  When a medium composed of microscopic elements is subjected to a high
intensity field, the individual behaviors of microscopic elements can become
chaotic. In such cases it is important to consider the effects of this
irregularity at microscopical level onto the macroscopic behavior of the
medium. We show that the macroscopic field produced by a large group of chaotic
scatterers can remain regular, due to the partial or complete phase coherence
of the scattering elements and the incoherence of the chaotic components of
their responses. Thus when only macroscopic fields are observed, one may be
unaware of chaotic microscopical motion, as it appears to be hidden from the
observer. The coupling among the elements may lead to partial chaos
synchronization, which exposes the chaotic nature of the system making the
oscillations of macroscopic fields more irregular.
