The wavelength of a wave is the distance from one crest to the next.
Click on image for full size
Windows to the Universe original artwork.
The wavelength of a wave describes how long the wave is. The distance from
one crest to the next, or from one trough to the next, of a wave is its wavelength.
Water waves in the ocean, sound waves in air, and light waves of electromagnetic
radiation all have wavelengths.
The greek letter "l" (lambda) is often used in equations to
represent wavelength. The wavelength of a wave is inversely proportional to
frequency. A long wavelength means a low frequency, while a short wavelength
means a high frequency.
Sound waves in
the range that humans
have wavelengths ranging from less than 2 cm (an inch) to about 17 meters (56
feet). The waves of electromagnetic
radiation that make up the visible
light that we can see have wavelengths between 400 (purple light) and 700 (red light) nanometers (10-9 meters).
The frequency and wavelength of a wave are related to each other by this equation:
l = c / f
where "l" is the wavelength, "c" is the speed of
the wave, and "f" is the frequency. For light or other electromagnetic
waves traveling in a vacuum, c = 299,792.458 km/sec (186,282 miles/sec), the
speed of light.
For sound waves moving through air, c is around 343 meters/second (767 miles/hour).
Red light with a frequency around 440 terahertz has waves about 682 nm long
( l = c / f = 2.99 x 108 m s-1 / 440 x 1012 s-1
= 682 x 10-9 m = 682 nm).
Sound waves with a pitch of 1,000 hertz (1 kHz) produce waves with wavelengths
around 34 cm (l = c / f = 343 m s-1 / 1000 s-1 =
Shop Windows to the Universe Science Store!
Our online store
includes issues of NESTA's quarterly journal, The Earth Scientist
, full of classroom activities on different topics in Earth and space science, as well as books
on science education!
You might also be interested in:
Electromagnetic radiation is the result of oscillating electric and magnetic fields. The wave of energy generated by such vibrations moves through space at the speed of light. And well it should... for...more
Have you ever seen the Southern or Northern Lights? Did you know that Earth isn't the only planet that puts on these beautiful light shows, also known as the "aurora"? Auroral displays have also been observed...more
Radio waves are a type of electromagnetic radiation. A radio wave has a much longer wavelength than does visible light. We use radio waves extensively for communications. Radio waves have wavelengths as...more
Radiation comes in two basic types: electromagnetic radiation transmitted by photons, and particle radiation consisting of electrons, protons, alpha particles, and so forth. Electromagnetic radiation,...more
Energy from the Sun is one of the primary drivers of the Earth system. The Sun warms our planet, heating the surface, the oceans and the atmosphere. This energy feeds atmospheric processes and is a primary...more
I am monitoring the C-Band Doppler radar aboard the Ron Brown. It is the most prominent observing system on the ship. The radar measures the intensity of falling rain drops from the stratocumulus clouds....more
Some concepts are used in many different fields of science and serve as a general purpose "toolbox" that helps us understand and manipulate ideas across disciplines. These "tools for math and science"...more