Anomalies, Chance Finds and SETI

by Paul Gilster on August 8, 2008

‘Hanny’s Voorwerp’ may soon enter the astronomical lexicon as a reference to anomalous objects in deep space. ‘Hanny’ is Hanny van Arkel, a 25-year old Dutch school teacher and participant in the Galaxy Zoo project, where she and 150,000 other volunteers worldwide help to scan galaxy images online. ‘Voorwerp’ is the Dutch word for ‘object,’ in this case a conglomeration of gas heated to about 10,000 degrees Celsius and marked by a hole in its center. The suspicion grows that van Arkel has stumbled upon an entirely new class of astronomical object.

Out of such finds does the work of a computer-armed volunteer become fodder for the Hubble Space Telescope, which will soon have ‘Hanny’s Voorwerp’ under observation. The object is apparently being illuminated by a source we cannot see, leading the Galaxy Zoo team to look at the nearby galaxy IC 2497. The quasar at the heart of this galaxy seems to have shut down some time in the past 100,000 years — at least, that’s the theory — while its ‘light echo’ persists in our view of the Voorwerp. Chris Lintott, an organizer of the Galaxy Zoo project, puts it this way:

“From the point of view of the Voorwerp, the galaxy looks as bright as it would have before the black hole turned off – it’s this light echo that has been frozen in time for us to observe. It’s rather like examining the scene of a crime where, although we can’t see them, we know the culprit must be lurking somewhere nearby in the shadows.”

Image: ‘Hanny’s Voorwerp’ : the green blob of gas [center] believed to be a ‘light echo’ from the bright, stormy centre of a distant galaxy that has now gone dim. Credit : Dan Smith, Peter Herbert, Matt Jarvis & the ING.

But what caused the hole 16,000 light years across that lies at the center of Hanny’s find? Chances are we’ll be pondering that for some time, with growing interest in what Hubble will see. What a boost for the Galaxy Zoo, which has produced 50 million classifications for a set of one million images online. And what a reminder, too, that at their present state of development, computers aren’t always as capable as people at finding unusual patterns. What they have allowed, of course, is the fecund networking that makes such an exciting project possible.

And if you’re thinking about anomalous objects in deep field images, you should ponder a question Adam Crowl asked recently on his Crowlspace site. Supposing a species somewhere in the universe attains a ‘Singularity’ state and is able to render itself essentially immortal, what will it then do for energy? We may be able to conceive of machine-based intelligence gaining a kind of immortality, and perhaps even the uploading of a biological creature’s consciousness, but stars aren’t immortal, as the inexorable physics of fusion attest.

Adam looks at two recent papers that consider how stellar lifetimes might be extended (see his site for the references), none of them stranger than the black hole quasi-star, which he explains thus:

A star is essentially an object in which the pressure created by inward pull of gravity is counteracted by the outward pressure of escaping electromagnetic energy – either indirectly as particle agitation (what we call ‘heat’) or directly as radiation pressure. Inside a quasi-star the hot layers of gas above the black hole are bloated into a heat-pressure supported radiating surface, a luminous star, by the energy of infalling matter. As matter falls into a black hole it can lose up to ~5.7% of its mass energy as radiation – this is more efficient than a star’s piddling 0.7% energy production via nuclear fusion.

The downside? Violent instability as the result of stellar opacity, which can cause the gaseous envelope around the star to be blown away, exposing the accreting black hole beneath. But maybe there’s another way, a star that actually uses dark matter in the form of WIMPs — Weakly Interacting Massive Particles — to the density of about a billion per milliliter. Now this gets interesting indeed:

…with the right density of WIMPs (about a billion per millilitre) a 20 Solar Mass star can be ‘frozen’ and still be happily burning on the Main Sequence for as long as the current age of the Universe. That’s a life extension of about ~2,000 fold, so it’s definitely enticing to imagine ETIs shepherding Dark Matter into the Galactic Core and giving their stars a life-extension. With a mass-energy conversion efficiency of ~60% the Galaxy’s 1.2 trillion Solar Masses of Dark Matter could keep its stars burning at 30 billion Solar Luminosities (current output) for ~350 trillion years. Much of that luminosity is from over-active O, B and A stars, so the useful light level is more like ~3 billion, thus 3.5 quadrillion years of starlight is available for all to bask in. Not forever, but substantially better than the darkness awaiting the natural Galaxy in that epoch.

