Do radioactive half-lives vary with the Earth-to-Sun distance?

Recently, Jenkins, Fischbach and collaborators have claimed evidence that radionuclide half-lives vary systematically over a ±0.1% range as a function of the oscillating distance between the Earth and the Sun, based on multi-year activity measurements. We have avoided the time-dependent instabilities to which such measurements are susceptible by directly measuring the half-life of (198)Au (t(1/2)=2.695 d) on seven occasions spread out in time to cover the complete range of Earth-Sun distances. We observe no systematic oscillations in half-life and can set an upper limit on their amplitude of ±0.02%.

Tests of nuclear half-lives as a function of the host medium and temperature: refutation of recent claims.

When radioactive isotopes that decay by alpha, beta(-), beta(+) and electron-capture transitions are placed in a conducting host material, it has recently been claimed that their half-lives show a significant dependence on temperature-up to a 6% difference between room temperature and 12K. We have refuted two of these claims by measuring: (1) the beta(-) decay of (198)Au in gold, for which we find the half life to be the same within 0.04% between room temperature and 19K; and (2) the electron-capture decay of (97)Ru in ruthenium, for which we find any half-life difference to be <0.1%.

Carotid injury secondary to blunt head trauma: case report.

Internal carotid artery (ICA) injuries including dissection, pseudoaneurysm, occlusion, and carotid-cavernous fistula (CCF) are well-recognized as potential consequences of blunt head trauma. We discuss a patient with a basal skull fracture and several types of carotid injury who was managed conservatively with excellent outcome.