Question

Hello Rabbi, I tried to study Rabbeinu Tam’s view regarding sunset and twilight. Seemingly, from his words in Sefer HaYashar (242) and from the words of Nachmanides, who discusses him (Torat HaAdam, Gate of Mourning), it appears that Rabbeinu Tam was speaking about a “second sunset” 3 and a quarter mil before the commonly accepted sunset, and therefore practically almost nothing would result from this for Jewish law. That would also explain the basic difficulty of the mismatch between the appearance of three stars and nightfall according to Rabbeinu Tam as usually understood. (And it would seem to be almost explicit this way in Tosafot on Berakhot 2b regarding “and the sun sets and he becomes pure.”)