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
Graduate Why Does the Energy-Stress Tensor Exclude Other Forces?
- VictorMedvil
- · Replies 13 ·
High School Did the Sun's gravity redshift light in Eddington's 1919 eclipse observation?
- Gfellow
- · Replies 3 ·
Undergrad Event Horizon Gravity: Infinite or Not?
- Mike Holland
- · Replies 6 ·
Undergrad Can probes measure time dilation to find absolute zero velocity?
- Engineer_pleb
- · Replies 14 ·
High School Does light reflect back slower from a planet near an event horizon?
- Benplace
- · Replies 14 ·
Graduate How much more sensitive did Weber bars need to be to detect gravitational waves?
- marcusl
- · Replies 10 ·
Undergrad What is the Invariant Mass of Two Perpendicular Photons?
- rashida564
- · Replies 9 ·
Undergrad Energy Density in SR Energy-Momentum Tensor
- George Keeling
- · Replies 12 ·
Undergrad How to relate E = mc² and the time dilation equation
- samuel toco
- · Replies 3 ·
Undergrad What does energy equal in special relativity with a time translation Killing field?
- Wledig
- · Replies 7 ·
High School Do Perpendicular Velocities Affect Relative Motion?
- rashida564
- · Replies 1 ·
Undergrad Time Dilation Effects of Travel to Star 10ly Away
- virgil1612
- · Replies 3 ·
High School Do moving clocks prove multiple times exist?
- Julius Ceasar
- · Replies 21 ·
Undergrad Special Relativity Controversy: Solving the Paradox
- LukasMont
- · Replies 5 ·
Undergrad Is the stress-energy tensor defined at a point or across a surface?
- dsaun777
- · Replies 17 ·
High School What does a clock measure: time or its own aging?
- dayalanand roy
- · Replies 20 ·
Undergrad An observer passing the event horizon of a black hole
- DennisN
- · Replies 12 ·
Undergrad Deriving the 4-momentum of a free particle moving in curved spacetime
- jcap
- · Replies 2 ·
Undergrad Why does time dilation seem symmetric in both reference frames?
- Haorong Wu
- · Replies 6 ·
High School Agreeing on relative separations and accelerations
- etotheipi
- · Replies 13 ·
High School Why does matter fall toward Earth's center in all directions?
- Tomer Aman
- · Replies 4 ·
High School Apparent contradiction in time dilation
- Julius Ceasar
- · Replies 15 ·
High School Development of Special Relativity
- NoahsArk
- · Replies 53 ·
High School Would a fast electron count 1 or 10 years of sunrises?
- jefals
- · Replies 41 ·
Undergrad Relativistic Notation in Waves: Confusion Solved
- kent davidge
- · Replies 4 ·
Graduate Lorentz Transformations: Why We Need the Same $\gamma$
- LagrangeEuler
- · Replies 7 ·
High School Relativistic explanation of electromagnetism
- Karl Coryat
- · Replies 34 ·
Undergrad Time dilation for twins on adjacent planets moving at 3c/5
- Gordie19
- · Replies 37 ·
Undergrad LIGO Gravitational Wave Detection News
- Wrichik Basu
- · Replies 26 ·
High School SR Thought: Spacetime Interval w/ Bounds of ##0<\alpha<1##
- benorin
- · Replies 4 ·
Undergrad When do cosmologists actually use all components of the energy-momentum tensor?
- dsaun777
- · Replies 7 ·
Graduate Heuristic Approach EFE: Why 10 DOF?
- binbagsss
- · Replies 5 ·
Graduate Difference of Christoffel Symbols Transforms as Tensor
- binbagsss
- · Replies 7 ·
High School How does time dilation work mechanically?
- Grimble
- · Replies 21 ·
Undergrad What Happens When a Planet Nears the Speed of Light Near a Black Hole?
- John SpaceY
- · Replies 64 ·
High School Kinetic Energy of an Object Falling Into an Event Horizon
- Andrew Wright
- · Replies 11 ·
Graduate Why does removing the Shapiro delay approximation make the integral diverge?
- exmarine
- · Replies 6 ·
Graduate Can Photon Have Orbital Angular Momentum?
- Physics4Funn
- · Replies 9 ·
Undergrad The Simultaneity Paradox: Investigating Net Rotation of a Balanced Beam
- e2m2a
- · Replies 36 ·
High School Can someone tell me if I got this line from the Feynman lectures right?
- Rishabh Narula
- · Replies 21 ·
Undergrad Speed Difference of Time on Poles vs Equator of Earth and Other Planets
- some bloke
- · Replies 16 ·
High School Gravitational Time Dilation in L1 Point: Summed, Canceled or Else?
- Chris Miller
- · Replies 2 ·
Undergrad About the solution of the parallel transport equation
- Jianbing_Shao
- · Replies 14 ·
Undergrad Is the real acceleration in GR upward at Earth's surface?
- Karl Coryat
- · Replies 6 ·
High School Absolute Time, I know its wrong and all but tell me if I got it right
- Rishabh Narula
- · Replies 9 ·
High School Can Dropping Stuff Challenge Einstein's Relativity Theory?
- jedishrfu
- · Replies 2 ·
High School Misunderstanding of "proper velocity"
- etotheipi
- · Replies 17 ·
Undergrad Can p=mc apply to massless photons?
- Aaron121
- · Replies 15 ·
Undergrad E=mc^2 Mass: Rest Mass m0 vs Relativistic Mass γm0
- Aaron121
- · Replies 2 ·
High School Would Earth fly off into space if the Sun disappeared?
