Jun.-Prof. Dr. Thomas Kissinger - TU Ilmenau
From the Nippur cubit to the gravitational wave interferometer - the exciting development of length measurement
The exact measurement of lengths is, besides the measurement of weights, of fundamental importance for the development of mankind. It allows standardization and division of labor in trade and industry and led to decisive scientific breakthroughs. Standardized measures of length have been used for thousands of years and were usually established on the basis of the limb of kings. The French Revolution then placed their definition on an objective basis, the circumference of the earth. However, ultimately only the traceability to a natural constant, the speed of light, allows a satisfactory meter definition. Since the 19th century, length measuring technology has developed rapidly, e.g. Ernst Abbé and Carl Zeiss in Jena provided important impulses. Today, precision length metrology is an important driver of technological progress, e.g. in the semiconductor industry. Important contributions to this are also made in Ilmenau, e.g. with the nanopositioning and nanometrology machines designed here. Finally, length measurement at the very highest precision level in a gravitational wave interferometer enabled direct observation of the phenomenon predicted by Einstein. The lecture will take you in a vivid way through the interesting history of length measurement and show its fundamental importance for today's technological and scientific progress.