If we narrow the question still further, to volunteer firemen, we eliminate one obvious answer: It's a living. Then the darkness yawns before us. Because the core question, "what could possibly make them think that it was worthwhile to risk their own lives to save others," can be spun and flipped in a number of important ways. From Why do firemen do what they do? to Why don't the rest of us do what they do? to Why shouldn't the rest of us do what they do? and even How dare we not do what they do? Superheroes become a way of addressing these questions. If science fiction is the literature of ideas, the superhero story is the literature of ethics. Or say, rather, it should be. As "literature" need not mean "sober-sided drudgery," I would even say the formulation holds for kids' superhero tales.

Fantasy provides external analogs of internal conflicts, and the subtype of fantasy about superheroes is a way of externalizing questions of duty, community, and self. How should the powerful behave? (Most Americans are, in global-historical terms, "the powerful" in one aspect or another.) These questions are salient whether you wear tights or not. They apply to you. Because most of us, certainly most of us in the developed world, have more power, wealth, or wherewithal than somebody. Certainly almost everybody reading this essay could, in principle, quit his or her present job and work pro bono for an African AIDS clinic while subsisting on donated food, or maintain a couple of homeless people instead of taking vacation, or -- join the volunteer fire department. Depending on your politics, you may believe that people like yourself or people like Bill Gates really do owe some non-trivial portion of time, wealth, influence, or attention to something or someone. The poor, the ill, the frightened, alienated, the "doomed, damned, and despised" as Jesse Jackson once put it.

A diving team has found the wreckage of author Antoine de Saint-Exupéry's military plane, almost 60 years after it plunged into the Mediterranean near Marseille, French government researchers announced Wednesday.

Saint-Exupéry disappeared on a solo flight in July 1944 while photographing southern France in preparation for an Allied landing there.

While the diversity of its distribution makes it a marketing man's dream, does one salt really taste very different from another? Steingarten maintains that it does, and in 2000 set up an experiment at the bi-annual meeting of scientists and super-foodies at Erice in Sicily to prove his point. This he did, at least to his own satisfaction: he was the only one in a group that included Blumenthal and American food science writer, Harold McGee, who correctly identified the salts in question. The experiment was repeated back in Britain at the research centre in Leatherhead with inconclusive results. Or rather, the most exclusive salts did not live up to their billing.

Astronomers at the Paranal Observatory in Chile have obtained the best images yet of Titan - Saturn's major moon.

They show what may be clouds in its thick and hazy atmosphere of nitrogen, methane and oily hydrocarbons.

The Chandra X-ray telescope in orbit also studied Titan's atmosphere as the moon passed in front of the glowing wreckage of an exploded star.

Researchers have been studying the body found in Petrarch's tomb at the small town where he died outside Padua in northern Italy in 1374.

The body seems to match Petrarch's own description.

But the head doesn't.

In fact, it looks more like a woman's, according to anatomists from Padua University. Worse: the DNA of the head does not match that of the body.