Special and General Relativity Forum

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

  • Sticky

Insights When Discussing the Twin Paradox: Read This First

  • PeterDonis
  • · Replies 2 ·
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2
  • Sticky

Graduate Relativity Insights: FAQs on Photons, Gravity, Time Dilation, and More!

  • Greg Bernhardt
  • · Replies 4 ·
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4

Graduate Is photon frequency intrinsic or observer-dependent?

  • Roberto Pavani
  • · Replies 13 ·
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13

Undergrad Homogeneity of space and time in Landau & Lifshitz

  • Mike_bb
  • · Replies 21 ·
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21

High School RocketGirl receives a radio message from Earth

  • smaricic
  • · Replies 24 ·
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24

Undergrad Definition of distance in GTR

  • wolfgang6444
  • · Replies 4 ·
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4

Graduate Square root of Kretschmann scalar: any known uses?

  • Roberto Pavani
  • · Replies 7 ·
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7

Undergrad Why can coefficient "a" between spacetime intervals depend on velocity between systems?

  • Mike_bb
  • · Replies 42 ·
2
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42

Graduate Why is there gauge freedom in ADM formalism?

  • concerned citizen
  • · Replies 3 ·
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3

Undergrad Why is gravity a fictitious force?

  • Mike_bb
  • · Replies 153 ·
6
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153

Graduate Applicability of Spin-2 Field Interpretation of GR

  • Matterwave
  • · Replies 5 ·
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5

Undergrad Simplified Special Relativity: Looking to get roasted on this

  • DavidMiranda
  • · Replies 61 ·
3
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61
  • Featured

Undergrad Some notes on LET for reference

  • robphy
  • · Replies 14 ·
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14

High School Can Curved Spacetime Enable Faster-Than-Light Travel?

  • Marcarious Thomas
  • · Replies 13 ·
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13

High School A simple Black Hole question I can't find an answer for

  • davel18
  • · Replies 39 ·
2
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39

Undergrad Why is the Lorentz Force always perpendicular to velocity?

  • JiuBeixin
  • · Replies 56 ·
2
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56

High School For a lighter take on relativity....

  • Nugatory
  • · Replies 4 ·
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4

Graduate Error in Landau-Lifshitz Vol 2, Fig. 20, page 310

  • Kostik
  • · Replies 9 ·
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9

Graduate The Lagrangian of a free particle ##L=-m \, ds/dt##

  • Kostik
  • · Replies 5 ·
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5

Graduate Singularity Theorems

  • Matterwave
  • · Replies 8 ·
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8

High School The problem of energy appearing out of nowhere

  • DanteKennedy
  • · Replies 33 ·
2
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33

Undergrad Special relativity and diffracting beams

  • calacone
  • · Replies 3 ·
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3

Undergrad Why did the photon lose its license?

  • drzbigniew31
  • · Replies 8 ·
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8

Undergrad Could the (SR) forbidden photon's own referential mean something?

  • drzbigniew31
  • · Replies 4 ·
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4

High School A question about special relativity

  • BadgerBadger92
  • · Replies 9 ·
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9

High School Do Dark Energy and the Casimir effect indicate Exotic Matter could exist?

  • okabe rintarou
  • · Replies 16 ·
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16

Undergrad Does the Alcubierre drive shorten distances?

  • Jaime Rudas
  • · Replies 171 ·
6
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171

High School Calculating an impossible reference frame as my own homework problem

  • Ignorantsmith12
  • · Replies 12 ·
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12

Graduate Is the variation of the metric ##\delta g_{\mu\nu}## a tensor?

  • Kostik
  • · Replies 68 ·
3
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68

High School Lorentz Transformation of Electric & Magnetic Fields Visualized

  • SiennaTheGr8
  • · Replies 26 ·
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26

Graduate How valid is the Block Universe theory?