Dark matter as an energy source for an advanced civilization takes us way out on a speculative limb, but it’s also an energizing way to ponder our options in next-generation SETI. For if such long-lasting stars, imagined either as ‘quasi-stars’ with black holes at their center or as ‘dark stars’ using the annihilation of dark matter, could be created, what would be their most obvious signature? Would there be a quick way to identify them, something that sets them apart from the wide range of other stellar objects? Or would they, like ‘Hanny’s Voorwerp,’ languish in archival records until dug up by a researcher noting an anomaly?

Geb August 8, 2008 at 17:55

If you are working with megascale engineering, the most sensible way to ensure energy in the long term is to take apart a star and use the material you take from it to make a large number of gas giant planets. Efficiency in production of energy is an insignificant consideration compared to the massive amounts of power that a star wastes in lighting up empty space. Unlike a Dyson sphere which would also prevent loss, you have very fine control over the rate of production of energy.

Once you’ve run out of fusable material you still have plenty of matter left to fuel more exotic schemes such as black hole power.

James M. Essig August 8, 2008 at 22:01

Hi Paul;

This is indeed a very interesting article.

Perhaps one way to power a civilization far beyond 3.5 quadrillion years, perhaps many orders of magnitude beyond, might involve artificial Dyson Sphere like worlds that are electromagnetically extraordinarily highly insulated from interstellar or intergalactic space. Multiple levels of superconducting layers could effectively keep energy within the spheres.

In order to provide a thermodynamic gradient, the energy within a given Dyson Sphere might somehow be gathered into an energy and/or mass beam and transmitted to another Dyson Sphere like mechanism. As the energy within these adjacent energy storage spheres built up, a mechanism to convert the energy back into an appropriate beam form and transmitted it back to the originating Dyson Sphere like habitats could be provided. The energy could be transferred back and forth almost like a friction free pendulum. As the efficiency of the transmission and reradiating system approached 100 percent, the system would tend to a perpetual energy exchange and thermodynamic gradient production machine.

Adam Crowl is doing good work pondering the distant future of humanity and ETI civilizations. As the universe expands and cools, the term sustainability and renewable energy will take on a whole new practical meaning. It is never to late to start planning for the future and I find Adam’s concepts fascinating.

I can imagine methods to extract CMBR as it becomes ever more red-shifted but that is a different story.

Thanks;

Jim

Adam Crowl August 9, 2008 at 0:50

Hi Geb

I don’t imagine that ETIs will just senselessly radiate their star’s energies into space. They will intercept as much as physically possible. Perhaps they will construct a multi-layer habitat around the star – a Matrioshka Shell-World – in which each layer uses the ‘waste’ heat of the layer below it. That way a many and varied energetic ‘ecosystem’ can be employed. We’ve discussed such artefacts before – they will be gigantic if they radiate at just twice the CMB. A 0.1 solar mass star would need a radiator some 600 AU in radius. A more modest radiator at 15 K will still be 20 AU in radius. Such objects would make very interesting microlensing transients – does anyone recall all the fuss over ‘MACHOs’ a few years ago? Too small to be Matrioshka Shell-Worlds, but that’s the kind of thing that a SETA search might look for.

Geb August 9, 2008 at 12:47

My main objection to Dyson sphere type systems is that unless you have some truly incredible energy storage mechanism, you are just reducing waste by using up more energy. Trying to simultaneously put your power budget to more efficient use and reducing the amount of power generated by your star system is a relatively simple fix.

Adam Crowl August 9, 2008 at 23:15

Hi Geb

Dyson and Matrioshka shells both assume massive energy needs by a very, very large number of entities (space cities or Jupiter Brains) – the assumption is that a Type II civilization is running its affairs by using the full total output of its star. Thus waste is arguable. Disassembly of a star like the sun needs about 50 million years of its output in energy – Jupiter is about ~14 million years worth. Where do you propose we get the rest if not from the Sun? And after all that enveloping and star mining why bother to then disassemble it? Your plan makes no sense.

Icelander August 10, 2008 at 8:31

“Hanny’s Voorwerp” sounds like something straight out of “The Hitchhiker’s Guide to the Galaxy.”

djlactin August 11, 2008 at 3:12

actually, icelander is on the right track: but the proper term is ‘great green arkle-seizure’

ljk August 15, 2008 at 8:04

A Bursting Radio Transient in the Direction of the Galactic Center

Authors: Paul S. Ray, Scott D. Hyman, T. Joseph Lazio, Namir E. Kassim, Subhashis Roy, David L. Kaplan, Deepto Chakrabarty

(Submitted on 13 Aug 2008)

Abstract: The radio sky is poorly sampled for rapidly varying transients because of the narrow field-of-view of most imaging radio telescopes at cm and shorter wavelengths. The emergence of sensitive long wavelength observations with intrinsically larger fields-of-view are changing this situation, as partly illustrated by our ongoing meter-wavelength monitoring observations and archival studies of the Galactic Center.

