Part of the IT standards and organizations glossary: The Stefan-Boltzmann constant, symbolized by the lowercase Greek letter sigma (), is a physical constant involving black body radiation.A black body, also called an ideal radiator, is an object that radiates or absorbs energy with perfect efficiency at all electromagnetic wavelength s.art of the IT standards and organizations glossary: The Stefan-Boltzmann constant, symbolized by the lowercase Greek letter sigma (), is a physical constant involving black body radiation.
Definition of memoir for English Language Learners. memoirs : a written account in which someone (such as a famous performer or politician) describes past experiences.
A biography is solely about an individual's life, while a memoir would be about something the author experienced (i.e. a historical event or a disease) or a person the author knew. A memoir is a sort of semi-autobiographical sketch, but it does not focus solely on the author's own life.