The luminosity determination for the ATLAS detector at the LHC during pp collisions at √ s = 8 TeV in 2012 is presented. The evaluation of the luminosity scale is performed using several luminometers, and comparisons between these luminosity detectors are made to assess the accuracy, consistency and long-term stability of the results. A luminosity uncertainty of δL/L = ±1.9% is obtained for the 22.7 fb −1 of pp collision data delivered to ATLAS at √ s = 8 TeV in 2012.

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Seismological exploration companies and Defense Department proving grounds occasionally experience liability suits for damage wrought by explosions. Good forecasts of troposphere temperature and wind structure can be used to predict where shocks will strike, and with fair accuracy whether or not the shock will crack windows. Formulas are derived by which these predictions may be made.

Five thousand tons of high explosives detonated on Helgoland, April 18, 1947, created air pressure perturbations recorded on microbarographs between 66 and 1000 km SSE from the blast. Instruments responded to frequencies 0.05–5 c.p.s. Arrival times of abnormal signals at six stations more distant than 220 km, supplemented by high altitude meteorological data and the assumption of negligible winds above 30 km, permit upper atmosphere temperature calculations. Temperatures agree with N.A.C.A. values up to 42 km, but show a reduced gradient above that altitude, and a maximum value 294°K in the temperature hump between 30 and 70 km. This temperature maximum establishes critical ray which is refracted to infinity. A new explanation for observed outer boundaries of abnormal zones is therefore proposed, and substantiated by recorded evidence of dispersion near the temperature maximum. In the signal received near the abnormal zone outer boundary, high frequency content predominates.