IC 342: Evidence of Dust

"The problem," said Professor Aurel Vint, settling into the chair across from his student, "is not that they are silent. The problem is that they are silent in precisely the wrong way." He was a small, tidy man who believed that every mystery was simply a question nobody had yet asked properly, and he had called Idra Solm to his office because she had, in his opinion, finally asked one.

The galaxy in question hung in the sky of their world like a pinwheel of frost. For three centuries they had broadcast toward it, and for three centuries nothing had come back, so a great many serious people had concluded that no one lived there. Idra did not believe it. "Consider their position," she said. "Their sun sits inside the disk of their galaxy, close to the midplane, where the dust is thickest. When they look toward us, they look straight through it."

Vint steepled his fingers. "Go on." "Then to them we are dim. Not invisible. We are bright enough that if the dust were gone, they would see us with the naked eye. But the dust is not gone, so their ancient sky-watchers missed us entirely. Someone found us late, I'd guess, some patient amateur sweeping the sky for something else. And then they got our distance wrong. Dust makes a galaxy fainter, and fainter looks farther. Their estimates would wander by half again. Some of their best minds would decide we belonged to their own little family of galaxies, and then have to take it back." She spread her hands. "A civilization that cannot agree how far away we are is not going to aim a transmitter at us."

Vint was quiet for a long moment. Then he laughed, which he rarely did. "So the silence is not evidence of absence. It is evidence of dust." "It is evidence of geometry," Idra said. "They aren't ignoring us. They are standing in a fog and squinting." "Then what do you propose? We cannot clear their sky for them."

"No," said Idra. "But the fog thins when we climb high above their horizon. Somewhere over there, I would wager, there is at least one stubborn observer who has noticed. He waits each night until we rise clear of the murk, and gathers our light as long as he can, night after night, fourteen hours of it if that's what it takes, just to see our arms clearly once." She smiled. "We don't need a louder signal, Professor. We need to wave at the one man who is actually looking."

View the full-resolution image and technical details on AstroBin.