"To get anywhere, or even live a long time, a man has to guess, and guess right, over and over again, without enough data for a logical answer."
- Robert Heinlein

He uses this idea again in 1943, with a bit more detail:

"What do you make of this, Toom?" He seemed not to have heard me, so absorbed he was in the sternward view-screen. I reached him. "Five degrees gamma of Terra." He told me where to look.

A star was missing, out of Draco.

"I see. Thuban's blotted out."

"Has been for the last five minutes."

"So there's a meteor moving along the straight line between us, either away from, or following us."

"Following us." Rade's voice was so tense it thrummed. "And not a meteor. Take a look through the electelscope."

Karsdale's remarkable application of electronics to optics that in the space of a tube no larger than a man's arm reduces the apparent distance of an object to one-tenth the actual, was already switched in, but the thing that obscured Thuban must have moved since Rade focused it. I twirled thumbscrews until I got it clear again.