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The UKSRN met for the first time at NAM2013 in St Andrews, on Friday, July 5 2013.


Session 1  Chair: Alan Penny 
Tim O’Brien SETI at Jodrell Bank
Ian Crawford SETI on the Moon: Limiting the Fermi Paradox
Eamonn Ansbro Searches for Robotic Probes in the Solar System
Duncan Forgan Detecting Class A Stellar Engines Using Exoplanet Transit Curves
Martin Dominik Are there gravitationally-lensed non-repeating short SETI signals?
Session 2  Chair: Bob Nichol 
William Edmondson The Intelligence in ETI
John Elliott Signatures of Post-Biological Intelligence: Extending the Search Spectrum
Stephen Baxter Interstellar Probes and Encounters with Extraterrestrial Intelligence
Anders Sandberg Spamming the universe: very long range colonisation and the Fermi question
Austin Gerig Universal Doomsday: Analysing our Prospects for Survival
Session 3  Chair: Martin Dominik 
Panel Future Prospects for SETI in the UK
Members: Edmondson, Forgan, O’Brien, Penny
General Discussion
William Edmondson Using Exoplanets to refine the Pulsar Beacon approach to SETI
Alan Penny What do you do if you find ET – SETI and the Discovery of Pulsars
Anders Sandberg Hunters in the dark: game theory analysis of the deadly probes scenario

Abstracts and Slides 

Eamonn Ansbro Searches for Robotic Probes in the Solar System
Eamonn Ansbro
Eamonn Ansbro talk 
In the endeavour to detect evidence of ETI in the solar neighbourhood, instrument technologies exist that allow the formation of a scientific search strategy to carry out a search for interstellar robotic probes of possible extraterrestrial origin within the Solar System. The range of hypothetical probe features/characteristics and of currently available detection technologies influence the search strategy and instrument selection.A strategy is proposed including observatory design with the goal of providing an economical, flexible and robust path toward collecting reliable data which has the potential of adding to Solar System knowledge as well as for potential ETI detection. It permits observational sensitivity, multiple bandwidths and high-speed processing to establish a robotic detection system. A scientific search method for robotic probe(s) must use multiple instruments concurrently because multiple characteristics may be present. With multiple instruments and sensors, the data fusion, management, and organisation process is more complicated and analytically challenging. It is also more scientifically sound due to the potential for correlations, and of greater inherent scientific value owing to the richer potential for discovery of unexpected natural phenomena as well as exploring the ETI hypothesis.

A proof of concept proposal for instrumentation is offered to show a design for the purpose collecting scientific data on anomalous observational phenomena that is suitable for the application of rigorous analytical techniques.

Stephen Baxter  Interstellar Probes and Encounters with Extraterrestrial Intelligence
Stephen Baxter
Stephen Baxter talk 
How should we prepare an unmanned probe with general scientific objectives for the possibility of detecting ETI (extraterrestrial intelligence) at the target system? The Pioneer and Voyager probes carried messages in case of contact with ETI. The probability of a probe making a first detection of ETI may be low, but it seems pragmatic to prepare for such possibilities. This paper considers how a probe might detect signs of ETI at the target system, and indeed how ETI might detect a probe. Contact with ETI is a low probability but high impact event, and the philosophy should be that existing systems, especially comms and science suites, should be adapted for the eventuality, rather than dedicated systems added to the design. Options following detection are sketched here. At present we have no publicly agreed policies regarding the management of this kind of contact. Such a policy, balancing the possible benefits of a positive contact on the one hand with threats to the security of mankind following a negative contact on the other, should be developed before the launch of any such probe.
Ian Crawford SETI on the Moon: Constraining the Fermi Paradox
Ian Crawford
Ian Crawford talk 
Scientific interest in the Moon is undergoing a renaissance, and multiple reasons exist for renewed human and robotic exploration of the lunar surface. Although the main scientific reasons for exploring the Moon relate to planetary science questions unrelated to SETI, an ambitious programme of lunar exploration may be expected to advance SETI in at least three ways:(i) The lunar far-side provides a radio-quiet environment unique in the inner Solar System, and SETI would benefit from a lunar radio astronomy infrastructure.

(ii) The lunar regolith may preserve extraterrestrial artefacts. In addition to macroscopic objects that may have been deliberately left on the Moon, these might more plausibly include micron-sized fragments of artificial materials (e.g. exotic alloys) ejected by radiation pressure from planetary systems harbouring spacefaring civilisations. Even non-detection of such particles may permit quantitative limits to be placed on the prevalence or otherwise of technological civilisations in the Galaxy (and thereby constrain inferences drawn from the Fermi Paradox).

(iii) Building up a scientific and industrial infrastructure on the Moon is a potential stepping stone to developing future capabilities (from lunar and/or space-based interferometric telescopes to robotic interstellar probes) that will advance the search for life in the universe in the future.

Progress in all these areas will be greatly facilitated by a human presence on the Moon.

