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 How Can I Design an Experiment to Ensure Simultaneous Light Arrival?
- AlMetis
- · Replies 39 ·
Undergrad A Hidden Zero in Einstein's Simple Derivation
- RandyReukauf
- · Replies 22 ·
Undergrad Observation of the effect of gravity on the motion of antimatter
- hyksos
- · Replies 1 ·
Undergrad Why do A and B see different ages in the mirror if light comes from the same object?
- Imaxx
- · Replies 45 ·
Undergrad Why are Kruskal coordinates related to a freely falling observer?
- Haorong Wu
- · Replies 11 ·
Undergrad I think the special theory of relativity self-contradicts
- Leepappas
- · Replies 32 ·
Undergrad Ricci Scalar For Astronomical Body
- dsaun777
- · Replies 2 ·
Undergrad Analog TV reception in a spacecraft moving relative to the Earth
- Dean Talboys
- · Replies 9 ·
High School Twin paradox aging observed from 100 light-years away
- ironirc
- · Replies 12 ·
Undergrad Is Simultaneity Absolute or Relative in the Theory of Relativity?
- CClyde
- · Replies 38 ·
High School How fast do space-time changes propagate?
- log0
- · Replies 4 ·
Undergrad Eddington-Finkelstein coordinates for Schwarzschild metric
- andyl01
- · Replies 9 ·
Graduate Galactic Rotation and Energy-Momentum Tensor
- Christian Thom
- · Replies 6 ·
Undergrad Physical meaning of null spacetime interval
- Jakz
- · Replies 35 ·
High School Creating Metric Describing Large Disk
- Onyx
- · Replies 3 ·
High School Can Dark Flow Be measured, based on Special Relativity?
- Mikael17
- · Replies 6 ·
Graduate How is eq. 1.5.3 written using three-vectors and how does it lead to eq. 1.5.4?
- SwetS
- · Replies 3 ·
Undergrad How do you differentiate between the inner and lower indices on a Lambda tensor?
- QuarkMaster
- · Replies 12 ·
Undergrad Spacetime distance and ruler-measured length on an XT chart
- KDP
- · Replies 6 ·
Undergrad Why does static spacetime have no g_0α cross-terms in GR?
- andyl01
- · Replies 10 ·
Undergrad Do parallel vectors to a geodesic satisfy the geodesic equation?
- Antarres
- · Replies 19 ·
Undergrad What is the proper time of a vertically moving inertial clock?
- KDP
- · Replies 4 ·
Undergrad How can a square-based lattice turn into a circular-based one?
- DaTario
- · Replies 31 ·
Undergrad Is an accelerating frame the same as an inertial frame at a point?
- Sciencemaster
- · Replies 11 ·
High School How to measure time in reference frame with clock?
- Mike_bb
- · Replies 22 ·
Undergrad Obtaining the matter Lagrangian from the stress energy tensor
- Bishal Banjara
- · Replies 11 ·
High School Further Understanding Simultaneity Conventions
- Freixas
- · Replies 51 ·
Graduate Born rigid acceleration with arbitrary initial velocity in 2D
- KDP
- · Replies 14 ·
Undergrad What are the effects on a stationary observer for Kerr metric?
- member 657093
- · Replies 43 ·
Undergrad Action of metric tensor on Levi-Civita symbol
- Baela
- · Replies 11 ·
Undergrad Covariant divergence of vector; physical meaning with contracted Tuv
- Tertius
- · Replies 2 ·
High School Mathologer on logarithms and hyperbolic functions in special relativity
- robphy
- · Replies 13 ·
Undergrad Are photons definitely massless?
- LightningInAJar
- · Replies 16 ·
High School Rocket laser timing in special relativity
- sphyrch
- · Replies 15 ·
High School Is there a lining to our Universe?
- Andre55
- · Replies 6 ·
Undergrad How to derive equation 3.6 in Covariant Physics by Emam
- louvig
- · Replies 5 ·
Undergrad Galilean relativity for 2 frames
- gionole
- · Replies 52 ·
Undergrad Do all particles falling into a black hole reach the singularity at the same time?
- jurap
- · Replies 2 ·
Undergrad Inverse Square Law for Black Holes
- dsaun777
- · Replies 32 ·
Undergrad Can you increase the mass of a closed system with information?
- Pony
- · Replies 14 ·
High School What is the distinction between the Weak and Strong Equivalence Principles?
- Shirish
- · Replies 2 ·
Undergrad Asymmetry in Length contraction?
- substitute materials
- · Replies 7 ·
High School Is Time a Fundamental Force in Physics?
- Jim Robison
- · Replies 15 ·
High School Is Time Defined by Relative Motion in SR and GR?
- Islam Hassan
- · Replies 24 ·
Undergrad Special Relativity Paradox "Terrorist and Spaceship"
- sergiokapone
- · Replies 11 ·
Undergrad Car, wheels and Lorentz contraction of the road: Is this a Paradox?
- LikenTs
- · Replies 72 ·
Undergrad Invariant Mass-Energy in FRW Spacetime
- Tertius
- · Replies 19 ·
Undergrad Galilean relativity in terms of homogeneity
- gionole
- · Replies 51 ·
Undergrad What was the four-momentum meant to include?
- dsaun777
- · Replies 5 ·
Undergrad Noether's second theorem and infinite-dimensional symmetries in QFT and GR
- Husserliana97
- · Replies 7 ·
Undergrad Condition for Centering Starlight in a Water-Filled Telescope?
