Does time really pass at different speeds?
A short answer about moving clocks, gravity and GPS, with sources from NASA and NIST.
TIME TRAVELER’S DIGEST · SEP 29, 2026SCIENCE · STORIES · VIDEO · AUDIO
Time travel, explained.
Time Traveler’s Digest is a website about time travel in science and fiction. ProfessorClock is the source work for its stories and characters.
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SCIENCE DESK
Time, under examination.
A little red dot. A much bigger question.
Webb observations support a model of a black hole surrounded by dense gas.
NASA · JUN 10, 2026Measuring time to the 19th decimal place.
NIST’s 2025 aluminum-ion clock result advances precision timekeeping.
NIST · JUL 14, 2025THE OBSERVABLE WORLD
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EDITORIAL STANDARD
What the evidence supports.
Measured clock differences.
Motion and gravity change clock rates. Atomic clocks and satellite timing provide measured examples of relativistic time dilation.
NASA: time dilation and GPS ↗Reference sources: NASA, NIST, GPS.gov, Einstein Online.
Mathematics, with conditions.
Some solutions of general relativity contain wormholes or closed timelike curves. A mathematical model is not a demonstrated device.
Stanford: time travel and physics ↗Research sources: Physical Review, arXiv, INSPIRE. Preprints require review.
Feasibility remains unresolved.
Usable wormholes and backward time travel have not been demonstrated. Chronology protection and quantum effects remain subjects of research.
Read the physical constraints ↗Use Hawking’s chronology-protection work and academic research for these questions.
Rules for thought and fiction.
Paradoxes, causal loops, self-consistency, and branching stories need explicit assumptions. A narrative rule is not evidence of a physical mechanism.
Read the philosophical context ↗Reference sources: Stanford Encyclopedia of Philosophy and IEP.
Quanta, Phys.org, and ScienceDaily are discovery and reporting sources. Factual claims require primary research or authoritative scientific references. Wikipedia, general facts sites, personal blogs, social explainers, and unscreened uploads are not final factual authorities for this edition.
PCLK-XV DOSSIERS 000-026
Twenty-seven lives. Across time.
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JACKSONVILLE · OCTOBER 25, 2026
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