the.com/nodal line
where a vibrating thing agrees to stand perfectly still.
means a line or point on a vibrating object or wave pattern that experiences zero displacement while everything around it oscillates.
from from latin nodus, meaning knot — the same root as the knot in a rope or a ship's speed unit, because these stationary points look like knots tying the wave down.
chladni platessand piles up exactly on the nodal lines
guitar stringsharmonics are just forced extra nodes
standing wavesnodes never move, antinodes move most
quantum orbitalselectron probability hits zero at nodes
for instance
chladni figures — 1787 experiment, sand traces nodal patterns on metal plates
guitar harmonics — lightly touching a string at its node produces a pure overtone
schrodinger's atom — p and d orbitals have nodal planes where electrons are never found
earthquake seismic waves — nodal planes on fault maps show zero first-motion in earthquake data