if the situation in the gemara is that the molad is right before chatzos, then the night before according to rashi we could see the moon , but what i don't understand is if the moon is ahead of the sun at sunset then by the time the sky is dark enough to see the moon the moon is no longer on this side of the globe and the converse should be true in bavel 18hours after the molad?
p.s. i've read your insights section with an explanation by Dr. Vidal , but he does not seem to address this problem.
thanks for taking the time to read this question and hopefully you will have time to respond. also your insights section is tremendous, a yashar koach.
d. yunger, toronto,canada
The explanation of Rashi, according to Dr. Vidal, is that the moon is visible in the sky even when the sun is up if the moon is 9 degrees away from the sun (i.e. it is 18 hours or more after the Molad or before the Molad).
It should come as no surprise to you that the moon is visible in clear daylight. You can find the moon in the sky by day nearly every single day of the month, if you just look for it in the correct place. The "Chidush" here is that it is visible even if it is only 18 hours from the Molad, and it is still relatively near to the sun (meaning that the blinding light of the sun is very near to it, and that the visible crescent of the moon is still very thin). However, this is not entirely impossible, and cases have been documented when the moon has been sighted by the naked eye only about 14-18 hours after the true Molad.
When the sun has set, and the moon is still above the horizon, then the new moon is visible even when it is only 3 degrees away from the sun (6 hours after the Molad).
Thus, the answer to your question is that yes, the new moon can indeed be seen by day if it is 18 hours from the Molad.
Let me know if this answers your question.
Best wishes,
Mordecai Kornfeld
(Please accept our apologies for the delay in getting back to you on this. Due to the pressures of organizing our Grand Siyum and Pesach vacation, the Kollel fell behind in keeping up with our email questions. We are now back on track, and you should receive prompt answers to any future questions, G-d willing.)