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.
Undergrad MTW exercise 21.26: junction conditions for a thin shell of dust
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Undergrad Eddington’s margin of error
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High School Can frame dragging do this?
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Undergrad Understanding the historical shift away from absolute simultaneity
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Graduate Is there any topology behind factor 2 in Schwarzschild radius?
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Graduate Is the constancy of c a postulate or a derivable theorem?
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Undergrad How do non-diagonal indices of a metric allow for local flatness?
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Undergrad Transformation for Lemaitre coordinates
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High School What reference frame is used for the velocity v in the Lorentz transformation?
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High School Oberth Effect Near Sag A*
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Graduate Error in Landau-Lifshitz Vol 2, equation (2), page 277
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High School Debating the Validity of a Conversion Factor for Mass-Energy Equivalence
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High School Can an expanding EM be quantized: E=mc^2?
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Undergrad Gravitation (MTW) Misner Thorne Wheeler - 50 years (RIP) C.W.Misner
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High School Conservation of kinetic energy in expanding space
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Graduate A global energy conservation law in general relativity
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Undergrad Gravitational lensing of gravitational waves - real?
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Graduate Uncertainties in the proof of Proposition 4.4.2 in Hawking and Ellis
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Graduate Weinberg's proof of ##{T^{\mu\nu}}_{,\nu}=0## for a perfect fluid
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Graduate How do you convert the Pound–Rebka redshift into time variation?
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High School Relativistic contraction factor
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Graduate Looking for linear frame dragging formula
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Undergrad Freefall and gravity
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Graduate Dirac's "comprehensive action principle" -- independent equations
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High School Time dilation for two clocks at different altitudes on Earth
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Graduate Dirac's "GTR" Eq (27.4): how momentum ##p^\mu## varies
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Undergrad How does GR deal with pointlike objects with mass?
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Undergrad Shwartzschild coordinate system
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Undergrad How to calculate basis vectors from metric tensor (as a matrix)?
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High School Can Curved Spacetime Enable Faster-Than-Light Travel?
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Graduate Weyl tensor and coordinate acceleration
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Undergrad With gravitational lensing, which way is down?
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Graduate The Lagrangian of a free particle ##L=-m \, ds/dt##
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High School Geometric and arithmetic means and contraction factor
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Undergrad Question about a Square Light Clock
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High School Gravity and speed of information for orbiting planets
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High School A question about warp bubbles and navigation
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Graduate Question about Weinberg's GR book
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Graduate Singularity Formation and Breakdown Ricci Tensor
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Graduate The Causal Bootstrap Paradox in General Relativity
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Undergrad Theoretically, can perfectly flat spacetime exist in the Universe?
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Undergrad Reframing Light Bending Using Density Instead of Radius
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Undergrad Why Is the Speed of Light Essential in 4-Velocity Invariance?
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Undergrad Intuitive look at bending of light by gravity
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Undergrad A "continous" gravitational field formula r=0 to infinity
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Graduate Question on Dirac's derivatives of the 4-velocity w.r.t. coordinates
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Graduate Sidney Coleman's Lectures on Relativity: New Book by CUP
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Graduate Does the New Paper on Singularities Offer Proof of Their Existence?
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Graduate Tensors in null basis
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Undergrad Another Time Dilation Question
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Undergrad ##\epsilon_{ijk}## in terms of ##\delta's##
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High School Does the gravitational distortion of mass still exist in the past?
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Undergrad Missing proof of the Shell theorem in General Relativity
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Graduate A Question on the TOV Limit: Continuous Forces vs. a Discrete Trigger
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Undergrad Effect of Radiation Pressure on a Moving Object
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Graduate Does the EP imply that a free-falling observer follows a geodesic?
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Undergrad Temporal length vs. Temporal displacement
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Graduate Covariant form of Maxwell's (inhomogeneous) equations (in GR)
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Graduate Error in Landau-Lifshitz Vol 2, Fig. 20, page 310
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Graduate "TImescape" models
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High School Mass of a gyroscope when rotating or not rotating
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High School A photon always travels in a black hole
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Undergrad Going Up-Down Elevator G-forces vs Bouncing off a Spring G-force
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High School Michelson Morley experiment and the Doppler effect
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Undergrad A thought about visualizing space-time
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High School Relativity and Biological Aging: How Time Dilation Slows Cell Activity
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Graduate Minimal property of Spacelike geodesics in GR/curved spacetime?
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High School An issue about the twin paradox
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High School Can mass/energy simply be distorted spacetime?
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Undergrad Principle of relativity in the proof of invariance of interval
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Undergrad Why are we looking for a graviton?
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Undergrad Epstein diagrams and a traveling ship
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High School Lorentz Transformation of Electric & Magnetic Fields Visualized
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Graduate Ricci tensor for Fermi normal coordinates
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High School Time Travel: Is it Physically Possible? | Scientific American
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Undergrad Question about geometrical engineering (placeholder name)
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Graduate "Looks" of gravitational wave emissions for an eclipsing ternary compact object?
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Graduate Is parallel transport exactly norm-preserving or only approximately?
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High School No object actually approaches the speed of light
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Undergrad What does g00 element of the Schwarzschild metric tensor tell us?
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High School Can anything work (including human brains) inside a black hole?
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Undergrad Integral subbundle of 6 KVFs gives a spacetime foliation by 3d hypersurfaces
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Undergrad A textbook passage describing coordinate lines in physical space
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High School When I jump up and down what is the Einsteinian way to describe it?
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Undergrad Twin Paradox Resolution
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Undergrad Notion of parallel worldlines in curved geometry
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High School Question about “Inertia arises from interaction with the Universe’s mass”
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Graduate Landau-Lifshitz pseudotensor - expressing the EM tensor ##T^{ik}##
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High School Space travel and time dilation
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Undergrad Where is the mass in a black hole?
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Undergrad Can light be reflected in a black hole?
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Undergrad Reconciling smooth spacetime with variable, rotating, earth gravity
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High School Is Gravity an illusion of a force but really a curvature of spacetime?
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High School Meaningfulness of the speed of light
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Undergrad Measuring the Spacetime Interval with a Ruler
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Undergrad Does the metric in general relativity depend only on position because of the equivalence principle?
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High School One-Way Speed of Light
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High School If light beam travels through a vacuum, then through diamond, then through more vacuum...
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Undergrad About the meaning of "expanding universe"
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Undergrad CTC on FLRW cosmological models
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