"Atoms. Elements. Look...." I grabbed up a fistful of the sheets and
thumbed through them. "Look ... each message starts with a list of
numbers. Then there's a long blank to separate the opening list from
the rest of the message. See? Every time, the same length list."
"So?"
"The periodic table of the elements!" I shouted into his ear. "That's
the key!"
Rizzo shook his head. "I thought of that two days ago. No soap. In the
first place, the list that starts each message isn't always the same.
It's the same length, all right, but the numbers change. In the second
place, it always begins with 100000. I looked up the atomic weight of
hydrogen--it's 1.008 something."
That stopped me for a moment. But then something clicked into place in
my mind.
* * * * *
"Why is the hydrogen weight 1.008?" Before Rizzo could answer, I went
on, "For two reasons. The system we use arbitrarily rates oxygen as
16-even. Right? All the other weights are calculated from oxygen's.
And we also give the average weight of an element, counting all its
isotopes. Our weight for hydrogen also includes an adjustment for tiny
amounts of deuterium and tritium. Right? Well, suppose _they_ have a
system that rates hydrogen as a flat one: 1.00000. Doesn't _that_ make
sense?"
"You're getting punchy," Rizzo grumbled. "What about the isotopes? How
can they expect us to handle decimal points if they don't tell us about
them ... mental telepathy? What about...."
"Stop arguing and start calculating," I snapped. "Change that list
of numbers to agree with our periodic table. Change 1.00000 to
1.008-whatever-it-is and tackle the next few elements. The decimals
shouldn't be so hard to figure out."
Rizzo grumbled to himself, but started working out the calculations. I
stepped over to the dome's microspool library and found an elementary
physics text. Within a few minutes, Rizzo had some numbers and I had
the periodic table focused on the microspool reading machine.
"Nothing," Rizzo said, leaning over my shoulder and looking at the
screen. "They don't match at all."
"Try another list. They're not all the same."
He shrugged and returned to his desk. After a while he called out,
"their second number is 3.97123; it works out to 4.003-something."