The Mexican Flag cocktail as an example of Schleirin Optics.
Layered cocktails typically comprise
alcoholic beverages of different densities: the lightest is
poured in first, the next lightest is placed underneath it
through a straw, and the last and densest underneath that.
Typical liqueurs are grenadine (red) and creme de menthe
(green): the Green / White / Red Mexican Flag has a
middle layer of tequila (clear).
Placed at an angle, the straw will appear to bend at the interface between layers of different densities, because light is diffracted differently in media of different densities. The same thing happens when a fishing line appears to bend where it passes from air to water. The distortion angle could be used to measure the difference in density. A photograph of the interfaces under very bright light can be made to show a dark line where the wave fronts cancel each other.
Placed at an angle, the straw will appear to bend at the interface between layers of different densities, because light is diffracted differently in media of different densities. The same thing happens when a fishing line appears to bend where it passes from air to water. The distortion angle could be used to measure the difference in density. A photograph of the interfaces under very bright light can be made to show a dark line where the wave fronts cancel each other.
All text material ©2020 by Steven M. Carr