Temporal Frequency, Spatial Frequency, and the Nature of Mass: A Short Synthesis

Modern physics provides precise mathematical relations connecting energy, momentum,
mass, temporal frequency, and spatial frequency. However, the ontological meaning of these
quantities remains unclear. This note examines what is directly established by known physics
and identifies the central unresolved question. Particular attention is given to the possibility
that mass is associated with an intrinsic temporal structure rather than being a primitive
substance.