7,004 research outputs found
Within the heart's darkness:The role of emotions in Arendt's political thought
Interest in the political relevance of the emotions is growing rapidly. In light of this, Hannah Arendt’s claim that the emotions are apolitical has come under renewed fire. But many critics have misunderstood her views on the relationship between individuals, emotions and the political. This paper addresses this issue by reconstructing the conceptual framework through which Arendt understands the emotions. Arendt often describes the heart – where the emotions reside – as a place of darkness. I begin by tracing this metaphor through her work to demonstrate that it is meant to convey the inherently uncertain nature of emotions rather than a devaluation of them. I proceed to challenge the notion that Arendt adopts the Enlightenment dichotomy between reason and emotion. In fact, she rejects both as a basis for politics. However, she does identify some constructive roles for the emotions. I argue that fear is intrinsically connected to courage – the principal political virtue – in Arendt’s philosophy. In light of my discussion, I then reinterpret the role of compassion and pity in On Revolution, concluding that Arendt’s insights can help us avoid the potential pitfalls of the contemporary project to recuperate the emotions in politics
New measurements of cosmic infrared background fluctuations from early epochs
Cosmic infrared background fluctuations may contain measurable contribution
from objects inaccessible to current telescopic studies, such as the first
stars and other luminous objects in the first Gyr of the Universe's evolution.
In an attempt to uncover this contribution we have analyzed the GOODS data
obtained with the Spitzer IRAC instrument, which are deeper and cover larger
scales than the Spitzer data we have previously analyzed. Here we report these
new measurements of the cosmic infrared background (CIB) fluctuations remaining
after removing cosmic sources to fainter levels than before. The remaining
anisotropies on scales > 0.5 arcmin have a significant clustering component
with a low shot-noise contribution. We show that these fluctuations cannot be
accounted for by instrumental effects, nor by the Solar system and Galactic
foreground emissions and must arise from extragalactic sources.Comment: Ap.J.Letters, in pres
Cosmic Infrared Background Fluctuations and Zodiacal Light
We have performed a specific observational test to measure the effect that
the zodiacal light can have on measurements of the spatial fluctuations of the
near-IR background. Previous estimates of possible fluctuations caused by
zodiacal light have often been extrapolated from observations of the thermal
emission at longer wavelengths and low angular resolution, or from IRAC
observations of high latitude fields where zodiacal light is faint and not
strongly varying with time. The new observations analyzed here target the
COSMOS field, at low ecliptic latitude where the zodiacal light intensity
varies by factors of over the range of solar elongations at which the
field can be observed. We find that the white noise component of the spatial
power spectrum of the background is correlated with the modeled zodiacal light
intensity. Roughly half of the measured white noise is correlated with the
zodiacal light, but a more detailed interpretation of the white noise is
hampered by systematic uncertainties that are evident in the zodiacal light
model. At large angular scales () where excess power above the
white noise is observed, we find no correlation of the power with the modeled
intensity of the zodiacal light. This test clearly indicates that the large
scale power in the infrared background is not being caused by the zodiacal
light.Comment: 17 pp. Accepted for publication in the Ap
Development of a general purpose airborne simulator
Variable stability system development for General Purpose Airborne Simulator /GPAS
Demonstrating the negligible contribution of optical ACS/HST galaxies to source-subtracted cosmic infrared background fluctuations in deep IRAC/Spitzer images
We study the possible contribution of optical galaxies detected with the {\it
Hubble} ACS instrument to the near-IR cosmic infrared (CIB) fluctuations in
deep {\it Spitzer} images. The {\it Spitzer} data used in this analysis are
obtained in the course of the GOODS project from which we select four
independent regions observed at both 3.6 and 4.5
\um. ACS source catalogs for all of these areas are used to construct maps
containing only their emissions in the ACS -bands. We find that
deep Spitzer data exhibit CIB fluctuations remaining after removal of
foreground galaxies of a very different clustering pattern at both 3.6 and 4.5
\um than the ACS galaxies could contribute. We also find that there are very
good correlations between the ACS galaxies and the {\it removed} galaxies in
the Spitzer maps, but practically no correlations remain with the residual
Spitzer maps used to identify the CIB fluctuations. These contributions become
negligible on larger scales used to probe the CIB fluctuations arising from
clustering. This means that the ACS galaxies cannot contribute to the
large-scale CIB fluctuations found in the residual Spitzer data. The absence of
their contributions also means that the CIB fluctuations arise at z\gsim 7.5
as the Lyman break of their sources must be redshifted past the longest ACS
band, or the fluctuations have to originate in the more local but extremely low
luminosity galaxies.Comment: Ap.J.Letters, in press. Minor revisions to mathc the accepted versio
Calibrating Array Detectors
The development of sensitive large format imaging arrays for the infrared
promises to provide revolutionary capabilities for space astronomy. For
example, the Infrared Array Camera (IRAC) on SIRTF will use four 256 x 256
arrays to provide background limited high spatial resolution images of the sky
in the 3 to 8 micron spectral region. In order to reach the performance limits
possible with this generation of sensitive detectors, calibration procedures
must be developed so that uncertainties in detector calibration will always be
dominated by photon statistics from the dark sky as a major system noise
source. In the near infrared, where the faint extragalactic sky is observed
through the scattered and reemitted zodiacal light from our solar system,
calibration is particularly important. Faint sources must be detected on this
brighter local foreground.
We present a procedure for calibrating imaging systems and analyzing such
data. In our approach, by proper choice of observing strategy, information
about detector parameters is encoded in the sky measurements. Proper analysis
allows us to simultaneously solve for sky brightness and detector parameters,
and provides accurate formal error estimates.
This approach allows us to extract the calibration from the observations
themselves; little or no additional information is necessary to allow full
interpretation of the data. Further, this approach allows refinement and
verification of detector parameters during the mission, and thus does not
depend on a priori knowledge of the system or ground calibration for
interpretation of images.Comment: Scheduled for ApJS, June 2000 (16 pages, 3 JPEG figures
The international origins of Hannah Arendt’s historical method
This article examines the multiple ways in which Hannah Arendt’s thought arose historically and in international context, but also how we might think about history and theory in new ways with Arendt. It is commonplace to situate Arendt’s political and historical thought as a response to totalitarianism. However, far less attention has been paid to the significance of other specifically and irreducibly international experiences and events. Virtually all of her singular contributions to political and international thought were influenced by her lived experiences of and historical reflections on statelessness and exile, imperialism, transnational totalitarianism, world wars, the nuclear revolution, the founding of Israel, war crimes trials, and the war in Vietnam. Yet we currently lack a comprehensive reconstruction of the extent to which Arendt’s thought was shaped by the fact of political multiplicity, that there are not one but many polities existing on earth and inhabiting the world. This neglect is surprising in light of the significant ‘international turn’ in the history of thought and intellectual history; the growing interest in Arendt’s thought within international theory; and, above all, Arendt’s own unwavering commitment to plurality not simply as a characteristic of individuals but as an essential and intrinsically valuable effect of distinct territorial entities. The article examines the historical and international context of Arendt’s historical method, including her critique of process- and development-oriented histories that remain current in different social science fields, setting out and evaluating her alternative approach to historical writing
Hannah Arendt
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