aperiodic

[ ey-peer-ee-od-ik ]

adjective

1. not periodic; irregular.
2. Physics. of or relating to vibrations or oscillations with no apparent period.

aperiodic

/ ˌeɪpɪərɪəˈdɪsɪtɪ; ˌeɪpɪərɪˈɒdɪk /

adjective

1. not periodic; not occurring at regular intervals
2. physics
   1. (of a system or instrument) being damped sufficiently to reach equilibrium without oscillation
   2. (of an oscillation or vibration) not having a regular period
   3. (of an electrical circuit) not having a measurable resonant frequency

Derived Forms

• ˌaperiˈodically, adverb
• aperiodicity, noun

Other Words From

• ape·ri·odi·cal·ly adverb
• a·pe·ri·o·dic·i·ty [ey-peer-ee-, uh, -, dis, -i-tee], noun

Word History and Origins

Origin of aperiodic¹

First recorded in 1875–80; a- ⁶ + periodic ¹

Example Sentences

Both therapies showed increased aperiodic activity levels in patients' brains post-treatment.

From Science Daily

For decades mathematicians have been hunting for tile shapes like these that can form only nonrepeating arrangements, called aperiodic tilings.

From Scientific American

The first such “aperiodic tiling” was discovered in the 1960s and comprised 104 different shapes.

From Science Magazine

Originally, the team discovered that the hat was part of a morphing continuum — an uncountable infinity of shapes, obtained by increasing and decreasing the edges of the hat — that produce aperiodic tilings using reflections.

From New York Times

If the mathematicians could prove that both of the polyiamond tilings are aperiodic, then the original tiling must be aperiodic as well.

From Scientific American