arrow of time
Why eggs break
The arrow of time is the one-way direction in which time flows—from past to future, never reversing.
The phrase comes from physics, where most fundamental laws work equally well in either direction, yet the universe stubbornly moves forward: eggs break but don't unbreak, entropy increases, memories form of the past but not the future.
The arrow of time explains why we remember yesterday but not tomorrow.
State of being permanent
- second lawEntropy inevitably rises
- thermodynamicsScience of heat-energy relationships
- disorderAbsence of organization
- heat deathUniverse's final entropic state
equilibrium · dissipation · randomness · microstates · fluctuations · degradation · diffusion · mixing
What produces an effect
- effectResult of a cause
- sequenceOrdered succession of elements
- beforePrior in time
- afterFollowing in time
determinism · consequence · precedence · antecedent · chain · correlation · influence · trigger
Loud explosive noise
- cosmic inflationUniverse's first exponential stretch
- expansionIncrease in scope
- singularityPoint where values explode
- redshiftWavelength stretch from recession
Hubble · heat death · universe · spacetime · black hole · event horizon · dark energy · multiverse
How observers differ
- quantum mechanicsPhysics at nanoscopic scales
- EinsteinByword for genius
- BoltzmannEntropy-probability linking physicist
- CPT symmetryCombined discrete transformation invariance
Retaining past information
- forgettingFailing to retain memories
- nostalgiaLonging for the past
- anticipationState of awaiting something
- hindsightRecognition after the fact
foresight · aging · experience · learning · regret · hope · traces · records
irreversibility
State of being permanent
- second lawEntropy inevitably rises
- thermodynamicsScience of heat-energy relationships
- disorderAbsence of organization
heat death · equilibrium · dissipation · randomness · microstates · fluctuations · degradation · diffusion · mixing
cause
What produces an effect
after · determinism · consequence · precedence · antecedent · chain · correlation · influence · trigger · outcome
big bang
Loud explosive noise
- cosmic inflationUniverse's first exponential stretch
- expansionIncrease in scope
- singularityPoint where values explode
redshift · Hubble · heat death · universe · spacetime · black hole · event horizon · dark energy · multiverse · beginning
relativity
How observers differ
- quantum mechanicsPhysics at nanoscopic scales
- EinsteinByword for genius
- BoltzmannEntropy-probability linking physicist
Penrose · CPT symmetry · decoherence · measurement problem · presentism
remembering
Retaining past information
- forgettingFailing to retain memories
- nostalgiaLonging for the past
- anticipationState of awaiting something
hindsight · foresight · aging · experience · learning · regret · hope · traces · records · fossils
- timesecond, minute, hour, day, seconds
- time sayingscarpe diem, seize the day, better late than never, tempus fugit, haste makes waste
- entropydisorder, randomness, dissipation, irreversibility, thermodynamics
- spacetime conceptsspacetime, dimension, relativity, continuum, duration
- relativityrelativity, spacetime, general relativity, relativity theory, reference frame
- nonequilibriumirreversibility, dissipation, steady state, steady states, steady-state
time, arrow, arrows, arrowhead, arrowed, bow and arrow, arrowing, arrowheads, arrowlike