Emotional Engineers: Toward Morally Responsible Design

Engineers are normally seen as the archetype of people who make decisions in a rational and quantitative way. However, technological design is not value neutral. The way a technology is designed determines its possibilities, which can, for better or for worse, have consequences for human wellbeing. This leads various scholars to the claim that engineers should explicitly take into account ethical considerations. They are at the cradle of new technological developments and can thereby influence the possible risks and benefits more directly than anybody else. I have argued elsewhere that emotions are an indispensable source of ethical insight into ethical aspects of risk. In this paper I will argue that this means that engineers should also include emotional reflection into their work. This requires a new understanding of the competencies of engineers: they should not be unemotional calculators; quite the opposite, they should work to cultivate their moral emotions and sensitivity, in order to be engaged in morally responsible engineering

The 1996 outburst of GRO J1655-40: the challenge of interpreting the multiwavelength spectra

We report on the results of a multiwavelength campaign to observe the soft X-ray transient (SXT) and superluminal jet source GRO J1655-40 in outburst using HST, RXTE and CGRO together with ground-based facilities. This outburst was qualitatively quite different from other SXT outbursts and from previous outbursts of this source, The onset of hard X-ray activity occurred very slowly, over several months, and was delayed relative to the soft X-ray rise. During this period, the optical fluxes declined steadily. This apparent anticorrelation is not consistent with the standard disc instability model of SXT outbursts, nor is it expected if the optical output is dominated by reprocessed X-rays, as in persistent low-mass X-ray binaries.Based on the strength of the 2175-Angstrom interstellar absorption feature we constrain the reddening to be E(B - V) - 1.2 +/- 0.1, a result which is consistent with the known properties of the source and with the strength of interstellar absorption lines. Using this result we find that our dereddened spectra are dominated by a component peaking, in the optical, with the expected nu(1/3) disc spectrum seen only in the ultraviolet. We consider possible interpretations of this spectrum in terms of thermal emission from the outer accretion disc and/or secondary star, both with and without X-ray irradiation, and also as non-thermal optical synchrotron emission from a compact self-absorbed central source. In addition to the prominent He Ir 4686-Angstrom line, we see Bowen fluorescence Lines of N III and O III, and possible P Cygni profiles in the ultraviolet resonance lines, which can be interpreted in terms of an accretion disc wind. The X-ray spectra broadly resemble the high-soft state commonly seen in black hole candidates, but evolve through two substates.Taken as a whole, the outburst data set cannot readily be interpreted by any standard model for SXT outbursts. We suggest that many of the characteristics could be interpreted in the context of a model combining X-ray irradiation with the limit-cycle disc instability, but with the added ingredient of a very large disc in this long-period system.</p

The remarkable rapid X-ray, ultraviolet, optical and infrared variability in the black hole XTE J1118+480

The transient black-hole binary XTE J1118 + 480 exhibited dramatic rapid variability at all wavelengths which were suitably observed during its 2000 April-July outburst. We examine time-resolved X-ray, ultraviolet, optical and infrared data spanning the plateau phase of the outburst. We find that both X-ray and infrared bands show large amplitude variability. The ultraviolet and optical variability is more subdued, but clearly correlated with that seen in the X-rays. The ultraviolet, at least, appears to be dominated by the continuum, although the lines are also variable. Using the X-ray variations as a reference point, we find that the ultraviolet (UV) variability at long wavelengths occurs later than that at short wavelengths. Uncertainty in the Hubble Space Telescope timing prohibits a determination of the absolute lag with respect to the X-rays, however. The transfer function is clearly not a delta-function, exhibiting significant repeatable structure. For the main signal we can rule out an origin in reprocessing on the companion star - the lack of variation in the lags is not consistent with this, given a relatively high orbital inclination. Weak reprocessing from the disc and/or companion star may be present, but is not required, and another component must dominate the variability. This could be variable synchrotron emission correlated with X-ray variability, consistent with our earlier interpretation of the infrared (IR) flux as due to synchrotron emission rather than thermal disc emission. In fact, the broad-band energy distribution of the variability from IR to X-rays is consistent with expectations of optically thin synchrotron emission. We also follow the evolution of the low-frequency quasi-periodic oscillation in X-rays, UV, and optical. Its properties at all wavelengths are similar, indicating a common origin.</p