which led to the identification of the equations of mechanical
motion. Nobody was surprised when these equations revealed that
Lunarian scientists had deduced the same laws as Newton. The
mathematicians progressed to tables of elementary first integrals
and standard forms of low-order differential equations. On later
pages were expressions which they suspected might describe systems
of resonance and damped oscillations. Here again, the uncertainty
over units presented a problem; expressions of this type would be
in a standard form that could apply equally well to electrical,
mechanical, thermal, or many other types of physical phenomena.
Until they knew more about Lunarian units, they could not be sure
precisely what these equations meant, even if they succeeded in
interpreting them mathematically.
Hunt remembered having noticed that many of the electrical
subassemblies from Charlie’s backpack had small metal labels
mounted adjacent to plugs, sockets, and other input-output
connections. He speculated that some of the symbols engraved on
these labels might represent ratings in units of voltage, current,
power, frequency, and so on. He spent a day in the electronics
labs, produced a full report on these markings, and passed it on to
Mathematics. Nobody had thought to tell them about it sooner.
The electronics technicians located the battery in the wrist unit
from Tycho, took it to pieces, and with the assistance of an
electrochemist from another department, worked out the voltage it
had been designed to produce. Linguistics translated the markings
on the casing, and that gave a figure for the Lunarian unit for
electrical voltage. Well, it was a start.
Professors Danchekker and Schom were in charge of the biological
side of the research. Perhaps surprisingly, Danchekker exhibited no
reluctance to cooperate with Group L and kept them fully updated
with a regular flow of information. This was more
the result of his deeply rooted sense of propriety than of any
change of heart. He was a formalist, and if this procedure was what
the formalities of the arrangement required, he would adhere to it
rigidly. His refusal to budge one inch from his uncompromising
views regarding the origins of the Lunarians, however, was total.
As promised, Schorn had set up investigations to determine the
length of Charlie’s natural day from studies of body chemistry and
cell metabolism, but he was running into trouble. He was getting
results, all right, but the results made no sense. Some tests gave
a figure of twenty-four hours, which meant that Charlie could be
from Earth; some gave thirty-five hours, which meant he couldn’t
be; and other tests came up with figures in between. Thus, if the
aggregate of these results meant anything at all, it indicated that
Charlie came from a score of different places all at the same time.
Either it was crazy, or there was something wrong with the methods
used, or there was more to the matter than they thought.
Danchekker was more successful in a different direction. From an
analysis of the sizes and shapes of Charlie’s blood vessels and
associated muscle tissues, he produced equations describing the
performance of Charlie’s circulatory system. From these he then
derived a set of curves that showed the proportions of body heat
that would be retained and lost for any given body temperature and
outside temperature. He came up with a figure for Charlie’s normal
body temperature from some of Schorn’s figures that were not
suspect and were based on the assumption that, as in the case of
terrestrial mammals, the process of evolution would have led to
Charlie’s body regulating its temperature to such a level that the
chemical reactions within its cells would proceed at their most
efficient rates. By substituting this figure back into his original
equations, Danchekker was able to arrive at an estimate of the
outside temperature or, more precisely, the temperature of the
environment in which Charlie seemed best adapted to function.
Allowing for error, it came out at somewhere between two and nine
degrees Celsius.
With Schorn’s failure to produce a reliable indication of the
length of the Lunarian day, there was still no way of assigning any
absolute values to the calendar, although sufficient corroborating
evidence had been forthcoming from various sources to verify beyond