Muon lifetime
Muon lifetime is the average time a free muon exists before decaying into other particles, such as an electron and neutrinos.
Also known as: muon mean lifetime
How big is it?
2.197 µs
Mean lifetime · measured
Typical recorded range: 2.197 µs to 2.197 µs.
A little perspective
Camera flash is about 455 times larger on this measurement.
Camera flash: A camera flash is a brief, intense burst of light used to illuminate a scene for photography.
Measurements, assumptions & sources +
Muon lifetime
A free positive muon has a mean lifetime of about 2.197 microseconds before decay. This is a statistical mean, not an identical lifetime for every muon.
Particle Data Group — Muon properties
The marked mean lifetime is calibrated. Unmeasured illustration details are representative.
Camera flash
A chosen 1 ms flash duration; equipment varies.
Defined examples — our methodology
The marked time is calibrated. Unmeasured illustration details are representative.
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Why this measurement?
Why we use 2.197 µs
For comparison, this page uses mean lifetime. This is labelled measured; the central value is useful for comparison, while real values or measurement solutions can vary. The recorded range is 2.197 µs to 2.197 µs.
A free positive muon has a mean lifetime of about 2.197 microseconds before decay. This is a statistical mean, not an identical lifetime for every muon.
The identifying illustration and the numerical comparison remain separate. How calibrated comparisons work →
Recorded properties
Muon lifetime dimensions and measurements
| Property | Selected value | Recorded range | Basis |
|---|---|---|---|
| 2.197 µs | 2.197 µs to 2.197 µs | measured |
Around this scale
Go smaller. Go bigger.
These links use compatible time records, ordered around the selected value.
Nearest lower value · Fundamental physicsCaesium-133 clock transition108.8 psThe caesium-133 clock transition is the specific change in energy state of a caesium-133 atom that defines the duration of one second in the International System of Units.
Nearest higher value · TimeCamera flash1 msA camera flash is a brief, intense burst of light used to illuminate a scene for photography.Sources and method
Want to check the number?
The source records and measurement method remain available for inspection.
- Particle Data Group — Muon propertiesRecommended mean lifetime for the positive muon.
There’s always another scale
Follow your curiosity.
TimeAtomic-scale transition1 fsAn atomic-scale transition is a rapid change in the energy state of an atom, often occurring in extremely short intervals.TimeTop quark lifetime5 × 10⁻²⁵ sThis is the average time a top quark exists before it decays into other particles.TimeCamera flash1 msA camera flash is a brief, intense burst of light used to illuminate a scene for photography.Fundamental physicsCaesium-133 clock transition108.8 psThe caesium-133 clock transition is the specific change in energy state of a caesium-133 atom that defines the duration of one second in the International System of Units.
TimeCinema frame at 24 frames per second41.67 msA cinema frame at 24 frames per second is the time interval between consecutive images in standard film projection.TimeBlink of an eye150 msA blink of an eye is the quick closing and opening of the eyelid, usually happening involuntarily.TimeHeartbeat1 sA heartbeat is the regular contraction of the heart that pumps blood through the body.
GravityParabolic-flight microgravity arc0.02 NA parabolic-flight microgravity arc is a flight manoeuvre that creates short periods of near-weightlessness for people and experiments inside an aircraft.