RA · Relativity, laboratory methods and specialised topics

A precise instrument can give consistently wrong results when its calibration is shifted.

Prerequisites: 21, 22, 42, 43, 44.

• Apply special-relativistic energy and spacetime relations
• Propagate measurement uncertainty and analyse experimental data
• Recognise nuclear, particle, condensed-matter and astrophysical concepts

Special relativity uses γ=1/sqrt(1−v²/c²). Rest energy is mc² and total energy is γmc².

For independent small uncertainties, combine contributions in quadrature; correlated uncertainties require covariance 协方差 terms.

Random scatter affects precision 精密度; calibration bias affects accuracy. A log plot can reveal a power law.

Nuclear, particle, condensed-matter and astrophysics questions require undergraduate vocabulary and models. School physics alone is not a complete preparation course.

Proper time 固有时 is measured between events at one position in a frame. For a particle speed 0.60c,

If its mean proper lifetime is 4.0 microseconds, A lifetime is a mean of a distribution; it does not predict an individual decay time.

Adding percentage uncertainties linearly gives a worst-case bound, not the independent statistical standard uncertainty.

precision: Closeness of repeated measurements to each other.

covariance: A measure of joint variation used for correlated uncertainties.