In 1834, a man sits beside a canal. It is summer. He watches boats moving up and down the waterway. Suddenly, one boat stops abruptly and shoves a curious wave of water forward. The man stands and observes this singular wave, which passes leaving only flat water behind it. John Scott Russel stands. The wave is still moving. Disappearing from sight. He leaps on his horse. He pursues it, overtakes it, and observes it over perhaps two miles of waterway. It holds its shape, and only gradually diminishes in height. Very strange. Very curious.
Russel, an engineer, mathematician, and accomplished ship builder, was the first person to spot such a wave, follow it, and then write about it. He described called the wave a ‘wave of translation.’ Modern physics calls such singular traveling waves solitons.
What’s the big deal?
Throw a stone in a pond, and ripples spread. They spread out in concentric rings, and the rings split into more rings, and these split further. The rings begin to overlap as the taller rings overtake the shorter, and they gradually all become imperceptible as the energy of the stone spreads and is redistributed across the entire surface of the pond. Not so for the soliton. A soliton, as Russel famously chased, can travel over long distances without losing its form or its energy.
Oh, and solitons occur in not only water but light (electromagnetism) as well as in phonons (thermodynamics) and potentially in gravity waves.
You might be a soliton if:
- You are a traveling wave in some medium
- You hold your shape as you travel – you don’t spread out or fall apart into other waves.
- You are a neat well defined little envelope of energy – you are not here, you arrive and pass, and then you are gone!
- If you ever cross paths with another soliton, you can pass through each other unchanged.
