Introduction: The Winding Road to Quantum Gravity Abhay Ashtekar Traveler, there are no paths; Paths are made by walking. ...

This white paper outlines the plans of the History Philosophy Culture Working Group of the Next Generation Event Horizon Telescope Collaboration.

Logarithmic ambiguities in the choice of asymptotically Cartesian coordinates at spatial infinity are discussed. It is shown that they do not affect the definitions of energy-momentum and angular momentum at i°. Thus, from a physical viewpoint, the ambiguities are “pure gauge.” A prescription is given for fixed this gauge freedom for the class of space-times in which the leading-order part of the Weyl tensor satisfies a certain reflection symmetry. This class admits, in all (relatively boosted) rest frames at infinity, a (...) one-parameter family of asymptotically distinct 3-surfaces (generalized 3-planes) on which the trace of the extrinsic curvature falls off faster than usual. (shrink)

This book is for physicists, historians and philosophers of physics as well as students seeking an introduction to ongoing debates in relativistic and quantum physics. This title covers the recent debates on the emergence of relativity and quantum theory. It includes chapters with an introductory character, comprehensible to students and science teachers. It strengthens the bonds between the communities of scientists, historians, and philosophers.