👉 The undefined fluid, often referred to as a "quasi-liquid" or "non-Newtonian fluid," is a substance that exhibits properties of both liquids and gases, but its behavior doesn't fit neatly into the traditional categories. Unlike typical liquids, which have a fixed volume and shape when not disturbed, or gases, which expand to fill any container, the undefined fluid can change its viscosity (thickness or flowability) depending on the applied force or stress. This means it can flow more like a liquid under low stress but behave more like a solid or gas under high stress. This unique characteristic makes it particularly intriguing in various scientific and industrial applications, such as in the study of complex fluids, biological systems, and even in everyday objects like toothpaste or ketchup.
