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Special and General Relativity Forum

Join in expert discussion on special and general relativity discussion. Relativity is the dependence of various physical phenomena on relative motion of the observer and the observed objects.

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High School Spacetime interval - alternative view - maybe?

May 10, 2019 · Replies 14 · May 10, 2019

Replies: 14

Views: 3K

High School Deriving the Lorentz transformations

May 10, 2019 · Replies 4 · May 10, 2019

Replies: 4

Views: 2K

Undergrad Invariant Mass in Gravitational Fields: Special Relativity

May 9, 2019 · Replies 17 · May 10, 2019

Replies: 17

Views: 2K

Undergrad Are Dimensions Truly Relative to the Observer in the Coastline Paradox?

May 8, 2019 · Replies 6 · May 9, 2019

Replies: 6

Views: 2K

Undergrad Length Contraction: Measuring a Difference of 55 Nanometers

May 8, 2019 · Replies 3 · May 9, 2019

Replies: 3

Views: 1K

Graduate A couple of interesting black hole papers

Nov 16, 2012 · Replies 2 · May 8, 2019

Replies: 2

Views: 2K

Undergrad Does Curving Space by an Approaching Mass Do Work?

May 7, 2019 · Replies 4 · May 8, 2019

Replies: 4

Views: 2K

Graduate Understanding Stokes Theorem and is the variation of the metric a tensor?

May 2, 2007 · Replies 3 · May 8, 2019

Replies: 3

Views: 5K

Undergrad Can all fundamental constants be set to 1 in natural unit systems?

May 7, 2019 · Replies 3 · May 7, 2019

Replies: 3

Views: 2K

Graduate SR Foundations: Parallax Methods? - Reference Request

Feb 13, 2012 · Replies 2 · May 7, 2019

Replies: 2

Views: 2K

Insights Defining Large-Scale Isotropy: A Formal Definition

May 7, 2019 · Replies 0 · May 7, 2019

Replies: 0

Views: 1K

High School Relativator: The circular slide-rule for physicists

Aug 28, 2014 · Replies 2 · May 7, 2019

Replies: 2

Views: 3K

Graduate Relativity Visualization: Aging Twin Paradox - Adam Toons

Apr 20, 2008 · Replies 1 · May 7, 2019

Replies: 1

Views: 2K

Graduate Correcting a Typo in d'Inverno's Lagrangian on Page 172 | Section 11.3 Results

Aug 7, 2008 · Replies 1 · May 7, 2019

Replies: 1

Views: 2K

Graduate Rotating black hole interiors take 2

Nov 19, 2006 · Replies 1 · May 7, 2019

Replies: 1

Views: 2K

Graduate Price's Power Law: Mass-Energy Dampening & h Constant

Feb 28, 2009 · Replies 1 · May 7, 2019

Replies: 1

Views: 2K

Graduate Vanishing twist of time - like killing field

Mar 11, 2013 · Replies 1 · May 7, 2019

Replies: 1

Views: 3K

Graduate EP and active/passive mass

Nov 20, 2011 · Replies 1 · May 7, 2019

Replies: 1

Views: 2K

High School Should the 'time' axis of a Minkowski diagram be time's imaginary unit?

May 4, 2019 · Replies 11 · May 7, 2019

Replies: 11

Views: 3K

Undergrad What is ds in ds2 = dx2 - cdt2

May 5, 2019 · Replies 9 · May 5, 2019

Replies: 9

Views: 6K

High School Trying to understand Lorentz Transformations

Mar 19, 2019 · Replies 69 · May 5, 2019

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Replies: 69

Views: 9K

Graduate Light interferometry as described in Thorne's black holes and time warps ?

May 25, 2010 · Replies 3 · May 5, 2019

Replies: 3

Views: 2K

Undergrad Black Holes: Time Bidirectional?

