If you shine a light at a mirror, the beam is reflected inward to a central focal point, bouncing back toward you in a predictable manner—it’s a simple reflection of light, a spatial inversion. When a ...

I SUPPOSE that everyone is familiar with the beautifully graded illumination of a paraffin candle, extending downwards from the flame to a distance of several inches. The thing is seen at its best ...

IT seems that the sorting out of foods by the reflection of light will soon be used in regular commercial practice. It is certainly quite feasible for sorting out foods the quality or maturity of ...