Chladni lines mark where a vibrating surface is motionless.

Evidence

The lines Chladni sketched, except the outline of the plate itself, are nodal lines—places where the plate is not moving when vibrating in a pure mode. Only at the quiescent nodal lines does the sand find refuge from the violent undulations of the surface. — Eric J. Heller, Why You Hear What You Hear- An…, 1380

Categorization

Category: Definitional Content

• DEFINE: Clarifies the concept of nodal lines in two-dimensional vibrating surfaces.