Students come to us from other science classes with experience
in thinking about one thing at a time. In fact, one of the
hallmarks of the scientific method, they have often been taught,
is to isolate out and control one parameter at a time, to set up
experiments in which there is one manipulated variable or
perhaps two. Then they show up in Earth Science class, and we
want them to think about interactions among many processes and
phenomena, all varying over time and space. To get your mind
around the water cycle, for example, requires understanding a
dozen or so different kinds of reservoirs, and the fluxes among
them, and the processes that speed up or slow down each flux.
And all of those things are going on at the same time. In
general, humans find it difficult to consider many different
processes or phenomena at the same time. We do, however, have
one sensory modality that is exceptionally good at processing
multiple simultaneous signals. That would be hearing. We can
pick out individual instruments in a