What does Revelation 8:1 mean?

In this verse the apostle John tells us there was silence in heaven for about half an hour. He must have estimated the time from an earthly perspective because such delays have little meaning in an eternal heaven. The silence is significant. Just as silence pervades a courtroom when the judge is about to render a verdict in a criminal trial, so the occupants of heaven fall silent as they anticipate what the Judge of the universe is about to do.

John tells us the Lamb opened the seventh seal. As each previous seal was opened, a specific judgment struck the earth. As we will learn later, the opening of the seventh seal includes all the horrific events described in Revelation 8:7—19:10. That is, the trumpet and bowl judgments are themselves the result of the opening of the seventh seal. Seven trumpet judgments occur near the middle of the tribulation period, and seven bowl judgments occur in the second half of the tribulation. Each series of judgments intensifies the outpouring of God's wrath.