equations until I’ve dreamed about them.” He turned to Lentz. “Do you
agree, Doctor?”
Lentz nodded slowly. “I believe so . . . Yes, I think I may say so.”
Harrington should have been pleased; he wasn’t. “I had hoped you could tell
me I was wrong,” he said, almost petulantly, “but I’m afraid there is no
further doubt about it. Dr. Destry included an assumption valid in molar
physics, but for which we have absolutely no assurance in atomic physics. I
suppose you realize what this means to you, Dr. King?”
King’s voice was dry whisper. “Yes,” he said, “yes — It means that if that
bomb out there ever blows up, we must assume that it will go up all at
once, rather than the way Destry predicted — and God help the human race!”
Captain Harrington cleared his throat to break the silence that followed.
“Superintendent,” he said, “I would not have ventured to call had it been
simply a matter of disagreement as to interpretation of theoretical
predictions — ”
“You have something more to go on?”
“Yes and no. Probably you gentlemen think of the Naval Observatory as being
exclusively preoccupied with ephemerides and tide tables. In a way you
would be right — but we still have some time to devote to research as long
as it doesn’t cut into the appropriation. My special interest has always
been lunar theory.
“I don’t mean lunar ballistics,” he continued. “I mean the much more
interesting problem of its origin and history, the problem the younger
Darwin struggled with, as well as my illustrious predecessor, Captain
T.J.J. See. I think that it is obvious that any theory of lunar origin and
history must take into account the surface features of the Moon —
especially the mountains, the craters, that mark its face so prominently.”
He paused momentarily, and Superintendent King put in: “Just a minute,
Captain — I may be stupid, or perhaps I missed something, but — is there a
connection between what we were discussing before and lunar theory?”
“Bear with me for a few moments, Dr. King,” Harrington apologized. “There
is a connection — at least, I’m afraid there is a connection — but I would
rather present my points in their proper order before making my
conclusions.” They granted him an alert silence; he went on:
“Although we are in the habit of referring to the craters of the Moon, we
know they are not volcanic craters. Superficially, they follow none of the
rules of terrestrial volcanoes in appearance or distribution, but when
Rutter came out in 1952 with his monograph on the dynamics of vulcanology,
he proved rather conclusively that the lunar craters could not be caused by
anything that we know as volcanic action.
“That left the bombardment theory as the simplest hypothesis. It looks
good, on the face of it, and a few minutes spent throwing pebbles into a
patch of mud will convince anyone that the lunar craters could have been
formed by falling meteors.
“But there are difficulties. If the Moon was struck so repeatedly, why not
the Earth? It hardly seems necessary to mention that the Earth’s atmosphere
would be no protection against masses big enough to form craters like
Endymion or Plato. And if they fell after the Moon was a dead world while
the Earth was still young enough to change its face and erase the marks of
bombardment, why did the meteors avoid so nearly completely the great dry
basins we call lunar seas?
“I want to cut this short; you’ll find the data and the mathematical
investigations from the data here in my notes. There is one other major
objection to the meteor-bombardment theory: the great rays that spread from
Tycho across almost the entire surface of the Moon. It makes the Moon look
like a crystal ball that had been struck with a hammer, and impact from
outside seems evident, but there are difficulties. The striking mass, our
hypothetical meteor, must be small enough to have formed the crater of
Tycho, but it must have the mass and speed to crack an entire planet.
“Work it out for yourself — you must either postulate a chunk out of the