through Feb. 3, Vox Theatre Company at the Walnut Studio Five Theater, 825 Walnut St., 215-569-9700

The sound you hear at the Walnut Studio is Lanford Wilson jumping on the bandwagon. In Sympathetic Magic, Wilson attempts what Michael Frayn (Copenhagen) and Tom Stoppard (Arcadia) have done with great success — to incorporate into a play epic themes of science and the universe.

Magic is the story of Ian Anderson, a young astrophysicist with nearly everything going for him. He’s a charismatic lecturer on the verge of the kind of major discovery that will alter his field. He’s also about to become a father.

The latter revelation is not the source of unalloyed joy we might imagine, and serves as the catalyst for much of Magic’s action. Along the way, we meet members of Anderson’s inner circle — his partner and her family (overbearing anthropologist mother and gay Episcopal priest brother), his department chair and more. For Anderson, his personal life and his promising discovery coexist uneasily. How can he deal with both?

On one level, Wilson ambitiously asks no less a question than "What might the ‘grand plan’ mean for our earthly existence?" That’s a tough nut for God (or even Stoppard), and unsurprisingly Wilson doesn’t find an answer. The least satisfying aspect of Magic is the treatment of the religious and scientific ideas, which regularly come and go nowhere.

Yet Wilson has nearly 40 years of experience at orchestrating large groups of characters, and treating with nuance the complex feelings among extended families. There’s something simple but sophisticated at the heart of his plays — the uneasy business of being a good friend (or parent or partner). Some familiar Wilson tropes are here: homosexuals and heterosexuals (and parents and children) trying delicately to find common ground, and AIDS and its aftermath. In Magic, even when Wilson’s sweeping ideas get away from him, the personal stories show his level of craft is happily undiminished.

The night I saw Magic, the Vox production seemed to still be finding its way. Several key plot points were glossed over; some young actors give performances a size too small for their roles (and one veteran, semaphoring and grimacing like Norma Desmond, is at least three too large). The big cast and complicated action aren’t always well-served by physical realization in the space.

Yet, flaws and all, there’s something likeable and reassuring about both play and production, which share the same virtues of directness and honesty. After the cynicism and poor playwriting on view in a couple of recent productions, this made a welcome change.