|a printed punctuation mark (‽), available only in some typefaces, designed to combine the question mark (?) and the exclamation point (!), indicating a mixture of query and interjection, as after a rhetorical question.|
|an extraordinary or unusual thing, person, or event; an exceptional example or instance.|
|Boltzmann (bôlts'män') Pronunciation Key
Austrian physicist who developed statistical mechanics, the branch of physics that explains how the properties of atoms (such as mass and structure) determine the visible properties of matter (such as viscosity and heat conduction). Through his investigations of thermodynamics, Boltzmann developed numerous theories about the laws governing atomic motion and energy.