“Good. I have a list, then. Has there been any change in speed of motion of any of them?”
“No. Impossible as it seems, it’s constant. What is your idea?”
“I want to check my theory first. If it works out into anything, I’ll call you.” But he forgot to.
It was a long, painful job. First, he made a chart of the heavens in the area between Ursa Major and Leo. Across that chart he drew four hundred and sixty-eight lines representing the projected path of each of the aberrant stars. At the border of the chart, where each line entered, he made a notation of the apparent velocity of the star—not in light years per hour—but in degrees per hour, to the fifth decimal.
Then he did some reasoning.
“Postulate that the motion which began simultaneously will end simultaneously,” he told himself. “Try a guess at the time. Let’s try ten o’clock tomorrow evening.”
He tried it and looked at the series of positions indicated upon the chart. No.
Try one o’clock in the morning. It looked almost like—sense!
Try midnight.
That did it. At any rate, it was close enough. The calculation could be only a few minutes off one way or the other, and there was no point now in working out the exact time. Now that he knew the incredible fact.