Day Without Yesterday quote

Thermodynamical principles from the point of view of quantum theory may be stated as follows: (1) Energy of constant total amount is distributed in discrete quanta. (2) The number of discrete quanta is ever increasing. If we go back in the course of time we must find fewer and fewer quanta, until we find all the energy of the universe packed in a few or even in a unique quantum.

Now, in atomic processes, the notions of space and time are no more than statistical notions: they fade out when applied to individual phenomena involving but small number of quanta. If the world has begun with a single quantum, the notions of space and time would altogether fail to have meaning at the beginning; they would only begin to have a sensible meaning when the original quantum had been divided into a sufficient number of quanta. If this suggestion is correct, the beginning of the world happened a little before the beginning of space and time.

Georges Lemaître, May 9, 1931, letter to Nature

The Day Without Yesterday, Lemaître, Einstein and the birth of modern cosmology