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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.

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High School Why does light travels in all directions?

Jul 31, 2015 · Replies 1 · Jul 31, 2015

Replies: 1

Views: 4K

Graduate Studying Special Features in Metrics: Tensors & Differential Geom.

Jul 30, 2015 · Replies 3 · Jul 30, 2015

Replies: 3

Views: 2K

Graduate Weyl tensor for the Godel metric interpretation

Jul 21, 2015 · Replies 26 · Jul 30, 2015

Replies: 26

Views: 5K

Graduate Does a Photon Experience Time or Space During Travel?

Jun 13, 2015 · Replies 32 · Jul 30, 2015

2

Replies: 32

Views: 4K

Graduate General Lorentz transformation, spatial vector components

Jul 29, 2015 · Replies 10 · Jul 30, 2015

Replies: 10

Views: 4K

Graduate Meaning of r in Schwarzchild coordinates

Jul 25, 2015 · Replies 56 · Jul 30, 2015

2

Replies: 56

Views: 5K

Graduate Train Experiment Problem: Solve Derailment Mystery!

Jul 30, 2015 · Replies 4 · Jul 30, 2015

Replies: 4

Views: 1K

Graduate Traveling near the speed of light

Jul 27, 2015 · Replies 69 · Jul 30, 2015

3

Replies: 69

Views: 8K

Graduate Describe the mechanism in GR causing *Space* expansion

Jul 28, 2015 · Replies 22 · Jul 30, 2015

Replies: 22

Views: 3K

Graduate What Happens to Euler-Lagrange in Field Theories (ADM)?

Jul 28, 2015 · Replies 4 · Jul 30, 2015

Replies: 4

Views: 1K

Graduate Does the Hubble expansion of space have a preferred frame?

Jul 20, 2015 · Replies 13 · Jul 29, 2015

Replies: 13

Views: 2K

Graduate Understanding the Doppler Effect: Formula and Examples for Light Waves

Jul 19, 2015 · Replies 50 · Jul 28, 2015

2

Replies: 50

Views: 6K

Graduate Twins Paradox: Nature Cheats but B Gets Fooled

Jul 27, 2015 · Replies 6 · Jul 28, 2015

Replies: 6

Views: 2K

Graduate Doubt in Relativity of Simultaneity

Jul 23, 2015 · Replies 46 · Jul 28, 2015

2

Replies: 46

Views: 6K

Graduate Torsion Scalar and Symmetries of Torsion Tensor

Jul 13, 2015 · Replies 5 · Jul 28, 2015

Replies: 5

Views: 2K

High School Time Travel - Does It Create a New Dimension?

Jul 27, 2015 · Replies 6 · Jul 27, 2015

Replies: 6

Views: 2K

High School Smallest Schwarzschild Radius: Theory & Facts

Jul 26, 2015 · Replies 12 · Jul 27, 2015

Replies: 12

Views: 2K

Graduate What Are the Differences Between Space-like and Time-like Events in Spacetime?

Jul 25, 2015 · Replies 8 · Jul 26, 2015

Replies: 8

Views: 2K

Graduate Why do diffeomorphic manifolds have physically identical properties?

Jul 20, 2015 · Replies 12 · Jul 26, 2015

Replies: 12

Views: 5K

Graduate Why does imaginary time behave like space?

Jul 25, 2015 · Replies 9 · Jul 26, 2015

Replies: 9

Views: 2K

Graduate Space-intervals, proper time, and proper distance

Jul 26, 2015 · Replies 5 · Jul 26, 2015

Replies: 5

Views: 4K

Graduate Measuring distance, speed and clock

Jun 28, 2015 · Replies 114 · Jul 26, 2015

4

Replies: 114

Views: 10K

Graduate Solving Exercise 13.7 MTW Using Light Signals

Jul 25, 2015 · Replies 2 · Jul 26, 2015

Replies: 2

Views: 1K

Graduate Special Relativity Train Scenario

Jul 23, 2015 · Replies 4 · Jul 25, 2015

Replies: 4

Views: 2K

Graduate Measuring Speed with Doppler Effect: Questions and Challenges

Jul 25, 2015 · Replies 9 · Jul 25, 2015

Replies: 9

Views: 2K

Graduate Doppler Effect in Relativity: Mirror vs Lamp

Jul 25, 2015 · Replies 5 · Jul 25, 2015

Replies: 5

Views: 2K

Graduate Is There a Connection Between the Higgs Field and Relativity's Time Distortion?

