In physics, a fluid is "a substance that continually deforms (flows) under an applied shear stress. Fluids are a subset of the phases of matter and include liquids, gases, plasmas and, to some extent, plastic solids."
Yeah, okay. There won't be a quiz later.
It's Illustration Friday on Saturday time, and this week's prompt is "fluid". I painted some paint. And a smiley face cup that has probably held some fluid.
When I was in college, I had to take many hours of "Fluids" class. I don't remember much of it now other than lots of airplanes and jets and wings in particular. And the book was red. And the professor seemed to really like himself.
So rather than wings - one of my first considerations - I painted paint. And a smiley face cup.
The sign in the background is meant to read "WET PAINT". I feel it's a bit of a fail when I have to explain an illustration.
Oh well, just take it out of my pay.