- Julius Ceasar
- · Replies 33 ·
High School Some questions about the Doppler Effect at high velocities
- neanderthalphysics
- · Replies 9 ·
Graduate Continuity Equation for fluid in a curved spacetime
- aliveone
- · Replies 18 ·
Undergrad What happens in the area between black holes before they collide
- tflahive
- · Replies 69 ·
High School What is Absolute Time and Space?
- Rishabh Narula
- · Replies 5 ·
High School Plotting the Space-Time Continuum: Is it Possible?
- FireAP
- · Replies 5 ·
Undergrad How it's known that the variational principle works for relativity
- kent davidge
- · Replies 25 ·
High School Clarification of Romer's Calculation
- etotheipi
- · Replies 2 ·
High School Does Lorentz contraction affect red and blue halves of a moving cylinder differently?
- AdirianSoan
- · Replies 4 ·
Graduate Stress-energy tensor of a rotating rod
- Ibix
- · Replies 21 ·
Graduate Does Birkhoff's theorem apply with a cosmological constant?
- pervect
- · Replies 4 ·
Undergrad Deriving AdS Poincare Coordinates from Global Coordinates
- formodular
- · Replies 2 ·
Undergrad Does Gravity Affect Mass Measurement in Flat Spacetime?
- AdirianSoan
- · Replies 11 ·
Graduate ANEC integral along null geodesics in wormhole spacetime
- wLw
- · Replies 22 ·
High School Why does the traveling twin age less if motion is relative?
- Robert Booth
- · Replies 16 ·
Graduate The derivation of the volume form in Ricci tensor
- bres gres
- · Replies 6 ·
Undergrad Muons Decaying on Mt Washington: Expert Answers
- bugatti79
- · Replies 5 ·
Undergrad Speed of Light in Inertial Ref Frames: Photon Perspective
- Saptarshi Sarkar
- · Replies 4 ·
Undergrad Momentum and energy calculation in special relativity
- liuxinhua
- · Replies 24 ·
Undergrad Metric compatibility? Why is it an additional property?
- George Keeling
- · Replies 6 ·
Undergrad Gravitational Waves: Difficulty Level of Study?
- kent davidge
- · Replies 7 ·
High School What are background and reference metrics in relativity?
- windy miller
- · Replies 2 ·
Graduate Calculating Nabla w V in General Relativity
- bres gres
- · Replies 9 ·
Graduate Proper time in Morris-Thorne traversable wormholes
- wLw
- · Replies 2 ·
Undergrad How Does Lorentz Theory Address the Concept of Velocity Becoming Zero?
- bos3yed651
- · Replies 2 ·
High School What is the positive energy theorem?
- windy miller
- · Replies 7 ·
Undergrad Why do objects fall due to time curvature, not space curvature?
- Gadhav
- · Replies 16 ·
Undergrad Who measures the meters and seconds in the speed of light?
- Gadhav
- · Replies 11 ·
Undergrad Is gravity a force even though it warps spacetime?
- Jehannum
- · Replies 15 ·
Undergrad What defines the initial frequency in SXS gravitational wave simulations?
- BillKet
- · Replies 2 ·
Undergrad Is the Nash embedding theorem useful for curved spacetime in GR?
- BWV
- · Replies 17 ·
High School Can a mass on a string be lowered past and pulled back from a black hole's event horizon?
- magneticanomaly
- · Replies 13 ·
Undergrad Parallel transport of a vector on a sphere
- bres gres
- · Replies 10 ·
Undergrad Can One Observe Anything Falling Into a Black Hole?
- Replusz
- · Replies 3 ·
Graduate Solving Covariant Derivative Notation Confusion
- Markus Kahn
- · Replies 2 ·
High School Can Info Travel FTL? Understanding Speed of Information
- Jenga_89
- · Replies 6 ·
High School Why does my length contraction calculation give expansion instead?
- makphi
- · Replies 12 ·
Undergrad Is General Relativity More General than Gravity?
- Demystifier
- · Replies 15 ·
Undergrad Does spacetime velocity equal escape velocity explain gravitational time dilation?
- Grav Velocity
- · Replies 37 ·
Undergrad Derivative consisting Levi-Civita
- vahdaneh
- · Replies 6 ·
Undergrad How to extract boost speeds and rotation angles from Lorentz boost matrices
- Athenian
- · Replies 4 ·
Graduate Meaning of the word "conserved" in relativity
- SiennaTheGr8
- · Replies 6 ·
Graduate Solved: Velocity of Isolated System in Different Inertial Sys.
- liuxinhua
- · Replies 9 ·
Undergrad Can point particles be smaller than the Planck length?
- jnorman34
- · Replies 6 ·
High School Lightwatch/Lightclock (Lichtuhr)
- Martin68
- · Replies 55 ·
Undergrad Observation of matter falling into Black Holes
- ObjectivelyRational
- · Replies 38 ·
High School Can infinite spacetime curvature lose energy via Hawking radiation?
- Castty
- · Replies 4 ·
High School What Would Light Look Like If Train Moved at > Speed of Light?
- sigr
- · Replies 12 ·
Undergrad GR: Clarifying Different Forms of the Metric for Self-Studiers
- Rollo
- · Replies 6 ·
High School Why does length contraction differ from Lorentz transformations?
- NoahsArk
- · Replies 52 ·
Undergrad Do These Equations Hold True Beyond Special Relativity?
- olgerm
- · Replies 17 ·