Escape lighting

A door opened not ten feet ahead of me. Although the light escaping from the entrance was in truth very faint, it seemed to flood the alley. It was not even bright enough to illuminate the man emerging, but I knew his voice. 

Evanescent means "vanishing" or fleeting" Light escapes" from the waveguide, but it vanishes over a short distance. 

The way a diamond is cut is one of the 4 Cs that gemologists use to determine a diamond s value. If diamond is the hardest mineral on Earth, then how is it possible to cut a diamond Diamond cutters use other diamonds and lasers to create facets that reflect and refract light. The more precisely the cuts are made, the greater the gems brilliance. If a diamond cut is too shallow or too deep, light escapes from the diamond without traveling back to the eye, resulting in a lackluster appearance. 

Ensure proper lighting, escape routes, safety vents with release points away from working areas, piping routes which will not hinder movement of personnel or... 

Taking advantage of the microbending effect, one even can measure the pressure, which helps improve plant and process safety as well as the quality of products. Light escapes from two ahgned glass fibres when core or cladding are under mechanical stress. 

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