I was horrified to discover an error on page 29 a day or two ago, and have worked with BookLogix to make a change on the fly to future printed copies.
Sentence on page 29 had read:
(We now know from science that the Earth's shadow causes these shapes.)
Changing it to read:
(We now know from science how the Moon's orbit causes these shapes.)
I was obviously thinking ahead to eclipses when I wrote this earlier!