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Transportation

Underwater Vehicle Uses a Balloon To Dart Like an Octopus 73

Zothecula writes When you inflate a balloon and then release it without tying the valve shut, it certainly shoots away quickly. Octopi utilize the same basic principle, although they suck in and then rapidly expel water. An international team of scientists have now replicated that system in a soft-bodied miniature underwater vehicle, which could pave the way for very quickly-accelerating full-size submersibles.
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Underwater Vehicle Uses a Balloon To Dart Like an Octopus

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  • octopi? (Score:5, Funny)

    by Hognoxious ( 631665 ) on Monday February 09, 2015 @04:07AM (#49015651) Homepage Journal

    Octopi? Pull the other one. Or the other other one. Or the other other one. Or the alternate other one. Or the other one. Or the other one. Or the other one.

    • Re: octopi? (Score:4, Informative)

      by ClickOnThis ( 137803 ) on Monday February 09, 2015 @04:43AM (#49015781) Journal

      This. Octopus is Greek, not Latin. Despite what Merriam-Webster might say, the plural is octopuses or octopodes, not octopi.

      • Re: octopi? (Score:5, Informative)

        by Anonymous Coward on Monday February 09, 2015 @05:19AM (#49015915)

        Octopus is English, derived from Greek. All three plurals are in current use, and it is usage, not etymology, that defines what is "correct".

      • Octopus is English from Greek extraction. Octopi is usually accepted and since English is by consensus rather than ordained by some authority all are valid.
        • Re: octopi? (Score:4, Informative)

          by TheMathemagician ( 2515102 ) on Monday February 09, 2015 @05:55AM (#49016035)
          Octopi is based on the mistaken assumption that octopus is a second declension Latin noun. It is simply wrong. Octopuses is the correct English plural.
          • Or is is like "moose" ... one moose, two moose, three moose? Look at all the octopus.

            Let's remember ... and I say this as a native speaker who has had to learn all of the exceptions ... English is a loose bastardization of French, Latin, German, Greek, Gaelic, and who knows what else.

            It consists of 'rules' which are inconsistent, random, arbitrary, and depend on you actually knowing the rules from the language we stole the word from.

            I've honestly given up on caring about some of the corner cases, and havi

            • Octopodes sounds incredibly stupid, because I can't think of another word in the English language which is pluralized with "podes" -- which makes it such an extreme outlier as to be doubtful.

              Antipode [merriam-webster.com]

              • OK, smart ass ... what's the singular of antipodes? Yes, antipode.

                Now, if it was antipus, I might think you have a point.

                I'm not saying there isn't an example but I'm not convinced there's anything else which would be done in the same way "octopus -> octopodes".

                If there is, I'd love to see it. We don't have circupodes, or discupodes. *Is* there another word in English which ends in "us" and is pluralized as "odes"? Does the 'p' play a role here?

                If this is an outlier from the Greek, do we have any

          • If enough people make the same mistake, then the language has to adopt and accept the usage. Remember the term "petitio principii" which meant circular argument that is translated into English as "begs the question"? (in the sense the answer is begging the question to be accepted as right) Well by consensus (or consensi ?) its meaning has changed. Now "begs the question" simply means "raises the question", no connection to circular arguments.

            I have used boni to mean bonuses and it did not raise too many e

        • by Anonymous Coward

          English is by consensus

          No it isn't.

          • by Anonymous Coward

            English is by consensus

            No it isn't.

            Yes it is. Who's with me?

        • If it is indeed so, then "then" and "than" are completely interchangable judging from internet use.
      • by moondo ( 177508 )

        Regardless of whether it is octopi or octopuses, I took a look at the design and I conclude that it needs more tentacles to really live up to its name.

    • Mmmm. Pie.

  • One-shot motor (Score:5, Insightful)

    by Rosco P. Coltrane ( 209368 ) on Monday February 09, 2015 @04:42AM (#49015779)

    So it's super-efficient and all... if you intend to move no farther than 10 ft forward.

    For greater distances, you could, say, keep the balloon constantly inflated with some kind of pump. And then, to save unnecessary weight and complication, you could do away with the balloon and let the pump shoot out the back of the vehicle directly.

    I shall call my invention a hydrojet. Genius!

    • by Splab ( 574204 )

      No no, this is great for submarines, just sit there and wait for the torpedo to hit you, and then in the last second, you unleash the balloons and instantly jump 10 feet away!

      It's flawless!

      • Well, it might be flawless, if submarines weren't 30+ feet in diameter....
        • And that's a problem because...? As I recall hydrodynamic systems tend to scale linearly - there is actually far less variation in biological speeds measured in body-lengths per second than when using an absolute metric. Well, at least when looking at "performance" animals - plenty of slowpokes out there too, not everyone is optimized for speed.

          • Hmm, 15 radius means the torp will still hit.

