Today’s invention is a way to make drinking more exciting.
A cup has a number of testtubes inside, each filled with some different liquid. The outside of the cup is tinted or opaque, so that users can’t see what is going on inside.
The green top forms a seal with the top of the testtubes. A drinker rotates the green top around a vertical axis, so that some testtubes are now in communication with a small number of bendy straws.
This allows the drinker to twist the top and make himself/herself an instant, random cocktail.
(See also #371: Rainbow drinks)