SERIES PREMIERE: In AMC’s The Son, a young actor and a veteran one share the same role, portraying the identical character at different times in his life. That’s the same approach used in this new National Geographic series, only the subject, and protagonist, in question is Albert Einstein. As a young man, he’s played by Johnny Flynn. Later in life, he’s played by Geoffrey Rush, who played a different type of genius, a musical one, in the 1996 movie Shine. For a full revi