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

High School What Is the Gravitational Memory Effect?

  • tionis
  • · Replies 16 ·
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16

Undergrad Schwarzschild radius of all matter created at the Big Bang

  • Ontophobe
  • · Replies 1 ·
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1

Undergrad How Does Length Contraction Influence Electromagnetic Forces?

  • djsourabh
  • · Replies 5 ·
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5

Undergrad Why is energy not Lorentz invariant?

  • Frank Castle
  • · Replies 31 ·
2
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31

Undergrad At what point does classical EM become relativistic EM?

  • Electric to be
  • · Replies 20 ·
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20

Undergrad Lorentz Transform: Justifying Use in Acceleration

  • Glenda
  • · Replies 4 ·
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4

High School Why do we know space-time is locally flat?

  • fxdung
  • · Replies 4 ·
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4

High School Why does time dilation apply only to the traveling twin in the twin paradox?

  • Bennie Grezlik
  • · Replies 52 ·
2
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52

Graduate Deriving Amplification of Images in Schwartzschild Metric

  • directbydirecct
  • · Replies 1 ·
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1

Graduate Linearized metric for GW emitting orbiting bodies

  • pervect
  • · Replies 31 ·
2
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31

Graduate Momentum Constraint in GR: ADM Formalism

  • Sergei65
  • · Replies 3 ·
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3

Undergrad Why is gravitational potential energy halved in Einstein's field equations?

  • t_r_theta_phi
  • · Replies 2 ·
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2

Undergrad What does the Einstein tensor actually tell you?

  • space-time
  • · Replies 7 ·
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7

High School Recovering length units in Schwarzschild geometry with c = G = 1

  • needved
  • · Replies 2 ·
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2

High School Is Time Perception Similar to Browsing the Web?

  • pBrane
  • · Replies 15 ·
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15

Undergrad Noticing CTC's / time travel in a Godel space-time

  • space-time
  • · Replies 5 ·
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5

Graduate Riemann Tensor Equation: Simplifying the Riemann-Christoffel Tensor

  • redtree
  • · Replies 5 ·
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5

Undergrad Does a metric g induce the metric topology?

  • nateHI
  • · Replies 10 ·
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10

High School Gravitational time dilation depth charge

  • tionis
  • · Replies 24 ·
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24

Undergrad Modeling the effects of GW and the "Earth Frame"

  • GeorgeDishman
  • · Replies 66 ·
3
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66

Undergrad Can one determine the velocity of a photon in the fourth dimension using limits?

  • physics22
  • · Replies 12 ·
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12

Undergrad Conformal transformation of the line element

  • physicality
  • · Replies 2 ·
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2

High School Why doesn't the universe spin apart when I rotate?

  • WCOLtd
  • · Replies 12 ·
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12

Graduate Relationship between metric tensor and position vector

  • redtree
  • · Replies 2 ·
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2

Undergrad Alice Sees Sudden Acceleration at Event Horizon

  • gl0Wyrm
  • · Replies 14 ·
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14

Undergrad Lorentz boost of a spinning ring in special relativity

  • Juxtaroberto
  • · Replies 13 ·
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13

Undergrad Relativistic thrust and specific impulse at 1% light speed

  • Sebastiaan
  • · Replies 12 ·
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12

High School Does light travel at c between two detectors moving toward its source?

  • Quandry
  • · Replies 53 ·
2
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53

Graduate Prep for Hawking/Ellis: Point Set Topology Needed

  • Andrew Kim
  • · Replies 1 ·
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1

Undergrad Comparing post-Newtonian predictions with detected gravitational waves

  • Vrbic
  • · Replies 2 ·
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2

Undergrad What is the Concept of Velocity and Acceleration in General Relativity?

  • AngPhysics
  • · Replies 2 ·
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2

Undergrad What Actually Happens vs What You See in SR

  • Afterthought
  • · Replies 6 ·
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6

Insights Spacetime Diagrams of Light Clocks [comments]

  • robphy
  • · Replies 22 ·
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22

High School Box in gravitational field

  • Einstein's Cat
  • · Replies 17 ·
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17

High School Could light be slowed down and be observed

  • RandyD123
  • · Replies 22 ·
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22

Undergrad What is the velocity of the photon through the fourth dimension x4?

