What the Brooklyn Academy of Music's current revival of the Philip Glass-Robert Wilson avant-garde opera "Einstein on the Beach" appears to establish is that this is one of the seminal artworks of the century -- possibly the seminal work, given its emblematic embrace of so much that is central to human experience in its era, and the trenchant, radical brilliance of its form.

Nor has the work's power to move and astound been attenuated. Despite its slow-moving, repetitive, intermissionless nature, it remains hypnotically riveting. The ovation prompted by last Saturday evening's performance -- from a capacity crowd at BAM's Opera House, standing and cheering uninterruptedly at the final curtain -- was as roof-shattering as anything one is ever likely to have encountered in a theater.

BAM's long anticipated restoration -- eight years after "Einstein's" world premiere at Avignon and two sold-out performances at the Metropolitan Opera House -- had come to seem almost a sacramental act even before previews began last Tuesday. At the time, the original "Einstein" had been widely regarded not only as a milestone in experimental music theater, but a landmark of 20th-century esthetics. In the intervening years, the reputations of Wilson, Glass and another crucial collaborator -- dancer-choreographer Lucinda Childs -- had mushroomed. And the already ballooning legend of the work itself and its Met performances was perpetuated and magnified by a briskly selling record album of the Glass score.

Inevitably, one wondered whether the reconstituted, 4 1/2-hour opus -- with some changes in personnel and content, but essentially the same work and cast -- would stand up to the test of time. The BAM production settles the matter -- the lapse has in no way diminished its impact or tarnished its aura of creative daring and originality.

A lot of debate has focused on whether "Einstein" is truly an opera, in any commonly understood sense. Certainly its means and effects lie well beyond operatic convention, and its "nonnarrative" character -- there's no story, just a mosaic of slowly transforming aural, visual and choreographic imagery -- can be a stumbling block for devotees of "La Bohe me." But it is a theatrical work set to music, involving, like so much of opera in traditional modes, solo and choral singing, dancing and spectacle. In any case, terminology seems beside the point -- "Einstein" fulfils the Wagnerian dream of a Gesamtkunstwerk, a unified marriage of collaborating media, in a way Wagner himself never approximated.

"Einstein on the Beach" isn't an account of Einstein's life or work. Rather, it's a mythical envisagement of Einstein as man, scientist and symbol, and by extension, an extended meditation on the relations of man to man and man to cosmos in the Einsteinian age.

The multitude of things the name Einstein connotes to the general, unscientific public -- not just relativity, gravitation, the fourth dimension, the space-time continuum, the equivalence of mass and energy, and all that, but also pacifism, the atom bomb, music and the mysteries of the infinite -- are somehow herein gathered into a hallucinatory, emotionally transporting tapestry of sights, sounds and movements.

In a number of ways, "Einstein" stands in relation to other works in the performing arts of our time the way Stanley Kubrick's "2001: A Space Odyssey" stood in relation to movies -- it's a watershed in the way it defines the consciousness of an epoch, the world view of a period in history.

There are other "2001" parallels. "Einstein" culminates in a giant, multilevel spaceship scene -- truly awesome in its sheer size and visual and musical wizardry -- followed by a coda, like that of Kubrick's film, that brings the cosmic down to human proportion once again, and poses questions about human values and the future. The mysterious slab of "2001" has its counterpart in a massive bar of light, which, in a scene preceding the spaceship, levitates across the stage and eventually rises to disappear in the flies -- in "Einstein," it also functions as the edge of a bed, one of a number of key props, this one evoking Einstein as dreamer and visionary. And all of "Einstein" has the same feeling of ushering the spectator into a "time warp" -- a suspension of everyday temporal passage and a sensation of eternity crammed into each moment -- that marked the "Stargate" episode in the Kubrick film.

Divided into four acts and nine scenes, separated and framed by five "knee plays" -- interludes and points of junction -- "Einstein" has a kind of cyclic structure revolving around critically recurring motifs and images, among them a train (first seen as a life-size smoke-belching locomotive in Act 1), a trial (with its suggestion of Einstein as a "lawbreaker" and iconoclast), and a field (inspired, in part, by Einstein's "unified field" theory of physical forces and their connection with cosmic geometry). Clocks and wristwatches, a compass, a moving gyroscope, a conch shell, a huge Erlenmeyer flask, an eclipsing moon, astronauts, and a man who seems to be flying through space are among the other visual data that swim through the matrix of stage apparitions.

The collaborative texture of "Einstein" is such that it is impossible to divide the impression of the whole into contributions of the separate media -- music, dance and visual elements fuse into an indissoluble union. The visual designs and stage direction came from Wilson. Glass, who generated the original conception hand in hand with Wilson -- a solo violinist, Tison Street, dressed and made up as Einstein, figures both in the musical ensemble and in the symbolic action -- composed the inspired score for acoustic and electronic instruments, solo and choral voices, which is stunningly performed by the Philip Glass Ensemble.

The choreography by Lucinda Childs -- whose magically vibratory solo dance on a diagonal is alone worth the price of admission -- replaces the original by Andrew de Groat to superb effect, with the help of Childs' own dance company and the extraordinary Sheryl Sutton, actress and dancer of the original cast. A company of 24 dancer-actor-singers manages the multiple role-playing in consummate fashion; among them, Samuel M. Johnson -- who portrays a judge in the trial scenes and the bus driver in the coda, whose text he composed -- is particularly charismatic. Among other collaborators, lighting designer Beverly Emmons and sound mixer Kurt Munkacsi provide levels of ingenuity and imagination indispensable to "Einstein's" spellbinding force.

The BAM production runs through Dec. 23, and though ticket sales have been heavy (most of the run is sold out), ample seats remain for the final weekend. CAPTION: Picture 1, A scene from the Brooklyn Academy of Music's revival of "Einstein on the Beach" Copyright (c) Pictures 2 and 3, Actress and dancer Sheryl Sutton and a scene from "Einstein."