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.
Threads
Undergrad Solving Spherically Symmetric Static Star Equations of Motion
- epovo
- · Replies 2 ·
Graduate Dirac's interpretation of density variation between matter world lines
- Kostik
- · Replies 7 ·
Undergrad Time dilatopause for black holes
- Feynstein100
- · Replies 36 ·
Graduate Get GR Tensor II: Where to Buy Program Library
- toabek
- · Replies 1 ·
High School How do we identify a stationary system?
- CClyde
- · Replies 43 ·
High School A thought experiment of the relativity of light
- CClyde
- · Replies 76 ·
Undergrad Doppler Effect on Light: Constant Speed of Light Confusion
- InquiringMind
- · Replies 9 ·
Undergrad Time Dilation Paradox: Geosynchronous Satellites
- InquiringMind
- · Replies 5 ·
Graduate Why are General relativity texts so much more formal?
- paralleltransport
- · Replies 28 ·
Undergrad How to rule out that the speed of light was different in the past?
- victorvmotti
- · Replies 76 ·
High School Find Geodesics in Dynamic Ellis Orbits Metric
- Onyx
- · Replies 92 ·
Undergrad How meaningful is the notion of now here on Earth?
- EclogiteFacies
- · Replies 1 ·
Graduate Going from Cauchy Stress Tensor to GR's Energy Momentum Tensor
- Luai
- · Replies 3 ·
Undergrad Effects of time dilation for near-speed-of-light travel
- Chenkel
- · Replies 65 ·
Undergrad Unit of orbital precession calculated from the sigma formula
- NODARman
- · Replies 20 ·
Undergrad Does vacuum energy affect gravity?
- swampwiz
- · Replies 24 ·
High School Proposed Experiment - Speed of Light
- DanAil
- · Replies 30 ·
Graduate Adding a fifth dimension to the spacetime interval: is this valid general relativity?
- Psip
- · Replies 1 ·
Graduate Can an Oscillating Eternal Universe be Described without Singularity?
- victorvmotti
- · Replies 3 ·
Graduate Do density perturbations contradict the cosmological homogeneity assumption?
- victorvmotti
- · Replies 13 ·
High School Why does spaghettification involve both stretching and squashing?
- DaveC426913
- · Replies 5 ·
High School Does General Relativity Really Support Nonlocality?
- Spathi
- · Replies 18 ·
High School Questions about the Speed of Light, Time, etc.
- John Mcrain
- · Replies 74 ·
Undergrad Proof of Lorentz Gauge Existence: Help Understanding Schutz 8.3
- epovo
- · Replies 2 ·
Undergrad Modeling the Earth and Sun (2 body orbits) using general relativity?
- James1238765
- · Replies 62 ·
Graduate Small and large extra dimension(s) of the physical space
- victorvmotti
- · Replies 12 ·
High School Why use Euclidean volume formula in curved space near Earth
- Shirish
- · Replies 29 ·
Undergrad Does Special Relativity Change Our Perception of Others?
- EclogiteFacies
- · Replies 47 ·
Undergrad Conservation of Energy in GR: A-B System Analysis
- Superposed_Cat
- · Replies 5 ·
High School Time Travel: Can Humans Go Faster Than Ordinary Speed?
- Jupiter60
- · Replies 9 ·
Undergrad Light in an accelerated elevator
- John Mcrain
- · Replies 17 ·
Insights Oppenheimer-Snyder Model of Gravitational Collapse: Implications
- PeterDonis
- · Replies 0 ·
High School Derivation of time dilation without light clocks
- Tazerfish
- · Replies 25 ·
Undergrad Why is muon decay time γT and not γ(T − x'v/c²)?
- realanswers
- · Replies 22 ·
Undergrad Gravity of the Sun: Einstein's Calculation and Beyond
- Nik_2213
- · Replies 1 ·
Undergrad Why Are the Two Diagrams in the Twin Paradox Not Symmetric?
- student34
- · Replies 27 ·
High School Relativity & Gravity: Resolving the Discrepancy
- Hornbein
- · Replies 88 ·
Graduate Two degrees of freedom in GR after boundary conditions specified?
- Fractal matter
- · Replies 6 ·
Undergrad Why do the clocks show simultaneous strikes if observer A sees the front flash first?
- Besso
- · Replies 11 ·
High School Light Speed In Forward and Backward Directions
- AlienGrey
- · Replies 51 ·
Undergrad Visualising Torsion Tensor: Is There a Picture?
- chartery
- · Replies 6 ·
Undergrad Special Relativity philosophy and anxiety
- EclogiteFacies
- · Replies 10 ·
Undergrad Physics Error in Larry Niven's "Neutron Star
- PeterDonis
- · Replies 28 ·
High School Does spaghetification occur at the event horizon or the singularity?
- MikeeMiracle
- · Replies 6 ·
Undergrad Contracting the stress energy tensor
- dsaun777
- · Replies 33 ·
Graduate Oppenheimer-Snyder Model of Gravitational Collapse: Mathematical Details
- PeterDonis
- · Replies 0 ·
Undergrad Gravitation Machine Invented? Research Idea
- susim
- · Replies 1 ·
Graduate Do Astrophysical Black Holes Contain CTCs?
- bIcyt265
- · Replies 4 ·
High School Speed of Light Unaffected by Moving Emitter
- marcosdb
- · Replies 25 ·
Undergrad How do angular displacement and rapidity relate in special relativity?
