A Study of the Aurora of 1859

The two great auroral displays of August 28-29 and September 1-2, 1859 are studied from a collection of world-wide descriptive observations. Both auroras reached to unusually low latitudes. Red glows were reported as visible from within 23° of the geomagnetic equator in both north and south hemispheres during the display of September 1-2. It is shown that by using graphic symbols, descriptive reports may be used to indicate the significant features of an auroral display. A series of world-wide maps show the hourly locations and lowest latitude limits of auroral visibility and overhead aurora for the most active hours. They illustrate how the progress of an aurora may be followed throughout the night. Both auroras seen in North America reached their southern limits near local midnight. During the larger display of September 1-2 the aurora moved to lower latitudes and also covered a wide range in latitudes. This indicates that during great displays the auroral activity appears to expand in latitude until local midnight, at the same time moving towards the geomagnetic equator. Over large areas both displays were predominantly red. Magnetic records indicate that there were two distinct disturbances associated with the two displays. A tabulation of all known available auroral observations reported from August 28 to September 5, 1859 illustrates that by using a letter code, significant auroral activity may be recorded for use in auroral catalogues.Ye

Computer program provides linear sampled- data analysis for high order systems

Computer program performs transformations in the order S-to W-to Z to allow arithmetic to be completed in the W-plane. The method is based on a direct transformation from the S-plane to the W-plane. The W-plane poles and zeros are transformed into Z-plane poles and zeros using the bilinear transformation algorithm

Constraints on anomalous spin-spin interactions from spin-exchange collisions

Measured and calculated cross sections for spin-exchange between alkali atoms and noble gases (specifically sodium and helium) are used to constrain anomalous spin-dependent forces between nuclei at the atomic scale ($\sim 10^{-8}~{\rm cm}$). Combined with existing stringent limits on anomalous short-range, spin-dependent couplings of the proton, the dimensionless coupling constant for a heretofore undiscovered axial vector interaction of the neutron arising from exchange of a boson of mass $\lesssim 100~{\rm eV}$ is constrained to be $g_A^n/\sqrt{4 \pi \hbar c} < 2 \times 10^{-3}$. Constraints are established for a velocity- and spin-dependent interaction \propto \prn{\mathbf{I} \cdot \mathbf{v}} \prn{\mathbf{K} \cdot \mathbf{v}}, where $\mathbf{I}$ and $\mathbf{K}$ are the nuclear spins of He and Na, respectively, and $\mathbf{v}$ is the relative velocity of the atoms. Constraints on torsion gravity are also considered.Comment: 6 pages, 4 figure

Social Security, Retirement and Wealth: Theory and Implications

The effect of Social Security rules on the age people choose to retire can be critical in evaluating proposed changes to those rules. This research derives a theory of retirement that views retirement as a special type of labor supply decision. This decision is driven by wealth and substitution effects on labor supply, interacting with a fixed cost of working that makes low hours of work unattractive. The theory is tractable analytically, and therefore well-suited for analyzing proposals that affect Social Security. This research examines how retirement age varies with generosity of Social Security benefits. A ten-percent reduction in the value of benefits would lead individuals to postpone retirement by between one-tenth and one-half a year. Individuals who are relatively buffered from the change—because they are wealthier or because they are younger and therefore can more easily increase saving to offset the cut in benefits— will have smaller changes in their retirement ages. Authors’ Acknowledgements This work was supported by a grant from the Social Security Administration through the Michigan Retirement Research Center (Grant #10-P-98358-5). The opinions and conclusions are solely those of the authors and should not be considered as representing the opinions or policy of the Social Security Administration or any agency of the Federal Government. The authors gratefully acknowledge this support.

Apparatus for remote handling of materials

Apparatus for remote handling of materials are described. A closed housing is provided with first and second containers and first and second reservoirs for holding materials to be mixed. The materials are transferable from the reservoirs to the first container where they are mixed. The mixed materials are then conveyed from the first container to the second container preferably by dumping the mixed materials into a funnel positioned over the second container. The second container is then moved to a second position for analysis of the mixed materials. For example, the materials may be ignited and the flame analyzed. Access, such as a sight port, is provided in the housing at the analysis position. The device provides a simple and inexpensive apparatus for safely mixing a pyrophoric material and an oxidizer which together form a thermite type mixture that burns to produce a large quantity of heat and light

Precautionary saving and precautionary wealth

This is an entry for The New Palgrave Dictionary of Economics, 2nd Ed. JEL Klassifikation: C61, D11, E2

Investigations of solid chemical barium release systems

Barium-copper oxide/canister barium vapor release system for geomagnetospheric measurement