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 Time Dilation: Doubts & Questions Answered
  • · Replies 4 ·
Replies
4
Views
1K
Graduate What Are the Speed and Energy Density Limits of Dark Matter?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Were Hawking Radiation & Singularity Theorem Controversial in 1965?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Einstein's Regret: Penrose Asserts on Relativity
  • · Replies 4 ·
Replies
4
Views
1K
Graduate Black Holes: Does Bob Survive Falling In?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Clarification of concepts: Tetrads (Vielbeins), etc
  • · Replies 43 ·
2
Replies
43
Views
5K
Graduate Confusion about parallel transport
  • · Replies 36 ·
2
Replies
36
Views
9K
Graduate Robertson-Poynting Effect & Relativistic Beaming
  • · Replies 17 ·
Replies
17
Views
2K
Graduate Einsteins field equations us what type of index notation?
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Travel Faster than Light: Veritasium's Spinning Satellite Explained
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Velocity & Mass: Does Speed Increase Gravity?
  • · Replies 5 ·
Replies
5
Views
1K
Graduate Electromagnetic tensor and restricted Lorentz group
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Fermionic Fields in Einstein Field Equations | Explained
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Can Time Be Reversed by Traveling Faster Than Light?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate A question about wormholes and their typical representation
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Relativity: Can a Spaceship Become a Black Hole?
  • · Replies 4 ·
Replies
4
Views
1K
Graduate Understanding Lorentz Group Generators: Derivation & Step in Eq 15
  • · Replies 1 ·
Replies
1
Views
2K
Graduate Forces on High Velocity Object - Newtonian Formula
  • · Replies 4 ·
Replies
4
Views
1K
Graduate Dark Energy: Is Stretching Space-Time the Answer?
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Gravitational Waves: Measurements & Experiments
  • · Replies 15 ·
Replies
15
Views
2K
Graduate What is the Unique Metric Tensor in this Line Element?
  • · Replies 46 ·
2
Replies
46
Views
4K
Graduate How are tidal effects explained by general relativity?
  • · Replies 4 ·
Replies
4
Views
4K
Graduate Understanding Gravitational Red Shifting with a Solar-Mass Black Hole
  • · Replies 1 ·
Replies
1
Views
1K
Graduate Understanding Simultaneity in Special Relativity
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Gravitational Time Dilation: Observing Planet Life
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Can Something Really Be "mass less"?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate In order to build a wormhole. .
  • · Replies 15 ·
Replies
15
Views
2K
Graduate Doppler effect and speed of light as a constant.
  • · Replies 1 ·
Replies
1
Views
2K
Graduate FTL & Causality: Understanding Time Travel
  • · Replies 10 ·
Replies
10
Views
2K
Graduate What does "invariance of proper time" mean?
  • · Replies 45 ·
2
Replies
45
Views
7K
Graduate A question of "Time" and pre-determination and has everything already happened?
  • · Replies 5 ·
Replies
5
Views
3K
Graduate Can clock transport tell us anything important
  • · Replies 48 ·
2
Replies
48
Views
4K
Graduate Is Grav & SR Time dilation additive?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Big Bang: A True Singularity That is Coordinate Independent
  • · Replies 1 ·
Replies
1
Views
2K
Graduate How can we combine metrics in a spacetime with multiple point masses?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Time dilations on confusing situations
  • · Replies 9 ·
Replies
9
Views
2K
Graduate Is Space-Time Dilation Just a Funny Concept or Does It Have Real Properties?
  • · Replies 57 ·
2
Replies
57
Views
5K
High School Why would Earth move in straight line without sun's gravity?
  • · Replies 3 ·
Replies
3
Views
3K
Graduate Detecting Gravity Waves: An Exploration of Using Them for Communication
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Gauss - Bonnet Gravity -> Curvature variations
  • · Replies 35 ·
2
Replies
35
Views
7K
Graduate The modelling of space time through Riemann tensor calculus
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Does Length Contraction Imply Superluminal Speeds?
  • · Replies 19 ·
Replies
19
Views
2K
Graduate Was Einstein lucky when not considering twin paradox as paradox?
  • · Replies 151 ·
6
Replies
151
Views
13K
Graduate Doubt: Why Quadratic in Matrix but Power 4 in Einstein-Rosen Metric?
  • · Replies 1 ·
Replies
1
Views
1K
Graduate What Causes the Unexpected Limit in Rindler Horizon Calculations?
  • · Replies 21 ·
Replies
21
Views
3K
Graduate Difficulty in understanding the notation
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Why Does General Relativity Use Coordinate Systems?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Light reflection in length contracted system
  • · Replies 11 ·
Replies
11
Views
2K
Graduate Difference Between Natario & Alcubierre Warp Drives
  • · Replies 2 ·
Replies
2
Views
6K
Undergrad Length contracting between objects
  • · Replies 8 ·
Replies
8
Views
1K
Undergrad Time dilation -- light clock on a train thought experiment
  • · Replies 9 ·
Replies
9
Views
2K
Graduate Quantum Tunneling: Can Photons Escape Black Holes?