Jul 24, 2015 · Replies 4 · Jul 25, 2015

Replies: 4

Views: 2K

Graduate Stationary/extremal L for timelike/null/spacelike geodesics

Jul 12, 2015 · Replies 42 · Jul 24, 2015

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Replies: 42

Views: 6K

Graduate Simultaneity of Events: Understanding Observer Perspectives on Time

Jul 22, 2015 · Replies 18 · Jul 24, 2015

Replies: 18

Views: 3K

Graduate Consequences of space-/time-/light-like separations

Jul 23, 2015 · Replies 4 · Jul 23, 2015

Replies: 4

Views: 2K

High School Speed of Light, Rapidity & Cantor's Infinities

Jul 23, 2015 · Replies 4 · Jul 23, 2015

Replies: 4

Views: 2K

Graduate Generic Soliton Solution Periodicity: Restrictions & Examples

Jul 23, 2015 · Replies 2 · Jul 23, 2015

Replies: 2

Views: 1K

Graduate D'Alembert operator is commute covariant derivative?

Jul 22, 2015 · Replies 3 · Jul 23, 2015

Replies: 3

Views: 4K

Graduate Time: Travelling Twins vs Black Hole Gravity

Jul 22, 2015 · Replies 5 · Jul 22, 2015

Replies: 5

Views: 1K

Undergrad Particles with mass can't reach speed of light?

Jul 17, 2015 · Replies 18 · Jul 22, 2015

Replies: 18

Views: 3K

Graduate Coincidence of spacetime events & frame independence

Jul 16, 2015 · Replies 41 · Jul 22, 2015

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Replies: 41

Views: 5K

Graduate Normal Vector for Null Surfaces: How to Define and Fix it Completely?

Jul 21, 2015 · Replies 4 · Jul 21, 2015

Replies: 4

Views: 3K

Graduate Proving Maxwell's Equations are Lorentz Invariant

Jul 20, 2015 · Replies 5 · Jul 21, 2015

Replies: 5

Views: 3K

Graduate Speed of Light - Questions & Answers

Jul 18, 2015 · Replies 11 · Jul 21, 2015

Replies: 11

Views: 2K

Graduate Athlete Holding a 20m Pole in a 10m House

Jul 21, 2015 · Replies 1 · Jul 21, 2015

Replies: 1

Views: 1K

Graduate How Does Time Dilation Affect Hawking Radiation Emission Near Black Holes?

Jul 17, 2015 · Replies 4 · Jul 20, 2015

Replies: 4

Views: 2K

Graduate Measuring One-Way Speed of Light

Apr 22, 2014 · Replies 48 · Jul 20, 2015

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Replies: 48

Views: 9K

Graduate Spacetime Curvature: Does It Affect Objects?

Jul 16, 2015 · Replies 10 · Jul 19, 2015

Replies: 10

Views: 2K

Graduate Force Transform Applying: Question on a Specific Case

Jul 19, 2015 · Replies 1 · Jul 19, 2015

Replies: 1

Views: 925

Graduate Let's Sort Out This Gravity Thing - c And All That

Jul 15, 2015 · Replies 14 · Jul 19, 2015

Replies: 14

Views: 2K

Graduate Is All Motion Relative to Feynman's Path Integral?

Jul 19, 2015 · Replies 1 · Jul 19, 2015

Replies: 1

Views: 960

Graduate Hamiltonian of General Relativity

Jul 18, 2015 · Replies 1 · Jul 18, 2015

Replies: 1

Views: 1K

Graduate New MINOS measurement of neutrinos speed through earth

Jul 17, 2015 · Replies 12 · Jul 18, 2015

Replies: 12

Views: 2K

Graduate How to determine which clock runs slower in relativity?

Jul 11, 2015 · Replies 26 · Jul 17, 2015

Replies: 26

Views: 5K

Undergrad Effects of Velocity Aberration?

Jul 17, 2015 · Replies 16 · Jul 17, 2015

Replies: 16

Views: 2K

Undergrad Speed of Light: Does Intensity & Frequency Affect It?

Jul 16, 2015 · Replies 14 · Jul 17, 2015

Replies: 14

Views: 2K

Graduate Is speed of light in vacuum an axiom in relativity?

