Fluid reversibility demonstration - GIF

[Toolmaker51]

While the liquids aren't revealed, there is a difference between mixing, soluble-insoluble, solutions and emulsions.
First one I remember, the original water soluble cutting oils. Another bit of amazement is water and alcohol; two equal quantities result in less than logical volume. They not only mix, but integrate.

Think we'd agree both knowledge and skepticism are healthy viewpoints.