"Sure. Movin' things take the shortest path."
The astronomer, frankly dubious, said, "But, really! An ellipse could
hardly do that because a 'shortest path'--"
"No?" said Hank. "You take a flat piece of paper. The quickest way
acrost it is a straight line, ain't it?"
"Naturally."
"You take a globe of the world, though, an' things don't work the same.
You want to go from, say, Los Angeles to Japan, you wouldn't follow
straight across one of them lines of latitude, would you? You'd sort of
hump up by way of Alaska."
A listener nodded eagerly. "That's right. You'd take the arc of a great
circle. The Great Circle route."
"Well," said Hank, "same thing in the universe--which has got, near's I
can figger out, another right angle in it besides the ones we know an'
see."
"You mean another dimension? A fourth dimension?"
"Call it that. Anyhow, in this sort of super-globe which has four
dimensions, stands to reason that the shortest distance from one point
to another will be a closed figger. A sort of lopsided circle."
* * * * *
That stopped them cold for a moment. But Tomkins, the astronomer,
wasn't through yet.
"Our observations, Hank, also indicate that in this universe, every
other galaxy is running away from ours as fast as it can. Why is this?"