Lunar Observations in Rosh Hashanah

The Daf Yomi cycle just finished studying Masechet Rosh Hashanah. Mazal tov to all those who have completed this study! In Masechet Rosh Hashanah observations of the Moon play a very significant role. A major topic of study in this tractate is how the ancient Jewish “calendar” worked. In fact, it was not really a…

Black Holes in Pesachim

The very first line of Pesachim focuses attention on one of astronomers’ favorite topics: light! Or does it?