When we think of time, it feels endless — a backdrop against which events play out forever. But modern physics suggests otherwise. Time is not a stage, it’s a measure of change. And measures need anchors. Without boundaries, “before” and “after” lose meaning, entropy has no arrow, and Einstein’s equations spin out into abstract mathematics. The fact that time works at all — that it gives direction to our lives, to stars, to the universe itself — means there must have been a first boundary. A beginning.
Some scientists imagine eternal inflating universes or infinite cycles of cosmic rebirth. These sound like ways to avoid the problem of a beginning. But look closely, and they don’t erase the need for boundaries — they just bury them deeper. Inflation requires a special field set up “just so.” Cyclic models rely on finely tuned bounces. In every case, something plays the role of a starting condition. Time cannot escape its need for edges.
The conclusion is startling but simple: the existence of time is itself evidence that the universe began. The beginning is not just a cosmological curiosity — it is written into the logic of time itself.