- zenterix
- · Replies 6 ·
Undergrad Did Born Rigidity Lead Einstein to Conclude Spacetime is Curved?
- luro1964
- · Replies 5 ·
Undergrad Quasi-local mass as a measure of the gravitational energy?
- Steve Rogers
- · Replies 3 ·
High School Trying to understand what "time" is (layperson)
- Josh S
- · Replies 21 ·
Undergrad Lorentz transformation in different quadrants
- Immer Tzaddi
- · Replies 5 ·
Undergrad Coulomb’s Law in a Moving Reference Frame
- LarryS
- · Replies 24 ·
Undergrad Measuring Time Dilation from 25Kg Lead Brick w/3 Cesium Oscillators
- Dc2LightTech
- · Replies 17 ·
Undergrad Covariant Derivative Rank 2 Contravariant Tensor
- Bishal Banjara
- · Replies 55 ·
High School What is the Experimental Basis of Special Relativity?
- Ibix
- · Replies 4 ·
Undergrad Observer on Earth watching a spaceship traveling at c/2
- dainceptionman_02
- · Replies 11 ·
High School How to compare the proper times of two spatially distant mass points?
- Peter Strohmayer
- · Replies 6 ·
High School What is the effect of the twin paradoxon?
- Peter Strohmayer
- · Replies 71 ·
High School Twin paradox: when does the traveling twin see the stationary twin age faster?
- Sophrosyne
- · Replies 20 ·
High School Why does length contraction occur and how does it relate to time dilation?
- syfry
- · Replies 63 ·
Undergrad Three inertial particles scenario with compass and straightedge
- Trysse
- · Replies 40 ·
Undergrad Why does Earth's gravity curve the ball's path but not my body?
- dodo
- · Replies 8 ·
Graduate What's the relationship between RMS framework and the Lorentz group?
- pervect
- · Replies 0 ·
Graduate Papapetrou transformation: Conditions to be satisfied to achieve transformation
- julian
- · Replies 1 ·
High School Max Speed of Molecules: 1 Electron Stripped?
- DanMP
- · Replies 9 ·
Undergrad Does the past of an observer still actually exist in their "now"?
- oxbaker
- · Replies 58 ·
High School Time dilation in a planet-moon system
- DanMP
- · Replies 58 ·
High School Are planetary orbits elliptical because of a space–time conic section?
- Vectronix
- · Replies 3 ·
Undergrad Forces and gravitational time dilation
- pervect
- · Replies 11 ·
Undergrad How to derive irreducible representations/tensors?
- Antarres
- · Replies 22 ·
High School Can we measure light's one-way speed or only the round-trip speed?
- dom_quixote
- · Replies 18 ·
High School Does length contraction occur between an apple and Earth?
- Hernik
- · Replies 11 ·
Undergrad How does an observer moving at relativistic speeds perceive a pulsar?
- King Solomon
- · Replies 34 ·
High School If gravity was a force wouldn't going back in time cause us to float?
- lolsurround
- · Replies 13 ·
High School Transfer speeds of forces affected by time dilation?
- jaketodd
- · Replies 18 ·
Undergrad Is There an Atomic Clock Experiment on the Moon Testing Relativity?
- DanMP
- · Replies 12 ·
High School The expansion of the Universe and time travel (By a non-scientist)
- Sarg
- · Replies 2 ·
High School What does 3-dimensional space deform into, in the presence of gravity?
- jaketodd
- · Replies 3 ·
Undergrad Relevant/irrelevant clocks for experimental tests of relativity
- DanMP
- · Replies 52 ·
High School Photons on a perpendicular bisector path from a black hole's core
- jaketodd
- · Replies 4 ·
Undergrad Atomic Clock Speed graph between two stationary masses
- MatthewKM
- · Replies 23 ·
Undergrad Event Horizon movie, with some interesting concepts (papers cited)
- jaketodd
- · Replies 1 ·
Undergrad Any advancements in the feasibility of Alcubierre warp drive science?
- jaketodd
- · Replies 1 ·
High School Detecting cosmological redshift in an empty part of the Universe
- Shirish
- · Replies 5 ·
Undergrad Stress-energy tensor and relativistic force four-vector in fluids
- kmm
- · Replies 21 ·
High School Define a vector that transfers the reference systems to the future
- Renato Iraldi
- · Replies 8 ·
Undergrad Why is there nothing faster than light?
- Thalita Luna
- · Replies 16 ·
Undergrad Is the constancy of light speed a postulate or assumption?
- Aromalsp
- · Replies 78 ·
Undergrad Radiatively efficient accretion onto BHs
- zviz
- · Replies 5 ·
Undergrad Time Measurement in Extremely Curved Space Regions
- Killtech
- · Replies 95 ·
Graduate Preserving Covariant Derivatives of Null Vectors Under Variation
- sarriiss
- · Replies 3 ·
High School Does the fact that gravity moves at the speed of light affect how planets move?
- peanutaxis
- · Replies 9 ·
Graduate Continuation of Coordinates Across Black Hole Horizons
- Antarres
- · Replies 5 ·
Undergrad Mass Density of Photons in Refractive Medium
- jeast
- · Replies 19 ·
Undergrad Taylor Expansion of Metric Transformation in RNCs
- chartery
- · Replies 9 ·
High School How much mass does the sun lose per second including all ejected particles?
- syfry
- · Replies 8 ·