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.
High School Photon Energy Without Rest Mass – How?
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Undergrad The wave equation interpretation of special relativity
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High School Is there a white hole inside every black hole?
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Undergrad Synchronizing clocks at different locations to measure speed of light
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Undergrad An invariant while crossing the horizon
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Undergrad I don't see how a black hole's event horizon can be crossed
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Undergrad Variation of the lightning train thought experiment
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High School Project GRE^2AT - GR on Mt. Ranier
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Undergrad How Is Intrinsic Curvature Measured in Higher Dimensions Like 4D Spacetime?
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Undergrad Conventionality of the One-Way Speed of Light
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High School Trying to calculate proper time of worldlines using rotating frames
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Graduate Reconciling units for the Einstein and Landau-Lifshitz pseudotensors
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Undergrad What Are the Limits of the Universe According to Cosmologists?
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Graduate Dirac's integral for the energy-momentum of the gravitational field
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Graduate Help me understand why “Block Universe” is not scientifically proven
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High School Could we ever create a black hole?
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Undergrad Follow-up Einstein Definition of Simultaneity for Langevin Observers
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Undergrad Symmetry of motion in the special theory of relativity
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Undergrad Hawking After 54 Years Confirmed: BH surfaces don't shrink
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Undergrad A sufficient condition for integrability of equation ##\nabla g=0##
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Undergrad Follow-up on the Expanding Universe Insight article
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Insights Relativator (Circular Slide-Rule): Simulated with Desmos - Insight
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Undergrad How do Tensors "work" in relation to linear algebraic objects?
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Undergrad Confused about time dilation -- motion vs energy
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Graduate 1-Way Speed of Light
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Graduate Gravitational Analysis of Wide Binaries
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Undergrad Mass conservation in black holes
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High School How can a black hole absorb matter?
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Undergrad Please explain how length contraction and time dilation result in a constant c
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Undergrad Can this experiment break Lorentz symmetry?
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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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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 ##\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 "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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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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