Special and General Relativity Forum

Post thread
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.
Undergrad Solving the Spherically Symmetric Einstein Equation
  • · Replies 3 ·
Replies
3
Views
2K
High School Gravitational Wave System and Locations
  • · Replies 2 ·
Replies
2
Views
2K
High School Who Won the 2020 Nobel Prize in Physics and What Did They Discover?
  • · Replies 48 ·
2
Replies
48
Views
9K
High School Value of this 'Science' Channel as quick intro
  • · Replies 38 ·
2
Replies
38
Views
4K
Undergrad Observing Black Holes in Finite Time
  • · Replies 10 ·
Replies
10
Views
2K
Undergrad Self-Study General Relativity: After Multivariate Calc in HS
  • · Replies 3 ·
Replies
3
Views
2K
High School Paradox of Simultaneous Flashing in a Moving Triangle of Lights
  • · Replies 18 ·
Replies
18
Views
2K
High School How can two ships pass each other twice at the same moment?
  • · Replies 15 ·
Replies
15
Views
2K
High School Mass Reduction in Combustion: Real or Myth?
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad Speed of Sound & Light: Is it True?
  • · Replies 1 ·
Replies
1
Views
1K
High School Contradictory time dilation equations
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad Is Teleportation & Time Travel Possible?
  • · Replies 17 ·
Replies
17
Views
2K
Undergrad What software can I use to make space-time diagrams?
  • · Replies 5 ·
Replies
5
Views
5K
Undergrad Riemann Curvature Tensor on 2D Sphere: Surprising Results
  • · Replies 4 ·
Replies
4
Views
2K
High School Event horizon for observer within main horizon
  • · Replies 1 ·
Replies
1
Views
885
High School E & B Field Oscillation with Time Dilation: Explained
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Does time dilation cause different aging rates for people?
  • · Replies 27 ·
Replies
27
Views
4K
Undergrad Precession of Mercury: Adaptation for Observers
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad How to communicate between planets?
  • · Replies 26 ·
Replies
26
Views
2K
Undergrad Thought Exp: Gen Relativity & Time Dilation
  • · Replies 4 ·
Replies
4
Views
2K
High School Twin Paradox: Radioactive Decay Tested
  • · Replies 15 ·
Replies
15
Views
2K
Undergrad Velocity Addition and Doppler Effect: Explained
  • · Replies 5 ·
Replies
5
Views
2K
High School How to derive the continuity equation for a perfect fluid?
  • · Replies 17 ·
Replies
17
Views
4K
High School First Experimental Confirmation of GR
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Are Derivatives of the Metric Different in Flat Spacetime?
  • · Replies 6 ·
Replies
6
Views
2K
Undergrad Magnetic Field Generated By Moving Charged Objects - Confusion Explained
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Dissolving Event Horizon w/Charged & Rotating BH
  • · Replies 2 ·
Replies
2
Views
1K
High School Time Travel Possibility with Two Black Holes Orbiting Each Other
  • · Replies 14 ·
Replies
14
Views
3K
High School Experimental Confirmation Length Contraction Velocity Addition
  • · Replies 27 ·
Replies
27
Views
2K
High School Why can't energy or information go faster than light?
  • · Replies 32 ·
2
Replies
32
Views
3K
High School General Relativity and the curvature of space: more space or less than flat?
  • · Replies 62 ·
3
Replies
62
Views
6K
Undergrad Const Curvature Scalar & 3-Torus: Is It Maximally Symmetric?
  • · Replies 12 ·
Replies
12
Views
3K
High School Relativistic Photon Mass: Can It Exist?
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad Explore Alternative Interpretations of Special Relativity
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Einstein Field Eqns: East/West Coast Metrics
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Understanding Feynman's Relativistic Electric Field Equation
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Explaining the Twin Paradox: A Big Problem?
  • · Replies 33 ·
2
Replies
33
Views
3K
Undergrad Is it feasible to measure one way speed of light this way?
  • · Replies 52 ·
2
Replies
52
Views
6K
Graduate Levi-Civita Connection & Length of Curves in GR
  • · Replies 9 ·
Replies
9
Views
3K
Undergrad How to Change Between Unit Systems w/ ##c \ne 1, \hbar \ne 1, G \ne 1##
  • · Replies 4 ·
Replies
4
Views
1K
High School Twin Paradox: Tom & Jerry Agree on Clock Time But Who is Older?
  • · Replies 5 ·
Replies
5
Views
1K
High School Einstein's Universe (1979) - Nigel Calder, Peter Ustinov
  • · Replies 2 ·
Replies
2
Views
2K
High School Transform to accelerating coordinates
  • · Replies 18 ·
Replies
18
Views
3K
Graduate Gravity Theories: GR vs Alternatives - Post 2018
  • · Replies 1 ·
Replies
1
Views
1K
High School Visualize 2D Intrinsic Curvature of Spacetime (1s+1t) in 3D
  • · Replies 14 ·
Replies
14
Views
5K
Undergrad Momentum Conservation in Special Relativity: mwu
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Inverting the metric coefficients in the Schwarzschild line element
  • · Replies 32 ·
2
Replies
32
Views
4K
Undergrad Proper time to reach the singularity of a Schwarschild black hole
  • · Replies 4 ·
Replies
4
Views
7K
Undergrad Time Dilation & Superluminal Travel: 2 Questions
  • · Replies 11 ·
Replies
11
Views
2K
Undergrad Why does an object initially at rest begin to fall?
  • · Replies 24 ·
Replies
24
Views
4K
Undergrad Does Light Curve Spacetime?
