Revelation 8:1

Chapter 8 - Last seal opened 4 trumpets sound

1 And when he had opened the seventh seal, there was silence in heaven about the space of half an hour.

After the parenthetical chapter of what will happen in the ministry of the 144,000 in the great tribulation, the sequence of the book continues. Jesus has just opened the final seal of the seven-sealed scroll. After it is opened, there is silence in heaven about the space of a half hour. No one really knows how long this time period is on earth or how long after the sealing the silence in heaven endures. This could be similar to the silence that you hear in a courtroom just prior to the judgment being announced. It is the silence before the storm. There also could be silence in heaven because God's two prophets have now begun their testimony on earth and everyone in heaven is listening to the message God gave the prophets to say (chapter 11).