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 Gravitational analog of electromagnetic force
  • · Replies 11 ·
Replies
11
Views
5K
High School A question about quarks and black holes
  • · Replies 12 ·
Replies
12
Views
2K
High School Questions about space and matter
  • · Replies 34 ·
2
Replies
34
Views
2K
Undergrad Why does general relativity break down at high energies?
  • · Replies 8 ·
Replies
8
Views
1K
Graduate Can an imminent laser strike ever be observable?
  • · Replies 102 ·
4
Replies
102
Views
5K
Undergrad Bell's spaceship paradox unknown? Interpretation?
  • · Replies 20 ·
Replies
20
Views
2K
High School Does Relativity Impact Gravity's Influence on Fast-Moving Objects?
  • · Replies 2 ·
Replies
2
Views
1K
Undergrad Why Is the Invariant Interval True for All Values of s?
  • · Replies 14 ·
Replies
14
Views
1K
Undergrad Twin Paradox - difference between outbound and inbound
  • · Replies 36 ·
2
Replies
36
Views
3K
Undergrad I have a question about gravity -- If the value of the energy momentum tensor (Tμν) becomes zero, can it become gravitational-free?
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad What if particles are moving near light speed and one slows?
  • · Replies 9 ·
Replies
9
Views
1K
Undergrad Does Phantom Dark Energy Violate Conservation of Energy?
  • · Replies 25 ·
Replies
25
Views
2K
High School What Are Gravitational Waves?
  • · Replies 7 ·
Replies
7
Views
1K
Graduate Parallel Transport and Geodesics
  • · Replies 6 ·
Replies
6
Views
1K
Undergrad Understanding the phrase "simultaneity convention"
  • · Replies 127 ·
5
Replies
127
Views
9K
Undergrad EM Faraday tensor transformation for conductor carrying current
  • · Replies 9 ·
Replies
9
Views
2K
High School E-field of a constant velocity charged particle
  • · Replies 35 ·
2
Replies
35
Views
2K
Undergrad Experimental evidence of the existence of an event horizon
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad Can “speed of light” distinguish all Timelapse videos from real motion?
  • · Replies 14 ·
Replies
14
Views
1K
Undergrad Spacetime coordinate smoothness requirement
  • · Replies 8 ·
Replies
8
Views
1K
Undergrad Gallilean v/s Lorentz transformation
  • · Replies 9 ·
Replies
9
Views
1K
Undergrad Did the Michelson-Morley Experiment Disprove the Ether Theory?
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Gravitational wave propagation in GR
  • · Replies 39 ·
2
Replies
39
Views
3K
Undergrad Information transfer between moving bodies - sped up or slowed down?
  • · Replies 2 ·
Replies
2
Views
1K
Graduate Dirac "GTR" Eq. 27.11 -- how to show that a boundary term vanishes?
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad Does expanding space cause cosmological redshift?
  • · Replies 3 ·
Replies
3
Views
999
Undergrad What if one is in 1905 and debating foundational fundamentals?
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Couple questions about time re-scaling function in Birkhoff’s theorem
  • · Replies 7 ·
Replies
7
Views
1K
High School Formation of a black hole using acceleration
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad Proving speed of light constant “c” is the same in all directions?
  • · Replies 11 ·
Replies
11
Views
2K
Graduate Proof of covariant derivative of spinor
  • · Replies 4 ·
Replies
4
Views
2K
Undergrad Intra-Universe Wormhole Metrics
  • · Replies 14 ·
Replies
14
Views
2K
Undergrad General Relativity and the precession of the perihelion of Mercury
  • · Replies 30 ·
2
Replies
30
Views
3K
Undergrad Does gravity bend gravitational waves?
  • · Replies 14 ·
Replies
14
Views
1K
Undergrad When time is not orthogonal to phi, that means there is a preferred direction in space? How?
  • · Replies 14 ·
Replies
14
Views
1K
Undergrad Basic Special Relativity question but the math isn’t working
  • · Replies 17 ·
Replies
17
Views
1K
Undergrad Are gravitons necessary?
  • · Replies 18 ·
Replies
18
Views
2K
Graduate Proving that Levi-Civita tensor density is invariant
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Can you indeed rescue a person from a Black Hole?
  • · Replies 7 ·
Replies
7
Views
1K
Graduate Relativity: Test charge moving perpendicular to a current carrying wire exhibits a force
  • · Replies 7 ·
Replies
7
Views
2K
High School How to intuitively understand the formula S² = x² - c²t²
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Why isn't TT gauge over constrained?
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Minkowski to Euclidean line element from coordinate changes?
  • · Replies 5 ·
Replies
5
Views
965
Graduate Diffeo-invariant action for a matter covector field
  • · Replies 1 ·
Replies
1
Views
918
Undergrad Final part of proof of timelike Killing w/ Frobenius --> static
  • · Replies 1 ·
Replies
1
Views
980
Undergrad Einstein field equations
  • · Replies 5 ·
Replies
5
Views
2K
Undergrad Online Christoffel Symbols Calculator
  • · Replies 7 ·
Replies
7
Views
2K
High School Question about bendability of objects in 4 dimensions
  • · Replies 57 ·
2
Replies
57
Views
2K
Undergrad A question about Relativity of Time using Time dilation experiment
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad On the existence of Gravitational energy in General relativity
  • · Replies 6 ·
Replies
6
Views
988
Undergrad Null energy condition constrains the metric
  • · Replies 5 ·
Replies
5
Views
1K
Undergrad SR flat Lorentzian manifold and Anderson simultaneity convention
  • · Replies 16 ·
Replies
16
Views
2K
Undergrad The generators of a ``Poincare-type'' group in momentum space
  • · Replies 29 ·
Replies
29
Views
2K
Undergrad Understanding Spacetime simultaneity in twin paradox scenarios
  • · Replies 35 ·
2
Replies
35
Views
3K
Undergrad Construct a Diagram that Illustrates The Galilean Law of Addition of Velocities
  • · Replies 7 ·
Replies
7
Views
2K
Undergrad Standing light waves if the one-way speed of light were not constant?
