Ripples

Concentric rings from one or more sources. Wavelength is the gap between crests; sources scatter from the seed.

Ripples: Concentric rings from one or more sources. Wavelength is the gap between crests; sources scatter from the seed.Ripples: Concentric rings from one or more sources. Wavelength is the gap between crests; sources scatter from the seed.

About this pattern

Ripples, wave, drawn by GART: Concentric rings from one or more sources. Wavelength is the gap between crests; sources scatter from the seed.
Ripples · CC BY 4.0

Concentric rings from one or more sources. Wavelength is the gap between crests; sources scatter from the seed. A radial slice is just a decaying 1D wave.

1D fold
A radial slice: crest, trough, crest. The sheet is this line spun around each source.