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Water Logic Gates Built at MIT 239

Posted by CowboyNeal
from the flood-gates-opened dept.
ndogg writes "This story is all wet. Paulo Blikstein at MIT has created a water computer. The one boolean logic gate he created functions as a half-adder (i.e. both XOR and AND). He then proceeded to create a four bit adder."
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Water Logic Gates Built at MIT

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  • Hurm . . . (Score:3, Funny)

    by OverlordQ (264228) on Friday February 16, 2007 @01:56AM (#18035308) Journal
    I wonder if the same principle could be used with hamsters and those little tubes they run around in . . .

    *goes off to patent the Hamster Computer*
  • by Anonymous Coward on Friday February 16, 2007 @01:58AM (#18035318)
    It's called fluidics, [wikipedia.org] and it's decades old.

    It uses compressed air or water to create logic circuits.

    There was a big interest during the cold war, since they wouldn't be affected by the electromagnetic pulse of a nuclear bomb.
    • by mrbluze (1034940) on Friday February 16, 2007 @02:16AM (#18035416) Journal

      They have proven very useful in the medical field with respect to fluid logic ventilators, and possibly more sophisticated surgical equipment (aside from drills and saws which commonly are driven by compressed air). Many portable ventilators are commonly available which have no electronic parts to speak of and run on the pressurized air or oxygen that goes with the patient during transfer. More modern ones generate small amounts of electricity to power logic curcuits to achieve smoother or more configurable ventilation modes. Improving fluid logic to avoid this electronic dependency would be quite interesting whilst still keeping size down.

      Just how water could play a part in ventilators escapes me, but such things as washing machines, dish washers and other appliances could benefit from not needing to use electricity.

      I think the interest in this stuff, thankfully, goes beyond the cold war.

      • by Knutsi (959723)
        To me water seems highly unpredictable though. Is is really possible to get any kind of computational accuracy from a device built like this?
        • Re: (Score:3, Interesting)

          by mrbluze (1034940)
          Water has been extensively studied, and fluid mechanics is a pretty well explored field, so I think water is well suited for the experiments. The thing that could be a problem as I see it is the speed of the system. The heavier the substance is, the greater force needed to change its direction, and the thing will be slower as a result.
        • by Fred_A (10934)

          To me water seems highly unpredictable though. Is is really possible to get any kind of computational accuracy from a device built like this?
          If the water is old enough you might get some fuzzy logic out of it.
        • Well the way this guy built it yes. Though if you build it like normal transisters IE, you build a normal AND gate using the pressure from one water source to open a valve to let the other source through, and OR gate using just two water sources together. A NOT gate from using an inverted AND gate (meaning you have a constant expected water source and the pressure from the input turns the water off). But such a system would require a lot of energy to drive the pumps. So.. You aren't really achieving much.
      • by Dunbal (464142)
        drills and saws which commonly are driven by compressed air

              You've obvioulsy never been into an orthopaedic surgery. The drill is electric, and pretty much what you'd find at your local hardware store ;)
        • Re: (Score:2, Informative)

          by stormpunk (515019)

          You've obvioulsy never been into an orthopaedic surgery. The drill is electric, and pretty much what you'd find at your local hardware store ;)
          Most general dentists will use the air variety of tools. A surgeon can afford to buy the more expensive electric type. And if your surgeon is using a common hardware store DeWalt drill in your mouth, try getting your surgery somewhere besides the back of a van in an alley.
      • by pla (258480)
        I think the interest in this stuff, thankfully, goes beyond the cold war

        Interest, yes (as this FP proves). Practical application, though?

        Fluidics never "caught on" for a reason - It requires relatively huge parts to get anywhere. Check out the pictures in the linked article for examples - He even mentions that his second try at the desired logic gate technically worked, but didn't allow sufficient flow to do anything with.

