Talk:Fluid thread breakup

In the History about da Vinci - misinterpreted the mechanism?

"He thus correctly attributed the fall of droplets to gravity, but misinterpreted the mechanism which drives thread breakup."

How did he misinterpreted that mechanism? He talks about "cohesion between its particles" which is pretty much what happens. The surface tension pulls the water in these shapes and even back against gravity. From the surface tension article:

At liquid–air interfaces, surface tension results from the greater attraction of liquid molecules to each other (due to cohesion) than to the molecules in the air (due to adhesion).

--Eheran (talk) 10:42, 23 February 2018 (UTC)

External fluid highly viscous

For the limiting case where the external environment of the fluid thread is much more viscous than the thread itself

And then later

"Examples of when this case would apply are when gas bubbles enter a liquid or when honey falls into water."

How is water, the external environment in the last example, much more viscous then honey? Its the other way around, when water is entering honey. This will sort of form a tunnel with a certain depht, depending on the speed of the water as well as the viscosity of the honey. With the right setting this can also result in a cavity of water forming in the honey, at the end of said tunnel, when the water keeps getting pressed into the honey due to the falling water above when it cant move up around this stream. Thus I will swap both liquids.

--Eheran (talk) 11:02, 23 February 2018 (UTC)

Plateau reference

The cited Plateau reference appears to be something like a reply to a comment, by its own description the original research is instead in "Experimentelle und theoretische Untersuchungen über die Gleichgewichtsfiguren einer flüssigen Masse ohne Schwere". CyreJ (talk) 16:19, 17 May 2022 (UTC)

Honey

According to the caption of the honey image "(t)he viscosity of honey is large enough to damp all surface perturbations that would lead to the breakup of the thread into droplets." This does not mix with the section Fluid_thread_highly_viscous. Quote: "(...) the viscosity of the fluid thread does not influence which wavelengths will be stable. Viscosity only acts to decrease how rapidly a given perturbation will grow or decay with time." (emphasis by me)

Dampening pertubations by a large amount would make the pertubations shrink rather than grow. This would be imply that the flow of honey would never break into droplets. However, as quoted above, viscosity does not stabilize the flow. It just makes pertubations grow more slowly. So the honey hits the floor before pertubations had enough time to cut the thread.

I am going to make the image caption consistent with the statement above. -<)kmk(>- (talk) 02:47, 28 August 2025 (UTC)