‘The Gate of Heavenly Peace’

In watching Richard Gordon and Carma Hinton’s superb three-hour documentary, you have to wonder whether without Beijing’s vast Tiananmen Square, capable of holding 1.5 million people, the seven-week, student-led demonstration calling for democracy that ended June 4, 1989 in a bloody massacre could have ever been launched. Gordon and Hinton were able to bring alive a historic event (KCET Sunday at 2 p.m.).