Free neutron mean lifetime
Free neutron mean lifetime is the average time a neutron exists outside an atomic nucleus before decaying into other particles.
Also known as: free neutron lifetime
How big is it?
14.67 min
Representative mean lifetime · measured approximate
Typical recorded range: 14.63 min to 14.68 min.
A little perspective
About 1.76 times the time of Earth–Sun distance.
Earth–Sun distance: The Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.
Measurements, assumptions & sources +
Free neutron mean lifetime
A free neutron survives for about 880 seconds on average before beta decay. Experimental methods still show a small unresolved discrepancy.
Particle Data Group — Neutron properties
The marked representative mean lifetime is calibrated. Unmeasured illustration details are representative.
Earth–Sun distance
One astronomical unit is exactly 149,597,870,700 m. It is a useful Earth–Sun orbital scale, not the separation at every instant. Light takes about 8 minutes 19 seconds to cross it.
NIST — 2022 CODATA fundamental constants
The marked time is calibrated. Unmeasured illustration details are representative.
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Why this measurement?
Why we use 14.67 min
For comparison, this page uses representative mean lifetime. This is labelled measured approximate; the central value is useful for comparison, while real values or measurement solutions can vary. The recorded range is 14.63 min to 14.68 min.
A free neutron survives for about 880 seconds on average before beta decay. Experimental methods still show a small unresolved discrepancy.
The identifying illustration and the numerical comparison remain separate. How calibrated comparisons work →
Recorded properties
Free neutron mean lifetime dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 14.67 min | 14.63 min to 14.68 min | measured approximate |
Around this scale
Go smaller. Go bigger.
These links use compatible time records, ordered around the selected value.
Nearest lower value · SpaceEarth–Sun distance8.317 minThe Earth–Sun distance, or astronomical unit, is the standard measure of separation between Earth and the Sun used in astronomy.
Nearest higher value · TimeA feature film2 hA feature film is a motion picture created to tell a complete story for viewers.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- Particle Data Group — Neutron propertiesRecommended free-neutron lifetime and experimental context.
There’s always another scale
Follow your curiosity.
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PeopleRed-cell circulation time1 minRed-cell circulation time is the typical duration for a red blood cell to complete a full circuit through the human circulatory system at rest.
GravityTen-metre centrifuge at two rpm0.4387 NA ten-metre centrifuge at two rpm is a rotating device used to simulate artificial gravity by spinning samples at a controlled speed.