Optical glass is a very important material in the development of technology and thus of the history of mankind as a whole. It first allowed access to the microand macrocosm, when, about 400 years ago, the microscope and the telescope were invented at almost the same time and location in the town Middelburg in the Netherlands. Although glass lenses were known before this time, only the combination of two or more lenses forming optical instruments could increase magnification to such an extent that new worlds were opened to human vision and investigation.
Glass was the only bulk material capable of changing the direction of light rays without impairing them by absorption or scattering that could be produced in large volume with comparatively low cost. This property is still the basis of a vast variety of optical systems in use today, not only for imaging but for light management in general. Today’s microscopes are highly sophisticated instruments with outstanding precision mechanics, computer control, and software assistance. But without the glass inside of them, they are worthless.
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