Economics: The next physical science?

We review an emerging body of work by physicists addressing questions of economic organization and function. We suggest that, beyond simply employing models familiar from physics to economic observables, remarkable regularities in economic data may suggest parts of social order that can usefully be incorporated into, and in turn can broaden, the conceptual structure of physics.Comment: 9 pages, 6 figures, to appear in Physics Toda

Anti-vortex dynamics in magnetic nanostripes

In a thin magnetic nanostripe, an anti-vortex nucleates inside a moving domain wall when driven by an in-plane magnetic field greater than the so-called Walker field. The nucleated anti-vortex must cross the width of the nanostripe before the domain wall can propagate again, leading to low average domain wall speeds. A large out-of-plane magnetic field, applied perpendicularly to the plane of the nanostripe, inhibits the nucleation of the anti-vortex leading to fast domain wall speeds for all in-plane driving fields. We present micromagnetic simulation results relating the anti-vortex dynamics to the strength of the out-of-plane field. An asymmetry in the motion is observed which depends on the alignment of the anti-vortex core magnetic moments to the direction of the out-of-plane field. The size of the core is directly related to its crossing speed, both depending on the strength of the perpendicular field and the alignment of the core moments and direction of the out-of-plane field.Comment: 10 pages, 3 figure

Antivortex Dynamics in Magnetic Nanostripes

In a thin magnetic nanostripe, an antivortex nucleates inside a moving domain wall when driven by an in-plane magnetic field greater than the so-called Walker field. The nucleated antivortex must cross the width of the nanostripe before the domain wall can propagate again, leading to low average domain wall speeds. A large out-of-plane magnetic field, applied perpendicularly to the plane of the nanostripe, inhibits the nucleation of the antivortex leading to fast domain wall speeds for all in-plane driving fields. We present micromagnetic simulation results relating the antivortex dynamics to the strength of the out-of-plane field. An asymmetry in the motion is observed which depends on the alignment of the antivortex core magnetic moments to the direction of the out-of-plane field. The size of the core is directly related to its crossing speed, both depending on the strength of the perpendicular field and the alignment of the core moments and direction of the out-of-plane field

Economics: the next physical science?

We review an emerging body of work by physicists addressing questions of economic organization and function. We suggest that, beyond simply employing models familiar from physics to economic observables, remarkable regularities in economic data may suggest parts of social order that can usefully be incorporated into, and in turn can broaden, the conceptual structure of physics.Economic theory, Physics, Econo-physics

What the 2008 Stock Market Crash Means for Retirement Security

Compares future retirement resources before and after the stock market decline, by gender, marital status, race/ethnicity, education, and retirement income quintile, under three scenarios: no recovery, full recovery, and partial recovery in ten years

Distributions, Assemblage Structure, and Habitat Associations of Fishes in Two Streams of the Red Bird River Watershed, Kentucky

The spatial and temporal variation in fish distribution, assemblage structure, and habitat associations were investigated in relation to the available macrohabitats (riffle, run, or pool) in Gilbert\u27s Big Creek and Elisha Creek, 2nd and 3rd order streams, respectively, located within the Red Bird River watershed in southeastern Kentucky. A total of 7,662 individuals were captured; 3,038 from Gilbert\u27s Big Creek (21 species) and 4,624 from Elisha Creek (19 species). The most prevalent species overall in both streams was the creek chub (Semotilus atromaculatus). Most fish species were distributed in the middle sampling sites in the spring, the lower sites in the summer, and the middle sites in the fall for both streams. Species richness increased from the upper to the lower sections of both streams during all seasons. Darter species (Etheostoma and Percina) selected riffles and runs while avoiding pools; whereas cyprinids selected pools while avoiding riffles and runs. Elisha Creek produced more total individuals; but overall the distributions, assemblage structures, and habitat associations exhibited by the fish communities in both Gilbert\u27s Big Creek and Elisha Creek were very similar to what has been reported for the same species within their geographical range

Studies on Nucleic Acid Reassociation Kinetics: Retarded Rate of Hybridization of RNA with Excess DNA

The rate of reaction of excess double-stranded bacteriophage phi X174 and plasmid RSF2124 DNA drivers with enzymatically synthesized asymmetric RNA tracers was measured. Other reactions were carried out with excess Escherichia coli DNA and E. coli RNA labeled in vivo. RNA and DNA fragment lengths were held approximately equal. For each case it was shown that in DNA excess the rate constant for RNA· DNA hybridization is 3- to 4.5-fold lower than that of the renaturation rate constant for the driver DNA. This retardation was also observed in pseudo-first-order hybridization reactions driven by excess strand-separated RSF2124 DNA. It was concluded that the rate constant for RNA· DNA hybridization depends partially on which species is in excess

A comparison of surface sensible and latent heat fluxes from aircraft and surface measurements in FIFE 1987

Surface fluxes of sensible and latent heat over a tall-grass prairie in central Kansas, as measured by 22 surface stations during FIFE 1987, are compared with values gained indirectly by linear extrapolation of aircraft-measured flux profiles to the surface. The results of 33 such comparisons covering the period 26 June to 13 October 1987 indicate that the sensible heat flux profiles were generally more linear with less scatter in the measurements at each level than were the latent heat flux profiles, the profile extrapolations of sensible heat flux in general underestimate the surface averages by about 30 percent, with slightly better agreement during periods of small flux, and the profile extrapolations of latent heat flux in general underestimate the surface averages by about 15 percent, with overestimates during periods of small fluxes (dry conditions) and overestimates during periods of large fluxes (moist conditions). Possible origins of the differences between the two sets of measurements are discussed, as directions for further research