We experience time as something that flows. Seconds pass. Moments disappear. The future becomes the present and then turns into the past.

But modern physics does not describe time this way.

In this video, we explore why time — as we intuitively understand it — may not exist at the fundamental level of reality.

Drawing on ideas associated with Leonard Susskind, this documentary examines how relativity and quantum physics challenge the idea of a flowing temporal river. Einstein’s theory removes the notion of a universal present. There is no global “now” that sweeps across the universe.

Without a universal present, the idea of time flowing becomes difficult to define physically.

In the relativistic picture, spacetime is a four-dimensional structure. Events are not created moment by moment. They are embedded in geometry. The equations of physics do not contain a moving present. They describe relations between events.