"The present is the time that is associated with the events perceived directly and in the first time,[1] not as a recollection (perceived more than once) or a speculation (predicted, hypothesis, uncertain). It is a period of time between the past and the future, and can vary in meaning from being an instant to a day or longer. It is also known as the here-now. In radiocarbon dating, the "Present" is defined as AD 1950.

It is sometimes represented as a hyperplane in space-time,[2] typically called now, although modern physics demonstrates that such a hyperplane can not be defined uniquely for observers in relative motion. The present may also be viewed as a duration (see specious present)."