Used with
permission of Maiken Naylor, University at Buffalo, Buffalo, NY, USA,
http://ublib.buffalo.edu/libraries/units/sel/exhibits/stamps
This Russian stamp of geological exploration has it all - underground explosion, airplane, truck, derrick, reflections of waves from different layers. This is what makes science stamps, and indeed many other stamps, so much fun: they tell a story of a process, an event, they are instructive.