        Even considering use in a water or air powered device, I have to wonder if an
    • Heh. (Score:4, Funny)

      by jhantin (252660) on Friday February 16, 2007 @02:30AM (#18035490)
      Guy L. Steele sketched this amusing commentary [catb.org] on problems in '70s fluidic computing, one episode of the Crunchly saga now entwined with the Jargon File [catb.org].
    • by darkfish32 (909153) on Friday February 16, 2007 @02:48AM (#18035584)
      Yeah, something tells me this isn't going to be the next Watergate....
    • by Brandybuck (704397) on Friday February 16, 2007 @03:19AM (#18035712) Homepage Journal
      This isn't decades old. The device being reported on, that is. The concept is old, but the implementation is new. Despite your feeble protestations, it's still cool.
      • Re: (Score:3, Insightful)

        by MrFlannel (762587)
        The page is old too.
        archive.org says the page was created April 2006, but I *know* I saw it before that as well.

        Further research reveals this:
        http://www.blikstein.com/paulo/projects/project_wa ter.html [blikstein.com]
        which dates all the way back to 2004.

        So yes, both the concept, and the site, are old.
      • by idlake (850372)
        is that the people who did this at MIT failed to reference the prior work. Either they didn't know about it (which is profoundly stupid), or they deliberately didn't reference it (which is dishonest).
        • RTFA (Score:5, Informative)

          by Fred Ferrigno (122319) on Friday February 16, 2007 @07:09AM (#18036632)
          From the website, emphasis mine:

          ...in fact, Fluidics is a very important field of study that is widely used in aerospace or mission-critical applications, where electronic control devices don't offer the reliability of cannot support the environment. Also, military technologies use Fluidics in order to prevent malfunction in a nuclear war, when electric devices cease to work.

          However, the idea was not to send people to space or to control missiles, but rather make a device that could help people build computation with their own hands - and demystifing the computer.
          I would assume that this is simply his personal write up of the project for a general audience. If it was submitted as a research project, I imagine it would be accompanied by a more thorough report which would have likely discussed the background of Fluidics with appropriate references.
    • by BigBlockMopar (191202) on Friday February 16, 2007 @03:47AM (#18035830) Homepage

      It's called fluidics, and it's decades old. It uses compressed air or water to create logic circuits.

      Yeah, I think the only real innovation here is describing the gates by Boolean concepts. His other accomplishment is no moving parts - except, of course, the fluid, I was expecting check balls and things; his system would probably work extremely well under very controlled pressure conditions... but I can't imagine there's much tolerance for real-world conditions or capacity for fan-out from the gates. Having said that, it's still a neat project. Kinda like the digital alarm clock I'm building using nothing but relays.

      Automatic transmissions have used hydraulic computers since their genesis in the late 1940s. Until electronically-controlled transmissions became widespread in the 1980s, automatic transmissions universally had a maze of check valves, pressure-operated cylindrical valves and diaphragms in order to select gear. It was called the valve body, and it is probably the most terrifying part of a car to have scattered across your workbench - orders of magnitude worse than even a California emissions 1983 Rochester Quadrajet. Inputs include selected gear, downshift linkage, engine speed, tailshaft speed. Outputs are a set of lines which are pulled "hi" (in pressure not voltage!) to engage bands on the outsides of planetary gearsets and therefore engage a given gear.

      Absolute nightmare. But they worked quite reliably - the valve bodies, anyway. The transmission itself was sometimes another matter (see hydraulic-controlled GM TH-200, Hondamatic, etc.). Ford C4 and C6 were one of the few to have a valve body design flaw - in Park, accumulated pressure would engage the reverse bands, causing the familiar scene from Cops: a Ford product reversing in driverless circles until it hits something. Shut off the engine when you get out of the driver's seat, and set your parking brake.

      • by Alioth (221270)
        I hope your relay contraption will at least have some nixie tubes involved :-)

        This guy should go for an encore - and make water gates with tri-state outputs so you can have a water bus!

      • by chthon (580889) on Friday February 16, 2007 @07:17AM (#18036670) Homepage Journal

        New for fluidics, or for hydraulics ?

