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Science

Make A Hole - And Sustain It Indefinitely 38

Posted by timothy from the could-come-in-handy dept.
Mick Ohrberg writes "Florian Merkt, Robert Deegan, and Erin Rericha, all at the University of Texas, have shown that a hole created in a water and cornstarch mixture with a puff of air can be persistent if the mixture is shaken at about 120Hz with acceleration being in the 12g-25g range. The physics behind the phenomenon has not yet been explained."
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Make A Hole - And Sustain It Indefinitely More

Make A Hole - And Sustain It Indefinitely

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  • I'm no physicist, so I have no idea what the implications of this are. The article and PDF gave no indication either. Anyone care to share?

    • Re:Cool and all (Score:2, Interesting)

      by djsmiley ( 752149 )
      Firstly, i would guess that the inside of this structure is PERFECTLY round. I mean, so 100% perfect, something which we cannot create atm. Which will then be used some how. (like creating ROUND m&ms?). Still, no one know what it all means?

  • Physics and particles (Score:5, Interesting)

    by GigsVT ( 208848 ) on Saturday May 08, 2004 @02:09PM (#9094917) Journal
    It seems that the world of physics as it relates to lots of macro sized particles interacting isn't very well explored.

    I remember reading an article years ago, about research into mixed nuts. Basically they wanted to find out why the brazil nuts always tended to come to the top. It turns out it's a semi-complex interaction, when the can is shaken vertically, the nuts closer to the walls are pulled down due to the friction and they fall into the gap created at the bottom of the can, creating a sort of convection current. The larger brazils had less contact area with the wall and were not as likely to be pulled back down IIRC.

    It's just kinda funny that we understand all kinds of interactions down on the atomic level, but are still researching basic things like the way mixed nuts or raisin bran sort and settle.

    • Re:Physics and particles (Score:2, Interesting)

      by oojah ( 113006 )

      I remember reading an article years ago, about research into mixed nuts. Basically they wanted to find out why the brazil nuts always tended to come to the top. It turns out it's a semi-complex interaction, when the can is shaken vertically, the nuts closer to the walls are pulled down due to the friction and they fall into the gap created at the bottom of the can, creating a sort of convection current. The larger brazils had less contact area with the wall and were not as likely to be pulled back down IIR

  • The physics are easy (Score:5, Funny)

    by ezraekman ( 650090 ) on Saturday May 08, 2004 @02:17PM (#9094976) Homepage
    It's quite simple, really. The glass container in which the corn starch is stored resonates perfectly at 120Hz. Had the researchers used a difference thickness, weight or purity of glass, the required frequency would be different, though far less stable. What they have done, in effect, is open a very small gateway into a sub-level dimension. It is fortunate that they did not accelerate the container to a rate generating more force, which would have caused the hole to open larger; they might have inadvertently unleashed one of these [gamespot.com].

  • so... (Score:5, Interesting)

    by hookedup ( 630460 ) on Saturday May 08, 2004 @02:46PM (#9095119)
    scale the whole project up, and easy access to sunken boats?

    treasure is always a good incentive...

    • Re:so... (Score:2, Funny)

      by LordMydrin ( 654748 )
      "Honey, is that an earthquake?" "No dear, they are just shaking the planet at 120MHz to maintain a hole so that sunken treasure can be salvaged..."
    • We just need a lot of corn starch.

    • Re:so... (Score:3, Informative)

      by Christopher Thomas ( 11717 )
      scale the whole project up, and easy access to sunken boats?

      Unlikely, for this approach, at least. This experiment is relying on special interactions between the cornstarch suspension and the sound waves passing through it. Water behaves a lot more like an ideal liquid than a cornstarch suspension does, so it's not going to exhibit the same effect.

      There are other patterns of motion you could induce in water to get access to sunken ships (e.g. dump in lots of sound and put an antinode in the channel volum

  • Mirror of video (Score:5, Informative)

    by Copperhead ( 187748 ) <.talbrech. .at. .speakeasy.net.> on Saturday May 08, 2004 @03:20PM (#9095339) Homepage
    I downloaded the removed video when the site was on Fark [fark.com] this week. You can get it off my server here [wcupa.edu] (3.8 meg wmv).

  • Likely the dynamic boron-mediated crosslinks (Score:1, Interesting)

    by Anonymous Coward
    So as the force from the air in the hole impacting with the edges of the hole increases as the frequency increases at some point it'll reach the point where it goes hard.

    Just like if you hit silly putty with a hammer.