- Logic314
- · Replies 3 ·
Undergrad Why do astronauts age more slowly in space if time moves faster there?
- InquiringMind
- · Replies 6 ·
Undergrad How can time only have one direction?
- student34
- · Replies 105 ·
Insights Oppenheimer-Snyder Model: Overview of Gravitational Collapse
- PeterDonis
- · Replies 5 ·
Graduate Static Gravitational Field: Why Must ##g_{m0} = 0##?
- Kostik
- · Replies 5 ·
High School Can there be time without mass?
- guptasuneet
- · Replies 64 ·
High School What if a needle hits Jupiter at nearly speed of light?
- member 728827
- · Replies 14 ·
Undergrad Converting Einstein summation notation to matrix equations
- epovo
- · Replies 10 ·
Undergrad Calculate Length Contraction for Accelerated Motion to Proxima Centauri
- ntrand
- · Replies 29 ·
High School My paraphrased explanation of the Twin Paradox
- ynojunin
- · Replies 24 ·
Undergrad Does general relativity require signal propagation between distant events?
- unparadoxical
- · Replies 27 ·
Graduate Two Questions about Novikov Coordinates
- PeterDonis
- · Replies 8 ·
Undergrad Arguments leading to the speed of light as a dimensionless constant
- Saw
- · Replies 64 ·
High School Why does Einstein's starlight deflection prediction double Newton's?
- Karl Coryat
- · Replies 6 ·
Undergrad Best Derivation of E=mc^2 - Fdx = V^2 dm
- JLT
- · Replies 17 ·
High School The One-Way Speed of Light: Speculation of a Tired Mind
- Matthew_p
- · Replies 8 ·
Undergrad Need to resort to spherical wavefront to derive the LTs?
- Saw
- · Replies 123 ·
Undergrad Charge conservation and special relativity
- Ahmed1029
- · Replies 9 ·
High School Could Traveling at Near-Light Speed Create Black Holes?
- Matt Fenwick
- · Replies 38 ·
Graduate Decomposing Rank-2 Tensors in Dirac's "General Theory of Relativity
- Kostik
- · Replies 5 ·
Graduate Integrating a three-form over a ball in Minkowski space
- kyp4
- · Replies 3 ·
Undergrad Photon ring flipped in Schwarzschild black hole simulation
- Jessie24789
- · Replies 15 ·
High School Deep Space Speed Limit: What Prevents Exceeding Light Speed?
- cmw
- · Replies 5 ·
High School Can relativistic velocity addition exceed c if input velocities do?
- mahoneywingo
- · Replies 16 ·
Undergrad Einstein's General Relativity w/o Cosmological Constant
- not my name
- · Replies 1 ·
Graduate Principal Invariants of the Weyl Tensor
- getjonwithit
- · Replies 6 ·
Undergrad Gravitational Waves from Vanishing Sun: What Happens?
- Zugr
- · Replies 4 ·
Graduate Diagonalizing a 2D metric in Chandrasekhar's black hole book
- kparchevsky
- · Replies 4 ·
High School Can gravitational redshift explain cosmological redshift instead of expansion?
- elevin
- · Replies 19 ·
Undergrad What does it mean for spacetime to admit a timelike Killing vector field?
- GR191511
- · Replies 1 ·
High School Time dilation - what is the time on the Earth?
- Lotto
- · Replies 32 ·
Graduate Visualizing Arbitrary Coordinate System - Example Needed
- BLevine1985
- · Replies 2 ·
Undergrad Twin Paradox: Calculating Stan's Time Elapsed According to Moe
- topsquark
- · Replies 20 ·
High School What is x' for Moving Rocket from P?
- Lotto
- · Replies 2 ·
Undergrad Magnetic Field vs Spacetime: Effects on Inertia Disk
- Gitirana
- · Replies 6 ·
Undergrad Jefimenko's Theory of Gravitation: Continued Discussion
- marcosdb
- · Replies 5 ·
Undergrad Why do timelike events have different spatial orders in different frames?
- BLevine1985
- · Replies 16 ·
Undergrad Is this just a typo in Schutz' book on General Relativity?
- Ahmed1029
- · Replies 4 ·
High School Is a Universe Without Mass and Energy Possible?
- alan123hk
- · Replies 25 ·
High School Solve General Geodesics in FLRW Metric w/ Conformal Coordinates
- Onyx
- · Replies 14 ·
Undergrad Comprehensive list of general relativity solutions with their history and viability
- dsaun777
- · Replies 1 ·
High School Calculate Unit Normal Vector for Metric Tensor
- Onyx
- · Replies 21 ·
High School A question about relativity of simultaneity
- DmitryS
- · Replies 116 ·
High School How much time passes on Earth?
- DaveC426913
- · Replies 9 ·
Undergrad Linearized Gravity: Bimetric Theory of General Relativity?
- dsaun777
- · Replies 8 ·
High School Calc. Christoffel Symbols of Hiscock Coordinates
- Onyx
- · Replies 11 ·
Undergrad Can Spherical Symmetry Be Achieved Without Varying Line Element?
- GR191511
- · Replies 14 ·
Undergrad How is photon momentum defined when m=0 and v=c?
- Ahmed1029
- · Replies 19 ·
High School Understanding twin paradox without math
- obtronix
- · Replies 122 ·
High School Speed of Point on Expanding Sphere
- Ad VanderVen
- · Replies 9 ·
Graduate Propagation Vector of Light in Kerr Spacetime: Reference Needed
- Haorong Wu
- · Replies 1 ·