In her YouTube video Bell’s Theorem Experiments on Entangled Photons, Dr. Fugate shows how polarization-entangled photons violate Bell’s inequality. In this Insight, I will use quantum information theory to explain why such entangled photon-polarization qubits violate the version of Bell’s inequality due to John Clauser, Michael Horne, Abner Shimony, and Richard Holt known as the...

The Relativator (revisited) This is an update of my 2006 post (reconstructed in 2014) Relativator: The circular slide-rule for physicists. This is a circular slide-rule for doing relativistic calculations for elementary particle physics that I learned about from – an article by Elizabeth Wade ( “Artifact: Relativator”, Symmetry (FNAL/SLAC), 01/01/06, https://www.symmetrymagazine.org/article/december-2005january-2006/artifact-relativator  https://www.symmetrymagazine.org/sites/default/files/legacy/pdfs/200512/artifact_relativator.pdf ), which is...

The “Addition of Velocities” formula (more correctly, the “Composition of Velocities” formula) in Special Relativity [tex]\frac{v_{AC}}{c}=\frac{ \frac{v_{AB}}{c}+\frac{v_{BC}}{c} }{1 + \frac{v_{AB}}{c} \frac{v_{BC}}{c}}[/tex] is a non-intuitive result that arises from a “hyperbolic-tangent of a sum”-identity in Minkowski spacetime geometry, with its use of hyperbolic trigonometry. However, I claim it is difficult to obtain this by looking at...

Definition/Summary The Einstein Field Equations (EFE) are a set of ten interrelated differential equations that form the core of Einstein’s general theory of relativity. These equations describe how matter and energy determine the curvature of spacetime, providing a mathematical framework to relate spacetime geometry to its energy-matter content. Mathematically, the EFE relate the Ricci curvature...