May 4, 2019 · Replies 3 · May 5, 2019

Replies: 3

Views: 2K

High School Implications of FTL signals in SR

Aug 23, 2018 · Replies 16 · May 4, 2019

Replies: 16

Views: 3K

Undergrad Fixing Rindler Coordinates when a=0

May 2, 2019 · Replies 7 · May 2, 2019

Replies: 7

Views: 1K

Undergrad Is a photon simply a vibration of the spacetime lattice?

May 1, 2019 · Replies 33 · May 2, 2019

2

Replies: 33

Views: 4K

High School Does Time Exist Without Motion?

Apr 20, 2019 · Replies 4 · Apr 29, 2019

Replies: 4

Views: 2K

Graduate Coord Transf. in Linearized GR: Understanding Metric Transformation

Apr 25, 2019 · Replies 5 · Apr 29, 2019

Replies: 5

Views: 2K

Graduate Einstein-Hilbert Action -> GR is a saddle point?

Sep 26, 2010 · Replies 4 · Apr 28, 2019

Replies: 4

Views: 3K

High School Understanding Final Form of Lorentz Transformations

Apr 23, 2019 · Replies 12 · Apr 28, 2019

Replies: 12

Views: 2K

Graduate Restframe of Photon: Explained

Apr 26, 2019 · Replies 5 · Apr 27, 2019

Replies: 5

Views: 3K

Graduate Question about "Rest frame of a photon" FAQ

Apr 26, 2019 · Replies 19 · Apr 27, 2019

Replies: 19

Views: 4K

Graduate Curved-spacetime, but why curved coordinates?

Nov 7, 2011 · Replies 4 · Apr 26, 2019

Replies: 4

Views: 3K

Graduate Gaussian to MKS Four-vector Conversion

Oct 21, 2009 · Replies 1 · Apr 26, 2019

Replies: 1

Views: 2K

Graduate Is the Schwarzschild spacetime with negative mass geodesically complete?

Mar 8, 2011 · Replies 1 · Apr 26, 2019

Replies: 1

Views: 3K

High School Is Time Relative? Understanding Special Relativity

Apr 25, 2019 · Replies 45 · Apr 26, 2019

2

Replies: 45

Views: 11K

Undergrad CMB Photons: 3000˚ K to 2.7˚ K in an Expanding Universe

Apr 25, 2019 · Replies 12 · Apr 26, 2019

Replies: 12

Views: 2K

Graduate Hawking singularity theorem - what if not all geodesics incomplete?

Sep 8, 2010 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 3K

Graduate Experimental tests of zero divergence for stress-energy?

Sep 15, 2012 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 3K

Graduate Wiki article on Unruh radiation

Nov 11, 2013 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 2K

Graduate Gullstrand-Painlevé coordinates

Dec 19, 2008 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 3K

Graduate The problem of the mass of a body

Apr 25, 2019 · Replies 5 · Apr 25, 2019

Replies: 5

Views: 9K

Undergrad What happens to the inertia of a mass falling into a black hole?

Apr 21, 2019 · Replies 40 · Apr 25, 2019

2

Replies: 40

Views: 4K

Graduate Lie derivative and Riemann tensor

Apr 12, 2008 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 5K

Graduate Killing vectors in space with torsion?

Jan 15, 2010 · Replies 1 · Apr 25, 2019

Replies: 1

Views: 2K

Undergrad Gravity and balls on rubber sheets

Apr 17, 2019 · Replies 10 · Apr 25, 2019

Replies: 10

Views: 4K

Undergrad Things that can be observed in a snapshot view of the universe

Apr 25, 2019 · Replies 3 · Apr 25, 2019

Replies: 3

Views: 1K

Graduate How Does the 3D Metric Relate to Volume in a Closed Universe?

Apr 4, 2019 · Replies 3 · Apr 24, 2019

Replies: 3

Views: 3K

Graduate Kepler & Einstein: Agree or Disagree?

