A self-reinforcing solitary wave (a wave packet or pulse) that maintains its shape while it travels at constant speed.
(The term "dispersive effects" refers to a property of certain systems where the speed of the waves varies according to frequency.)
- Arise as the solutions of a widespread class of weakly nonlinear dispersive partial differential equations describing physical systems.
The soliton phenomenon was first described by John Scott Russell (1808–1882) who observed a solitary wave in the Union Canal in Scotland. He reproduced the phenomenon in a wave tank and named it the "Wave of Translation".
Properties of soliton:-
- They are of permanent form;
- They are localised within a region;
- They can interact with other solitons, and emerge from the collision unchanged, except for a phase shift.
There is also the non-linear Kerr effect: the refractive index of a material at a given frequency depends on the light's amplitude or strength. If the pulse has just the right shape, the Kerr effect will exactly cancel the dispersion effect, and the pulse's shape won't change over time: a soliton.
Water wave properties:
- The waves are stable, and can travel over very large distances (normal waves would tend to either flatten out, or steepen and topple over)
- The speed depends on the size of the wave, and its width on the depth of water.
- Unlike normal waves they will never merge – so a small wave is overtaken by a large one, rather than the two combining.
- If a wave is too big for the depth of water, it splits into two, one big and one small.