Abstract

The cosmic-ray muon half-life, being proportional to g = 1 1-v2 c2 , depends upon its absolute velocity v v v o o 2 = ?2 +2 v? ? v + 2 , where v? is the muon velocity relative to the Earth and vo is the absolute velocity of the solar system. The sea-level muon flux then depends upon vo through v? ? vo . An approximate theory is presented for the absolute velocity of the solar system vo as a function of the expected anisotropy of the sea-level flux of muons as a function of the celestial direction of v? . A cosmic ray telescope was used to measure the muon flux as a function of the celestial direction. The observations yield a solar system velocity of vo = 359 ? 180 km/s in the direction of right ascension a o = 8.7 ? 3.5h and declination d o= ?1.1 ? 10.0? in reasonable agreement with results reported involving other methods.