Does slimy spit have a spring constant?

AI Thread Summary
Slimy spit exhibits properties similar to viscoelastic materials, allowing it to stretch and recoil like a spring when released. This behavior can be attributed to the surface tension and viscoelasticity of non-Newtonian fluids. Observations indicate that when slimy spit is elongated, it can break and then jump back, demonstrating its elastic characteristics. The discussion highlights the scientific principles behind these phenomena, suggesting that they can be explained through elementary fluid mechanics. Understanding these properties can enhance knowledge of fluid dynamics in biological substances.
bobby2k
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Hello

WARNING: Some people may find this post a little gross.

I observed something today that I didn't know could happen in fluids, only in solids. I let some slimy spit out from my mouth. It became a longer and longer connected line, and then the bottom broke off. What was interesting was what happened with the part connected to my mouth. It kind of jumped up again, like a spring that had been stretched. I've never thought about this before. Does slimy fluidshave some kind of spring constant?, can this be explained with elementary fluidmechanics?
 
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A.T. said:
It could be surface tension and/or viscoelasticity exhibited by non-Newtonian fluids:
http://en.wikipedia.org/wiki/Non-Newtonian_fluid
Yes. Mucus and spit are viscoelastic, and exhibit, among other things, the phenomenon of recoil.
 

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