Special and General Relativity Forum

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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.
B Thought experiment: The twin paradox, observed from far away
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I Is Simultaneity Absolute or Relative in the Theory of Relativity?
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B How fast do space-time changes propagate?
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I Eddington-Finkelstein coordinates for Schwarzschild metric
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A Galactic Rotation and Energy-Momentum Tensor
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I Physical meaning of null spacetime interval
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B Creating Metric Describing Large Disk
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B Can Dark Flow Be measured, based on Special Relativity?
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A How is eq. 1.5.3 written using three-vectors and how does it lead to eq. 1.5.4?
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I How do you differentiate between the inner and lower indices on a Lambda tensor?
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I Spacetime distance and ruler-measured length on an XT chart
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I A question about static spacetime in GR
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I A question about geodesics and notion of parallelism
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I What is the proper time of a vertically moving inertial clock?
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I How can a square-based lattice turn into a circular-based one?
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I Is an accelerating frame the same as an inertial frame at a point?
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B How to measure time in reference frame with clock?
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I Obtaining the matter Lagrangian from the stress energy tensor
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B Further Understanding Simultaneity Conventions
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A General equation for hyperbolic motion in a 2D plane -- Help needed please
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I What are the effects on a stationary observer for Kerr metric?
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I Action of metric tensor on Levi-Civita symbol
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I Covariant divergence of vector; physical meaning with contracted Tuv
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B Video: Mathologer on visual logarithms (and hyperbolic trig)
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I Are photons definitely massless?
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B Another special relativity related "paradox"
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B Is there a lining to our Universe?
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I Help Understanding Equation 3.6 in Covariant Physics by Moataz H. Emam
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I What is the Connection Between Black Holes and the Big Bang?
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I Inverse Square Law for Black Holes
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I Can you increase the mass of a closed system with information?
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B What is the distinction between the Weak and Strong Equivalence Principles?
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I Asymmetry in Length contraction?
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B Is Time Defined by Relative Motion in SR and GR?
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I Special Relativity Paradox "Terrorist and Spaceship"
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I Car, wheels and Lorentz contraction of the road: Is this a Paradox?
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I Invariant Mass-Energy in FRW Spacetime
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I Galilean relativity in terms of homogeneity
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I What was the four-momentum meant to include?
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I Noether's second theorem: two questions
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I Condition for Centering Starlight in a Water-Filled Telescope?
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I Did Born Rigidity Lead Einstein to Conclude Spacetime is Curved?
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I Quasi-local mass as a measure of the gravitational energy?
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B Trying to understand what "time" is (layperson)
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I Lorentz Transformation: Premises + Derivation
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I Coulomb’s Law in a Moving Reference Frame
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Measuring Time Dilation from 25Kg Lead Brick w/3 Cesium Oscillators
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I Covariant Derivative Rank 2 Contravariant Tensor
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B What is the Experimental Basis of Special Relativity?
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I Observer on Earth watching a spaceship traveling at c/2
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B How to compare the proper times of two spatially distant mass points?
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B What is the effect of the twin paradoxon?
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B A scenario to help understand the twin paradox in SR
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B Why does length contraction occur and how does it relate to time dilation?
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I Three inertial particles: Separating the twins from the paradox
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I Yet another spacetime-bending layman question
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A What's the relationship between RMS framework and the Lorentz group?
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A Papapetrou transformation: Conditions to be satisfied to achieve transformation
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B Max Speed of Molecules: 1 Electron Stripped?
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I Does the past of an observer still actually exist in their "now"?
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B Time dilation in a planet-moon system
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B Are planetary orbits elliptical because of a space–time conic section?
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I Forces and gravitational time dilation
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I How to derive irreducible representations/tensors?
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B Measuring Speed of Light: Transit Time & Interference
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B Length Contraction: Apple Hanging from Tree & Earth
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I How does an observer moving at relativistic speeds perceive a pulsar?
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B Transfer speeds of forces affected by time dilation?
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I Is There an Atomic Clock Experiment on the Moon Testing Relativity?
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B The expansion of the Universe and time travel (By a non-scientist)
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B What does 3-dimensional space deform into, in the presence of gravity?
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I Relevant/irrelevant clocks for experimental tests of relativity
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B Photons on a perpendicular bisector path from a black hole's core
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I Atomic Clock Speed graph between two stationary masses
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I Event Horizon movie, with some interesting concepts (papers cited)
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I Any advancements in the feasibility of Alcubierre warp drive science?
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B Detecting cosmological redshift in an empty part of the Universe
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I Stress-energy tensor and energy/momentum conservation clarification
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B Define a vector that transfers the reference systems to the future
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I Why is there nothing faster than light?
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I Constancy of Speed of Light: Postulate or Assumption?
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I Radiatively efficient accretion onto BHs
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I Time Measurement in Extremely Curved Space Regions
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A Preserving Covariant Derivatives of Null Vectors Under Variation
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B Does the fact that gravity moves at the speed of light affect how planets move?
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A Continuation of Coordinates Across Black Hole Horizons
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I Mass Density of Photons in Refractive Medium
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I Taylor Expansion of Metric Transformation in RNCs
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B Sun's Mass Loss: 4 Billion kg/sec from Sunlight & Ejected Particles
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I Compatibility of Classical Electromagnetism & Relativity
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B Can Relativistic Mass Create a Black Hole?
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B Pound & Rebka Experiment: Earth's Spin Rotation Speed
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I 3 clocks thought experiment - Absolute vs. relative aspects?
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B LIGO Back Online: Upgraded Detector to Spot Fainter Gravitational Waves
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B Understanding Time Dilation: How Passing Photons Affect Time Measurement
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I Locally Inertial Frames: Freefall & Relative Velocities
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I Adler's New Book on Relativity: Misprint on Page 16?
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I A question about metric compatibility equation
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B Time Dilation: Is This a Reasonable Explanation?
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B Triplets Paradox: Is There a Solution?
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