Aug 11, 2008 · Replies 1 · Apr 24, 2019

Replies: 1

Views: 3K

Graduate Redshift and blueshift in expanding universe

Mar 5, 2012 · Replies 2 · Apr 23, 2019

Replies: 2

Views: 3K

Graduate Why there can be only one invariant speed

Jul 4, 2009 · Replies 5 · Apr 23, 2019

Replies: 5

Views: 3K

Graduate Asymmetry in black hole formation, and a possible hand-wavy no-hair theorem

Oct 18, 2010 · Replies 1 · Apr 23, 2019

Replies: 1

Views: 2K

Graduate Video camera links in Special Relativity

Nov 21, 2009 · Replies 1 · Apr 23, 2019

Replies: 1

Views: 2K

High School Is time a unique dimension or a constant across all dimensions?

Dec 11, 2018 · Replies 14 · Apr 23, 2019

Replies: 14

Views: 15K

High School Einstein's Train Thought Experiment

Apr 22, 2019 · Replies 16 · Apr 22, 2019

Replies: 16

Views: 4K

Graduate Can red shift compare which clock go faster?

Dec 27, 2005 · Replies 2 · Apr 22, 2019

Replies: 2

Views: 2K

Graduate Flat time slices in Gullstrand–Painlevé coordinates?

Aug 12, 2010 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Graduate Energy-Momentum Tensor for a particle

Sep 26, 2012 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 3K

Graduate Falling into a charged black hole

Nov 24, 2009 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Graduate Does expanding space affect time dilation etc?

Sep 10, 2011 · Replies 2 · Apr 22, 2019

Replies: 2

Views: 2K

Graduate How do the energy conditions in GR relate to timelike and null vectors?

Jan 11, 2011 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Undergrad Centre of Mass-Energy: Griffiths Electrodynamics 4th Ed.

Apr 20, 2019 · Replies 5 · Apr 22, 2019

Replies: 5

Views: 1K

High School Time Dilation Dialogue: Understanding the Concept

Apr 22, 2019 · Replies 17 · Apr 22, 2019

Replies: 17

Views: 2K

Graduate Where does a radially falling test particle cross the inner horizon of RN BH?

Mar 10, 2011 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Graduate Clocks Falling into Gravity Wells: Variation Observed?

Sep 13, 2010 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Graduate Understand Logic of Wald & Zoupas' Expression on Conserved Quantities

Jan 17, 2019 · Replies 1 · Apr 22, 2019

Replies: 1

Views: 2K

Graduate The Physics of De Sitter Black Hole Heat Capacity

Mar 27, 2019 · Replies 2 · Apr 22, 2019

Replies: 2

Views: 1K

Undergrad Help Understanding Metric Tensor

Apr 20, 2019 · Replies 12 · Apr 21, 2019

Replies: 12

Views: 4K

Undergrad Schwarzschild Geodesics: An Overview

Apr 20, 2019 · Replies 7 · Apr 20, 2019

Replies: 7

Views: 2K

Graduate Orbit velocity in Schwarzschild metric?

Jan 9, 2019 · Replies 13 · Apr 20, 2019

Replies: 13

Views: 6K

High School Special Relativity Calc: Half Speed of Light - Jose

Apr 20, 2019 · Replies 1 · Apr 20, 2019

Replies: 1

Views: 2K

Undergrad Inside the Schwarzschild horizon

Apr 19, 2019 · Replies 5 · Apr 20, 2019

Replies: 5

Views: 1K

Undergrad Gravitational Waves: Prerequisites for Study

Apr 19, 2019 · Replies 1 · Apr 19, 2019

Replies: 1

Views: 1K

Undergrad Accelerating into a black hole?

Apr 18, 2019 · Replies 7 · Apr 19, 2019

Replies: 7

Views: 2K

Undergrad Is the Equation for Relativistic Two-Body Decay Correct?

Apr 19, 2019 · Replies 1 · Apr 19, 2019

Replies: 1

Views: 4K

Graduate Venus during the day, a test of relativity?

Dec 21, 2005 · Replies 8 · Apr 18, 2019

Replies: 8

Views: 4K

Graduate Does Komar Mass Include the Energy of Gravitational Field?

Apr 12, 2019 · Replies 38 · Apr 18, 2019

2

Replies: 38

Views: 5K

High School Black Hole Evaporation: What's Left?

