Birth, survival and death of languages by Monte Carlo simulation

Simulations of physicists for the competition between adult languages since 2003 are reviewed. How many languages are spoken by how many people? How many languages are contained in various language families? How do language similarities decay with geographical distance, and what effects do natural boundaries have? New simulations of bilinguality are given in an appendix.Comment: 24 pages review, draft for Comm.Comput.Phys., plus appendix on bilingualit

Spectroscopic test of Bose-Einstein statistics for photons

Using Bose-Einstein-statistics-forbidden two-photon excitation in atomic barium, we have limited the rate of statistics-violating transitions, as a fraction $\nu$ of an equivalent statistics-allowed transition rate, to $\nu<4.0\times10^{-11}$ at the 90% confidence level. This is an improvement of more than three orders of magnitude over the best previous result. Additionally, hyperfine-interaction enabling of the forbidden transition has been observed, to our knowledge, for the first time

Congener specific analysis of polychlorinated terphenyls

In order to identify and to quantify polychlorinated terphenyls (PCT) in environmental matrices, the chro- matographic behavior of coplanar and non-coplanar congeners was evaluated. A mixture of 16 single PCT congeners was used for method development. Four of these compounds were synthesized for the first time by SUZUKI-coupling reaction. These were p-PCT (2,200 ,6,600 -tetrachloro-, 20 ,3,300 ,4,400 ,50 ,-hexachloro-, 20 ,3,300 ,5,50 ,500 -hexachloro-) and m-PCT (2,200 ,3,300 ,5,500 -hexachloro-). They were characterized by NMR ( 1 H, 13 C) spectroscopy. By means of the new column chromatographic clean-up reported here, a good matrix removal and the separation of the coplanar PCT congeners from the non-coplanar ones was obtained. The recovery rates for all congeners were good for the PCT in different test matrices like fat, charcoal, and soil. The quality of the clean-up, the separation and the recovery rates were determined by GC/MS analysis. The method was applied for the first time to a real sample from a fire accident, where different PCT, obviously formed during the combustion process, were found. The conclusion is drawn that this method is suitable for the analysis of PCT in different environmental samples

Surface differential rotation and prominences of the Lupus post T Tauri star RX J1508.6-4423

We present in this paper a spectroscopic monitoring of the Lupus post T Tauri star RX J1508.6-4423 carried out at two closely separated epochs (1998 May 06 and 10) with the UCL Echelle Spectrograph on the 3.9-m Anglo-Australian Telescope. Applying least-squares convolution and maximum entropy image reconstruction techniques to our sets of spectra, we demonstrate that this star features on its surface a large cool polar cap with several appendages extending to lower latitudes, as well as one spot close to the equator. The images reconstructed at both epochs are in good overall agreement, except for a photospheric shear that we interpret in terms of latitudinal differential rotation. Given the spot distribution at the epoch of our observations, differential rotation could only be investigated between latitudes 15° and 60°. We find in particular that the observed differential rotation is compatible with a solar-like law (i.e., with rotation rate decreasing towards high latitudes proportionally to sin 2l, where l denotes the latitude) in this particular latitude range. Assuming that such a law can be extrapolated to all latitudes, we find that the equator of RX J1508.6-4423 does one more rotational cycle than the pole every 50 ±10 d, implying a photospheric shear 2 to 3 times stronger than that of the Sun. We also discover that the Hα emission profile of RX J1508.6-4423 is most of the time double-peaked and strongly modulated with the rotation period of the star. We interpret this rotationally modulated emission as being caused by a dense and complex prominence system, the circumstellar distribution of which is obtained through maximum entropy Doppler tomography. These maps show in particular that prominences form a complete and inhomogeneous ring around the star, precisely at the corotation radius. We use the total Hα and Hβ emission flux to estimate that the mass of the whole prominence system is about 10 20g. From our observation that the whole cloud system surrounding the star is regenerated in less than 4 d, we conclude that the braking time-scale of RX J1508.6-4423 is shorter than 1 Gyr, and that prominence expulsion is thus likely to contribute significantly to the rotational spindown of young low-mass stars

Computer-Simulation des Wettbewerbs zwischen Sprachen

Recent computer simulations of the competition between thousands of languages are reviewed, and some new results on language families and language similarities are presented.Comment: 16 pages including all figures; in GERMAN language, more results than first versio

Unimanual and Bimanual Weight Perception of Virtual Objects with a new Multi-finger Haptic Interface

Accurate weight perception is important particularly in tasks where the user has to apply vertical forces to ensure safe landing of a fragile object or precise penetration of a surface with a probe. Moreover, depending on physical properties of objects such as weight and size we may switch between unimanual and bimanual manipulation during a task. Research has shown that bimanual manipulation of real objects results in a misperception of their weight: they tend to feel lighter than similarly heavy objects which are handled with one hand only [8]. Effective simulation of bimanual manipulation with desktop haptic interfaces should be able to replicate this effect of bimanual manipulation on weight perception. Here, we present the MasterFinger-2, a new multi-finger haptic interface allowing bimanual manipulation of virtual objects with precision grip and we conduct weight discrimination experiments to evaluate its capacity to simulate unimanual and bimanual weight. We found that the bimanual ‘lighter’ bias is also observed with the MasterFinger-2 but the sensitivity to changes of virtual weights deteriorated

Modeling two-language competition dynamics

During the last decade, much attention has been paid to language competition in the complex systems community, that is, how the fractions of speakers of several competing languages evolve in time. In this paper we review recent advances in this direction and focus on three aspects. First we consider the shift from two-state models to three state models that include the possibility of bilingual individuals. The understanding of the role played by bilingualism is essential in sociolinguistics. In particular, the question addressed is whether bilingualism facilitates the coexistence of languages. Second, we will analyze the effect of social interaction networks and physical barriers. Finally, we will show how to analyze the issue of bilingualism from a game theoretical perspective.Comment: 15 pages, 5 figures; published in the Special Issue of Advances in Complex Systems "Language Dynamics