Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Logical synchronization: how evidence and hypotheses steer atomic clocks   A clock steps a computer through a cycle of phases. For the propagation of
logical symbols from one computer to another, each computer must mesh its
phases with arrivals of symbols from other computers. Even the best atomic
clocks drift unforeseeably in frequency and phase; feedback steers them toward
aiming points that depend on a chosen wave function and on hypotheses about
signal propagation. A wave function, always under-determined by evidence,
requires a guess. Guessed wave functions are coded into computers that steer
atomic clocks in frequency and position---clocks that step computers through
their phases of computations, as well as clocks, some on space vehicles, that
supply evidence of the propagation of signals. Recognizing the dependence of
the phasing of symbol arrivals on guesses about signal propagation elevates
`logical synchronization.' from its practice in computer engineering to a
discipline essential to physics. Within this discipline we begin to explore
questions invisible under any concept of time that fails to acknowledge the
unforeseeable. In particular, variation of spacetime curvature is shown to
limit the bit rate of logical communication.

34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
26
The categories of this paper are: bayes-an
5
The categories of this paper are: gr-qc
4
The categories of this paper are: cond-mat
3
The categories of this paper are: physics
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
1
The categories of this paper are: cs
2
The categories of this paper are: math
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
28
The categories of this paper are: alg-geom
12
The categories of this paper are: nucl-th
9
The categories of this paper are: nlin