Hi Georgina You can share "something = that." It is useless to divide zero. There is no past as a place for processes. You can call the past a point only on the abstract axis of measuring the duration of events.
The universe is voluminous. The universe is always in the present. If the present was a line or plane, then in the present there was a part of the Universe and the Universe could travel through time (from one present to another). The IMO Universe creates a process of time movement. Each process determines thermodynamics. Thermodynamics gives the 'direction' of the arrow of time.