13th–14th century) (Hebrew: יצחק בן שמואל דמן עכו, Yitzhak ben Shmuel d'min Akko) was a Jewish kabbalist who fled to Spain.
[citation needed] Abraham Zacuto states in his Yuḥasin, that Moses de Leon discovered the Zohar in the time of Isaac of Acre.
When Isaac met Moses of Leon at Valladolid, the latter took an oath that he had a copy of the Zohar written by Shimon bar Yochai himself in his house at Ávila.
Dafan told Isaac that Moses of Leon's wife and daughter had revealed to the wife of a certain Joseph of Ávila that Moses of Leon had written the book himself, an anecdote accepted as historical by Heinrich Graetz,[4] Hebrew University professor Yeshayahu Leibowitz, and academic authorities on the Kabbalah such as Gershom Scholem and Berkeley professor Daniel C. Matt, while Landauer claims it to be apocryphal and tries to demonstrate that the Zohar was discovered much later.
According to Kaplan, "From calculations based on the expanding universe and other cosmological observations, modern science has concluded that the Big Bang occurred approximately 15 billion years ago.
Rabbi Gil Student and Rabbi Ari Kahn describe some objections, citing sources which disagree, including the argument that the author of Sefer HaTemunah actually believed we were in the sixth, not seventh Shmitah, and that Isaac himself said that we were in the second, not seventh Shmitah, which would change the calculation dramatically, and bringing up the Arizal who was of the view that the matters discussed are spiritual and should not be applied to calculate physical years.