Berlin 2015 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 14: Invited Talks 6

GR 14.2: Invited Talk

Thursday, March 19, 2015, 10:10–10:50, H 2013

Where is the energy stored in the gravitational field? — •Gerhard Schäfer — Theoretisch-Physikalisches Institut, Friedrich-Schiller-Universität Jena, Jena, Germany

We are used to describe and understand physical processes in terms of energy density and energy current density. But what about gravity? Applying a special setting, it will be shown that the Newtonian gravitational field does not allow the definition of physical energy density or energy current density. The special setting is a natural outcome of Einstein's general relativity theory where gravitational energy density and energy current density, i. g., are also notions without physical meaning. Only to gravitational waves, which are completely foreign to Newtonian gravity, energy density and energy current density can be attributed physical meaning, at least to some extent. The Einstein equivalence principle and tidal forces, which are the true gravitational forces, will make the non-localizability of the gravitational field energy evident. Energy in cosmology will also find a discussion.