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Oobleck (a mixture of cornstarch and water) is a non-newtonian fluid, so it acts like a solid when under pressure, and like a liquid otherwise. My question is this, is there anything you could mix in with oobleck (a friend suggested vinegar, I don't know why) that would cause it to stop being non-newtonian (more specifically, to act like an ordinary liquid). The motivation for this is that I'm going to have a large amount of the stuff, and will need a practical way of disposing of it, like dumping it down a drain.

Thanks in advance for any answers!

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    $\begingroup$ Cornstarch and water is a great way of thickening sauces ;) P/S please don't really do this $\endgroup$ – orthocresol Apr 5 '17 at 19:08
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Disposal isn't a problem - add more water as you dump it down the drain.

There are two extremes to ooblek:

  • Almost all cornstarch and almost no water: this is a dry solid or slightly wet starch. No big deal.
  • Almost all water and very little starch: this is some water with a little bit of starch mixed in. Sometimes it clumps or falls out of suspension, but it's also no big deal.

The non-Newtonian mixture occurs at intermediate ranges.

Since cornstarch will degrade in the sewer system (e.g., feed bacteria), it's safe down the drain. Alternatively, I compost it.

But if you're worried about non-Newtonian behavior, you just add more water.

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  • $\begingroup$ As the old saying goes, "dilution is the solution to pollution". $\endgroup$ – J. Ari Apr 5 '17 at 20:06

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