Transverse wave


Transverse wave
Transverse plane wave
A light wave is an example of a transverse wave.
Propagation of a transverse spherical wave in a 2d grid (empirical model)

A transverse wave is a moving wave that consists of oscillations occurring perpendicular (or right angled) to the direction of energy transfer. If a transverse wave is moving in the positive x-direction, its oscillations are in up and down directions that lie in the y–z plane.

Contents

Explanation

Transverse waves are waves that are moving perpendicular to the direction of propagation. If you anchor one end of a ribbon or string and hold the other end in your hand, you can create transverse waves by moving your hand up and down. Notice though, that you can also launch waves by moving your hand side-to-side. This is an important point. There are two independent directions in which wave motion can occur. In this case, these are the y and z directions mentioned above.

'Polarized' waves

If you carefully move your hand in a clockwise circle, you will launch waves that describe a left-handed helix as they propagate away. Similarly, if you move your hand in a counter-clockwise circle, a right-handed helix will form. These phenomena of simultaneous motion in two directions go beyond the kinds of waves you can create on the surface of water; in general a wave on a string can be two-dimensional. Two-dimensional transverse waves exhibit a phenomenon called polarization. A wave produced by moving your hand in a line, up and down for instance, is a linearly polarized wave, a special case. A wave produced by moving your hand in a circle is a circularly polarized wave, another special case. If your motion is not strictly in a line or a circle your hand will describe an ellipse and the wave will be elliptically polarized.

Electromagnetic waves

Electromagnetic waves behave in this same way, although it is harder to see. Electromagnetic waves are also two-dimensional transverse waves. Ray theory does not describe phenomena such as interference and diffraction, which require wave theory (involving the phase of the wave). You can think of a ray of light, in optics,as an idealized narrow beam of electromagnetic radiation. Rays are used to model the propagation of light through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of ray tracing. [1] A light ray is a line or curve that is perpendicular to the light's wavefronts (and is therefore collinear with the wave vector). Light rays bend at the interface between two dissimilar media and may be curved in a medium in which the refractive index changes. Geometric optics describes how rays propagate through an optical system.[1]

This two-dimensional nature should not be confused with the two components of an electromagnetic wave, the electric and magnetic field components, which are shown in the electromagnetic wave diagram here. The light wave diagram shows linear polarization. Each of these fields, the electric and the magnetic, exhibits two-dimensional transverse wave behavior, just like the waves on a string.

The transverse plane wave animation shown is also an example of linear polarization. The wave shown could occur on a water surface.

Examples

Examples of transverse waves include seismic S (secondary) waves, and the motion of the electric (E) and magnetic (M) fields in an electromagnetic plane wave, which both oscillate perpendicularly to each other as well as to the direction of energy transfer. Therefore an electromagnetic wave consists of two transverse waves, visible light being an example of an electromagnetic wave. See electromagnetic spectrum for information on different types of electromagnetic waves. An oscillating string is another example of a transverse wave; a more everyday example would be an audience wave.

See also

References

  1. ^ a b Moore, Ken (2005-07-25). "What is a ray?". ZEMAX Users' Knowledge Base. http://www.zemax.com/kb/articles/23/1/What-is-a-ray/Page1.html. Retrieved 2008-05-30. 

External links


Wikimedia Foundation. 2010.

Look at other dictionaries:

  • transverse wave — Physics. a wave in which the direction of displacement is perpendicular to the direction of propagation, as a surface wave of water. Cf. longitudinal wave. [1920 25] * * * ▪ physics       motion in which all points on a wave oscillate along paths …   Universalium

  • transverse wave — UK / US noun [countable] Word forms transverse wave : singular transverse wave plural transverse waves physics a wave such as light that makes the substance through which it moves vibrate in a direction that is at 90 degrees to the direction in… …   English dictionary

  • transverse wave — noun : a wave in which the vibrating element (as the electric field in light waves or the particles of a vibrating medium) moves in a direction perpendicular to the direction in which the wave advances * * * ˌtransverse ˈwave 7 [transverse wave]… …   Useful english dictionary

  • transverse wave — skersinė banga statusas T sritis fizika atitikmenys: angl. transversal wave; transverse wave vok. Querwelle, f; Transversalwelle, f rus. поперечная волна, f pranc. onde transversale, f …   Fizikos terminų žodynas

  • transverse wave — /ˈtrænzvɜs weɪv/ (say tranzvers wayv) noun a wave in which the vibrations of particles of the medium (as in a wave motion in a stretched wire or string) or the directions of the oscillating electromagnetic fields (as in an electromagnetic wave)… …   Australian English dictionary

  • transverse wave — noun Date: 1912 a wave in which the vibrating element moves in a direction perpendicular to the direction of advance of the wave …   New Collegiate Dictionary

  • transverse wave —    A wave generated by shearing displacement where wave motion is perpendicular to direction of propagation [16] …   Lexicon of Cave and Karst Terminology

  • transverse wave — trans′verse wave′ n. phs a wave in which the direction of displacement is perpendicular to the direction of propagation • Etymology: 1920–25 …   From formal English to slang

  • transverse wave — noun Any wave in which the direction of disturbance is perpendicular to the direction of travel …   Wiktionary

  • transverse wave — a wave in which the oscillatory motion is perpendicular to the direction of propagation …   Medical dictionary