        In a course on automation in the eighties, I had already seen pneumatic components and their equivalent description by Boolean concepts.

        In 1995, I followed a course on automation which included pneumatics and hydraulics hands on, and the course also described certain components in Boolean terms. In fact, when I was there one of the teachers was building a pneumatic computer (never got the details on it, unfortunately).

        Since the basic functions of pneumatic and hydraulic components are about the same, there is no theoretical reason why it is not possible to build a hydraulic computer.

        There is one practical problem, however. Hydraulic components are mostly power components, designed to work with oil and with pressures from 10 to 100 bar, and they need a lot of space, and they are rather slow. Pneumatics is much faster and lightweight.

        Yes, the main accomplishment is that it has no moving parts.

      • Re: (Score:3, Informative)

        by Richard Kirk (535523)
        Yeah, I think the only real innovation here is describing the gates by Boolean concepts.

        Naah. I have a copy of the 'Tomorrow's World' Annual somewhere from about 1967 showing binary log fluidic gates without moving parts. At the time, this was considered to be a possible alternative to silicon electronics for speed and compactness. People had also been anticipating MEMS technology, and saying mechanical calculators would eventually overtake electronics. Back then a transistor was still a can with three

      • by argent (18001)
        Yeah, I think the only real innovation here is describing the gates by Boolean concepts. His other accomplishment is no moving parts - except, of course, the fluid, I was expecting check balls and things;

        The Scientific American article on fluidic computers had all that when I read it as a kid... after visiting an old WWII era submarine that used a fluidic computer. That was back in the '70s, and HMAS Ovens was of course decades old back then. :)
      • Then I'm kind of curious: If it's possible to make a computer using just hydraulics, why didn't people use them for that as far back as, say, the 18th century, when they had a use for them, and wouldn't need to "tame" electricity first?

        Is this another aeolipile [wikipedia.org]?
      • It's called fluidics, and it's decades old. It uses compressed air or water to create logic circuits.

        Yeah, I think the only real innovation here is describing the gates by Boolean concepts. His other accomplishment is no moving parts

        Niether 'accomplishment' is particularly impressive. I first saw the exact components he built described (and illustrated) back in the late 70's/early 80's- I considered building one for a high school science fair.

    • Re: (Score:3, Insightful)

      by eric76 (679787)
      I remember reading an article on this in Popular Science or Mechanics Illustrated back in the mid to late 60s.

      I never did understand why noone else ever seemed to know of it. I figured maybe they didn't read Popular Science and Mechanics Illustrated.
    • Soooo old (Score:3, Interesting)

      by Bruce Perens (3872) *
      I remember in the early 1960's, when my dad was working on the Lunar Module program at Grumman, he'd bring home engineering industry rags like Design News, and fluidic logic was the big thing then, there were always articles on it and press releases from manufacturers (most of whom probably didn't find many customers) about their new fluidic devices.

      Fluidic technology has been explored for a backup computer for intrinsicaly-unstable aircraft, I'm not sure it's been deployed on any.

      Bruce

    • Re: (Score:3, Funny)

      by codeButcher (223668)

      There was a big interest during the cold war, since they wouldn't be affected by the electromagnetic pulse of a nuclear bomb.

      But wouldn't the cold from the cold war freeze the water?

      (Ducks...)

      • by cybermage (112274)
        But wouldn't the cold from the cold war freeze the water?

        And, if you overclock it, how do you keep it cool?
    • Re: (Score:3, Interesting)

      by foobsr (693224) *
      Yes indeed ...

      from http://www.nanomedicine.com/NMI/9.2.7.6.htm [nanomedicine.com]

      * In the 1950s, Marvin Minsky and Rollo Silver^289 built a "hydroflip computer" using hydraulic logic elements consisting of millimeter-wide grooves and holes in multiple layers of plastic sheets with small rods and balls inserted in some of the grooves. When the assembly was pressed together and connected to a water supply, it became a hydraulic computer powered by a 3-inch high column of water, operating at ~30 Hz.

