Oobleck Revisited

Back at Minicon 27, a particularly clever microprogramming assistant obtained 100 pounds of cornstarch and went looking for a likely bathtub in which to mix oobleck. I was running the Minneapolis in '73 suite that year. Come Sunday night I gladly obliged. The microprogramming assistant had a clear grasp of the risks, and I knew he wouldn't break the hotel in the process of providing much fun and experimentation. Beside, I was curious to see if it was possible to dance on oobleck.

It is, if one has enough oobleck. And, as elisem revealed in "Ignorant Savages with a Certain Artistic Flair" (published in Idea #6), "100 lbs is dry weight; when water is added, considerably more oobleck results."

After several hours of fans walking on oobleck and other fun, it came time to dispose of the mess. Plan A -- careful and very thorough dilution -- instantly backfired on us. That much oobleck under the pressure of even a thin film of water resembles nothing so much as concrete. The microprogramming assistant started sweating a bit as he scrambled through Plans B, C, and on. Eventually a merry crew smuggled the oobleck out of the hotel in a brigade of pickle buckets. elisem raised the whole escapade to legend with her filk song, "Oobleck in the Bathtub," using markiv1111's tune "Crying in the Bathtub" to create a filksong I'll always be happy to hear.

Ever since, my own Adventures with Cornstarch have been limited to a smaller scale. At Smofcon 18 in Cocoa Beach, I shared the secrets of oobleck with miramon, eleyan, and others enjoying the Sunday night dead dog party in the consuite there. Another time, I discovered that food coloring is more trouble than it's worth. Regular oobleck doesn't leave your hands green....

We'd sometimes talk about wholesale sellers of cornstarch, and what might be done with sufficient quantities of the the stuff. Thanks to blackfyr, I now have a much better idea.

I gleefully clicked through on the link he posted to a YouTube film on non-Newtonian fluids. I knew what dancing in a bathtub the stuff was like; I was eager to see what could be done with a swimming pool full.

The footage shows oobleck fun on a grander if far more diluted scale than the Minicon experiment. In the Minneapolis in '73 bathtub, you only had to keep moving slowly to keep from sinking. When standing still, it took the same amount of time for us to sink to our ankles as it took these guys to sink to their chests. What we clearly need now is a series of pools with different mixes of oobleck, much like the series of tubs, each at a different temperature, at the Wyoming mineral baths I was at back in 1976. How much cornstarch/gallon do you need for oobleck you can sprint across, and how much more do you need to stroll?

Inquiring minds want to know....

Oobleck at the speed of sound

I present several more oobleck links for the curious:

Cornstarch Monster 1

Cornstarch Monster 2

I've danced on oobleck, but didn't know that oobleck dances, too. You've just got to give it the right music -- Cornstarch Music.

For a more thorough, scientific look at oobleck's behavior, take a look at Cornstarch Coolness.

This needs just a little more water to match the Minicon oobleck in consistency.

I may have been the first, but I'm not the only one. Even scientists dance on oobleck. Well, one scientist, at least. Last month, Assoc. Prof. Marc Spiegelman danced in a bathtub full of cornstarch and water. He was demonstrating how rocks can behave as a liquid or a solid under different conditions at Columbia University Lamont-Doherty Earth Observatory's annual Open House. That's how the YouTube summary describes it, anyway. My own dancing style is considerably different, even when oobleck is involved.