You can search this site: Note that this analysis of a beginning of time concerns intervals ’of the same length' ; if this qualifying phrase is not added, then the analysis would be invalid for a dense time. If time is dense and began, then for each interval of time there is another interval of a shorter length that is a part of that interval and which completely elapses before the interval of which it is a part completely elapses. Before (...) the first hour completely elapses, the first minute does so, and before the first minute, the first second, and so on ad infinitum. This entails that there is no 'first moment' of time in the sense of an interval that precedes every other interval, but there is a 'first moment' in the sense that there is a first interval of each length of time : there is a first hour, a first minute, etc. (shrink)