  • AstroMath
  • · Replies 14 ·
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14

High School Light follows Geodesics-Spacetime-Big Bang-Time dilation

  • chester20080
  • · Replies 11 ·
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11

Undergrad What happens during acceleration in time dilation?

  • Electric to be
  • · Replies 19 ·
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19

High School What can you calculate with the Schwarzschild metric?

  • AleksanderPhy
  • · Replies 14 ·
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14

Graduate Relativistic conduction current density?

  • ChristopherMDS
  • · Replies 3 ·
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3

Undergrad What are the independent components of the Riemann tensor

  • Andrew Kim
  • · Replies 7 ·
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7

Undergrad Classical formula for radar Doppler shift

  • penelopa
  • · Replies 17 ·
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17

Graduate Recognize 1-Way Horizon Coordinate-Independently?

  • strangerep
  • · Replies 12 ·
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12

Graduate Is there a mathematical proof for the existence of black holes?

  • parshyaa
  • · Replies 9 ·
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9

Undergrad Christoffel symbols transformation law

  • guitarphysics
  • · Replies 6 ·
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6

Graduate Hawking and Bekenstein derivation of black hole entropy from surface area

  • quickAndLucky
  • · Replies 4 ·
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4

Undergrad Can black holes form if time stops at the event horizon?

  • Cobalt101
  • · Replies 4 ·
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4

High School Can 5D Kaluza-Klein Theory Be Adapted for 2D Space-Time Models?

  • Spinnor
  • · Replies 12 ·
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12

Undergrad A light wave and a sound wave travelling together

  • freshnfree
  • · Replies 7 ·
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7

Undergrad Is Anything Truly at Rest in Every Frame of Reference?

  • parshyaa
  • · Replies 3 ·
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3

High School If in a lift we can tell if acceleration is due to g or to a push

  • alba
  • · Replies 4 ·
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4

High School Is there an opposite phenomenon for time dilation ?

  • steveJOBS
  • · Replies 2 ·
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2

High School Time on 1st & 2nd Floors: Gravity & Light Measurement

  • NewToThis
  • · Replies 3 ·
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3

High School How can we derive the value of energy in rest mass and the relationship to c^2?

  • alba
  • · Replies 19 ·
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19

Graduate Weyl Vacua Solutions to GR: Derivation from Riemann Tensor

  • redtree
  • · Replies 1 ·
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1

Undergrad Solving Mass-Speed Relation Proof Challenges

  • anachin6000
  • · Replies 5 ·
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5

High School What is the difference between curved spacetime and a field?

  • alba
  • · Replies 7 ·
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7

Undergrad Why does F=ma break down in special relativity at high speeds?

  • ReptileBaird
  • · Replies 7 ·
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7

Undergrad Is gravity really not a force according to the weak equivalence principle?

  • Figaro
  • · Replies 7 ·
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7

Undergrad What coordinate basis and geometry does the Gödel solution metric have?

  • space-time
  • · Replies 1 ·
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1

High School Which experiment proved the speed of light is invariant in vacuum?

  • freshnfree
  • · Replies 15 ·
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15

Undergrad Past Existence: Can Conjectures Be Tested?

  • Randy Subers
  • · Replies 3 ·
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3

High School Prerequisites for studying special relativity at 6th form level

  • TheAnt
  • · Replies 8 ·
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8

High School Why does sunlight bend during a solar eclipse?

  • parshyaa
  • · Replies 15 ·
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15

Undergrad Is There a Mistake in My Understanding of Planck Units and Dimensional Analysis?

  • facenian
  • · Replies 11 ·
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11

High School Can you explain GR without math?

  • alba
  • · Replies 30 ·
2
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30

Undergrad Trick for Remembering Schwarzschild Christoffel's/EFE's?

  • bolbteppa
  • · Replies 4 ·
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4

High School Is gravity only attractive, or does a repulsive force exist?

