"Not by a jug full. The index of refraction is higher at this edge than at the other. See? Walt held the cube before a newspaper and they squinted through the glass block.
"Seems to be. Now why?"
"Second harmonic distortion, if present, would tend to thin out one side and thicken up the other side. A sine-wave transmission would result in even thicknesses, but if second harmonic distortion is present, the broad loops at the top create a condition where the average from zero to top is higher than the average from zero to the other peak. Follow?"
"That would indicate that the distortion was coming in at this end. If both were even, they would cancel."
"Right. Your scanning at one end is regular—at the other end it is irregular, resulting in non-homogeneity."
"The corners aren't really sharp," objected Arden.
"That's an easy one. The wave-front isn't sharp either. Instead of clipping sharply at the end of the trace, the signal tapers off. That means higher frequency response is needed."
"We need a term. Audio for sonics; radio for electronics, video for television signals—"
"Mateo," said Arden.
"Um—sounds sort of silly," grinned Walt.