Soliton attacks and freak waves

Soliton attack

I was observing the motion of a boat which was rapidly drawn along a narrow channel by a pair of horses, when the boat suddenly stopped – not so the mass of water in the channel which it had put in the motion; it accumulated round the prow of the vessel in a state of violent agitation, then suddenly leaving it behind, rolled forward with great velocity assuming the form of a large solitary elevation, a rounded, smooth and well defined heap of water which continued its course apparently without change of form or diminution of speed. I followed it on horseback, and overtook it still rolling at a rate of some eight to nine miles per hour, preserving its original figure some thirty feet long and a foot to a foot and a half in height.
John Russell

Report of the 14th Meeting of the British Association for the Advancement of Science, 1844.

This is Russell’s famous description of the formation of a soliton, a phenomenon that has been well studied since then.

But what of Russell’s contention that, as the soliton formed, the boat suddenly stopped? An attempt in 1995 to recreate this effect failed but there are numerous anecdotal accounts of boats appearing to hit non-existent barriers.

Now Stanyslav Zakharov and Alexey Kryukov from the Lebedev Physical Institute at the Russian Academy of Sciences in Moscow have put the phenomenon on firmer theoretical footing and added a little intrigue of their own.

They say that there are two solutions to this problem that depend very sensitively on the width and depth of the reservoir in which the ship is moving. In one case an ordinary soliton is formed without the ship experiencing a hydrodynamic shock. In the other much rarer case, a different kind of soliton forms along with the hydrodynamic barrier that decelerates the boat. Zakharov and Kryukov call this a “soliton attack”.

They suggest that the phenomenon can occur in open sea when the water near a ship becomes unexpectedly shallow and might explain the formation of freak waves that are sometimes reported.

More intriguingly, Zakharov and Kryukov suggest that a similar phenomenon may occur when particles interact with electromagntic waves in specific circumstances.

So if you’ve  seen an electron stopped dead in its tracks, let us know. You may have been the first to witness an electromagnetic soliton attack.

Ref: Ship-induced Solitons as a Manifestation of Critical Phenomena

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