We cannot feel the shudderings, hear the gasps behind the visors, or smell the burning metal. Our imaginings are dreadful. But the images that summon them are eerily benign.

A slanting streak of vapor has been chalked on a blue sky. The line burps, then divides.

The blue is clear and innocent. The vapor streak is puffy, white. It's like a piece of yarn made of twisted cloud. The silence is complete. Until the roar descends.

But we do not hear the roar. We only see the pictures. By now they're unforgettable. They're also oddly empty.

That's the curious thing about them. These pictures of Columbia disintegrating suddenly, these pictures of white vapor streaks, tell us next to nothing until we fill them up with words.

A picture, we've been told, is worth a thousand words. Here that's been reversed.

Seven brave people died, their bodies pulled to shreds. A million pounds of modern high-tech engineering -- 230 miles of wire, hundreds of circuit breakers, gauges, pipes, computers -- were turned into burned bits. And of this we see only a sudden interruption in a white streak in the sky.

We expect much more of big news events. When Lee Harvey Oswald takes a bullet, we get to see him wince. When O.J. drives off aimlessly, we're right there with the Bronco. Here we see a woolly line drawn across the sky.

The picture of Columbia breaking into pieces doesn't do what news shots are supposed to do. It isn't self-explanatory, it doesn't tell the story. It's more an emblem, or a symbol. It's practically abstract.

Symbols can be huge, or course. Abstractions can be loaded. The hammering of the nails, the vinegar-soaked sponge, the gambling for the robe, and the salvation of the world can all be seen by Christians in the two lines of the cross.

That white streak over Texas does not explain the shuttle's loss, or, indeed much of anything. But still it is enough to cause -- every time you see it -- a clenching of the heart.

The burned bits strewn through Texas and Louisiana -- here a piece of metal, there a bit of boot -- are also visually powerful. They're not just clues for investigators. They're like relics of a martyrdom that all of us have mourned but none of us has seen.

Although it's too soon to make a firm determination, there are some who fear the shuttle's fate was sealed at its liftoff, when a chunk of debris -- a piece of insulating foam -- struck the fragile insulating tiles of the craft's left wing.

We've seen pictures of that, too. At least we think we've seen it. What we've really seen is blurs.

Blurs, of course, are food for open speculation. Turn on your TV almost any evening, and flip through the back channels, and you are likely to see images -- of sea monsters in Scottish lochs, or zooming flying saucers, or ghosts in haunted houses -- that are similarly out of focus.

We like our science crisp, our facts in black and white. When Challenger exploded shortly after liftoff in 1986 we got to see it happen, but the pictures recording the break-up of Columbia are far less precise.

Visual imprecision feeds imagination. Blurred images promote theories of conspiracy. The destruction of Columbia may have been a simple "mishap," a cascade of tiny accidents leading to disaster, but the pictures do not show that. If seeing is believing, what should we believe?

A vague streak tells little of the overwhelming story of the shuttle disaster.Every picture tells a story (or does it?): Photos of Columbia's breakup over Texas on Saturday, above, and of debris hitting the shuttle's left wing shortly after liftoff on Jan. 16.