  • Cornstarch/Water a "sheer-thickening" fluid (Score:5, Interesting)

    by Salis ( 52373 ) on Saturday May 08, 2004 @03:52PM (#9095517) Journal
    Similar to the 'liquid body armor' reported on Slashdot a while back, cornstarch + water is a "sheer-thickening" fluid, or a fluid that increases its viscosity when it experiences sheer (or tangential force).

    Perhaps the interaction between the cornstarch/water and the vibrations cause the cornstarch/water to increase its viscosity and "hold" up the walls of the hole.
    • I like this idea. if I still had mod points today you'd get +1 insightful.

    • Re:My thoughts exactly (Score:5, Insightful)

      by Bastian ( 66383 ) on Saturday May 08, 2004 @06:18PM (#9096406)
      Given that cornstarch and water is a shear-thickening fluid, and the vibration (at 15-25g no less) is certainly a shear force, this phenomenon is almost certainly due to the vibration causing the cornstarch and water to gain viscosity. This wouldn't necessarily give you a stable hole, though, so it's probably also helped by the cohesive forces in the fluid and some other effects, too.

      I would guess that it's not that the scientists don't know why this is happening, just that their models aren't accurate/precise enough to predict it. Or maybe they left out some effect or force that is normally negligible in the models, but suddenly becomes important in this situation.
    • Equipment needed:

      1 bowl, medium size
      1 pack of cornflour (presumably cornstarch is the US word for cornflour)
      1 source of water

      Put approximately 'some' cornflour in the bowl.
      Add water and stir until you have a liquid.

      Mess about with the amounts of water and cornflour until you have a reasonably thin liquid, but one which if you punch (!) will not splatter all over the place. If you stir it with a spoon, very slowly, it will feel like water. If you try and stir it fast, you will feel great resistance.

      You m

  • So that's how Moses did it.... (Score:4, Funny)

    by Shipud ( 685171 ) on Saturday May 08, 2004 @05:47PM (#9096234)
    How much cornstarch do you need for the Red Sea anyway?


    • > How much cornstarch do you need for the Red Sea anyway?

      Moses stole the technology from the Egyptians, who were using it to make Stargates.

    • Where does "a strong East wind" resonate? (Score:1, Insightful)

      by Anonymous Coward
      The waters "congealed" and this certainly looks like "congealed" to me. The waters also fell back again quickly enough to engulf a million soldiers cannon weapons out on the Saudi shore, which doesn't sound like enormous amounts of cornstarch. Four million people could only carry a limited amount of it along with their other supplies.

      The most likely explanation is that "a strong east wind" was just that, and cold, too. People forget that the desert gets damn cold at night, cold enough for the natives to ma
      • Anyone who has lived in cold weather would realize this would be very unlikely (impossible?). If a strong wind (tornado like force) were to push into a body of water, it could create a "hole" in the water. However, the sides of the hole would be water moving at high speeds. Water at high speeds requires VERY low temperatures to freeze, lower than a desert would reach.
    • probably more like how charlton heston did it in the movie moses. I think noone has beeen able to figure out how they did it. Maybe this is how?
    • Probably it's how they did it in Charlton hestons moses movie. If i remember correctly noone has been able to figure out how they did it and kept it secret

  • Already been done (Score:5, Funny)

    by damien_kane ( 519267 ) on Saturday May 08, 2004 @07:32PM (#9096790)
    Doesn't ACME have a patent on portable holes? I think these guys may want to check with their lawyers...
    • Doesn't ACME have a patent on portable holes? I think these guys may want to check with their lawyers...

      I shouldn't worry. All ACME's lawyers have been tied up for years in a class-action lawsuit that's been brought by the Coyote Association, for knowingly selling dangerously substandard equipment.

  • This is grade school science fair type stuff. Corn starch forms very long polymer-like molecules. Thats why corn starch thickens when you stir it -- its molecules get tangled on each other. Obviously the sound they are pumping into the corn strach is agitating the molecules and causing them to be act like a sheer liquid.

  • Not explained? (Score:1, Interesting)

    by Anonymous Coward
    My physics is a bit rusty, but isn't this just a special case of a standing wave?

  • But what I really want to know is... (Score:3, Funny)

    by Enigma_Man ( 756516 ) on Monday May 10, 2004 @08:22AM (#9105900) Homepage
    How'd they come across this?

    Hey Joe... Let's take some water... and add some cornstarch.. and then. hmm... apply a really high frequency, and then puff some air down into it.

    Ya know Bob, that's a really great idea.

    -Jesse

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