Uncertainty is the situation which involves imperfect and/or unknown information. In other words, it is a term used in subtly different ways in a number of fields, including insurance, philosophy, physics, statistics, economics, finance, psychology, sociology, engineering, metrology, and information science. It applies to predictions of future events, to physical measurements that are already made, or to the unknown. Uncertainty arises in partially observable and/or stochastic environments, as well as due to ignorance and/or indolence.
Strange is our situation here on Earth. Each of us comes for a short visit, not knowing why, yet sometimes seeming to divine a purpose.
From the standpoint of daily life, however, there is one thing we do know: that man is here for the sake of other men — above all for those upon whose smiles and well-being our own happiness depends.
— Albert Einstein