Speaking through an interpreter on a three-way video call from a chilly Tel Aviv, Sara Lanesman, a linguist at Haifa University’s Sign Language Research Laboratory, signs with energetic motions that convey the intensity of what she felt during two formative moments of her life. The first: having to flee Algeria as a child with her family. The second: finding the country again through a sign language she didn’t know existed. Several years ago, Lanesman and her mentor, the late linguist Irit Meir, were documenting the history of Israeli Sign Language…