  • · Replies 36 ·
2
Replies
36
Views
3K
Undergrad Evaporating black hole: First principles consideration
  • · Replies 1 ·
Replies
1
Views
1K
High School Falling into a black hole
  • · Replies 43 ·
2
Replies
43
Views
4K
Undergrad Pullback & orthogonal projector
  • · Replies 2 ·
Replies
2
Views
834
Undergrad Unruh Radiation and Black Holes
  • · Replies 10 ·
Replies
10
Views
2K
High School Is velocity the reason for the time dilation effect?
  • · Replies 55 ·
2
Replies
55
Views
5K
Undergrad What Would the Universe Look Like as a Manifold with Boundary?
  • · Replies 2 ·
Replies
2
Views
785
Undergrad How to get metric field using a path dependent parallel propagator
  • · Replies 24 ·
Replies
24
Views
2K
Undergrad What are Killing vectors?
  • · Replies 15 ·
Replies
15
Views
2K
Undergrad Is this a Killing vector field?
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Which theory of time is the most evidence-based?
  • · Replies 32 ·
2
Replies
32
Views
3K
High School Implications of negative Michelson-Morley result
  • · Replies 12 ·
Replies
12
Views
1K
Graduate Variation of CMFR mass density ##\rho## along a world line
  • · Replies 17 ·
Replies
17
Views
2K
Undergrad Time dilation from galactic gravitational mass
  • · Replies 49 ·
2
Replies
49
Views
6K
High School Detection of red-shifted photons near an event horizon
  • · Replies 7 ·
Replies
7
Views
1K
Undergrad Is time dilation a real effect?
  • · Replies 54 ·
2
Replies
54
Views
4K
Undergrad Falling through the event horizon of an evaporating black hole
  • · Replies 51 ·
2
Replies
51
Views
5K
High School Mass defect and electron transition
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Synchronous to Newtonian gauge
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad A. P. French "Matter and Radiation: The Inertia of Energy"
  • · Replies 4 ·
Replies
4
Views
1K
High School Excellent Free Course On Einsten, Relativity, His Views Etc from Harvard
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Killing fields commute if they are asymptotically coordinate?
  • · Replies 7 ·
Replies
7
Views
851
Undergrad Meaning of the invariants built from the angular momentum tensor
  • · Replies 1 ·
Replies
1
Views
1K
Undergrad Conservation of stress-energy tensor
  • · Replies 19 ·
Replies
19
Views
2K
Undergrad Can the expansion of the Universe reduce the energy of a photon to 0?
  • · Replies 29 ·
Replies
29
Views
1K
High School The relationship between mc^2 and mc^2 x 1/2
  • · Replies 16 ·
Replies
16
Views
2K
Graduate Boundary conditions in ##\delta I=0## to derive Einstein's equations
  • · Replies 8 ·
Replies
8
Views
1K
Undergrad Orbital Period In General Relativity
  • · Replies 3 ·
Replies
3
Views
961
Undergrad Strange index notation for linear transformation matrix
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad Israel Junction Conditions: Finding Continuous Metric Across Shell
  • · Replies 20 ·
Replies
20
Views
2K
Undergrad Dark energy and conservation of energy
  • · Replies 4 ·
Replies
4
Views
1K
Undergrad On the physical meaning of Minkowski's spacetime model
  • · Replies 40 ·
2
Replies
40
Views
3K
Undergrad Why Does a Charged Box Exhibit Higher Inertia Due to Mass-Energy Equivalence?
  • · Replies 3 ·
Replies
3
Views
1K
High School Why is it impossible to go faster than the speed of light?
  • · Replies 21 ·
Replies
21
Views
4K
Undergrad Linearised gravity approach to Lense Thirring metric
  • · Replies 7 ·
Replies
7
Views
2K
Graduate Retarded time and advanced time (and binning)
  • · Replies 3 ·
Replies
3
Views
1K
Undergrad Black Holes Colliding Exactly Head On
  • · Replies 2 ·
Replies
2
Views
1K
Graduate What does Dirac mean by "the suffixes would not balance"?
  • · Replies 13 ·
Replies
13
Views
959
Graduate How do we interpret measurements of Mercury's position?
  • · Replies 11 ·
Replies
11
Views
1K
Graduate Dirac comment on tensor densities (Dirac GTR, p. 37)
  • · Replies 3 ·
Replies
3
Views
945
Undergrad Transition of spherically symmetric gravitation
  • · Replies 3 ·
Replies
3
Views
1K
Graduate Dirac's coordinates ##(\tau, \rho)## for the Schwarzschild metric with ##r \le 2m##
  • · Replies 5 ·
Replies
5
Views
894
Graduate Variation of the kinetic term in scalar field theory
  • · Replies 1 ·
Replies
1
Views
1K
High School Do observers always agree on the number of waves in a beam of light?
  • · Replies 12 ·
Replies
12
Views
2K
Undergrad Questions about Hawking radiation and extremal black holes...?
  • · Replies 4 ·
Replies
4
Views
2K