Life has evolved on Earth for 3 billion years in the presence of background ionizing radiation (IR). All organisms on Earth are continuously exposed to varying amounts of natural radiation and they have therefore incorporated in their normal biology a daily stimulus of ultra-low–dose radiation. A question arises about the biological effects of environmental background radiation and whether the ...

We calculate the flux of neutrinos generated by the propagation of ultra-high energy nuclei over cosmological distances. The propagation takes into account the interactions with cosmic background radiations including the CMB and the most recent estimates of higher energy (infra-red, optical, and ultra violet) backgrounds. We assume that the composition of ultra-high energy cosmic rays (UHECRs) ...

We present the analysis of the complete 3-year data set obtained with the Degree Angular Scale Interferometer (DASI) polarization experiment, operating from the Amundsen-Scott South Pole research station. Additional data obtained at the end of the 2002 Austral winter and throughout the 2003 season were added to the data from which the first detection of polarization of the cosmic microwave back...