Fire ants' raft building skills react as fluid forces change

Fire ants build living rafts to survive floods and rainy seasons. Georgia Tech scientists are studying if a fire ant colony's ability to respond to changes in their environment during a flood is an instinctual behavior and ...

Fossils reveal swimming patterns of long extinct cephalopod

Computational fluid dynamics can be used to study how extinct animals used to swim. Scientists studied 65 million-year-old cephalopod fossils to gain deeper understanding of modern-day cephalopod ecosystems.

Low-frequency sound may predict tornado formation

How can you tell when a storm is going to produce a tornado even before the twister forms? Research from Oklahoma State University and University of Nebraska-Lincoln indicates prior to tornado formation, storms emit low-frequency ...

Fluid dynamics taught through dance

A collaboration at University of Michigan is taking a unique approach to fluid mechanics by teaching it through dance. Fluid mechanics professor Jesse Capecelatro and choreographer Veronica Stanich, both from the University ...

Fluid dynamics provides insight into wildfire behavior

The Kincade Fire has been burning through Sonoma County, California, displacing people from their homes and leaving destruction in its wake. It is a stark reminder of the increasingly pressing need for a better understanding ...

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In physics, a fluid is a substance that continually deforms (flows) under an applied shear stress, no matter how small. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids.

In common usage, "fluid" is often used as a synonym for "liquid", with no implication that gas could also be present. For example, "brake fluid" is hydraulic oil and will not perform its required function if there is gas in it. This colloquial usage of the term is also common in medicine and in nutrition ("take plenty of fluids").

Liquids form a free surface (that is, a surface not created by the container) while gases do not. The distinction between solids and fluid is not entirely obvious. The distinction is made by evaluating the viscosity of the substance. Silly Putty can be considered to behave like a solid or a fluid, depending on the time period over which it is observed. It is best described as a viscoelastic fluid. There are many examples of substances proving difficult to classify. A particularly interesting one is pitch, as demonstrated in the pitch drop experiment currently running at the University of Queensland.

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