Food coloring in glycerine is mixed by turning a drum, then unmixed by reversing. Has entropy decreased?
What it shows:
Ink is squirted into a fluid and mixed in until it disappears. By precisely undoing the motions in the reverse direction, the ink becomes unmixed! The demonstration seems to defy thermodynamics in that it appears that entropy decreases, but in actuality the reversible mixing is made possible by insuring that the mixing/unmixing is done without turbulence.
How it works:
The space between two, transparent and concentric...
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