View from the Pennines: Accelerating Solitons

摘要

In 1834 a Scottish engineer, .John Scott Russell, was conducting experiments on barge design in a canal when a barge came to a sudden halt. His description of the wave this created must be one of the most frequently quoted passages in applied mathematics: 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 motion; it accumulated round the prow of the vessel in a state of violent agitation, then suddenly leaving it behind, tolled forward with great velocity, assuming the form of a large solitary elevation, a rounded, smooth o and well-defined heap of water, which continued its course along the channel apparently without change of form or diminution of speed. I followed it on horseback, and overtook it still rolling on at a rate of some eight or nine miles an hour, preserving its original figure some thirty feet long and a foot to a foot and a half in height Its height gradually diminished, and after a chase of one or two miles I lost it in the windings of the channel. Such, in the month of August 1834, was my first chance, interview with that singular and beautiful phenomenon which I have called the Wave of Translation.