"Why not?" he demanded. "If we face north, the sun rises on our right,
doesn't it?"
"Yes. Even in the southern hemisphere."
"Well, then. So it doesn't make any difference which hemisphere they're
in."
"You're correct. But you're also making the assumptions that Venus
rotates on its axis, that the axis is aligned parallel to the Earth's
and that the direction of rotation is the same."
"We know that Venus rotates!"
"We have every reason to believe so," I agreed. "But only because
thermocouples measure a temperature on the darkside that is too high
to support the theory that the diurnal period of Venus is equal to the
year. I think the latest figures say something between a couple of
weeks and a few months. Next, the axis needn't be parallel to anything.
Shucks, Crandall, you know darned well that the solar system is a
finely made clock with no two shafts aligned, and elliptical gears
that change speed as they turn."
* * * * *
"Practically everything in the solar system rotates in the same
direction."
I looked at him. "Would you like to take a chance that Venus agrees
with that statement? You've got a fifty percent chance that you'll
be right. Guess wrong and we have a metric ton of hardware trying to
occupy the same space as another metric ton of matter."
"But--"
"And furthermore," I went on, "we're just lucky that Polaris happens
to be a pole star right now. The poles of Mars point to nothing that
bright. Even then, we can hardly expect the Venusian to have divided
the circumpolar sky into the same zoo full of mythical animals as our
forebears--and if we use the commonplace expression, maybe the Venusian
never paused to take a long-handled dipper of water from a well. Call
them stewpots and the term is still insular. Sure, there's lots of
pointers, but they have to be identified. My mother always insisted
that the Pleiades were--er--was the Little Dipper."
Teresa Dwight spoke up, possibly for the second or third time in her
life without being spoken to first. She said, "Harla has been listening
to you through me. Of astronomy he has but a rudimentary idea. He
is gratified to learn from you that there is a 'sun' that provides
the heat and light. This has been a theory based upon common sense;
_something_ had to do it. But the light comes and goes so slowly that
it is difficult to determine which direction the sun rises from.
The existence of other celestial bodies than Venus is also based on
logic. If, they claim, they exist, and their planet exists, then there
probably are other planets with people who cannot see them, either."
"Quoth Pliny the Elder," mumbled Paul Wallach.