History on the Line: time as dimension

Boyd Davis’s work concerns representation, principally visual and spatial. This article discusses mapping historical time to a graphical surface, such as in timelines, focusing on the orientation of the time axis. Boyd Davis gained a £92K EPSRC grant to develop these inquiries into digital formats in 2012, and £70K from the Leverhulme Trust ending in 2010. It contrasts the paucity of intellectual debate on mapping time with the controversies over competing geographic projections, a dearth that Boyd Davis’s work is dedicated to correcting. The article proposes a research agenda derived from a synthesis of the literatures of cognitive science and gesture studies, revealing that the metaphorical direction of time differs between verbal and gestural usage, and to a lesser extent between cultures. It features original archive research into the emergence of modern chronographics in the mid-18th century, a shift from typographic, tabular layouts to truly graphical time-maps based on a changing model of time spawned by Descartes and Newton. Research into the timelines of Nicole Oresme (1350s) and Jacques Barbeu-Dubourg and Joseph Priestley (1750s) reveals their difficulties in finding the ‘right’ direction for time. Related work included a co-written paper for ‘Electronic Visualisation and the Arts’, London (2010), selected for the 2013 Springer book of best full papers (21 of c.160); a paper for the 26th ‘Computers and the History of Art’, London (2010); experimental work using virtual environments to represent historic time, a Leverhulme project co-led by Boyd Davis: two co-written articles for Computers & Education (2012); a chapter in Huang (ed.), Handbook of Human Centric Visualization (2013); a guest article for Joseph Priestley House Museum, PA, USA (2011); an invited talk on original research into French 18th-century contributions to chronographics, Centre de Recherches Texte/Image/Langage, Université de Bourgogne (2012); and a paper for ‘EVA2013’, London (2013)

Launch Commit Criteria Monitoring Agent

The Spaceport Processing Systems Branch at NASA Kennedy Space Center has developed and deployed a software agent to monitor the Space Shuttle's ground processing telemetry stream. The application, the Launch Commit Criteria Monitoring Agent, increases situational awareness for system and hardware engineers during Shuttle launch countdown. The agent provides autonomous monitoring of the telemetry stream, automatically alerts system engineers when predefined criteria have been met, identifies limit warnings and violations of launch commit criteria, aids Shuttle engineers through troubleshooting procedures, and provides additional insight to verify appropriate troubleshooting of problems by contractors. The agent has successfully detected launch commit criteria warnings and violations on a simulated playback data stream. Efficiency and safety are improved through increased automation

Gamma-ray and radio tests of the e+e- excess from DM annihilations

PAMELA and ATIC recently reported an excess in e+e- cosmic rays. We show that if it is due to Dark Matter annihilations, the associated gamma-ray flux and the synchrotron emission produced by e+e- in the galactic magnetic field violate HESS and radio observations of the galactic center and HESS observations of dwarf Spheroidals, unless the DM density profile is significantly less steep than the benchmark NFW and Einasto profiles.Comment: 16 pages, 4 figures; v2: normalizations fixed in Table 2 and typos corrected (no changes in the analysis nor the results), some references and comments added; v3: minor additions, matches published versio

On-site correlation in valence and core states of ferromagnetic nickel

We present a method which allows to include narrow-band correlation effects into the description of both valence and core states and we apply it to the prototypical case of nickel. The results of an ab-initio band calculation are used as input mean-field eigenstates for the calculation of self-energy corrections and spectral functions according to a three-body scattering solution of a multi-orbital Hubbard hamiltonian. The calculated quasi-particle spectra show a remarkable agreement with photoemission data in terms of band width, exchange splitting, satellite energy position of valence states, spin polarization of both the main line and the satellite of the 3p core level.Comment: 14 pages, 10 PostScript figures, RevTeX, submitted to PR

The Shapes of Dirichlet Defects

If the vacuum manifold of a field theory has the appropriate topological structure, the theory admits topological structures analogous to the D-branes of string theory, in which defects of one dimension terminate on other defects of higher dimension. The shapes of such defects are analyzed numerically, with special attention paid to the intersection regions. Walls (co-dimension 1 branes) terminating on other walls, global strings (co-dimension 2 branes) and local strings (including gauge fields) terminating on walls are all considered. Connections to supersymmetric field theories, string theory and condensed matter systems are pointed out.Comment: 24 pages, RevTeX, 21 eps figure