      289. Marvin Minsky, "
    • by julesh (229690)
      It's called fluidics, and it's decades old.

      It uses compressed air or water to create logic circuits.

      There was a big interest during the cold war, since they wouldn't be affected by the electromagnetic pulse of a nuclear bomb.


      To be fair, the gates this guy has built appear to be substantially simpler (and therefore probably more useful) than the old-style ones.
    • by PhotoGuy (189467)
      TFA didn't claim it was new. In fact, the first paragraph says the following.

      The idea of the project was to build some devices that could do computation without eletrons. Water was a interesting choice, in fact, Fluidics is a very important field of study that is widely used in aerospace or mission-critical applications, where eletronic control devices don't offer the reliability of cannot support the envoronment. Also, military technologies use Fluidics in order to prevent malfunction in a nuclear war, w
    • by iamhassi (659463)
      "It's called fluidics, and it's decades old."

      exactly, so why was this a final project for a PhD student? I seem to recall final projects to be rather complicated and inventive, looking at what he created seems to be very easy almost childish. A 12-yr-old doing this and I'd be interested, but an adult?
  • by Anonymous Coward on Friday February 16, 2007 @01:59AM (#18035322)
    They should try mentos and pop soda gates
  • by TodMinuit (1026042) <<todminuit> <at> <gmail.com>> on Friday February 16, 2007 @01:59AM (#18035324)
    Gives a whole new meaning to the term "wetware".
  • Wait for it.... (Score:5, Interesting)

    by Duncan3 (10537) on Friday February 16, 2007 @02:00AM (#18035330) Homepage
    Any second now, some archaeologist is gonna scream "So that's what that was!"

    I can't wait to see the references in the paper :)

  • by ArcherB (796902) * on Friday February 16, 2007 @02:02AM (#18035344) Journal
    "This story is all wet. Paulo Blikstein at MIT has created a water computer. The one boolean logic gate he created functions as a half-adder (i.e. both XOR and AND). He then proceeded to create a four bit adder."

    And then he proceeded to plug it in and electrocuted himself...

    • Oy. Mains. (Score:3, Interesting)

      by jpellino (202698)
      I had a student who log ago built his own Apple II replica - used the ROMs from a real one and got it working.
      Night before the science fair he decided he needed a quick disconnect for the cassette interface instead of a permanent line. He figured the cheapest easiest solution on his bench was the lightweight AC extension cord, cut the middle and soldered the bare ends to the computer board and the cassette innards, leaving the plug/receptacle in the middle.
      Guess which end was on the computer side? Guess w
  • by Inmatarian (814090) on Friday February 16, 2007 @02:03AM (#18035352)
    Great idea... the ultimate water park. The path down the massive water slide would be controlled by the very calculations going on. People could be used as math symbols!
  • Oh No! (Score:5, Funny)

    by Mr_Tulip (639140) on Friday February 16, 2007 @02:05AM (#18035360) Homepage
    Get the mop, I've just had and arithmetic overflow error!
  • by straponego (521991) on Friday February 16, 2007 @02:06AM (#18035372)
    We were joking around, and I mentioned starting a Linux on Plumbing project. I should have known somebody at MIT would actually be working on it...
  • Heh. (Score:3, Funny)

    by gardyloo (512791) on Friday February 16, 2007 @02:08AM (#18035376)
    I bet this guy's nickname is Princess Nell. Lucky fellow.
  • by atamyrat (980611) on Friday February 16, 2007 @02:12AM (#18035402)
    From his home page [blikstein.com]

    Water Computer (Slashdotted on Oct/2003)
  • Issues... (Score:5, Funny)

    by Anonymous Coward on Friday February 16, 2007 @02:14AM (#18035412)
    With all the heat surrounding this announcement, I wonder how long it will take for it to become vaporware...
  • by swordfishBob (536640) on Friday February 16, 2007 @02:23AM (#18035440)
    It's a series of tubes!
    • Re: (Score:2, Funny)

      by kfg (145172)
      The batch run is going a bit slow today; hair clog. Somebody hand me the plunger so I can flush the system.

