Does time actually flow — or is that a trick your mind plays?

It feels obvious that time moves: the future rushes toward you, becomes a fleeting "now," then slips into a fixed past. Philosophers call this intuitive view the A-theory of time — the idea that there is a real, moving "present" and that the flow of time is a genuine feature of reality. On this view, only now is fully real; the future hasn't happened and the past is gone.

But many thinkers, following a famous 1908 argument by J. M. E. McTaggart, doubt this. The rival B-theory says there is no special "now" at all. Instead, all moments — your birth, this breakfast, your hundredth birthday — exist equally, laid out like frames of a film. Events aren't past or future in any absolute sense; they're just earlier than or later than one another. This picture is often called the block universe, and it fits neatly with how physics treats time as a fourth dimension.

If the B-theory is right, the "passage" of time is something like a perspective illusion. Just as "here" isn't a special place in space — it's just wherever you happen to be — "now" isn't a special moment in time. It only feels like the present is racing forward because your consciousness experiences moments one after another. The river of time may not be moving at all; you're simply reading its map one page at a time.