Jul 16, 2015 · Replies 11 · Jul 17, 2015

Replies: 11

Views: 3K

Graduate Special Relativity: Astronaut & Earth Light Speed Paradox

Jul 11, 2015 · Replies 6 · Jul 15, 2015

Replies: 6

Views: 2K

Graduate Metric Tensor of a line element

Jul 15, 2015 · Replies 2 · Jul 15, 2015

Replies: 2

Views: 4K

Graduate Deriving the Definition of the Christoffel Symbols

Jul 14, 2015 · Replies 8 · Jul 14, 2015

Replies: 8

Views: 3K

Graduate Time Travel & Gravitational Time Dilation Function

Jun 24, 2015 · Replies 3 · Jul 14, 2015

Replies: 3

Views: 1K

Graduate Is Poincaré's Space Dilemma the Key to Understanding Gravity?

Jul 1, 2015 · Replies 71 · Jul 14, 2015

3

Replies: 71

Views: 17K

Graduate Gravity Forces Us to Move: PF Forum

Jul 10, 2015 · Replies 7 · Jul 14, 2015

Replies: 7

Views: 2K

Graduate "Semi" Synchronous coordinates

Jul 13, 2015 · Replies 1 · Jul 13, 2015

Replies: 1

Views: 924

Graduate Is there measureable spacetime distortion from EM fields

Jul 10, 2015 · Replies 19 · Jul 13, 2015

Replies: 19

Views: 3K

Graduate How should I think about null geodesics?

Jul 10, 2015 · Replies 17 · Jul 12, 2015

Replies: 17

Views: 2K

Graduate Apparent horizon for the eternally accelerated observer

Jul 5, 2015 · Replies 29 · Jul 12, 2015

Replies: 29

Views: 3K

Graduate Schutz page 294 (Deflection of light)

Jul 6, 2015 · Replies 9 · Jul 12, 2015

Replies: 9

Views: 2K

Graduate Electric Field in Gravitational Shockwave Geometry?

Jul 12, 2015 · Replies 0 · Jul 12, 2015

Replies: 0

Views: 1K

Undergrad What is the smallest practical unit of time?

Jul 11, 2015 · Replies 2 · Jul 12, 2015

Replies: 2

Views: 2K

Graduate What is the difference between locality and causality?

Jul 10, 2015 · Replies 6 · Jul 11, 2015

Replies: 6

Views: 3K

Graduate Understanding the Laws of Physics in SR: Questions & Answers

Jul 7, 2015 · Replies 12 · Jul 11, 2015

Replies: 12

Views: 2K

Graduate Write Torsion Tensor: Definition, Metric Tensor & Equation

Jul 10, 2015 · Replies 1 · Jul 10, 2015

Replies: 1

Views: 2K

Graduate Age of Universe for High Velocity Planet?

Jul 7, 2015 · Replies 7 · Jul 10, 2015

Replies: 7

Views: 2K

Undergrad Can Space Aircraft Reach Speed of Light in Vacuum?

Jul 9, 2015 · Replies 5 · Jul 10, 2015

Replies: 5

Views: 2K

Graduate Bending space and space time - what is the difference?

Jul 9, 2015 · Replies 9 · Jul 10, 2015

Replies: 9

Views: 2K

Graduate What is the cause of time dilation in Special Relativity?

Jul 9, 2015 · Replies 33 · Jul 10, 2015

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Replies: 33

Views: 4K

Graduate What info do I get from these tensors?

Jul 4, 2015 · Replies 7 · Jul 9, 2015

Replies: 7

Views: 2K

Undergrad What exactly is a hypersurface?

Jul 8, 2015 · Replies 5 · Jul 9, 2015

Replies: 5

Views: 3K

Graduate Einstein-Cartan Field Equations Derivation

Jul 8, 2015 · Replies 2 · Jul 9, 2015

Replies: 2

Views: 2K

Undergrad What is the 4th Dimension - 3D World + Time or 4 Axis?

Jul 8, 2015 · Replies 5 · Jul 9, 2015

Replies: 5

Views: 2K

Undergrad Basis Vector in GR: Cartesian Plane Comparisons

Jul 8, 2015 · Replies 2 · Jul 9, 2015

Replies: 2

Views: 1K

Graduate Penrose Diagrams: How to Create with Known Spacetime Metric

Jun 19, 2015 · Replies 18 · Jul 9, 2015

Replies: 18

Views: 4K

Graduate Is time a vector? if it is, what is its direction?

