The Universal Label http://xkcd.com/1123/
Ingredients: Hydrogen, time
Is this available as a sticker? This should be a sticker.
“First direct observation of the orbital structure of an excited hydrogen atom”!
Original article: Stodolna et al. 2013. “Hydrogen Atoms under Magnification: Direct Observation of the Nodal Structure of Stark States.” Phys. Rev. Lett. 110, 213001 DOI: 10.1103/PhysRevLett.110.213001