I said that the events of interest to particle physicists can never be directly
perceived by humans. This is not quite true. There are devices, such
as cloud chambers and bubble chambers, in which (some) particles leave a
visible track behind them, like the wake of a boat or jet contrails. The
photographs of these trails are certainly a lot more impressive than the chunky
computer graphs particle physicists produce now-a-days; nor is the simplicity
of the technique to be sneezed at. When my father was an architecture student at Berkeley in the mid-60s, we worked part time at ``reading'' bubble
chamber photographs for the Lawrence Lab. They prefered not
to use physics students, who were too prone to see interesting events which
simply weren't there - which would not have surprised William James.
Alas, bubble chambers and cloud chambers have to be filled with some sort
of fluid (bubble chambers used liquid hydrogen), so they the particle beams
and the actual point of collision cannot be inside it. This is fine if you
are interested in the decay products, but not in the actual process of the
collision. Also, the rates at which events occur in modern accelerators are
so high that even if bubble chambers could be used, it would be impractical
to take so many photographs in such rapid succession.