Strong Field Gravitational Tests

|

When the density of the body becomes large enough, general relativity predicts the formation of a black hole. The neutron stars of about 1.4 solar masses and the black holes are the final stage for the evolution of the massive … Read More

Modern Tests of Relativistic Gravitational Theories

|

Dicke and Schiff established a framework for testing general relativity, [1] including through null experiments and using the physics of space exploration, electronics and condensed matter, such as the Pound-Rebka experiment and laser interferometry. The gravitational lens tests and the … Read More

Classic gravitational tests of post-Einsteinian theories

|

With the help of PPN formalism, gravity theories are confronted with the results of experiments in the solar system. The γ parameter in this formalism highlights the light deflection and the light delay. By calculations according to PPN, light deflection … Read More

Testing the relativistic theories of gravity

|

Clifford M. Will describes, in Theory and Experiment in Gravitational Physics, [1] the emergence of a new era for general relativity, testing and checking at very high levels of accuracy. In 1959, scientists at Lincoln Laboratories in Massachusetts bombarded the … Read More

Evaluation of post-Einsteinian gravitational theories through parameterized post-Newtonian formalism

|

Proliferation of post-Einsteinian gravitational theories Right after the elaboration and success of general relativity (GR), alternative theories for gravity began to appear, which can fall into four broad categories: [1] Bifurcated theories (with the Lakatosian[2] hard core identical or very … Read More

Heuristics of the General Relativity

|

The essential principle of coordination in GR is the principle of equivalence, including a negative heuristic. The argument “is not that all reference frames are equivalent, but that the classical coordination of uniform motion in a straight line with the … Read More

Epistemology of General Relativity

|

Early philosophical interpretations of the general theory of relativity are very diverse, each trying to identify Einstein as a follower of that philosophy. Mach’s supporters highlighted Einstein’s attempt to implement a “relativization of inertia” in general relativity (GR), and his … Read More

Ontology of Gravitational Singularities

|

Peter Bokulich and Erik Curiel (Curiel and Bokulich 2018) assert that general relativity (GR) allows singularities, and that we need to understand the ontology of singularities if we want to understand the nature of space and time in the present … Read More

Gravitational Singularities

|

Within the classical theory of Newton’s gravity there is the fundamental possibility of singularity. No signal can propagate from within a singularity, but its gravitational influence is permanently present externally and depends only on the total mass, the angular momentum, … Read More

The Ontology of General Relativity

|

In classical vision, space and time are containers; matter is the content. The distinctive property of matter is that it carries energy and impulse, preserved over time, resulting in energy and impulse being fundamental ontologically. (Norton 2012) General Relativity (GR) … Read More

Grandfather paradox in time travel

|

(Top: original billiard ball trajectory. Middle: the billiard ball emerges from the future, and delivers its past self a strike that averts the past ball from entering the time machine. Bottom: the billiard ball never enters the time machine, giving … Read More

Time Travel

|

Sfetcu, Nicolae (2019). “Time Travel”, in Telework, DOI: 10.13140/RG.2.2.29776.76804/1, https://www.telework.ro/en/time-travel/   Abstract Time travel is a recognized concept in philosophy and science, but whose scope is highly disputed, giving rise to numerous paradoxes in both philosophy and science. Time travel … Read More

1 2 3