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
Undergrad Movement of a guitar string at relativistic speeds
- Joda
- · Replies 61 ·
Graduate The "no metric, no nothing" view
- jake jot
- · Replies 2 ·
Undergrad Can Time Travel Into the Future Really Happen?
- Azrion
- · Replies 19 ·
Undergrad 4 spaceships are pulling a membrane through an asteroid belt
- eaglechief
- · Replies 8 ·
High School Why do you need a light clock?
- Atstill77
- · Replies 7 ·
High School Comparing Rates: Why Don't Units Cancel?
- jaketodd
- · Replies 24 ·
Undergrad What is the four-momentum of a photon?
- jbergman
- · Replies 17 ·
Undergrad GTR & STR: Could 9 Dimensions Unify Theory?
- eaglechief
- · Replies 6 ·
High School Measuring the One Way Speed of Light
- RandyD123
- · Replies 171 ·
High School On the four dimensions of special relativity
- trees and plants
- · Replies 22 ·
High School Understanding the Relationship Between c and c2 in the Famous Formula e = mc2
- curiousat61
- · Replies 8 ·
Undergrad Cosmic Censorship: Does it Hold?
- john baez
- · Replies 2 ·
Graduate Understanding Kerr Black Holes: Metric, Killing Vectors & Event Horizons
- JD_PM
- · Replies 8 ·
Graduate Temp of Moving Body: 110 Yrs of Debate | Current Tech Update?
- johnscitech
- · Replies 20 ·
High School Explaining Spaghettification w/ Spacetime Curvature
- Karl Coryat
- · Replies 25 ·
Undergrad What is the Role of Matter in General Relativity's Lagrangian?
- dsaun777
- · Replies 10 ·
Graduate Understanding Tensor Notation: What is the Difference?
- LagrangeEuler
- · Replies 16 ·
Undergrad Relativistic Velocity, Perp. Accel., Momentum: Explained
- em3ry
- · Replies 6 ·
High School A few questions about the covariant derivative
- etotheipi
- · Replies 7 ·
Undergrad Gravity: Compounded Space (Time) Signal?
- CuriousGiles
- · Replies 5 ·
Graduate Geodesic Eq Derived from Einstein Field Equations?
- Intrastellar
- · Replies 25 ·
Undergrad Disappearing Sun: A Thought Experiment on the Effects of Gravity and Light
- Byron Forbes
- · Replies 20 ·
Undergrad Conservation of energy in general relativity
- Qwet
- · Replies 42 ·
Undergrad Recovering Newton's energy conservation law for an Earth's lab
- epovo
- · Replies 35 ·
Undergrad Is coordinate speed affected by gravitational waves?
- Haorong Wu
- · Replies 17 ·
Undergrad Hawking Radiation: Info vs Semanticity? - Hossenfelder
- gerald V
- · Replies 4 ·
Undergrad Spacetime invariance algebraic proof
- john t
- · Replies 8 ·
Graduate The g_ij as potentials for the gravitational field
- dx
- · Replies 108 ·
Undergrad The Sub Photon Sphere Escape Game
- .Scott
- · Replies 8 ·
Undergrad Unravelling the Mysteries of the Kerr Black Hole Ergosphere
- Marilyn67
- · Replies 19 ·
Undergrad Radius Excess of Curvature in Relativity: Explained
- italicus
- · Replies 6 ·
High School Understanding the active/passive transformation of a scalar field
- etotheipi
- · Replies 15 ·
High School Light Clock: Why Aren't Delta T and 2D/c Equal?
- Point Conception
- · Replies 17 ·
Undergrad Investigating The Photon Sphere
- .Scott
- · Replies 3 ·
Undergrad Solving Relativistic Inelastic Collisions: 150 GeV Energy
- Eirik
- · Replies 8 ·
High School Transforming the Electric Field Measured by an Observer with 4-velocity U
- etotheipi
- · Replies 2 ·
Undergrad Solving the Spherically Symmetric Einstein Equation
- Tomas Vencl
- · Replies 3 ·
High School Gravitational Wave System and Locations
- Eumeme
- · Replies 2 ·
High School Who Won the 2020 Nobel Prize in Physics and What Did They Discover?
- martinbn
- · Replies 48 ·
High School Value of this 'Science' Channel as quick intro
- D.S.Beyer
- · Replies 38 ·
Undergrad Observing Black Holes in Finite Time
- kmm
- · Replies 10 ·
Undergrad Self-Study General Relativity: After Multivariate Calc in HS
- SirMadame
- · Replies 3 ·
High School Paradox of Simultaneous Flashing in a Moving Triangle of Lights
- O Great One
- · Replies 18 ·
High School How can two ships pass each other twice at the same moment?
- O Great One
- · Replies 15 ·
High School Mass Reduction in Combustion: Real or Myth?
- iVenky
- · Replies 12 ·
Undergrad Speed of Sound & Light: Is it True?
- TheGeneMan
- · Replies 1 ·
High School Contradictory time dilation equations
- O Great One
- · Replies 13 ·
Undergrad Is Teleportation & Time Travel Possible?
- danielhaish
- · Replies 17 ·
Undergrad What software can I use to make space-time diagrams?
- phoenix-anna
- · Replies 5 ·
Undergrad Riemann Curvature Tensor on 2D Sphere: Surprising Results
- epovo
- · Replies 4 ·
High School Event horizon for observer within main horizon
- Swamp Thing
- · Replies 1 ·
High School E & B Field Oscillation with Time Dilation: Explained
- jaketodd
- · Replies 3 ·
Undergrad Does time dilation cause different aging rates for people?
