We experimentally demonstrate ultrafast polarization switching of terahertz (THz) radiation generated by dual-color driving pulses composed of orthogonally polarized fundamental and second-harmonic waves, which can be controlled by field-free molecular alignment in air by modulating the relative phase between the two field components as a transient dynamic wave plate. By fine-tuning the time de...

A national radon survey is still lacking for Greece. Some groups have carried out several more or less local or extended radon surveys and valuable experience has been gained. After the first preliminary survey carried out by our group, where 500 Kodak LR-115 etched track detectors were placed in Greek schools and dwellings for one year, indoor radon measurements were continued by placing the s...

The calculations of Guang-Wen Ma’s recent Letter [Phys.Lett. A239, (1998) 209] contain an easily detectable error which makes his conclusions irrelevant. ∗E-mail: [email protected]

Blazar emission of gamma rays and cosmic ray production of gamma rays in gas-rich clusters have been proposed recently as alternative sources of the high energy extragalactic diffuse gamma ray background radiation. We show that these sources also produce a very different high energy extragalactic diffuse neutrino background radiation. This neutrino background may be detected by the new generati...

An epoch of accelerated expansion, or inflation, in the early universe solves several cosmological problems. While there are many models of inflation only recently has it become possible to discriminate between some of the models using observations of the cosmic microwave background radiation and large-scale structure. In this talk, we discuss inflation and its observational consequences, and t...

I review the discovery of the temperature fluctuations in the cosmic microwave background radiation. The underlying theory and the implications for cosmology are reviewed, and I describe the prospects for future progress.

S INCE 1920 there has been a marke(l increase in the recorded incidence of leukemia and the lymphomas. At the same time, exposure to iomiizing radiation has been shown to increase the frequency of these diseases. Consequently there is now mounting concern about tile gradually rising level of background radiation in the environment. In this paper, the incidence of leukemia and the Ivniphomnas in...

We would like to thank Ferlazzo and Foray (1) for their very important comments and suggestions. We will keep in mind that “scientists should take particular care to justify their methodology and moderate their conclusions.” One concern of Ferlazzo and Foray (1) is that our control experiment entailed exposure to the ground radiation of Japan, rather than to a high natural radiation background ...