For a bit of summertime diversion, how about immersing yourself in the world of theoretical physics? No takers? Well, this isn't as academic an exercise as it sounds. In fact, even if your idea of complex science is decoding the SPF rating on a bottle of suntan lotion, Olney Theatre Center's elegantly accessible "Copenhagen" might still qualify as a seasonal refreshment.

Good writing has a way of relaxing the spirit in much the manner that a session in the hot tub releases the tension in one's neck and back, and Michael Frayn, author of the Tony-winning play, is in this regard a stress-relief wizard. His six-year-old drama tackles some morally challenging subjects, among them the nature of the scientist's culpability in the origins of weapons of mass destruction. But it also explores the responsibility of the poet to remind us of the symmetries and incongruities and frailties in even the most rigorously mathematical of lives.

Jim Petosa, Olney's artistic director, has staged the play with a keen understanding of both its humanity and its moral force. The trio of actors he's assembled, Valerie Leonard, Alan Wade and Chris Lane, have worked with one another often, and it shows; they lean on each other as securely as if they were sides of an equilateral triangle. The design team meshes no less satisfactorily. In particular, the lighting by Daniel MacLean Wagner and sound effects by Tony Angelini offer chilling, moving intimations of the Armageddon that pricks the consciences of Frayn's characters.

The play revolves around a 1941 reunion at the Copenhagen home of the revered Danish physicist Niels Bohr (Wade) and his wife, Margrethe (Leonard), with Bohr's old student, Werner Heisenberg (Lane), who earned renown as the author of the uncertainty principle of quantum theory. The meeting is reconstructed from the memories of the three participants, now speaking to each other from beyond the grave. James Kronzer's metallic mirrored set seems an apt distillation of the coolly cerebral realm to which they've all departed, and Pei Lee's costumes in shades of vanilla help to evoke the neutrality of the territory they now inhabit.

It is Heisenberg's ethical torment that forms the core of the story. A German of no meager nationalistic pride who worked on the applications of nuclear fission under Hitler, Frayn's haughty Heisenberg is seeking approbation or absolution, or both. Fortunately for the world, the Nazis did not succeed in making an atomic bomb. Still, Heisenberg returns to the Bohrs to pin down the elusive truth of his own wartime motivations. Did he pay his dangerous visit to his mentor in Nazi-occupied Denmark for emotional sustenance, or to pry out the secrets of the Allies' nuclear program? Was he a man of science, or of politics? An emissary of armistice or annihilation?

The play is all about ambiguity, about how it is both honorable and impossible to separate one's nobler intentions from the more primitive instincts; how much of a given outcome is chance, how the principles of uncertainty apply as much to the human heart as to particles in space. Often in "Copenhagen," you are put in mind of the burdens on contemporary figures to make high-stakes decisions in the face of terrible uncertainty, and how difficult it is for rational men to ever really know whether the choice was the right one.

Frayn's discussions of physics and classical mechanics are beautiful and utterly convincing, at least to this English major's ear; part of the delight of the play is in that Stoppardesque sensation of delving into realms that seem patently untheatrical, and discovering that they belong on the stage after all. Suffusing the work is the notion of physicists as artists, creative thinkers painting on vast canvases of the mind, and it is Frayn's special province to enable us to see them from the ebulliently human side of the equation.

Lane is especially strong as Heisenberg; he's a warming presence on the stage, and he's able to embody the paradoxical strains in Heisenberg, the guilt and self-loathing, the wiliness and self-regard. Wade locates Bohr's reserves of vanity and humor, and Leonard proves a skillful partisan, gently chiding her husband but challenging his former student with a zesty, wifely zeal.

It somehow enhances one's enjoyment to know that Frayn is also the author of "Noises Off," the supremely well-constructed backstage farce, not to mention the extraordinary new play "Democracy," now running in London and soon to come to New York, about the career of the late West German chancellor Willy Brandt. Range is one of Frayn's more infuriating attributes.

Copenhagen, by Michael Frayn. Directed by Jim Petosa. Approximately 2 hours 35 minutes. Through Aug. 8 at Olney Theatre Center, 2001 Olney-Sandy Spring Rd., Olney. Call 301-924-3400 or visit www.olneytheatre.org.

Chris Lane, Valerie Leonard and Alan Wade in Olney Theatre Center's winning production of Michael Frayn's "Copenhagen."