- richengle
- · Replies 27 ·
Undergrad Precession of Mercury: Adaptation for Observers
- Mickey1
- · Replies 11 ·
Undergrad How to communicate between planets?
- Haorong Wu
- · Replies 26 ·
Undergrad Thought Exp: Gen Relativity & Time Dilation
- starkreactor
- · Replies 4 ·
High School Twin Paradox: Radioactive Decay Tested
- Kairos
- · Replies 15 ·
Undergrad Velocity Addition and Doppler Effect: Explained
- Kairos
- · Replies 5 ·
High School How to derive the continuity equation for a perfect fluid?
- etotheipi
- · Replies 17 ·
High School First Experimental Confirmation of GR
- phoenix-anna
- · Replies 8 ·
Undergrad Are Derivatives of the Metric Different in Flat Spacetime?
- etotheipi
- · Replies 6 ·
Undergrad Magnetic Field Generated By Moving Charged Objects - Confusion Explained
- hjwu
- · Replies 2 ·
Undergrad Dissolving Event Horizon w/Charged & Rotating BH
- arusse02
- · Replies 2 ·
High School Time Travel Possibility with Two Black Holes Orbiting Each Other
- slimak
- · Replies 14 ·
High School Experimental Confirmation Length Contraction Velocity Addition
- jeremyfiennes
- · Replies 27 ·
High School Why can't energy or information go faster than light?
- danielhaish
- · Replies 32 ·
High School General Relativity and the curvature of space: more space or less than flat?
- Martian2020
- · Replies 62 ·
Undergrad Const Curvature Scalar & 3-Torus: Is It Maximally Symmetric?
- George Keeling
- · Replies 12 ·
High School Relativistic Photon Mass: Can It Exist?
- virgil1612
- · Replies 13 ·
Undergrad Explore Alternative Interpretations of Special Relativity
- Charlie K Trout
- · Replies 6 ·
Undergrad Einstein Field Eqns: East/West Coast Metrics
- DuckAmuck
- · Replies 6 ·
Undergrad Understanding Feynman's Relativistic Electric Field Equation
- bryanso
- · Replies 3 ·
Undergrad Explaining the Twin Paradox: A Big Problem?
- Marilyn67
- · Replies 33 ·
Undergrad Is it feasible to measure one way speed of light this way?
- kostarak
- · Replies 52 ·
Graduate Levi-Civita Connection & Length of Curves in GR
- Blub
- · Replies 9 ·
Undergrad How to Change Between Unit Systems w/ ##c \ne 1, \hbar \ne 1, G \ne 1##
- Haorong Wu
- · Replies 4 ·
High School Twin Paradox: Tom & Jerry Agree on Clock Time But Who is Older?
- imsmooth
- · Replies 5 ·
High School Einstein's Universe (1979) - Nigel Calder, Peter Ustinov
- robphy
- · Replies 2 ·
High School Transform to accelerating coordinates
- etotheipi
- · Replies 18 ·
Graduate Gravity Theories: GR vs Alternatives - Post 2018
- andrew s 1905
- · Replies 1 ·
High School Visualize 2D Intrinsic Curvature of Spacetime (1s+1t) in 3D
- Martian2020
- · Replies 14 ·
Undergrad Momentum Conservation in Special Relativity: mwu
- Feynmanisthegoat
- · Replies 3 ·
Undergrad Inverting the metric coefficients in the Schwarzschild line element
- Bishal Banjara
- · Replies 32 ·
Undergrad Proper time to reach the singularity of a Schwarschild black hole
- Reggid
- · Replies 4 ·
Undergrad Time Dilation & Superluminal Travel: 2 Questions
- jkbhagatio
- · Replies 11 ·
Undergrad Why does an object initially at rest begin to fall?
- Grasshopper
- · Replies 24 ·
Undergrad Does Light Curve Spacetime?
- trees and plants
- · Replies 11 ·
High School Doubt about the relativity of simultaneity
- Ideassimples
- · Replies 33 ·
Undergrad Interpreting Schwarzschild Metric: Photon Falls Toward Black Hole
- snoopies622
- · Replies 18 ·
Undergrad Charged Particle Free Fall in Grav Field: Does Anyone Know Answer?
- lerus
- · Replies 7 ·
High School Why and how does the frequency of a moving clock affect its ticking speed?
- John Mcrain
- · Replies 69 ·
Graduate Find 2D Geometry of Line Element in Coordinates
- steve1763
- · Replies 14 ·
High School Where Does Momentum Go Near Merging Black Holes?
- Filmo
- · Replies 5 ·
Insights Does the Block Universe of Physics Mean Time is an Illusion?
- RUTA
- · Replies 56 ·
Graduate Covering Group of SO(g) & Understanding Spinors on Curved Spacetime
- schieghoven
- · Replies 15 ·
High School Lagrangian Point in General Relativity
- D.S.Beyer
- · Replies 52 ·
High School Looking Out of the Window: Phys & Math Meaning in Postulates & Principles
- roineust
- · Replies 14 ·
High School Shape of Hubble sphere at relativistic velocity
- Chris Miller
- · Replies 54 ·
High School Can someone please explain Feynman's index notation?
- etotheipi
- · Replies 12 ·
High School Are time and light at the same speed?
- adafus
- · Replies 36 ·