The representation of science and scientists on postage stamps

There has been much academic study into the ubiquitous postage stamp as a communications medium. But no-one has looked at the 'science' messages being sent to the public as the secondary function of the stamp. And why now, when the number of mail items being serviced by the world's post offices is falling at about 10% per year? Paradoxically the post offices are issuing more stamps year on year and many of these send a science message.

It is an interesting phenomena as the style and context of the message can be seen to have developed in line with the public awareness of science.