Martin Dominik Are there gravitationally-lensed non-repeating short SETI signals? 
Martin Dominik
Martin Dominik talk 
Gravitational lensing of compact emitters by Milky Way stars has the potential to yield huge magnifications, provided the angular alignment between foreground and background objects is sufficiently small. This might lead to short putative SETI signals arising from extragalactic civilisations, which due to their nature do not repeat. These would allow us to look deep into the Universe, therefore dramatically increasing the search space. On the other hand, the Universe is mostly empty. However, a substantial number of WOW-like signals happens to be observed. If these are related to gravitational lensing by Milky Way stars, their distribution on the sky would follow a characteristic pattern.
William Edmondson The Intelligence in ETI
William Edmondson
William Edmondson talk 
William Edmondson panel talk 
In this talk I revisit and update arguments published in Edmondson (2012). That work elaborated the notion that the functional specification of the brain can be considered to be that it serves the Sequential Imperative (see also Edmondson 2010). The argument in relation to any beings we might consider to be “Extra-Terrestrial Intelligences” is that we can reasonably suppose certain characteristics of their ‘biology’ which include the need for a brain and for that brain to have certain properties. The most important functional property of an ETI’s brain is that it serves the Sequential Imperative (regardless of its neural architecture or biological basis). The chain of reasoning will be set out, with some fresh thinking in respect of both language and cognition.
John Elliott Signatures of Post-Biological Intelligence: Extending the Search Spectrum
John Elliott
John Elliott talk 
In the pursuit for detecting intelligent life beyond our own biosphere, we have (for pragmatic reasons) focused initial efforts that implicitly anthropomorphize detectable phenomena. Whilst developing such methods furthers our capabilities, it still leaves areas on the search spectrum unexplored and potentially ‘blind’ to post-biological [machine] intelligence. Although the rationales behind searches to detect non-biological sentience are not our concern in this paper, our remit is to investigate the likely signatures and contrasting structures such non-biological communicators may present.In the event a signal is detected, our initial categorization and assessment will focus on analyzing comprising constructs, to ascertain whether structures indicate signs of information content; a fundamental signature of intelligence. To ensure our systems are capable of encompassing such intelligent communicators, we need to investigate both the contrasts and similarities of such non-biological communication and how this extends the known spectrum.

To enable this, we present initial findings from investigating a range of known machine communication phenomena and discuss how such contrasting forms of information exchange can aid, extend and refine our detection and decipherment capabilities.

Duncan Forgan Detecting Class A Stellar Engines Using Exoplanet Transit Curves
Duncan Forgan
Duncan Forgan talk 
Stellar engines are defined as megastructures or macro-engineering projects which are designed to leverage a significant fraction of a star’s energy output to generate work.  The Class A stellar engine (also known as a Shkadov thruster) is a spherical arc mirror, designed to use the impulse from a star’s radiation pressure to generate a thrust force, perturbing the star’s orbit around the Galactic centre. If this mirror obstructs part of the stellar disc during the transit of an exoplanet, then this can be detected by studying the shape of the transit light curve, presenting another means by which the action of extraterrestrial intelligence (ETI) can be discerned.We model the light curves produced by exoplanets transiting a star which possesses a Shkadov thruster, and show how the parameters of the planet and the properties of the thruster can be disentangled.  We also estimate the a priori probability of witnessing such a transit, given the existence of the Shkadov thruster, and speculate on the utility of this detection technique as a serendipitous SETI search method in current and future exoplanet transit surveys.
Austin Gerig Universal Doomsday: Analysing our Prospects for Survival
Austin Gerig
Austin Gerig talk 
(co-authors Ken Olum and Alexander Vilenkin)Given a sufficiently large universe, numerous civilizations almost surely exist. Some of these civilizations will be short-lived and die out relatively early in their development, i.e., before having the chance to spread to other planets. Others will be long-lived, potentially colonizing their galaxy and becoming enormous in size. What fraction of civilizations in the universe are long-lived? The “universal doomsday” argument states that long-lived civilizations must be rare because if they were not, we should find ourselves living in one. Furthermore, because long-lived civilizations are rare, our civilization’s prospects for long-term survival are poor. Here, we develop the formalism required for universal doomsday calculations and show that while the argument has some force, our future is not as gloomy as the traditional doomsday argument would suggest, at least when the number of early existential threats is small.
Tim O’Brien SETI at Jodrell Bank
Tim O'Brien
Tim O’Brien talk 
(co-authored with Professor Simon Garrington)Jodrell Bank’s role in SETI dates back to the seminal 1959 paper by Cocconi & Morrison. Their proposal to search for radio signals from extraterrestrial civilisations was inspired by the capabilities of new instruments like Jodrell’s 250 foot Mark I radio telescope. Much later the Lovell Telescope did take part in SETI, working alongside the Arecibo Telescope in the SETI Institute’s Project Phoenix from 1998 to 2003. We are currently completing commissioning of the e-MERLIN array of seven radio telescopes, including the Lovell Telescope, connected by optical fibres and spread over 217 km from Jodrell Bank to Cambridge. At the focus of the synthesised telescope is the new e-MERLIN correlator, a specialised supercomputer which samples and combines signals from the individual telescopes. I will describe the capability of this new system for SETI programmes and report on progress in initial test observations.
Alan Penny Future Prospects for SETI in the UK
Alan Penny
Alan Penny talk 
This session 3 of the SETI sessions will consist of a Panel Discussion, with contributions from the floor, of the future prospects for SETI in the UK.

