Ooze Tube Viscosity Contrast

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Many colors (and two sizes) to choose from: 

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Ooze Tube Viscosity Contrast: this set of ooze tube timers comes with 3 mixtures of polyisobutene fluid, each with a different viscosity where green always wins the race: green (thin), yellow (medium), and red (thickest). A curious periodicity in the rate of flow is related to the formation of non-spherical bubbles as the air and fluid trade places (an hour shown in time-lapse). The fluid also displays the “liquid rope-coil effect” where the fluid thread coils and stacks as it lands on the pooling surface.The physics of the liquid rope-coil effect is pretty complex. Here is a recent scientific paper on the topic with nice illustrations. 
Journal of Fluid Mechanics: Multiple coexisting states of liquid rope coiling