move along."

    --
    mcgrew's razor: Never attribute to stupidity that which can be explained by greedy self-interest
  30. Re:They did this in ancient times in the middle ea by N1ck0 · · Score: 2, Informative

    It sounds more like they created a substance that uses intermolecular forces to have a high attraction to water (like salt or any other desiccant). The secret is making it so that under a specific condition these water molecules can be released again (heat, pressure, etc). Then possibly combined it with standard evaporation methods through compression and cooling (standard dehumidifier).

    So in all they probably just found, or dynamically adjust, the 'sweet spot' between the two methods to produce the most amount of water with the least power.

  31. Re:Shelf life? by CorSci81 · · Score: 3, Insightful

    Of course it has a shelf life. Over time bacteria could potentially grow in your bottled water. Bottling methods aren't 100% sterile, nor do they maintain their seal until the end of the universe. Hence you assign everything meant for human consumption a shelf life based on some extremely conservative estimate of how long the product is likely to remain uncontaminated under "normal" storage conditions.

  32. Not having read the article... by attemptedgoalie · · Score: 3, Informative

    Two things.

    1: Water does have a shelf life, which is why if you're storing it for long periods you have to add stabilizers.

    2: The bottles can leach into the water over time, and some plastic bottles are set up so that they will begin to bio-degrade in a couple years, hence the date stamped on each bottle when you buy them.

    --
    My mom says I'm cool.
  33. Re:And remember kids... by erice · · Score: 4, Informative

    It's only an issue if water is permanently removed from the environment, which it generally won't be. Water was in the air and in a few hours, it is back again.

    This is actually much better than trucking in water from afar or pulling it out of deep wells. In that case, you are altering the environment. Water not previously in the environment is being added.

  34. Re:Windtraps and KFC by timeOday · · Score: 2, Insightful

    Besides, a recipe isn't just ingredients, but also the process, which can be equally important. Think about wine: "Ingredients: grapes."

  35. George.. by msimm · · Score: 2, Funny

    what did we tell you about trolling the forums?

    --
    Quack, quack.
  36. Can I get a shoutout from all the foodies? by jjohn · · Score: 4, Interesting
    From the article:
    "We figured out how to tap it in a very unique and proprietary way," Sher said. "We figured out how to mimic nature, using natural salt to extract water and act as a natural decontamination.

    "Think of the Dead Sea, where nothing grows around it because the salt dehydrates everything. It's kind of like that."

    All the Alton Brown geeks in the house should have perked up their ears when they read that. Salt is hydroscopic; it attracts water. Sugar is also hydroscopic, but salt is much cheaper (especially if you don't need food-grade salt).

    There are two ways salt is harvested by humans: evaporation and mining.

    I can see using salt to grab the moisture in the air present in the pre-dawn skies, but I don't rightly know how to make the salt give it back up. I assume they just cook the rocks and capture the steam. Salt, being a rock, can be heated lots of times before degrading.

    I imagine a process like this would produce fairly clean water.

    Give up for Food Science! Hell ya!

  37. Re:They did this in ancient times in the middle ea by GIL_Dude · · Score: 2, Funny

    Maybe it was only red spray paint from PETA after they got mad at Moses for breaking the pet rock.

  38. Re:I have one of these in my car... by Dun+Malg · · Score: 3, Insightful
    I have to think at some point, dehydrating the air in an already arid region is going to have negative effects on the local climate.
    Typical overestimation of man's power. You need to spend some time thinking (with apologies to Douglas Adams) about how phenomenally big the earth's atmosphere is. You might think that 300 gallons a day is a lot of water, but keep in mind that the atmosphere contains 1.12E17 gallons of it, and that only represents 0.0031% of the water on earth. Humanity does not have the wherewithal to affect the humidity such that it makes a fart in a thunderstorm's difference to the climate, even locally.
    --
    If a job's not worth doing, it's not worth doing right.
  39. Old technology by tsotha · · Score: 3, Funny
    This technology is actually pretty old.

