01
Force becomes a visible record.
A bowed edge sets the plate in motion; fine grains disclose where the surface stands still.
The figure is the evidence.
02
Symmetry arrives by constraint.
Each frequency admits one exact arrangement, repeated evenly across a measured field.
03
Silence draws the clearest line.
Sand leaves the active regions and settles only along the nodal geometry.
04
Variation remains legible.
Change the pitch, retain the method: a new figure, a precise new condition.