  • DarkloidNeos
  • · Replies 71 ·
3
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71

Undergrad Special Relativity in a closed universe

  • kochanskij
  • · Replies 9 ·
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9

Undergrad Black hole questions

  • EdwardRo
  • · Replies 29 ·
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29

Undergrad Relativistic Uniform Circular Motion

  • renormalize
  • · Replies 15 ·
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15

Undergrad KE of rotating disc

  • Ibix
  • · Replies 87 ·
3
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87

Help with problem in MIT open course general relativity

  • DavidL070949
  • · Replies 18 ·
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18

Graduate Aether equal to spacetime?

  • quark69
  • · Replies 5 ·
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5

Undergrad Another Time Dilation Question

  • InquiringMind
  • · Replies 42 ·
2
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42

Graduate Struct parallels between curvature behavior/abstract geometric cycles?

  • Thor Jackson
  • · Replies 21 ·
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21

Graduate Rotating Disk Method to Attain Light Speed?

  • aLeaf
  • · Replies 40 ·
2
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40

Graduate Feynman's bug (hot plate) in generality

  • gerald V
  • · Replies 5 ·
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5

High School Rotating disc: tidal relativity across surface of disc

  • red_ed
  • · Replies 14 ·
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14

Undergrad Differentiation of the connections

  • JimWhoKnew
  • · Replies 14 ·
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14

Graduate Gravitational wave propagation in GR - follow up

  • cianfa72
  • · Replies 37 ·
2
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37

Undergrad Relativistic Space Travel: Optimizing Proper Time [Project Hail Mary]

  • rocky
  • · Replies 36 ·
2
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36

Graduate Topological constrains for the solutions of EFE

  • cianfa72
  • · Replies 31 ·
2
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31

Undergrad With gravitational lensing, which way is down?

  • .Scott
  • · Replies 29 ·
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29

Graduate What Exactly Is The Physical Content Of Maxwell's Equations?

  • bhobba
  • · Replies 21 ·
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21

Undergrad Relativity, time, and quantum mechanics

  • anuttarasammyak
  • · Replies 47 ·
2
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47

Undergrad Raising and lowering indices using metric tensor

  • cianfa72
  • · Replies 9 ·
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9

Graduate About the definition of Born rigidity

  • cianfa72
  • · Replies 38 ·
2
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38

Undergrad Euclidean geometry and gravity

  • raagamuffin
  • · Replies 169 ·
6
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169

Graduate Spacetime interval in Galilean relativity

  • LightPhoton
  • · Replies 8 ·
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8

Undergrad EPR revisited

  • anuttarasammyak
  • · Replies 38 ·
2
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38

Graduate Orbits of a photon that can't quite cross the photon sphere of a BH

  • pervect
  • · Replies 1 ·
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1

Undergrad Looking closely at the descent into a black hole

  • .Scott
  • · Replies 51 ·
2
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51

Undergrad One way speed of light

  • HansH
  • · Replies 26 ·
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26

Undergrad The paradox of symmetrical time dilation

  • spacecadet2563
  • · Replies 15 ·
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15

Graduate Can a causal or time-like structure emerge without assuming a metric?

  • DavidMartin
  • · Replies 56 ·
2
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56

Undergrad Why is ##(t_1'-t_2')^2## constant in proof(invariance of intervals)?

  • Mike_bb
  • · Replies 2 ·
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2

Undergrad Ships passing each other at near light speed

  • Skaperen
  • · Replies 5 ·
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5

Graduate Does a truly static "Block Universe" allign with "experience" aspect?

  • OmniThoughts
  • · Replies 2 ·
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2

Graduate Regarding Relativity of Simultaneity, is non-local "now" impossible?

  • OmniThoughts
  • · Replies 2 ·
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2

Undergrad How many sorts of time are there in physics?

  • pervect
  • · Replies 12 ·
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12

Undergrad Einstein's time formula

  • spacecadet2563
  • · Replies 3 ·
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3

Graduate Stability of the Kerr–Newman black hole under small perturbations

  • zhumataidana22
  • · Replies 2 ·
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2

High School Light & Time

  • spacecadet2563
  • · Replies 10 ·
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10

Undergrad Photons & Time: t=0 What?