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Disk rotating in a gravitational field, like a clock
  • · Replies 13 ·
Replies
13
Views
2K
Graduate Can Going the Speed of Light Create Waste in a Vacuum?
  • · Replies 11 ·
Replies
11
Views
1K
Undergrad Why Can't Objects Accelerate to Light Speed?
  • · Replies 5 ·
Replies
5
Views
2K
Graduate What Happens to a Baseball Thrown from a Light Speed Ship?
  • · Replies 6 ·
Replies
6
Views
2K
Graduate Spacetime: How It Is One & How It Moves
  • · Replies 19 ·
Replies
19
Views
2K
Graduate What is the Significance of 4-Velocity in Special Relativity?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Speed of Light & Red Shift: My Understanding
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Light Speed Photon: Everywhere at Once?
  • · Replies 1 ·
Replies
1
Views
1K
Graduate Big Bang: Spacetime Created in 1 Sec
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Understanding Einstein's Theory of Relativity: Laser Technique Questions
  • · Replies 7 ·
Replies
7
Views
1K
Graduate Distinguishing Special Relativity from Classical Mechanics
  • · Replies 13 ·
Replies
13
Views
2K
Graduate An atomic clock and a normal clock
  • · Replies 9 ·
Replies
9
Views
2K
Graduate Problem with a piece of calculation
  • · Replies 4 ·
Replies
4
Views
1K
Graduate Mass Inflation in BH: A Depreciated Concept?
  • · Replies 1 ·
Replies
1
Views
1K
Graduate Is the speed of light truly constant?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Help with Lorentz Transformation Notation & Matrix Entries
  • · Replies 5 ·
Replies
5
Views
1K
Graduate Gravity: Examining Force, Magnitude, & Limitations
  • · Replies 15 ·
Replies
15
Views
2K
Graduate Time Real or Not? - Arguments For & Against
  • · Replies 6 ·
Replies
6
Views
1K
Graduate Length contraction of particles
  • · Replies 2 ·
Replies
2
Views
1K
High School I have a dumb question about gravitational fields
  • · Replies 2 ·
Replies
2
Views
1K
High School Can Meeting Your Future Self Create a Time Loop?
  • · Replies 6 ·
Replies
6
Views
1K
Graduate Free fall into BH and horizons
  • · Replies 20 ·
Replies
20
Views
3K
Graduate Evidence for Variable Speed of Gravity in Coordinate Spacetime
  • · Replies 6 ·
Replies
6
Views
2K
Graduate What Are the Dimensions of Energy and Matter in Physics?
  • · Replies 1 ·
Replies
1
Views
1K
Graduate Can g_00 of the metric tensor depend on time
  • · Replies 14 ·
Replies
14
Views
3K
Graduate Explaining the Paradox of Measuring Photons from the Sun
  • · Replies 9 ·
Replies
9
Views
2K
Graduate Travel 10x the Speed of Light: Warp Drive Explained
  • · Replies 55 ·
2
Replies
55
Views
10K
Graduate Gravitational red- or rather blue-shift when approaching Schwarzschild radius
  • · Replies 4 ·
Replies
4
Views
2K
Graduate Where should I ask about mathematical problems with Riemann curvature tensor
  • · Replies 5 ·
Replies
5
Views
2K
Graduate Can a photon truly slow down in a dense medium?
  • · Replies 12 ·
Replies
12
Views
2K
Graduate Non-Dimensional Accretion Rate λ: Overview and Questions
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Black Hole/Entanglement Question
  • · Replies 18 ·
Replies
18
Views
2K
Graduate Slow Motion Observed in SR Spaceships?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Invariance of the speed of light
  • · Replies 18 ·
Replies
18
Views
2K
Graduate 4-velocity of an observed object in GRT
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Can light experience Gravity assist?
  • · Replies 8 ·
Replies
8
Views
2K
Graduate Physical interpretation of the stress energy momentum tensor
  • · Replies 4 ·
Replies
4
Views
3K
Graduate Could the Twin Paradox in GR be Generalized to Completely Empty Space?
  • · Replies 21 ·
Replies
21
Views
3K
Graduate Acceleration-free twin paradox
  • · Replies 35 ·
2
Replies
35
Views
5K
Graduate Does gravity have a similar effect on energy as it does with time?
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Time dilation through velocity of a moving body
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Geodesic quation coordinate time
  • · Replies 3 ·
Replies
3
Views
2K
Graduate By what method did Einstein derived his gravitational field equation?
  • · Replies 8 ·
Replies
8
Views
2K
Undergrad Can Numerical Simulations Accurately Predict Orbital Precession?
  • · Replies 5 ·
Replies
5
Views
1K
Graduate Can a black hole slow down time and create a time difference between observers?
  • · Replies 2 ·
Replies
2
Views
2K
Graduate Acceleration and the twin paradox
  • · Replies 172 ·
6
Replies
172
Views
20K
Undergrad Twin Paradox: Which Twin is Older?
  • · Replies 18 ·
Replies
18
Views
2K
Graduate LIGO & GRB 070201 - Ruling Out a Neutron Star Merger
  • · Replies 2 ·
Replies
2
Views
1K