You prepare a letter by folding the paper, sliding it into an envelope, sealing the flap, and applying the postage stamp. Walking to the street mailbox, you raise the metal flag and insert the envelope through the slot.
The immediate aftermath shows no alteration. The street mailbox returns to its everyday posture. Over the next days, the sender sees no visible change. At the recipient's end, the mailbox looks ordinary as it fills and empties in its usual rhythm, with no sign of the new envelope.
This interval stretches from one day to several, depending on the route length. During that span, nothing in the scene indicates where the envelope is or how far it has traveled. The cause has already occurred, while the outcome remains unseen.
Eventually, the recipient turns the key or lifts the lid of their mailbox. There, amid the usual items, sits the envelope, now plainly present.
The act of mailing occurred at the outset, followed by a span where outcomes stayed hidden, revealing the role of latency in connecting the two moments.