    One of the problems which has dogged airships from day 1 is the inability to replace the weight of burned fuel. There's a couple ways you can deal with this problem, but none of them are ideal. Modern blimps and airships are actually heavier than air, relying on lift from engine pods to get the airship in the air. As they burn fuel they get lighter, but they're never actually "lighter than air". Early airships were much too large for this strategy especially since engine technology was far less advanced.

    The most successful airship in history, the Graf Zeppelin, used a gas called Blau Gas to power its engines. Blau Gas is just a mixture of propane and hydrogen that weighs the same as air, so when you burn it and the gas volume is replaced by air of the same weight you don't have any buoyancy problems. Graf Zeppelin used hydrogen, which is relatively cheap, for its lifting gas. If it became too light they could vent enough hydrogen to restore neutral buoyancy.

    But this scheme wasn't very efficient, from an engineering perspective. Every cubic meter of fuel was a cubic meter that couldn't be used for lift. Also, as they designed the Hindenburg they were concerned about safety, so they decided the Hindenburg would be filled with helium instead of hydrogen. Since heliem is about 10% less efficient as a lifting gas, Zeppelin engineers decided they just couldn't live with Blau Gas. Also, Blau Gas has the same safety drawbacks as hydrogen. Helium is much more expensive than hydrogen, so if the company was to be profitable there was no way they could just vent helium when the ship was too light. So if they were to use diesel fuel exclusively in the Hindenburg, they needed a way to add weight to the airship in flight.

    The solution was to remove water from the air and use it as ballast to replace the now-missing diesel fuel. The system they designed used a silica gel, the same stuff that comes in a little packet labeled "DO NOT EAT" when you buy a pair of shoes. Ambient air was blown over the gel, which is highly water absorbent. The gel was then heated using waste engine heat to produce water vapor, which was collected in a condenser. Eventually they decided to use the diesel exhaust (which is apparently very humid) instead of ambient air. This was 70 years ago.

  40. Re:They did this in ancient times in the middle ea by AJWM · · Score: 2, Funny

    Of course, there's always the chance as the verbal history was passed down, tellers embellished a bit to impress the kids better.

    "In my day, we not only had to walk uphill both ways to school, we had to part the seas to do it!"

    "You parted the seas?! Lucky bastard! We had to hold breath and walk along the bottom..."

    "Oh yes. Well, at least you were walking. We had to outrun the whole Egyptian army.. And wander in the desert for forty days."

    "Days? We had to wander for forty weeks!"

    "Well I say days, it was really forty years. But we were tough, it just seemed like days to us..."

    --
    -- Alastair
  41. Re:Lucas - king of the rip-offs by AJWM · · Score: 3, Insightful

    Yep. Star Wars, the story of a poor kid on Arakkis who grew up and went to Trantor. But movies and TV series routinely rip off whatever they can, tweaking it just enough to (usually) avoid lawsuits.

    Not to say that science fiction (and other) writers don't rip off too, but they're usually much better at filing off the serial numbers, and taking from totally different genres (as well as being long since in the public domain). Asimov's inspiration for the Foundation Trilogy (back when it was a trilogy) was, loosely speaking, "The Rise and Fall of the Roman Empire". Forbidden Planet was loosely based on Shakespeare's "The Tempest" (and of course Star Trek ripped off a lot from Forbidden Planet). And so on.

    (In fact Hollywood is often closer to the original when they rip something off than they are when they buy the property and make a movie from it. Joke. Joke.)

    --
    -- Alastair
  42. Re:They did this in ancient times in the middle ea by ozmanjusri · · Score: 2, Informative
    Having some old dude and a bunch of his fleeing kin at the exact right spot just as tsunami drains enough water to create a land bridge would be plenty magical I think.

