3,867 research outputs found
The application of the Mid-IR radio correlation to the sample and the search for advanced extraterrestrial civilisations
Wright et al. 2014 have embarked on a search for advanced Karadashev Type III
civilisations via the compilation of a sample of sources with extreme mid-IR
emission and colours. In this scenario, the mid-IR emission is then primarily
associated with waste heat energy by-products. I apply the Mid-IR radio
correlation to this sample (Griffith et al. 2015). I demonstrate that
the mid-IR and radio luminosities are correlated for the sample with
. By comparison, the First Look Survey (FLS) has
. The fact that the G-HAT sample largely follows the Mid-IR
radio correlation, strongly suggests the vast majority of these sources are
associated with galaxies in which natural astrophysical processes are dominant.
This simple application of the mid-IR radio correlation can substantially
reduce the number of false positives in the catalogue, since galaxies
occupied by advanced Kardashev Type III civilisations would be expected to
exhibit very high values of . Indeed I identify 9 outliers in the sample
with of which at least 3 have properties that are relatively well
explained via standard astrophysical interpretations e.g. dust emission
associated with nascent star formation and/or nuclear activity from a heavily
obscured AGN. I also note that the comparison of resolved Mid-IR and radio
images of galaxies on sub-galactic (kpc) scales can also be useful in
identifying and recognising artificial mid-IR emission from less advanced
intermediate Type II/III civilisations. Nevertheless, from the bulk properties
of the sample, I conclude that Kardashev Type-III civilisations are
either very rare or do not exist in the local Universe.Comment: Accepted A&A letters, 6 pages, 2 figures in Letter in Astronomy &
Astrophysics, 201
Big Data analytics and Cognitive Computing: future opportunities for Astronomical research
The days of the lone astronomer with his optical telescope and photographic
plates are long gone: Astronomy in 2025 will not only be multi-wavelength, but
multi-messenger, and dominated by huge data sets and matching data rates.
Catalogues listing detailed properties of billions of objects will in
themselves require a new industrial-scale approach to scientific discovery,
requiring the latest techniques of advanced data analytics and an early
engagement with the first generation of cognitive computing systems.
Astronomers have the opportunity to be early adopters of these new technologies
and methodologies: the impact can be profound and highly beneficial to
effecting rapid progress in the field. Areas such as SETI research might
favourably benefit from cognitive intelligence that does not rely on human bias
and preconceptions.Comment: 4 pages, 1 figure. Paper presented at 2nd Radio and Antenna Days of
the Indian Ocean (RADIO 2014
SETI reloaded, Next Generation Radio Telescopes, Transients and Cognitive Computing
The Search for Extra-terrestrial Intelligence (SETI) using radio telescopes
is an area of research that is now more than 50 years old. Thus far, both
targeted and wide-area surveys have yet to detect artificial signals from
intelligent civilisations. In this paper, I argue that the incidence of
co-existing intelligent and communicating civilisations is probably small in
the Milky Way. While this makes successful SETI searches a very difficult
pursuit indeed, the huge impact of even a single detection requires us to
continue the search. A substantial increase in the overall performance of radio
telescopes (and in particular future wide-field instruments such as the Square
Kilometre Array, SKA), provide renewed optimism in the field. Evidence for this
is already to be seen in the success of SETI researchers in acquiring
observations on some of the world's most sensitive radio telescope facilities
via open, peer-reviewed processes. The increasing interest in the dynamic radio
sky, and our ability to detect new and rapid transient phenomena such as Fast
Radio Bursts (FRB) is also greatly encouraging. While the nature of FRBs is not
yet fully understood, I argue they are unlikely to be the signature of distant
extra-terrestrial civilisations. As astronomers face a data avalanche on all
sides, advances made in related areas such as advanced Big Data analytics, and
cognitive computing are crucial to enable serendipitous discoveries to be made.
In any case, as the era of the SKA fast approaches, the prospects of a SETI
detection have never have been better.Comment: 5 pages, 3 figures, Acta Astronautica 201
All-sky Radio SETI
Over the last decade, Aperture Arrays (AA) have successfully replaced
parabolic dishes as the technology of choice at low radio frequencies - good
examples are the MWA, LWA and LOFAR. Aperture Array based telescopes present
several advantages, including sensitivity to the sky over a very wide
field-of-view. As digital and data processing systems continue to advance, an
all-sky capability is set to emerge, even at GHz frequencies. We argue that
assuming SETI events are both rare and transitory in nature, an instrument with
a large field-of-view, operating around the so-called water-hole (1-2 GHz),
might offer several advantages over contemporary searches. Sir Arthur C. Clarke
was the first to recognise the potential importance of an all-sky radio SETI
capability, as presented in his book, Imperial Earth. As part of the global SKA
(Square Kilometre Array) project, a Mid-Frequency Aperture Array (MFAA)
prototype known as MANTIS (Mid- Frequency Aperture Array Transient and
Intensity-Mapping System) is now being considered as a precursor for SKA-2.
MANTIS can be seen as a first step towards an all-sky radio SETI capability at
GHz frequencies. This development has the potential to transform the field of
SETI research, in addition to several other scientific programmes.Comment: 7 pages, 4 figures, accepted for publication, Proceedings of Science,
workshop on "MeerKAT Science: On the Pathway to the SKA", held in
Stellenbosch 25-27 May 2016. Comments welcom
Near-field antenna testing using the Hewlett Packard 8510 automated network analyzer
Near-field antenna measurements were made using a Hewlett-Packard 8510 automated network analyzer. This system features measurement sensitivity better than -90 dBm, at measurement speeds of one data point per millisecond in the fast data acquisition mode. The system was configured using external, even harmonic mixers and a fiber optic distributed local oscillator signal. Additionally, the time domain capability of the HP8510, made it possible to generate far-field diagnostic results immediately after data acquisition without the use of an external computer
No ifs, ands or butts: Illinois casinos lost revenue after smoking banned
Gambling industry ; Tobacco industry ; Illinois
Casino revenue and the Illinois smoking ban
Smoking was banned in all Illinois casinos in January 2008. We explore the effects that the smoking ban has had on Illinois casino revenue and attendance. Our empirical methodology extends and enhances that of previous literature in that we observe a natural experiment in comparing the performance of Illinois casinos with out-of-state casinos (no smoking ban) that share a market with Illinois casinos. Estimates suggest that revenue and admissions at Illinois casinos declined by more than 20 percent (200 million.Gambling industry ; Tobacco industry ; Illinois
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