Why is there silence in heaven at the seventh Seal?

When the seventh seal is broken, Revelation records, "And when he had opened the seventh seal, there was silence in heaven about the space of half an hour." This silence is not an event of judgment itself. The seals had served as a kind of table of contents, previewing what was written on the outside of the sealed book: the white horse rider, war, famine, death, martyrdom, and the sweeping summary vision of the sixth seal covering earthquake, cosmic signs, the sealing of the 144,000, and the great multitude before the throne. Once that outward writing had been fully disclosed through the six seals, the seventh seal was the last one holding the book itself shut.

The silence marks the solemn pause between the finished preview and the actual unfolding of what had been hidden inside the book. It is a moment of reverence because the time had come for the once sealed secrets of God concerning the end to be revealed to everyone. Nothing new is announced during the silence; it is simply the hush before the book is opened and its contents, the seven trumpet judgments, begin to sound.

Immediately after this half hour of silence, the scene moves forward: seven angels are given seven trumpets, another angel stands at the altar with a golden censer, and the smoke of incense rises with the prayers of the saints before God. Then the angel takes the censer, fills it with fire from the altar, and casts it into the earth, and there are voices, thunderings, lightnings, and an earthquake. This shows that the silence gives way to the first actual events on the prophetic timeline, since up to that point the seals had only been previews, not the events themselves.