The current issue of Physik Journal, the member magazine of the German Physical Society, focuses on the topic of precision tests in space. In their overview article "Einstein auf dem Prüfstand", QuantumFrontiers members Eva Hackmann, Sven Herrmann and Claus Lämmerzahl from ZARM Bremen, together with Maike List from the DLR Institute of Satellite Geodesy and Inertial Sensing, shed light on how ever-improving measurement methods are making it possible to subject the general theory of relativity to ever more precise tests.
High-precision measurements of location, time and gravity are used in geodesy, metrology, positioning systems such as Galileo and astronomy. These include gravimeters, gradiometers, clocks, laser interferometers, lunar laser ranging and very long baseline interferometry. These precise measurement methods not only rely on sophisticated technologies, but are also based on the fundamental principles of the special and general theory of relativity and quantum mechanics. The validity of these theories forms the basis for our understanding of the physical world. A tiny change in these fundamental laws would dramatically affect physics and call into question all measurement methods and definitions, including the new International System of Units (SI). It is therefore of utmost importance that particles, clocks, light beams and other objects behave in the gravitational field exactly as predicted by the special and general theory of relativity and quantum mechanics.
In the article, the researchers present the remarkable progress that has recently been made in tests of general relativity based on increasingly precise instruments, new logistical possibilities and experiments in space. DPG members can read the complete article on pro-physik.de.