    Yeah, that's why it's more likely to be the result of "wind setdown" and the resulting bore when the wind failed. The water being pushed back to expose a path would have been a reasonably common event. If you were a local, you'd know it would be a dangerous path to use, but if you were desperate to escape it might have seemed worth the risk.

    There's some interesting theories, including this one, here. http://www.europhysicsnews.com/full/33/article6.pd f#search=%22part%20the%20seas%20moses%20science%22

    --
    "I've got more toys than Teruhisa Kitahara."
  43. Not so impressive by pauljuno · · Score: 2, Insightful

    Water out of thin air? I'm not impressed. Every morning when I leave for work I need to wipe off the windshields of my car as there is so much water on it without any rain happening. Bought the dang thing to get from point A to point B and it's always producing water. I'll bet if we parked it into a desert an oasis would form!

  44. Re:Lucas - king of the rip-offs by tygt · · Score: 2, Informative
    No doubt; Asimov even had the Empire's last great general be named "Bel Riose", who worked tirelessly to win back as much of the old empire for his strong emperor, just as the Eastern Roman General Belisarius did for the emperor Justinian (who is echoed as "Cleon II" by Asimov).

    All roads, of course, led to Trantor (Rome). I don't think that Asimov hid his borrowing from history - note that any author generally freely borrows from history, past or present (reality). Borrowing so heavily from another author's works, on the other hand, is another matter IMHO.

  45. Damp Rid? by fozzy1015 · · Score: 2, Interesting

    The quote reminds me of my younger years when I had to... um... quickly dry things I grew before they rotted.

    Take a tupperware container. Wedge two layers of chicken wire, with a few inches between the bottom, middle, and top. On the bottom layer of wire
    put a cotton cloth with Damp Rid(Potassium Chloride). Put the items you want to dehydrate on the top layer. Seal up. The salt will leech the water out and
    when it saturates, dump it at the bottom of the container.

    So given a big enough contraption to hold enough salt with a large enough surface area, a way to move enough air over it(fan), and a way to get the water out and stored(pump), could you
    collect 600 gallons of a water a day in a desert?

  46. Daedalus of New Scientist got there first. by Nate+Eldredge · · Score: 2, Informative

    I have here a copy of a book entitled "The Inventions of Daedalus", which reprints the column of the same name by David E. H. Jones from New Scientist magazine. This column would propose unusual inventions, generally based upon sound scientific principles and seeming entirely reasonable except for their total absurdity. Previous proposals include a scheme for slaughter-free meat production by harvesting reptile tails which then regenerate; a weapon called "Shattergas" causing sudden and catastrophic corrosion of militarily important metals and plastics; and an addictive birth control pill which the user would never forget to take.

    Anyway, it includes a column dated May 25, 1978 entitled "The Desert Waterer" in which "Daedalus" proposes just such a device, whereby moisture is collected from the air by means of a hygroscopic liquid. The water can then be extruded through a semi-permeable membrane if the liquid is under sufficient pressure. This can be accomplished simply by placing the liquid in a tall column; moisture enters at the top and the hydrostatic pressure at the bottom allows recovery. Daedalus then considers some convenient liquids for the purpose. Sulfuric acid is readily available in industrial quantities but would need a column 2400 meters high, which is somewhat awkward. Invert sugar syrup has a higher molecular weight and would require a column merely 720 meters high, as well as being nontoxic, and even edible in case of an emergency. Best of all, he says, is a product called "Carbowax", for which a column of only 50 meters would suffice.

    The firm in charge of this present project has a suspiciously similar name, so perhaps they have just created a better Carbowax.

    Daedalus, in the book, cites a number of cases where an invention from the column has become the subject of serious research. So this is just one more example...

  47. Re:Invented a long time ago, in a galaxy far away. by hey! · · Score: 2, Funny

    Why do you think the DoD funded this? They want to keep those Arab wannabe jedis down on the farm.

    --
    Post may contain irony: discontinue use if experiencing mood swings, nausea or elevated blood pressure.