Make A Hole - And Sustain It Indefinitely

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."

Comments

Physics and particles

[GigsVT]

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.

Mirror of video

[Copperhead]

I downloaded the removed video when the site was on Fark this week. You can get it off my server here (3.8 meg wmv).

Cornstarch/Water a "sheer-thickening" fluid

[Salis]

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.

Already been done

[damien_kane]

Doesn't ACME have a patent on portable holes? I think these guys may want to check with their lawyers...