Father and son who saw the new moon should both go to testify, even though it's not clear that they can be paired together as witnesses. Which leads into a discussion about who can't be witnesses. Including the discussion about women. And what can be done on Shabbat to facilitate the witnesses' travel to the Beit Din. Also, the second chapter of the masekhet: How important is it that the court trust the witnesses? There's a historical shift in the answer to that question. Including the description of how the court spread the word of the new moon - hilltops and mountaintops, and the corruptability of the system.