twins paradox
Spacefaring sibling ages slower
The twins paradox is a thought experiment in special relativity that illustrates time dilation.
If one twin travels at near-light speed while the other stays on Earth, the traveling twin ages more slowly and returns younger than their sibling.
It's called a paradox because both twins might seem entitled to claim the other was moving relative to them, but the asymmetry comes from the traveling twin's acceleration and deceleration.
The effect has been confirmed experimentally with atomic clocks on aircraft.
Clocks slow at speed
- special relativityTheory uniting space, time
- simultaneityState of coexisting temporally
- spacetimeMerged dimensional framework
- reference frameBasis for measuring position
light speed · relativistic effects · Einstein · velocity · causality · boost
Hypothetical scenario for reasoning
- reunionGathering after separation
- asymmetryAbsence of balanced form
- round tripTravel both directions
- turnaroundShift in opposite direction
departure · return journey · biological age · elapsed time · separation · homecoming · synchronized clocks · initial conditions
Decrease in speed
- general relativityGravity as curved spacetime
- accelerometerDevice measuring motion forces
- g-forceAcceleration in gravitational units
- midpointExact center between two
Spacecraft crew member
- cosmonautRussian orbital traveler
- interstellar travelVoyaging between distant suns
- spacecraftVehicle for outer space
- missionPurpose-driven task
orbit · deep space · light-year · GPS satellites · particle accelerator · starship · space station · voyage
Quantum-vibration timekeeping device
- elapsed timeTime that has passed
- synchronizationAligning timing across systems
- chronometerPrecision timekeeping instrument
- clock rateProcessor cycle speed
biological clock · heartbeat · lifespan · metabolic rate · circadian rhythm · time interval · duration · nanoseconds
time dilation
Clocks slow at speed
- special relativityTheory uniting space, time
- simultaneityState of coexisting temporally
- spacetimeMerged dimensional framework
reference frame · light speed · relativistic effects · Einstein · velocity · causality · boost
thought experiment
Hypothetical scenario for reasoning
- reunionGathering after separation
- asymmetryAbsence of balanced form
- round tripTravel both directions
turnaround · departure · return journey · biological age · elapsed time · separation · homecoming · synchronized clocks · initial conditions
deceleration
Decrease in speed
- general relativityGravity as curved spacetime
- accelerometerDevice measuring motion forces
- g-forceAcceleration in gravitational units
astronaut
Spacecraft crew member
- cosmonautRussian orbital traveler
- interstellar travelVoyaging between distant suns
- spacecraftVehicle for outer space
mission · orbit · deep space · light-year · GPS satellites · particle accelerator · starship · space station · voyage · rocket ship
atomic clock
Quantum-vibration timekeeping device
- elapsed timeTime that has passed
- synchronizationAligning timing across systems
- chronometerPrecision timekeeping instrument
clock rate · biological clock · heartbeat · lifespan · metabolic rate · circadian rhythm · time interval · duration · nanoseconds · microseconds
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