International Year of Light- FDC – Liechtenstein 2015
A Unique stamp issued by Liechtenstein on 02 Mar 2015 to mark International Year of Light. This special stamp permits the observer to conduct three experiments related to Theory of Light.
(a) The background of stamp glows in dark due to fluorescent (b) Turns into source of light if exposed to sunlight beforehand (c) Wave theory explained as light is diffracted through the holes (d) For quantum theory the special pink color changes to violet when irradiated through UV light.
A FDC is listed