So all of a sudden today the Late Answer review queue exploded to more than 500 posts. All that I looked at were not new, but something kicked them back in to play.
As a still newish person here, what happened?
The Late Answers Review Queue contains answers which were posted by new users much later than when the question was asked. Late answers tend to be seen by fewer people than answers posted soon after the question was asked, so the review queue helps ensure that these answers meet the same quality standards as all other answers.[source]
Following this meta discussion, the decision threshold for late answers to enter the Late Answers Review Queue has been raised from 10 to 50 reputation. This applies to all sites, not just physics.SE.
Due to this change, many old answers retroactively entered the Late Answers Review Queue. This caused a spike in the number of answers in the queue.