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 memoir does not contain everything from this particular slice of the authorâs life, but rather, events are selected and examined for meaning relative to the purpose of the book. The author has questioned what happened and come to some kind of new understanding or lesson learned by it.