Once for Yes, Twice for No is a simple document, grassroot film’s answer to A Brief History of Time. Victor Blok is a scientist and Russian political dissident with amyotrophic lateral sclerosis, better known as Lou Gehrig’s disease. Diagnosed shortly after immigrating to the United States, Blok’s ability to continue living—as in writing and publishing a magazine, teaching, and coping with personal losses—depends not only on aggressive medical interventions but also on dedicated friends who have set aside careers in physics and mathematics to provide basic human care to their friend. Their emotional and spiritual accomplishment, revealed in this 20-minute document, rivals modern scientific discoveries. It has a home-movie quality that is endearing and congruent with its subject matter.  LI