twin paradox
Siblings age differently
The twin paradox is a thought experiment in special relativity: one twin travels at near-light speed while the other stays on Earth.
When the traveler returns, less time has passed for them—they've aged less than their sibling.
It's called a paradox because both twins could seemingly claim the other was moving, yet the asymmetry is real.
The resolution involves the traveling twin's acceleration and deceleration, which breaks the symmetry between their reference frames.
Theory uniting space, time
- time dilationClocks slow at speed
- simultaneityState of coexisting temporally
- spacetimeMerged dimensional framework
- frame of referenceContext for judgment
light speed · rapidity · boost · relativistic effects · Einstein
Absence of balanced form
- resolutionFormal decision or determination
- accelerationRate velocity changes
- turnaroundShift in opposite direction
- equivalenceState of being equal
distinguishability · thought experiment · counterintuitive · explanation
Device displaying time
- agingGrowing older over time
- elapsed timeTime that has passed
- synchronizationAligning timing across systems
- atomic clockQuantum-vibration timekeeping device
GPS satellites · time measurement · desynchronization · chronometer
Spacecraft crew member
- rocketPropulsion-driven spacecraft
- interstellar travelVoyaging between distant suns
- journeyTravel from place to place
- departureAct of going away
return trip · spacecraft · voyage · homecoming · elapsed time · cosmonaut
Cause-effect connection
- determinismDoctrine of causal necessity
- personal identityOne's defining characteristics
- persistenceContinuing despite difficulty
- ontologyStudy of existence's nature
special relativity
Theory uniting space, time
- time dilationClocks slow at speed
- simultaneityState of coexisting temporally
- spacetimeMerged dimensional framework
frame of reference · light speed · rapidity · boost · relativistic effects · Einstein
asymmetry
Absence of balanced form
- resolutionFormal decision or determination
- accelerationRate velocity changes
- turnaroundShift in opposite direction
equivalence · distinguishability · thought experiment · counterintuitive · explanation
clock
Device displaying time
- agingGrowing older over time
- elapsed timeTime that has passed
- synchronizationAligning timing across systems
atomic clock · GPS satellites · time measurement · desynchronization · chronometer
astronaut
Spacecraft crew member
- rocketPropulsion-driven spacecraft
- interstellar travelVoyaging between distant suns
- journeyTravel from place to place
departure · return trip · spacecraft · voyage · homecoming · elapsed time · cosmonaut
causality
Cause-effect connection
- determinismDoctrine of causal necessity
- personal identityOne's defining characteristics
- persistenceContinuing despite difficulty
- paradoxescatch-22, causal loop, self-contradiction, ship of Theseus, infinite regress
- mind-bending sciencequantum entanglement, time dilation, observer effect, relativity, black holes
- relativityrelativity, spacetime, general relativity, relativity theory, time dilation
- time dilationrelativistic effects
- timesecond, minute, hour, day, seconds
- Einstein's theoriesspecial relativity, general relativity, E=mc2, time dilation, spacetime
twin, twins, paradox, twinned, twinning, paradoxical, paradoxes, paradoxically, twinship