  We study the emergence of Minkowski space-time from a causal network.
Differently from previous approaches, we require the network to be
topologically homogeneous, so that the metric is derived from pure
event-counting. Emergence from events has an operational motivation in
requiring that every physical quantity---including space-time---be defined
through precise measurement procedures. Topological homogeneity is a
requirement for having space-time metric emergent from the pure topology of
causal connections, whereas physically homogeneity corresponds to the
universality of the physical law. We analyze in detail the case of 1+1
dimensions. If we consider the causal connections as an exchange of classical
information, we can establish coordinate systems via an Einsteinian protocol,
and this leads to a digital version of the Lorentz transformations. In a
computational analogy, the foliation construction can be regarded as the
synchronization with a global clock of the calls to independent subroutines
(corresponding to the causally independent events) in a parallel distributed
computation. Thus the Lorentz time-dilation emerges as an increased density of
leaves within a single tic-tac of a clock, whereas space-contraction results
from the corresponding decrease of density of events per leaf. The operational
procedure of building up the coordinate system introduces an in-principle
indistinguishability between neighboring events, resulting in a network that is
coarse-grained, the thickness of the event being a function of the observer's
clock.
