unexpected-effects-of-new-technologiesUnexpected effects must always be expected withnew technologies. One example of this is sub-criticalcrack growth in glass exposed to moist air.Modern pyrometer with aflexible glass fiber light conductorGlass fiber light conductorHeat radiation ofthe measures areaFractures of glass fibers underhigh tension stress due to sub-critical crack growthSub-critical crack growth originating at a chip in the edge of the glassSub-critical crack growth originating at a chip from a stoneSub-critical crack growth in glass; two examples from everyday life