4 ms·
Ketchup stuck to the sides of a bottle doesn't mean it's a non-Newtonian liquid though, right? Wouldn't it actually reinforce Newton's law of constant viscosity
by branon 4y ago
Ketchup stuck to the sides of a bottle doesn't mean it's a non-Newtonian liquid though, right? Wouldn't it actually reinforce Newton's law of constant viscosity, because ketchup is _constantly_ viscous enough that it ends up stuck to the bottle? It won't come out once the bottle lacks a critical mass of ketchup, because gravity is no longer able to overcome the liquid's constant viscosity.
- jaclaz 4y agoAFAIK, it is non-Newtonian allright: >The Law of viscosity states that a fluid flows at a speed proportional to the force that is applied, where the constant of proportionality is the viscosity. Because ketchup does not obey this Law, it is known as a non-Newtonian fluid. https://www.futurity.org/ketchup-physics-rheology-1321922-2/ https://www.futurity.org/ketchup-physics-rheology-1321922-2/ Maybe you are thinking of those (starch based) mixes like ooblek that are shear thickening whilst ketchup (and mayonnaise, and similar) are shear thinning, but both are non-Newtonian: https://en.wikipedia.org/wiki/Non-Newtonian_fluid https://en.wikipedia.org/wiki/Non-Newtonian_fluid
- smegsicle 4y agoarticle author only seems to have a half understanding of the concept in the first place > Sometimes you just can’t get the ketchup out of the bottle, but after you shake it, it becomes runnier and therefore easily gets out. should say "as you shake it" not after, since the decreased viscosity effect only lasts as long as the stress