Where is zero time line?

Answer 1

The zero time line, often referred to as the "timeline origin" or "zero point," is a conceptual reference point used in various fields, such as physics and history, to denote the starting point of measurement. In historical contexts, it can refer to a specific date from which events are measured, like the year 0 in the Gregorian calendar. In physics, particularly in the context of relativity, it can signify the moment when an event occurs relative to other events in spacetime. Overall, its precise definition depends on the context in which it's being used.