Jul 6, 2015 · Replies 15 · Jul 9, 2015

Replies: 15

Views: 2K

Graduate Is Λa_b the Same as Λba in Tensor Notation?

Jul 7, 2015 · Replies 4 · Jul 8, 2015

Replies: 4

Views: 2K

Graduate Are Newton's Laws Still Valid Near Black Hole Orbits?

Jun 29, 2015 · Replies 58 · Jul 8, 2015

2

Replies: 58

Views: 5K

Graduate Implications of the tensorial form of the EFE

Jul 7, 2015 · Replies 26 · Jul 8, 2015

Replies: 26

Views: 3K

Undergrad Scalar Product of Orthonormal Basis: Equal to 1?

Jul 8, 2015 · Replies 6 · Jul 8, 2015

Replies: 6

Views: 2K

Graduate Reconciling Constant Speed of Light & Relativity

Jul 7, 2015 · Replies 13 · Jul 8, 2015

Replies: 13

Views: 2K

High School How many times did the machine actually travel around the Earth?

Jun 4, 2015 · Replies 23 · Jul 8, 2015

Replies: 23

Views: 3K

Graduate Space-Time Relativity: Finite Time & Measuring Time

Jul 6, 2015 · Replies 5 · Jul 8, 2015

Replies: 5

Views: 2K

Graduate What is the definition of Locality (in QFT)

Jul 7, 2015 · Replies 16 · Jul 7, 2015

Replies: 16

Views: 5K

Graduate Time Dilation with a Tennis Ball

Jul 5, 2015 · Replies 14 · Jul 7, 2015

Replies: 14

Views: 4K

Graduate How Does Time Dilation Affect the Forces Between Fast-Moving Objects?

Jul 5, 2015 · Replies 4 · Jul 7, 2015

Replies: 4

Views: 2K

Graduate Generalized velocity addition and aberration formulas

Jul 2, 2015 · Replies 4 · Jul 6, 2015

Replies: 4

Views: 2K

Graduate Simultaneous events, space-like separation & QFT

Jul 6, 2015 · Replies 19 · Jul 6, 2015

Replies: 19

Views: 4K

Graduate Equations of motion for an observer falling radially into a blackhole

Jul 6, 2015 · Replies 8 · Jul 6, 2015

Replies: 8

Views: 2K

Graduate Orthonormal Basis: Definition & Scalar Product in GR

Jul 6, 2015 · Replies 2 · Jul 6, 2015

Replies: 2

Views: 1K

Graduate Doppler Effect & Time Dilation: Explained

Jul 4, 2015 · Replies 15 · Jul 6, 2015

Replies: 15

Views: 3K

Graduate On the one way speed of light....

Jun 20, 2015 · Replies 55 · Jul 6, 2015

2

Replies: 55

Views: 6K

Graduate Energy conservation and wormholes

Jul 2, 2015 · Replies 25 · Jul 5, 2015

Replies: 25

Views: 4K

Graduate 2 simple special relativity thought experiments

Jun 25, 2015 · Replies 16 · Jul 5, 2015

Replies: 16

Views: 3K

Undergrad What if the Halo Ring from "Halo" turned into a blackhole?

Jul 4, 2015 · Replies 7 · Jul 5, 2015

Replies: 7

Views: 1K

Graduate Energy Tensor & Field Equation | Einstein Theory

Jul 5, 2015 · Replies 2 · Jul 5, 2015

Replies: 2

Views: 1K

Graduate Quantized Kinetic Energy of Relativistic Objects

Jun 30, 2015 · Replies 3 · Jul 4, 2015

Replies: 3

Views: 1K

Relativity

The theory of relativity, formulated by Albert Einstein, comprises two fundamental theories—special and general relativity. Special relativity, proposed in 1905, redefines our understanding of space and time by asserting the constancy of the speed of light for all observers and introducing concepts like time dilation and length contraction.

General relativity, presented in 1915, extends these principles to incorporate gravity. It describes gravity as the curvature of spacetime caused by massive objects, leading to phenomena like gravitational time dilation and the prediction of black holes. Einstein's equations have been consistently validated through experiments and observations, profoundly influencing our comprehension of the universe's fabric and dynamics.

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