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

Graduate Simple question about time dilation in accelerated reference frames

  • enfield
  • · Replies 10 ·
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10

Undergrad How did light speed become the governor of relativity?

  • narrator
  • · Replies 31 ·
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31

Graduate SR: Questions on Time Synchronization & Relativity

  • goodabouthood
  • · Replies 6 ·
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6

Graduate Different Slices of Now Observable from Earth?

  • Vanadium90
  • · Replies 37 ·
2
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37

Graduate Can Negative Mass Really Defy Gravity?

  • stglyde
  • · Replies 9 ·
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9

Graduate What experiment shows that the universal speed limit is the same as light?

  • thenewmans
  • · Replies 3 ·
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3

Undergrad Why Is Light Speed a Limit for Spacecraft?

  • machine_slave
  • · Replies 11 ·
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11

Graduate I would like to see the math of something

  • JT73
  • · Replies 30 ·
2
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30

Graduate Question about how Time varies with Velocity

  • rsclafani
  • · Replies 4 ·
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4

Graduate Spacetime desynchronized in quantum realm?

  • stglyde
  • · Replies 2 ·
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2

Graduate Diagonal Metric and General Relativity: A Fundamental Question

  • isidrago
  • · Replies 3 ·
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3

Graduate What happens to stars in front of a falling observer entering a black hole?

  • Passionflower
  • · Replies 2 ·
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2

Graduate Does a Photon Traveling at Light Speed Imply Infinite Mass and Energy?

  • E=mc4
  • · Replies 30 ·
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Graduate Question of units of B, H in Gaussian system

  • Master J
  • · Replies 4 ·
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4

Undergrad I have a question for the masses. if you were traveling at 60 mph

  • trix5153
  • · Replies 20 ·
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20

Graduate Metric of 2 Bodies: Superposition & Resulting Tensor

  • tarquinius
  • · Replies 5 ·
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5

Graduate Can a Car's Stereo Still Function at the Speed of Light?

  • Ransom7D
  • · Replies 1 ·
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1

Graduate Understanding Inextendible Worldlines in Manifolds: Examples and Applications

  • Matterwave
  • · Replies 11 ·
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11

Mind-Bending Mirror Puzzle: Experience the Impossible in Bali

  • PatrickPowers
  • · Replies 5 ·
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5

Graduate Does time stop for a photon? Why is that a nonsensical question?

  • JamieForum
  • · Replies 51 ·
2
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51

Graduate Gravitational field conceptual question

  • PrakashPhy
  • · Replies 8 ·
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8

Graduate Calculating GPS Accuracy Using Special Relativity and General Relativity

  • godtripp
  • · Replies 1 ·
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1

Graduate What is the observed precession of Mercury?

  • utesfan100
  • · Replies 33 ·
2
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33

Graduate Can Time Dilation Allow for Survival of the Universe's Death?

  • Mind Bender
  • · Replies 9 ·
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9

Graduate Solving Sliding Clock Fun with Two Photons

  • Zula110100100
  • · Replies 11 ·
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11

Graduate How Does General Relativity Explain Earth's Shape and Gravity?

  • PatrickPowers
  • · Replies 6 ·
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6

Graduate Is Gravity Just Inertia in Disguise?

  • Gomjabbar
  • · Replies 2 ·
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2

Graduate Relativistic mass increase appearing to form a black hole vs. a real black hole

  • Meatbot
  • · Replies 9 ·
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9

Graduate Twins Paradox: The paradox within the paradox

  • YummyFur
  • · Replies 5 ·
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5

Graduate Studying special relativity and using the idea of four vectors

  • JFo
  • · Replies 8 ·
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8

Graduate Objects move into gravity=shorter time?

  • gabeeisenstei
  • · Replies 25 ·
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25

Graduate Lorentz Transformations Acceleration: A simple problem

  • Albertgauss
  • · Replies 2 ·
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2

Graduate A problem in special relativity with a surprising result

  • pervect
  • · Replies 4 ·
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4

Graduate The principle of inertia and hypothetical FTL particles

  • lalbatros
  • · Replies 5 ·
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5

Graduate Is a gravitational circuit possible?