  • SaltburnRhys
  • · Replies 5 ·
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5

Undergrad Speed of light and speed of sound both constant

  • freshnfree
  • · Replies 38 ·
2
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38

High School Why do different observers measure different detection rates for the same photon?

  • AstroMath
  • · Replies 20 ·
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20

Undergrad Morris-Thorne Wormhole Metric Terms

  • space-time
  • · Replies 9 ·
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9

Undergrad Correctly Using Lorentz Transformations: A Special Relativity Problem

  • JuanC97
  • · Replies 8 ·
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8

Undergrad Physical meaning of the inner ergosurface and CTCs in Kerr black holes

  • Markus Hanke
  • · Replies 14 ·
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14

Undergrad Uniform acceleration and hyperbola

  • mertcan
  • · Replies 11 ·
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11

Undergrad Could I travel to andromeda in my lifetime?

  • tomasbede
  • · Replies 10 ·
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10

Undergrad Stupid question on index lowering and raising using metric

  • smodak
  • · Replies 17 ·
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17

Graduate Einstein Hilbert action integral

  • mertcan
  • · Replies 32 ·
2
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32

Undergrad What is an angle deficit in the curved space in GR?

  • felicja
  • · Replies 28 ·
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28

High School How are matter and spacetime connected above the Planck scale?

  • gva
  • · Replies 2 ·
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2

Undergrad Are There Black Holes in Galaxy Clusters?

  • BadgerBadger92
  • · Replies 5 ·
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5

Undergrad LIGO light changes frequency not wavelength

  • exponent137
  • · Replies 105 ·
4
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105

Undergrad Radio Comm Between 2 Points Diff Gravity: True?

  • Hongo
  • · Replies 3 ·
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3

High School Nobel Prize in Physics for Relativity?

  • Deepak K Kapur
  • · Replies 6 ·
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6

High School Energy Stored in Charged Capacitor: Kaluza-Klein Theory

  • Spinnor
  • · Replies 3 ·
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3

Graduate Domain Wall Geometries: Continuous Coordinates, Discontinuous Metric

  • Roy_1981
  • · Replies 3 ·
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3

Undergrad Why can't you use Simultaneity when doing Length Contraction

  • Afterthought
  • · Replies 13 ·
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13

Graduate Lorentz Fitzgerald contraction

  • Ritika
  • · Replies 8 ·
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8

Undergrad Need for GR: Historical Indications

  • greypilgrim
  • · Replies 12 ·
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12

Undergrad Schwarzschild line element and gravitational time dilation in a worked example

  • space-time
  • · Replies 10 ·
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10

High School Observeving Black Hole and Time Dilation Question

  • Seiten Maoh
  • · Replies 15 ·
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15

Undergrad Newtonian 4-Momentum Norm Analogue

  • greypilgrim
  • · Replies 5 ·
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5

Undergrad Why does Cox & Forshaw consider s^2 = (ct)^2 - x^2 in the spacetime interval?

  • EveningLight
  • · Replies 4 ·
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4

Graduate Why require metric compatibility in an affine connection

  • nearlynothing
  • · Replies 28 ·
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28

High School How does a gravitational field affect the dimensions of a box?

  • Einstein's Cat
  • · Replies 7 ·
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7

Undergrad Total Energy of Particle in Potential: SR Explanation

  • greypilgrim
  • · Replies 4 ·
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4

Undergrad Did the Big Bang separate space and time

  • willem govaerts
  • · Replies 4 ·
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4

Undergrad Vector Transformation Law and Vector Spaces: Is it Abuse?

  • Rburto
  • · Replies 1 ·
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1

Undergrad Lines of simultaneity in Twin Paradox spacetime diagram

  • soothsayer
  • · Replies 8 ·
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8

High School Would confining photons to a box the size of a Planck volume affect their speed?

  • jonatron5
  • · Replies 17 ·
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17

Undergrad What does the Ricci tensor measure in Einstein's field equations?

  • AleksanderPhy
  • · Replies 4 ·
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4