Battle of Algiers, showing this weekend at the Science Center, was made eight years ago and it has already become a political classic. The film is a semi-documentary about the decade-long fight against imperialism in the French colony of Algeria; it is a remarkable movie because in the subtlest and most subdued way it tells the truth about a contemporary political situation. In addition to its value as an historical document, the movie poses in clear and human terms the moral problem of terrorism. The Algerian battle cry that is sounded throughout is an amazing noise, one that will haunt you for a long time to come if you see this film, as well you should. 7 and 9:30, $1.50.

Traitors is another political film showing in the Science Center tonight and tomorrow, and another film worth your attention. Unlike Battle of Algiers, Traitors has a more obvious ideological edge. The movie, which is having its N.E. premier here, was made by a collective of Argentine leftists, and it traces the career of a Peronist labor leader who turns against the working-class struggle. Sponsored by the Chile Action Group, donation is $2.

Wedding in Blood, playing with The Touch, continues its week-long run at Harvard Sq., and if you're not up for one of the political films, this is your best bet in Cambridge's commercial houses. If the plot is all that interests you, Wedding is pretty much a rehash of the old crimes of passion story. If technique arouses you, if you are inspired by brilliant performances and intelligent social comment, then this is the film for you.

On the Waterfront and Angels With Dirty Faces opens up at the Orson Welles Cinema I on Sunday as part of the Welles's continuing "Heroes and Rebels" series. On the Waterfront is a marvellous bit of social reconstruction and Brando is at his best as the young fighter working on New York's racket-corrupted docks. Angles is a cliched period piece, certainly not near Cagney's prime.