  • Tosh5457
  • · Replies 12 ·
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12

Graduate Abraham's light momentum breaks special relativity?

  • sciencewatch
  • · Replies 153 ·
6
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153

Undergrad Can a human travel to distant stars? And other questions.

  • WindScars
  • · Replies 24 ·
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24

Graduate Solving the Assassin Paradox: A Q&A with Adrian

  • AdrianMay
  • · Replies 3 ·
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3

Graduate What is the effect of a neutron star's gravity on vertical rays of light?

  • penomade
  • · Replies 4 ·
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4

Graduate Twin Paradox: Who is Older - B or C?

  • Waaaaaaaa
  • · Replies 16 ·
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16

Graduate Usefulness of Kretschmann scalar

  • HolyCats
  • · Replies 5 ·
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5

High School List of different relative speeds?

  • JT73
  • · Replies 13 ·
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13

High School If light hits a mirror and then switches direction

  • seerskater
  • · Replies 5 ·
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5

Graduate FTL implies Backward Time Effect

  • stglyde
  • · Replies 13 ·
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13

Graduate About dark matter and the limits of the universe.

  • WindScars
  • · Replies 3 ·
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3

Undergrad Why cant an object travel faster than the speed of light?

  • homeylova223
  • · Replies 13 ·
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13

Graduate What are the differences between an object with mass 0 and mass > 0 ?

  • digi99
  • · Replies 4 ·
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4

Graduate What Do Upper and Lower Indices in Tensor Notation Signify?

  • taylrl3
  • · Replies 1 ·
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1

Graduate Einstein's original 'thought experiment'

  • M1keh
  • · Replies 19 ·
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19

Graduate Relativistic doppler effect - inconsistency in my derivations

  • osturk
  • · Replies 4 ·
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4

Graduate Why does light always travel at c in different reference frames?

  • Xilor
  • · Replies 6 ·
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6

Graduate 2nd order correction to gauge transformation

  • matt91a
  • · Replies 4 ·
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4

Graduate Does Time Dilation Apply to the Big Bang's Mass?

  • eddybob123
  • · Replies 1 ·
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1

Graduate The speed of light and the mass of a photon

  • JollyOlly
  • · Replies 24 ·
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24

Graduate Wald's definition of the Cauchy Horizon

  • Matterwave
  • · Replies 1 ·
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1

Graduate What if speed limit is slightly faster than light?

  • thenewmans
  • · Replies 8 ·
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8

Graduate Redshift and Weak equivalence principle

  • Zula110100100
  • · Replies 10 ·
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10

Graduate What is the Metric Tensor and How is it Used in Tensors?

  • Mazulu
  • · Replies 52 ·
2
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52

High School Explaining Causality: How and Why it Works

  • Casco
  • · Replies 1 ·
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1

Graduate Noob question about lorentz factor

  • Waaaaaaaa
  • · Replies 6 ·
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6

Graduate How do accelerometers measure acceleration without using relative motion?

  • Zula110100100
  • · Replies 38 ·
2
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38

Graduate How Does Gravity Store Arbitrarily Negative Energy?

  • Lapidus
  • · Replies 3 ·
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3

Graduate How to explain time dilation easily to others, maybe like this ?

  • digi99
  • · Replies 19 ·
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19

Graduate Derivation of relativistic acceleration and momentum

  • phys23
  • · Replies 13 ·
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13

Graduate Variational methods on Lagrangians (D'Inverno Chapter 11) - continued

  • TerryW
  • · Replies 21 ·
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21

Graduate The Illusion of Time and distant observers

  • mjames
  • · Replies 20 ·
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20

Graduate Black holes and time dilation around the event horizon

  • Domisterwoozy
  • · Replies 38 ·
2
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38

Graduate Speed of light - why is it a constant?

