Beauty, elegance, grace, and sexiness compared

Beauty is the single most frequently and most broadly used aesthetic virtue term. The present study aimed at providing higher conceptual resolution to the broader notion of beauty by comparing it with three closely related aesthetically evaluative concepts which are likewise lexicalized across many languages: elegance, grace(fulness), and sexiness. We administered a variety of questionnaires that targeted perceptual qualia, cognitive and affective evaluations, as well as specific object properties that are associated with beauty, elegance, grace, and sexiness in personal looks, movements, objects of design, and other domains. This allowed us to reveal distinct and highly nuanced profiles of how a beautiful, elegant, graceful, and sexy appearance is subjectively perceived. As aesthetics is all about nuances, the fine-grained conceptual analysis of the four target concepts of our study provides crucial distinctions for future research

Pulse-stimulated radiation from a plasma due to an energy-dependent gyrofrequency

A plasma excited by two short pulses at the electron gyrofrequency which have a time separation τ, is considered in the single particle approach. It is shown that the relativistic mass effect can lead to a series of radiation maxima after the second pulse. In the case of a cold plasma in an inhomogeneous magnetic field these maxima arise at multiples of the time τ; in the case of a warm plasma in a homogeneous magnetic field at multiples of τ/|1 ± D|, where D is the strength of the second pulse relative to the first one. The shape of the radiation maxima is given by the square of the Fourier transform of the distribution of the inhomogeneities or the initial energies, respectively. The two effects have the tendency to cancel each other. (i) If the plasma is excited by three pulses, the time separation of the second and third pulse being T, radiation maxima occur at times t = Kτ + LT, (±K, L = 0, 1, 2,... but t > 0) after the third pulse in the case of cold plasma with field inhomogeneities, and at t = (Kτ + LT)/|1 ± D ± D_2| in the case of a warm plasma. (ii) If collisions are taken into account the dependence on T of the radiation maxima with L = 0 is determined by inelastic collisions only, while the other decay times are determined by all kinds of collisions

On the Theory of Pulse Stimulated Radiation from Plasma

By including the relativistic mass change in the motion of electrons gyrating in a slightly inhomogeneous field, it is possible to account for the cyclotron echoes observed by Hill and Kaplan

The Gunn-Peterson effect and the Lyman alpha forest

We show that spatial correlations in a stochastic large scale velocity field in an otherwise smooth intergalactic medium (homogeneous comoving density) superposed on the general Hubble flow, may cause a `line-like' structure in QSO spectra similar to the population of unsaturated Ly-alpha forest lines which usually are attributed to individual clouds with 10^{11} <= N(HI) <= 5*10^{13} cm^{-2}. Therefore there is no clear observational distinction between a diffuse intergalactic medium and discrete intergalactic clouds. It follows that the HI-density in the diffuse intergalactic medium might be substantially underestimated if it is determined from the observed intensity distribution near the apparent continuum in high resolution spectra of QSOs. Our tentative estimate implies a diffuse neutral hydrogen opacity tau_{GP} = 0.3 at z = 3 and a current baryon density Omega_{IGM} = 0.08$, assuming a Hubble constant H = 70 km s^{-1} Mpc^{-1}.Comment: 9 pages, 3 Postscript figures, a MNRAS Letters submissio