What does wavelength mean?
Wavelength is the distance between two successive corresponding points of a wave, most often measured from one crest to the next. In physics, it is especially important for describing electromagnetic radiation, including visible light, radio waves, infrared radiation, and ultraviolet radiation. Longer wavelengths correspond to lower frequencies, and shorter wavelengths correspond to higher frequencies. The word also has a well-established figurative meaning: people who are "on the same wavelength" share a perspective, attitude, or way of understanding something, while those who are "not on the same wavelength" do not. This figurative sense is useful for describing agreement, communication, and differences in experience. Wavelength is thus both a precise scientific measurement and a familiar metaphor for the invisible alignment of people's thoughts and expectations.
nounIn physics, the distance between two successive corresponding points of a wave, such as the distance between adjacent crests of an electromagnetic wave. Figuratively, it means a particular range of perception, experience, or way of thinking.
- The distance between successive corresponding points on a wave, especially the distance between adjacent crests of an electromagnetic wave.
- A particular range of perception, experience, attitudes, or ways of thinking shared by people.
"The two colleagues were on the same wavelength and quickly found common ground."
"Infrared cameras detect infrared radiation at a wavelength longer than visible light."
"After several misunderstandings, they discovered that they were not on the same wavelength."
Used when referring to multiple wave measurements or to different wavelength ranges.
"The instrument can detect several wavelengths in the sample."
A wavelength measures distance between wave peaks rather than elapsed time, linking the rhythm of a wave to the physical size of something invisible.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of wavelength
Wavelength is a compound formed in the 19th century from "wave" and "length." Both elements are native English words: "wave" descends from Old English wǣf, while "length" comes from Old English lengþ, meaning length or extent. The compound initially referred to the measured distance associated with waves and was later especially applied to the distances between corresponding points in electromagnetic radiation.
How wavelength is actually used
The technical use is standard in science, while the figurative use is common in general and professional conversation. The expression "on the same wavelength" conveys agreement or a shared perspective, while "not on the same wavelength" indicates incompatible views or approaches.