Abraham the Astronomer

There is an obviously very appealing idea extant in Jewish sources that Abraham the Patriarch was an astronomer. Where do we see this idea? And where does it originate?

Rosh Hashanah vs. The Sun Blessing

The Rosh Hashanah Machzor says היום הרת עולם and depending on your edition, probably translates it something like “today is the birthday of the world” or some fairly similar translation. But… Says who? This holiday is not called “Rosh Hashanah” (“start of year” or more colloquially, “new year”) in the Torah. It’s called a יום…