            A torp passing rather farther away will still detonate (we haven't used contact torpedoes since WW2) and break the sub's hull. How far away? well, that depends on the torpedo and the sub, but it's probably still classified.

            Suffice it to say that unless that hydrodynamic system scales linearly from octopus to SSN688-sized, it won't be far enough away when the torpedo booms to make a difference....

            • Fair point, but I'd add some caveats.
              Firstly, if the torpedo is on a proximity fuse, then it's going to be at least detonation distance + escape burst away, which should at least reduce damage from a single survivable blast. The blast would also then be coming from behind, which I suspect would reduce the damage dramatically compared to a broadside hit.

              Secondly, the point of such evasion tactics is typically just that - evasion. I would suspect that it would be accompanied by chaff, decoys, or active count

    • Nope, then you've utterly lost the hydrodynamic performance benefits. 10 body-lengths per second is pretty respectable by biological standards, and an order of magnitude beyond anything we've created except for torpedoes, which only maintain their speed by consuming embarrassing quantities of fuel.

      Obviously at this stage it's kind of useless, but it's the first significant boost in our artifacts underwater performance in many decades, and I would bet that before the end of the century many craft will engag

    • Using gas propulsion on a submersible is hardly a new idea. Compressed air torpedos, like the Whitehead torpedo [wikipedia.org], were used in the XIXth century. Some of them were used by Norway during WWII to sink a Nazi cruiser [wikipedia.org]. The torpedos were over 30 years old by then but they still worked.

      Even a lot of more modern torpedos still use gas propulsion. The VA-111 Shkval [wikipedia.org] uses a solid-fuel rocket for propulsion. Other rockets use hydrogen peroxide monopropellant rocket propulsion or other kinds of rocket propulsion.

      Nothing

    • Use a flexible internal skelton to stretch the elastic skin and draw in water from the front through a one-way valve. When it's full, the skelton can return to normal and a valve at the back can release the pressure to let it jet forward.

  • by Anonymous Coward

    But it doesn't mention 'climate change', how did it get on Slashdot?

  • Why does the linked paper [iop.org] refer to it as a "robot"? It seems to be a projectile at best. Is there some definition of robot I'm not aware of?
  • by Anonymous Coward

    This article is nothing. Not a vehicle, not a robot. If water is held in a stretched bladder and the contents are allowed to escape, much like a balloon filled with air, the bladder moves. We should investigate. Maybe there is a basic premise that Newton missed. Next Slash dot will present electrolysis: free energy from the explosive gas HYDROGEN!

    • It's an early stage performance analysis device - and it's performing an order of magnitude better than anything else we've got. I'd say that's at least an interesting curiosity.

      • by PPH ( 736903 )

        This. The effect being analyzed is that of the contracting body cross section contribution to the propulsion provided by the expelled water. Thrust provided by a jet of water is already well understood, as this is already available on boats and other watercraft.

  • It sounds like magic! Scientists at Slashdot have invented a mechanism that can propell any vehicle, both under water and on land. The invention works by attaching an external string. An also external human then pulls said string, and the object moves in direction of the string. Youtube video follows.
    • by Anonymous Coward

      You'll never guess how this guy propels a submarine with this one neat trick.

  • by some old guy ( 674482 ) on Monday February 09, 2015 @08:18AM (#49016413)

    For maximum speed and efficiency, they need to combine it with the rapid-inflation capability of the blow fish.

    Presto! A suck and blow!

    (Not to be confused with the Cessna OV-10)

  • Lol. This is an Onion worthy gag-uralism! Author name: Ben Coxworthy. Quote from article: "...keeps it from deflating to the point that it becomes limp and unstreamlined. It can be seen in action, in the following video." Only complaint: didn't include the words "turgid" or "engorged."
  • by OzPeter ( 195038 ) on Monday February 09, 2015 @09:18AM (#49016597)

    I will admit that it was last year, but its still a dupe Octopus-Inspired Robot Matches Real Octopus For Speed [slashdot.org]

    • by q4Fry ( 1322209 )
      Agreed. I came here in hopes that it was the next step in the development of that article. Namely, that they could pump water back in and keep going.

      Any fool can let go of a water balloon. The neat thing would be refilling and releasing it in a self-contained system.
  • Queue the music from The Hunt for Red October....

  • I'm all for this sort of noodling around, but it seems, ah, a little low-brow for such an esteemed bunch of folks, and I say this with two of my three degrees from MIT whence the research came.

    From the article, "While it at first glance might appear to be a glorified toy..." and that is certainly the truth. Dispelling that impression is in no way helped by the audio track on the released video where someone intones "pewnnnnnnggggggg" as the vehicle is released, making the same sound that a kid would.

    I'm su

  • of scientists" to pull it off? I realize that term is used to as puffery under the best of situations but here it just makes it sadder. At least they went "pewwwww..." when they launched it. That means the same thing in any language. Oh, and "hyper-inflated"?
  • This kind of vehicle will be awesome for jello-people.

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