Einstein CentennialAnswer
Why does quantum physics seem so weird, even to physicists?
Why electrons can produce wave-like patterns, what two-slit experiments show, and why a physical measurement differs from a conscious observer.
THE QUESTION LIBRARY EINSTEIN CENTENNIAL
Has Einstein’s relativity ever failed a test?
What happened to OPERA's 2011 faster-than-light claim, how relativity is tested, and why successful measurements do not prove every possible prediction.
THE SHORT ANSWER
Relativity has survived the tests discussed here; an apparent failure is not automatically a confirmed failure. In 2011, OPERA reported neutrinos apparently arriving faster than light. Follow-up measurements and checks of its timing equipment resolved that anomaly. Other experiments continue testing Einstein's predictions within measured uncertainties. Those successes support relativity without proving that it is a complete description of every possible situation.
- OPERA's anomaly was resolved through timing checks and follow-up measurements.
- Different experiments test different predictions.
- A tested limit is supported by evidence, not universal observation.
WHAT WE DON’T KNOW YET
These tests do not observe every event or establish that relativity is complete in all situations. Each result has a defined sensitivity and assumptions.
WHAT WOULD CHANGE THIS ANSWER
A reproducible discrepancy beyond stated uncertainties, independently checked after timing, equipment, and analysis alternatives are examined.
Relativity has survived the tests discussed here; an apparent failure is not automatically a confirmed failure. In 2011, OPERA reported neutrinos apparently arriving faster than light. Follow-up measurements and checks of its timing equipment resolved that anomaly. Other experiments continue testing Einstein's predictions within measured uncertainties. Those successes support relativity without proving that it is a complete description of every possible situation.
THE LONG ANSWER
THE LONG ANSWER · ABOUT 2 MINUTES
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Keep asking
Why does quantum physics seem so weird, even to physicists?
Quantum physics seems weird because the rules that describe electrons and photons do not fit the familiar picture of tiny balls following definite paths.
New here?
God Plays Dice answers big questions in plain words, with sources and one of six honest labels.
Words worth knowing (3)
- special relativity
- Einstein's theory relating space, time, and motion.
- general relativity
- Einstein's theory of gravity as spacetime geometry.
- uncertainty
- The reported limits on a measurement or inferred result.
Sources & further reading
(4) · Checked Oct 5, 2026
- Ask an Astrophysicist: Relativity ↗NASA Goddard Space Flight CenterHistorical explanatory archive distinguishes special/general relativity, evidence from proof, and the energy required to accelerate a massive object.
- OPERA experiment reports anomaly in flight time of neutrinos from CERN to Gran Sasso ↗CERNSeptember 2011 report with February, March, and June 2012 updates; the final update resolves the anomaly through timing-system checks and four experimental comparisons.
- Results and Implications: Gravity Probe B ↗NASAOfficial account reports the 2011 gyroscope results and their measured uncertainties; supports two particular gravitational predictions.
- GWTC-5.0: Tests of General Relativity ↗LIGO Scientific, Virgo and KAGRA CollaborationsJuly 2026 research preprint; tested gravitational-wave signals were overall consistent with general relativity, with stated analysis limitations.
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CONTINUE THE THREAD
Where this question leads.
Einstein CentennialAnswer
Can quantum entanglement send messages faster than light?
Einstein called it “spooky action at a distance,” and the matching is real, but here is why nobody can use it to send a message faster than light.
Einstein CentennialAnswer
Did Einstein lose his argument that God does not play dice?
A century after his famous letter to Max Born, experiments have ruled on part of Einstein’s hope, while the question of dice itself is still argued.