      KFG
  • Apparently, if you heat it up, you have a steam-driven computer.
    • Apparently, if you heat it up, you have a steam-driven computer.

      ...That's called severe overclocking.

  • by eldurbarn (111734) on Friday February 16, 2007 @02:24AM (#18035448)
    Windows, of course.

    Being closed source, it should keep the water out. Maybe.

    (Mind too tired: AND gates, XOR gates, BILL gates...)

    • by patio11 (857072) on Friday February 16, 2007 @03:05AM (#18035648)
      Mac OS X -- Your computer needs water which is dyed a special shade of plastic white, is only available from one manufacturer, and costs about double what water usually costs. On the plus side, you chuckle every time you see the iFlow ads.

      Gentoo -- You spend all of your day running submerge.

      Windows 95 -- Your water has frozen. Press Ctrl-Alt-Del to reboot.

      Windows 98 -- Your water got some virii in it while you were searching for water sports. I swear, they should put a warning label around the English language some days. You now need to buy some chlorine from one of the numerous providers who specialize in cleaning up Microsoft's messes.

      Windows XP SP2 -- Your water suddenly looks a whole lot like plastic Fisher Price toy, but with your newfound determination to never, ever again search for watersports your system is actually pretty secure. Slashdot still makes fun of you, but they're all wet.

      Windows Vista -- It looks like you're trying to NAND 0 and 1 together. Do you want to permit this action?
    • Water was a interesting choice, in fact, Fluidics is a very important field of study that is widely used in aerospace or mission-critical applications, where eletronic control devices don't offer the reliability of cannot support the envoronment. Also, military technologies use Fluidics in order to prevent malfunction in a nuclear war, when eletric devices cease to work.

      Well, since it's used in eletronic control devices that don't offer the reliability of cannot support the envoronment, I can definitely se

  • I remember reading identical news articles from the 1980s and 90s about "water circuits". How is this an innovation?

  • I've been pointing my Intro to Computer Science students to that web page since 2003.

    As a side issue, I kind of think that the specific photos Paulo has there are a tad mis-wired; it supposed to a full 2-bit adder, but doesn't quite work right if all 3 inputs are on (last time I looked at this was 2004, maybe someone can correct or confirm that).

    Nonetheless, it's a great demonstration, kudos again to Paulo!
    • by julesh (229690)
      As a side issue, I kind of think that the specific photos Paulo has there are a tad mis-wired; it supposed to a full 2-bit adder, but doesn't quite work right if all 3 inputs are on (last time I looked at this was 2004, maybe someone can correct or confirm that).

      Yeah, I noticed that. He has four input pipes and four output pipes, but two of the outputs only depend on two inputs, so it can't work right, as in a correct adder, only the least significant bit has only two dependencies.
      • by julesh (229690)
        Yeah, I noticed that. He has four input pipes and four output pipes, but two of the outputs only depend on two inputs, so it can't work right, as in a correct adder, only the least significant bit has only two dependencies.

        In more detail, I'm looking at this picture: http://alumni.media.mit.edu/~paulo/courses/howmake /mlfab4bitaddertop.jpg [mit.edu]

        From his description of the gates, and naming the inputs a1, b1, a2, b2 from top to bottom, the outputs (also from top to bottom) are:

        o1 = a1 ^ b1
        o2 = (a1 & b1) ^ (a2
  • by zdc (1064870)
    "...a young gentlemen from Carnegie Mellon University places water-logic-gate in the microwave to reinvent vaporware."
  • by dotoole (881696) on Friday February 16, 2007 @02:34AM (#18035512)
    This guy obviously didn't think this through. Any script kiddie with a garden hose could create buffer overflows at will.
  • Bowdoin Water Adder (Score:5, Interesting)

    by drDugan (219551) * on Friday February 16, 2007 @02:53AM (#18035610) Homepage
    My good friend Tim Aron and Josh Rady built a water adder at Bowdoin in 1994, capable of adding 2 8-bit values.