  • spacecadet2563
  • · Replies 23 ·
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23

High School Time travel without paradox

  • spacecadet2563
  • · Replies 7 ·
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7

Graduate Dirac's 1958 lecture on spinors

  • grzz
  • · Replies 4 ·
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4

Graduate Another derivation from Quantum Fields on curved spacetime

  • mad mathematician
  • · Replies 1 ·
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1

Undergrad Gravitational analog of electromagnetic force

  • synch
  • · Replies 20 ·
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20

Undergrad Macroscopic objects in free-fall

  • cianfa72
  • · Replies 32 ·
2
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32

Undergrad Light clock treating horizontal and vertical motion differently?

  • foxeamonn1969
  • · Replies 38 ·
2
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38

Undergrad Linear vs rotary motion

  • Physicist248
  • · Replies 28 ·
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28

High School True static equilibrium and effects on time

  • atnu8
  • · Replies 25 ·
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25

High School Car spinning on a frictionless sheet of ice = absolute motion?

  • ESponge2000
  • · Replies 15 ·
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15

High School Relativistic simultaneity and effects on time

  • pervect
  • · Replies 9 ·
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9

Undergrad Acceleration calculation in Special Relativity

  • Bob Walance
  • · Replies 5 ·
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5

High School Need tips to understand Relativistic Energy in Special Relativity

  • mcastillo356
  • · Replies 6 ·
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6

High School Why does a Wormhole not look like an hourglass?

  • Aayush Thakur
  • · Replies 12 ·
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12

High School Traveling through space at zero km/s

  • mike9731
  • · Replies 11 ·
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11

Graduate Kruskal Coordinates in Schwartzchild metric

  • mad mathematician
  • · Replies 9 ·
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9

Undergrad Convention for writing $\binom{1}{1}$ tensors in matrix form?

  • Kick-Stand
  • · Replies 8 ·
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8

Undergrad Derive the Lorentz transformation in Minkowski four-dimensional spacetime spacetime

  • Xinze
  • · Replies 8 ·
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8

Undergrad Relational event horizons?

  • scakpinar
  • · Replies 11 ·
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11

Graduate Stumped by a Lagrangian in Einstein's 1916 paper

  • Isaek_
  • · Replies 3 ·
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3

High School Am I understanding the concept of proper frame of reference?

  • mcastillo356
  • · Replies 33 ·
2
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33

High School Why is the constant speed of light so unique?

  • PLAGUE
  • · Replies 19 ·
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19

Undergrad Synchronizing clocks in an inertial frame if light is anisotropic

  • James Hasty
  • · Replies 67 ·
3
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67

High School Why Do Events Freeze For Me at the Speed of Light?

  • RobbyQ
  • · Replies 4 ·
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4

Undergrad Revisiting the Light Clock

  • DmitryS
  • · Replies 25 ·
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25

Undergrad Question about Parallel Transport

  • geordief
  • · Replies 58 ·
2
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58

High School Thought Experiment: Behavior of shadow of object moving at speed c

  • Mohiaz
  • · Replies 14 ·
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14

Undergrad Can a Gyroscope in a Satellite Detect Orbit?

  • zanick
  • · Replies 51 ·
2
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51

Undergrad Physical Interpretation of Frame Field

  • cianfa72
  • · Replies 41 ·
2
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41

Undergrad Is this another "paradox" or a veritasium mistake?

  • mgkii
  • · Replies 28 ·
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28

Graduate Assumptions of Hawking-Penrose 1970 Singularity Theorem

  • Cerenkov
  • · Replies 35 ·
2
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35

Undergrad Gyroscope angular momentum: direction and curvature

  • HansH
  • · Replies 2 ·
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2

Undergrad Does a person's mass affect time?

  • Johndough_
  • · Replies 6 ·
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6