The knife-edge effect is explained by Huygens-Fresnel principle, which states that a well-defined obstruction to an electromagnetic wave acts as a secondary source, and creates a new wavefront. This new wavefront propagates into the geometric shadow area of the obstacle.
The knife-edge effect is an outgrowth of the half-plane problem, originally solved by Arnold Sommerfeld using a plane wave spectrum formulation. A generalization of the halfplane problem is the wedge problem, solvable as a boundary value problem in cylindrical coordinates. The solution in cylindrical coordinates was then extended to the optical regime by Joseph B. Keller, who introduced the notion of diffraction coefficients through his geometrical theory of diffraction (GTD). Pathak and Kouyoumjian extended the (singular) Keller coefficients via the uniform theory of diffraction (UTD).
Katahdin's cutting Edge ; Few besides adventure seekers and scenery junkies brave the unforgiving Knife Edge.
Jul 15, 2007; Text and photos by Shawn Patrick Ouellette/Staff Photographer Portland Press Herald (Maine) 07-15-2007 Katahdin's cutting Edge ;...
Knife Edge's trainer cuts straight to chase ; Trainer Michael O'Brien is known for his decisiveness - just ask Tom Rudd, who lost the ride on Knife Edge because of his lack of experience. Brian O'Connor listens to some straight talking
Mar 13, 2002; Michael O'Brien has a theory and when the trainer believes something, he isn't the type to keep it to himself. "The way I look at...