  Quantum foundations are still unsettled, with mixed effects on science and
society. By now it should be possible to obtain consensus on at least one
issue: Are the fundamental constituents fields or particles? As this paper
shows, experiment and theory imply unbounded fields, not bounded particles, are
fundamental. This is especially clear for relativistic systems, implying it's
also true of non-relativistic systems. Particles are epiphenomena arising from
fields. Thus the Schroedinger field is a space-filling physical field whose
value at any spatial point is the probability amplitude for an interaction to
occur at that point. The field for an electron is the electron; each electron
extends over both slits in the 2-slit experiment and spreads over the entire
pattern; and quantum physics is about interactions of microscopic systems with
the macroscopic world rather than just about measurements. It's important to
clarify this issue because textbooks still teach a particles- and
measurement-oriented interpretation that contributes to bewilderment among
students and pseudoscience among the public. This article reviews classical and
quantum fields, the 2-slit experiment, rigorous theorems showing particles are
inconsistent with relativistic quantum theory, and several phenomena showing
particles are incompatible with quantum field theories.