  • · Replies 11 ·
Replies
11
Views
2K
High School Doubt about the relativity of simultaneity
  • · Replies 33 ·
2
Replies
33
Views
4K
Undergrad Interpreting Schwarzschild Metric: Photon Falls Toward Black Hole
  • · Replies 18 ·
Replies
18
Views
2K
Undergrad Charged Particle Free Fall in Grav Field: Does Anyone Know Answer?
  • · Replies 7 ·
Replies
7
Views
2K
High School Why and how does the frequency of a moving clock affect its ticking speed?
  • · Replies 69 ·
3
Replies
69
Views
7K
Graduate Find 2D Geometry of Line Element in Coordinates
  • · Replies 14 ·
Replies
14
Views
3K
High School Where Does Momentum Go Near Merging Black Holes?
  • · Replies 5 ·
Replies
5
Views
1K
Insights Does the Block Universe of Physics Mean Time is an Illusion?
  • · Replies 56 ·
2
Replies
56
Views
7K
Graduate Covering Group of SO(g) & Understanding Spinors on Curved Spacetime
  • · Replies 15 ·
Replies
15
Views
2K
High School Lagrangian Point in General Relativity
  • · Replies 52 ·
2
Replies
52
Views
6K
High School Looking Out of the Window: Phys & Math Meaning in Postulates & Principles
  • · Replies 14 ·
Replies
14
Views
2K
High School Shape of Hubble sphere at relativistic velocity
  • · Replies 54 ·
2
Replies
54
Views
5K
High School Can someone please explain Feynman's index notation?
  • · Replies 12 ·
Replies
12
Views
3K
High School Are time and light at the same speed?
  • · Replies 36 ·
2
Replies
36
Views
3K
Undergrad Video camera in a moving rocket
  • · Replies 6 ·
Replies
6
Views
1K
Graduate Block Universe Theory: Implications & Multiverse
  • · Replies 6 ·
Replies
6
Views
3K
Undergrad Gravitons Replacing General Relativity: Can it Work?
  • · Replies 18 ·
Replies
18
Views
3K
High School Do we feel the Earth going around the Sun as acceleration?
  • · Replies 10 ·
Replies
10
Views
2K
Graduate Determining Geometry of Line Element: A General Method?
  • · Replies 5 ·
Replies
5
Views
2K
High School Light Behaviour at High Speed: Explained
  • · Replies 2 ·
Replies
2
Views
1K
High School Paradox about black hole evaporation
  • · Replies 35 ·
2
Replies
35
Views
4K
Undergrad Is it possible to extend Newtonian gravity to include energy as well as mass?
  • · Replies 24 ·
Replies
24
Views
2K
Graduate Black Holes & White Holes: Same or Different?
  • · Replies 20 ·
Replies
20
Views
3K
Undergrad Temporal Gradients at Event Horizons of Black Holes
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad Electrodynamics of Dielectrics: 4D to 3D
  • · Replies 1 ·
Replies
1
Views
1K
High School Bob & Ted See Different Ages for Alice on Earth
  • · Replies 5 ·
Replies
5
Views
1K
Undergrad The Speed of Light: Can it Travel in Opposite Directions?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad EM Field Strength in Curved Spacetime: Is it Unchanged?
  • · Replies 7 ·
Replies
7
Views
2K
High School Why is the speed of light constant?
  • · Replies 18 ·
Replies
18
Views
2K
Undergrad The center of mass & relativistic collisions
  • · Replies 7 ·
Replies
7
Views
3K
Undergrad Q re de Sitter–Schwarzschild metric
  • · Replies 35 ·
2
Replies
35
Views
4K
Undergrad How Does Relativity of Simultaneity Clash w/Thermodynamics?
  • · Replies 9 ·
Replies
9
Views
2K
Undergrad Special Relativity: Intuition & Quantities Explained
  • · Replies 13 ·
Replies
13
Views
2K
Undergrad Check for geodesically-followed path in a coordinate-free way
  • · Replies 95 ·
4
Replies
95
Views
7K
Undergrad Logic question on relativity- no math
  • · Replies 26 ·
Replies
26
Views
2K
Undergrad Riemann Tensor, Stoke's Theorem & Winding Number
  • · Replies 5 ·
Replies
5
Views
2K
High School Understanding Strong Equivalence Principle Errors & Misunderstandings
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Finite Lorentz Transformation via Poisson Bracket
  • · Replies 3 ·
Replies
3
Views
2K
Undergrad Special Relativity & Non-Instantaneous Force Equations
  • · Replies 7 ·
Replies
7
Views
1K
Graduate Axisymmetric vs Spherical Metric Comparison
  • · Replies 16 ·
Replies
16
Views
3K
High School Particle Horizon & Coformal Time Near c - Observer Effects
  • · Replies 2 ·
Replies
2
Views
972
Undergrad Gravity transition directly at the underside of a "shell planet"
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Another spacetime visualization
  • · Replies 23 ·
Replies
23
Views
3K
Undergrad Variation of Ricci scalar wrt derivative of metric
  • · Replies 3 ·
Replies
3
Views
3K
Undergrad Acceleration in Special Relativity
  • · Replies 26 ·
Replies
26
Views
3K
High School Twin paradox explained for laymen
  • · Replies 254 ·
9
Replies
254
Views
21K
High School Black hole horizon and Hawking evaporation
  • · Replies 30 ·
2
Replies
30
Views
3K
Graduate Parallel plate capacitor in the Rindler metric
  • · Replies 26 ·
Replies
26
Views
3K
Undergrad Can Newtonian Gravity be Thought of as a Theory of Curved Time?
  • · Replies 20 ·
Replies
20
Views
4K
Undergrad Geodesics using 2 Variables: Time & Radius from Mass
  • · Replies 1 ·
Replies
1
Views
2K