Apr 17, 2019 · Replies 1 · Apr 17, 2019

Replies: 1

Views: 1K

Undergrad Deriving E&B Fields from Plane Wave 4-Potential

Apr 16, 2019 · Replies 5 · Apr 17, 2019

Replies: 5

Views: 2K

Graduate Uniformity of universe expansion

Oct 2, 2009 · Replies 3 · Apr 17, 2019

Replies: 3

Views: 2K

Undergrad Compute Physical Coordinates of an Event in a Curved Spacetime

Apr 16, 2019 · Replies 1 · Apr 16, 2019

Replies: 1

Views: 1K

Graduate Could a Fixed Point on a Strong Fishing Line Influence Space-Time?

Feb 12, 2007 · Replies 1 · Apr 16, 2019

Replies: 1

Views: 3K

Graduate Can Wormholes Accurately Determine Points in Space and Time?

Dec 24, 2007 · Replies 1 · Apr 16, 2019

Replies: 1

Views: 3K

Undergrad Vaidya Metrics: Outgoing M(u) Conditions & Phys. Situations

Apr 15, 2019 · Replies 3 · Apr 16, 2019

Replies: 3

Views: 1K

Graduate Einstein-Strauss solution with one or two bubbles

Jun 5, 2007 · Replies 1 · Apr 15, 2019

Replies: 1

Views: 3K

Graduate Effect of gravitational potential on energy

Mar 22, 2008 · Replies 1 · Apr 15, 2019

Replies: 1

Views: 3K

Graduate Frequency shift and relative velocity

Oct 28, 2008 · Replies 2 · Apr 15, 2019

Replies: 2

Views: 4K

Graduate What does the image of the black hole say about general relativity?

Apr 15, 2019 · Replies 1 · Apr 15, 2019

Replies: 1

Views: 2K

Graduate Causality & Hyperspace: FTL Communication Paradoxes

Dec 10, 2004 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 2K

High School What does the constancy of speed of light mean?

Apr 12, 2019 · Replies 32 · Apr 14, 2019

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Replies: 32

Views: 4K

Graduate Is Empty Spacetime Observable or Merely Theoretical?

Jun 14, 2005 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 4K

Graduate Bigbang Bigcrunch Singular event?

Dec 28, 2009 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 3K

Graduate Local coordinates, physical coordinates

Sep 5, 2007 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 4K

Graduate Mach's principle and variable speed of light.

Nov 14, 2005 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 4K

Graduate Length contraction and wave length transformation

Nov 30, 2006 · Replies 1 · Apr 14, 2019

Replies: 1

Views: 5K

Undergrad Does this contradict or require GR?

Apr 12, 2019 · Replies 15 · Apr 13, 2019

Replies: 15

Views: 2K

Graduate About the validity of Einstein’s 1905 Principle of Relativity

Nov 8, 2007 · Replies 1 · Apr 13, 2019

Replies: 1

Views: 3K

Graduate Help with Relativistic Collision

Aug 17, 2011 · Replies 1 · Apr 13, 2019

Replies: 1

Views: 2K

Undergrad E on q independent of v - confusing?

Nov 23, 2010 · Replies 1 · Apr 13, 2019

Replies: 1

Views: 2K

Graduate Quantum gravitational uncertainty

Jul 13, 2006 · Replies 1 · Apr 13, 2019

Replies: 1

Views: 2K

Relativity

The theory of relativity, formulated by Albert Einstein, comprises two fundamental theories—special and general relativity. Special relativity, proposed in 1905, redefines our understanding of space and time by asserting the constancy of the speed of light for all observers and introducing concepts like time dilation and length contraction.

General relativity, presented in 1915, extends these principles to incorporate gravity. It describes gravity as the curvature of spacetime caused by massive objects, leading to phenomena like gravitational time dilation and the prediction of black holes. Einstein's equations have been consistently validated through experiments and observations, profoundly influencing our comprehension of the universe's fabric and dynamics.

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