  • Shenstar
  • · Replies 53 ·
2
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53

Graduate Reflecting light seen by two moving persons, explanation already known?

  • digi99
  • · Replies 20 ·
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20

Undergrad Measuring Distance to a Star One Light Year Away at 0.5c Speed

  • PatrickPowers
  • · Replies 2 ·
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2

Graduate You approach a planet at a velocity near c, what do you see?

  • cowmoo32
  • · Replies 3 ·
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3

Graduate Is Time Speeding Up? The Possibility of a Universally Accelerating Clock

  • dshaw
  • · Replies 4 ·
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4

Graduate Is SR and GR Time Dilation the same thing?

  • goodabouthood
  • · Replies 50 ·
2
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50

Graduate Mathematical Basis for Learning Relativity

  • gordonj005
  • · Replies 1 ·
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1

Graduate Can time slow down infinitely in black holes?

  • Xilor
  • · Replies 6 ·
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6

Graduate Question about Brian Greene's wormhole illustration in Fabirc of the Cosmos

  • Caeru
  • · Replies 7 ·
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7

Graduate Length contraction and accelerating frames

  • yoron
  • · Replies 2 ·
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2

Graduate How does relativity explain the different experiences of now for two observers?

  • jtaravens
  • · Replies 18 ·
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18

Graduate Why so many definitions of an inertial frame?

  • peter46464
  • · Replies 13 ·
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13

Graduate Scientific measurement standards

  • mes314159
  • · Replies 2 ·
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2

Graduate Can Quantum Entanglement Enable Time Loops and Superluminal Communication?

  • stglyde
  • · Replies 2 ·
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2

Graduate What Are Lapse Functions in 3+1 General Relativity?

  • Mazulu
  • · Replies 1 ·
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1

Undergrad Time Dilation - Relative to Light Speed or Reference Point - I'm Confused?

  • Dickie_Boy
  • · Replies 9 ·
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9

Graduate Is there really an absolute reference frame?

  • pche8701
  • · Replies 22 ·
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22

Undergrad Is it Possible for A to See B Moving Faster?

  • JT73
  • · Replies 6 ·
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6

Graduate Finding Equations of Motion from the Stress Energy Tensor

  • Matterwave
  • · Replies 49 ·
2
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49

Graduate Why Is General Relativity Hard to Work With?

  • PatrickPowers
  • · Replies 2 ·
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2

Graduate Symmetry in special relativity

  • PatrickPowers
  • · Replies 9 ·
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9

Graduate The Lorentz Transformations and a Few Concerns

  • Anamitra
  • · Replies 43 ·
2
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43

Graduate Triplet paradox: where's the error in my logic?

  • gespex
  • · Replies 18 ·
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18

Graduate Does Relativistic Mass Change at the Speed of Light?

  • jishitha
  • · Replies 4 ·
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4

Graduate How does the Twin Paradox demonstrate the effects of general relativity?

  • PatrickPowers
  • · Replies 2 ·
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2

Graduate Twin Paradox Explanation Needed

  • jam.muskopf
  • · Replies 8 ·
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8

Graduate Precession of the LRL Vector in SR

  • utesfan100
  • · Replies 2 ·
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2

Graduate Different values for the inertia of a moving object?

  • csmcmillion
  • · Replies 5 ·
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5

Graduate Going back in space vs Going back in time

  • Shannon185
  • · Replies 14 ·
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14

Graduate Acceleration thought experiment

  • Zula110100100
  • · Replies 1 ·
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1

Undergrad Michelson-Morley experiment doubts

  • Highwaydude
  • · Replies 3 ·
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3

Graduate Is SOL infinite? (from its own point of view)

  • Lukas_23
  • · Replies 12 ·
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12

Undergrad Newton's Second Law: Acceleration Proportional to Force

  • mzntr
  • · Replies 20 ·
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20