Date:	Thu, November 19, 2020
Time:	13:00
Place:	online via zoom (please write the organizer for the meeting id and passcode)

Abstract: With new optical clocks and laser interferometers in space new instruments are at work to measure the gravitational field of the Earth with highest precision. The measurement procedures as well as the highest precision make it necessary to employ General Relativity. Accordingly, in the talk a fully general relativistic approach to geodesy is presented. Starting from a stationary situation the fully relativistic geoid is defined. Since relativistic gravity has more degrees of freedom than Newtonian gravity, a second "geoid" has been found which is related to the rotational degrees of freedom of gravity. The methods to practically measure these geoids are described and the deviation from Newtonian gravity is discussed. In the outlook remaining tasks for a formalism for general relativistic geodesy are outlined.