    http://academic.bowdoin.edu/computer-science/proje cts/html/wateradder2.shtml [bowdoin.edu]


  • First time I hear about eletron. Are those like electron but can support envoronment?
  • by kestasjk (933987) * on Friday February 16, 2007 @03:05AM (#18035646) Homepage
    It would be a very good teaching aid. Even those people in my Hardware Fundamentals course who just "didn't get it" would be able to see clearly what's going on.
    • by jefu (53450)

      I built (many years ago) a couple of small boolean circuits using this kind of water gate (specifically the things described in the Scientific American article way back when). Had some time on my hands, a big sink in a chemistry lab that was otherwise more or less unused, and lots of glass and rubber tubing and some stands and clamps. It was cranky and wet and messy and very tough to get working. At that time I had only seen minimal computer science stuff, so I didn't really appreciate what was going on

  • ...if the Greeks had invented this about 2000 years ago.
  • You'd need some kind of protective footwear.

    Never go near the adders without water moccasins.
  • by advocate_one (662832) on Friday February 16, 2007 @04:14AM (#18035948)
    does it have one?
  • by dam.capsule.org (183256) on Friday February 16, 2007 @04:32AM (#18036008) Homepage
    I've seen this somewhere....

    http://hardware.slashdot.org/article.pl?sid=02/10/ 25/1444241 [slashdot.org]
  • Steam powered logic has been used in explosives factories for process control.
  • So will the next version of Windows require every house to be a water park?
  • A Microsoft spokesman said that his company are currently working on a new OS for these water based machines. We can expect Microsoft Vista "Tsunami Edition" to hit the shelves sometime in 2011. Details are a bit sketchy but apparently the storage requirements are roughly the size of the Caspian Sea...

    On a side note, this is really neat. Now I wonder when he'll figure out that he'll get a lot more instructions per (minute?) if he uses steam, as well as losing the dependence on gravi
  • Yeah, but it's been possible to use water for addition -- even in base 10! -- for even longer.

    Measure out 100ml. of water into a measuring jug. Measure out 200ml. of water into another jug. Now pour the second jug into the first, taking care not to spill any, and read the amount ..... 300ml. So 100 + 200 = 300. You can do subtraction, too. Pour water from the first jug into the second jug until there is 50ml. of water in the second jug. You will find that there is 250ml. in the first jug. So 300 -
  • It was while I was studying Computer Sciences, more than 10 years ago. But I was young and let my friends convince me that it was just stupid.

    If you have an idea for something, don't let people convince you it's stupid, not even if it really is.
  • When I was a kid I had the opportunity to visit an old WWII-era submarine, HMAS Ovens, and since I was already a geeky kind of kid my cousin took particular pleasure in pointing out that it used a fluidic computer.
  • He should have used beer instead of water, and set up a recirculating pump so it wouldn't go to waste.

    There's some sort of "drink and drive" joke hiding in there, but I'm missing it at the moment.
  • This story is making me moist as a snackcake down there.
  • I'm a big fan of MIT and most all of what it does but what on Earth does this little gimmick really have to offer? It's like some of the other MIT hackery that makes it onto slashdot such as the teddy bear with the gigabit LAN ports. I'd wager dollars to donuts that were it not for mit.edu at the end of the URL this story would have gone nowhere. I doubt MAKE would bother carrying this bit of cuteness.
  • by RudeDude (672) *
    This is a dupe from 2002!!!
    http://hardware.slashdot.org/article.pl?sid=02/10/ 25/1444241 [slashdot.org]
    The link is exactly the same and according to "Page Info",
    the server side suggests the last update was July 2003!

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