There is at present very limited SETI activity within the UK academic community and no research council funding at all. Given the substantial prospects for SETI, the substantial work done elsewhere, and its Impact in promoting interest in science in a very receptive public, especially amongst the young, it has been claimed that there is a case for increasing this activity. This session is planned to discuss: whether these prospects are indeed sensible and real; the reasons why the present activity is limited; where there are realistic prospects for greater activity; and the paths forwards.

Starting from a base of the newly formed network of academics in the UK active in SETI, the panel members will make short contributions on their view on the future of SETI in the UK. (The panel members will be four of the morning’s speakers – Edmondson, Forgan, Penny, O’Brien.) There will then be a general discussion, with all contributions from the floor, even negative ones, welcome.

Anders Sandberg Spamming the universe: very long range colonisation and the Fermi question 
Anders Sandberg
Anders Sandberg talk 
Extragalactic SETI and colonisation scenarios have been little analysed, despite the large number of papers on their intragalactic counterparts. This paper presents an exploratory engineering study of the feasibility and requirements of extreme long-range colonisation using automated probes, and the impact this has on the Fermi question. We find that given certain technological assumptions the resources found within a single solar system are more than enough to launch long-range colonisation in such a way that eventually all reachable parts of the universe are touched, and that the timespan and energy expenditures are small enough to be easily overlooked by remote observers. A high fan-out strategy reduces risks of goal divergence between the probes. It appears likely that a species able to perform interstellar colonisation is also able to perform extragalactic colonization on a huge scale. Given the accelerating expansion of the universe early colonizers gain a large advantage in reach: the Milky Way could have been reached by colonizers from millions to billions of galaxies, depending on their speed and time of origin. This makes the Fermi question stronger: any answer involving a low probability filter needs to reduce the probability correspondingly. The exception is “already here” answers like the Zoo hypothesis, that are unchanged or strengthened by this argument. The alternative is to assume a surprisingly low technology ceiling for all civilizations.


William Edmonson Using Exoplanets to Refine the Pulsar Beacon Approach to SETI
William Edmondson
William Edmonson poster 
In this talk I reprise the thinking behind Edmondson & Stevens (2003) which proposes a scheme for using Habstar/Pulsar alignments as the basis for examining specific stars for specific signals. In the intervening period since then the number of exoplanets known has increased markedly (~860 currently) and it now makes sense to consider two elaborations of the original proposal. Firstly, it is worthwhile examining the specific Habstars listed in Edmondson & Stevens 2003 to search for exoplanets, and if any should be found prioritise those Habstars for further examination. Secondly, it is also sensible to consider the inventory of exoplanets found to see if there are any favourable alignments in the manner identified in Edmondson & Stevens.Edmondson, W.H. & Stevens, I.R. 2003. The utilization of pulsars as SETI beacons. International Journal of Astrobiology, 2(4): 231-271.
Alan Penny What do you do if you find ET – SETI and the Discovery of Pulsars 
Alan Penny
Alan Penny poster 
This is a history of astronomy talk, and a lesson on what to do if in your research you stumble on what seems to be evidence for extraterrestrial intelligence.

In the winter of 1967 Cambridge radio astronomers discovered a new type of radio source of such an artificial seeming nature that for a few weeks some members of the group had to seriously consider whether they had discovered an extraterrestrial intelligence. Although their investigations lead them to a natural explanation (they had discovered pulsars), they had discussed the implications if it was indeed an artificial source: how to verify such a conclusion and how to announce it, and whether such a discovery might be dangerous. In this they presaged many of the components of the SETI Detection Protocol.

Anders Sandberg Hunters in the dark: game theory analysis of the deadly probes scenario 
Anders Sandberg
Anders Sandberg poster 
One group of proposed explanations for the Fermi paradox is the “deadly probes scenario”, where some civilizations produce self-replicating devices that prevent other civilizations from coming into being. Whether this kind of scenario works as an explanation depends on whether it is stable and compatible with our own observations (including our own existence as observers). This paper analyses these conditions in more detail.

We analyse a minimalist model of competing probes: probes with finite sensing and action radius are spread out in space, trying to replicate to replace normal attrition losses but in doing so incurring risk of detection from opposing probes. We study different strategies, finding the conditions where incumbent civilizations can retain their advantage versus newcomers. We find that due to the difficulties of quorum sensing rapid widespread replication seems to be the stable strategy, making the scenario a less likely explanation across much of the parameter space.

Anthropic considerations also put restrictions on the scenario: our existence as relatively late observers is incompatible with deadly probe systems effective enough to work as Fermi paradox explanations.

Last updated – 2013 July 22nd

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