Searching for modifications to the exponential radioactive decay law with the Cassini spacecraft

Data from the power output of the radioisotope thermoelectric generators aboard the Cassini spacecraft are used to test the conjecture that small deviations observed in terrestrial measurements of the exponential radioactive decay law are correlated with the Earth-Sun distance. No significant deviations from exponential decay are observed over a range of 0.7 - 1.6 A.U. A 90% Cl upper limit of 0.84 x 10^-4 is set on a term in the decay rate of Pu-238 proportional to 1/R^2 and 0.99 x 10^-4 for a term proportional to 1/R.Comment: 3 pages, 3 figures, Late

Competition, Learning and Persistence in the Effects of Unmeritocratic Hiring Decisions

Sometimes wide disparities in workers' earnings are defended as simply the meritocratic outcome of a competitive process. While inequalities due to discrimination or luck are admitted as temporary possibilities, it is frequently argued that competition and the profit motive will eliminate them in the longer term. In the present paper, this position is challenged. A model is developed to demonstrate that hiring errors can have persistent effects on individual workers' earnings under conditions of capitalist competition. Hiring errors give the beneficiaries opportunities to learn and improve in their new jobs, raising the possibility that their initial advantages can become locked in. The model shows how fundamental features of the capitalist system (competition, the profit motive, the free labour exchange) can reinforce, and not always eliminate, these early advantages. While the emphasis is on random error, the same factors will play a comparable role in perpetuating the effects of discriminatory hiring decisions.Job competition; learning; inequality; luck; chance; discrimination

Should organic farmers be rewarded for sequestering C in soil?

The question of whether farmers, and organic farmers in particular, should be rewarded for sequestering C in soils is controversial. A review of the literature on long term experiments comparing organic and conventional systems, demonstrates that soils under organic management tend to have higher soil organic carbon (SOC) contents than conventionally managed soils. But the logistics of designing a system that compensates individual farmers for this ecosystem service are challenging. Agreements would have to be reached on the baseline system used for calculation of relative gains in SOC, values for emissions of other GHGs from soils (e.g. methane and nitrous oxide), the direct and indirect CO2 emissions associated with energy use and crop production inputs in the C sequestering system, and emissions associated with sources of SOC imported onto the farm. Alternatively, the evidence for generally higher SOC under organic management could justify an additional payment, for example under the UK Government’s Organic Entry Level Scheme

Measuring the masses of the charged hadrons using a RICH as a precision velocity spectrometer

The Selex experiment measured several billion charged hadron tracks with a high precision magnetic momentum spectrometer and high precision RICH velocity spectrometer. We have analyzed these data to simultaneously measure the masses of all the long lived charged hadrons and anti-hadrons from the pi to the Omega using the same detector and technique. The statistical precision achievable with this data sample is more than adequate for 0.1% mass measurements We have used these measurements to develop and understand the systematic effects of a RICH as a precision velocity spectrometer with the goal of measuring 10 masses with precision ranging from 100 KeV for the lightest to 1000 KeV for the heaviest. This requires controlling the radius measurement of RICH rings to the ~10^{-4} level. Progress in the mass measurements and the required RICH analysis techniques developed are discussed.Comment: Submitted to special edition of NIMA, Proceedings of RICh2010. v2 as accepted for publicatio