In this search, we discovered a transient, bursting, radio source in the direction of the Galactic Center, GCRT J1745-3009, with extremely unusual properties. Its flux and rapid variability imply a brightness temperature >10^12 K if it is at a distance >70 pc, implying that it is a coherent emitter.

I will discuss the discovery of the source and the subsequent re-detections, as well as searches for counterparts at other wavelengths, and several proposed models.

Comments: 11 pages, 2 figures, to appear in proceedings of “Bursts, Pulses and Flickering: Wide-field monitoring of the dynamic radio sky” held in Kerastari, Tripolis, Greece in June 2007, published by Proceedings of Science, PoS(Dynamic2007)008

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0808.1899v1 [astro-ph]

Submission history

From: Paul S. Ray [view email]

[v1] Wed, 13 Aug 2008 21:20:06 GMT (369kb,D)

http://arxiv.org/abs/0808.1899

ljk August 21, 2008 at 22:53

http://newsinfo.nd.edu/printerFriendly.cfm?topicid=29146

Extraterrestrials invade Notre Dame: The truth is out there…in the library

By: Michael O. Garvey

Date: August 20, 2008

On March 13, 1997, thousands of people in Arizona, Nevada and the Mexican state of Sonora reported the appearance of strangely mobile luminescent formations in the night skies.

Among the witnesses of what soon became known as the “Phoenix Lights” was Arizona’s governor, Fife Symington, who first ridiculed the credulity of the predictably ensuing throngs of UFO advocates—during a news conference at which he stood beside an aide dressed in an “ET” costume—but later admitted that he had, in fact, seen something he thought otherwise inexplicable, observing to a reporter that “the universe is a big place. We’re conceited to think we’re alone.”

Alone or not, we may be forgiven at least a degree of chariness when invited to consider “The X Files” as anything more than light entertainment. Nevertheless, the loony vulgarity of contemporary obsession with extraterrestrial life can obscure the fact that this is an ancient and respectable speculation which has interested even greater and perhaps less credulous thinkers than Gov. Symington for more than two millennia.

Michael Crowe puts it wryly and arrestingly in the preface to his book “The Extraterrestrial Life Debate, Antiquity to 1915: A Source Book,” which recently was published by the University of Notre Dame Press.

“Although making no claims about whether or not extraterrestrials exist,” he writes, “I shall cite evidence to show that they have long since invaded and that their effects can be uncovered by historical research.”

Crowe, Notre Dame’s Rev. John J. Cavanaugh Professor Emeritus in Humanities in the Program of Liberal Studies, is not talking about crop circles and flying saucer wreckage in the New Mexican desert. He is talking about the writings of Aristotle, Lucretius, St. Thomas Aquinas, Galileo, Kepler, Pascal, Newton, Voltaire, Kant, Darwin, and Dostoevsky, to name only a few.

In fact, Crowe argues that the debate over extraterrestrial life is evident throughout Western history and has involved half its most celebrated intellectuals. In other words, “already in the premodern period extraterrestrials had made their entrance into terrestrial thought.”

One fascinating conclusion Crowe draws from his research regards the 16th century astronomer Nicolaus Copernicus, whom he holds responsible for the extraterrestrial invasion of the modern era. It was the Copernican displacement of the Earth from the center of the universe which unwittingly “opened the door an inch” and allowed moderns to imagine a plurality of worlds.

“To put the point differently,” Crowe writes, “the celibate canon of the cathedral in Frauenberg acted in a manner that has left him open to the charge that he is the father, or at least the grandfather, of Darth Vader, ‘ET’, Alf, Mork and the whole tribe of extraterrestrials we know so well.”

One early and enthusiastic reviewer of Crowe’s book was Steven J. Dick, director of NASA’s history vision, who praised the book for its arrangement of material “not available anywhere else. . . . Crowe’s purpose is to let the reader see the original words of the authors who discussed other worlds. . . . Such a source book serves an important purpose, and is ideal for teaching and generating discussion in class. The subject is of increasing importance as we find more and more about the possibilities of extraterrestrial life through current disciplines such as astrobiology, bioastronomy, and the Search for Extraterrestrial Intelligence (SETI).”

Indeed, Crowe will be using his new book to teach and generate discussion in the University Seminar course he teaches each fall, “The Extraterrestrial Life Debate: A Historical Perspective.”

“One of my goals in the course is to present the students with the history and present state of one of the great questions we have faced for 25 centuries and that continues to challenge us,” Crowe says. “I also hope that the students will come to see an approach to this question very different from what sometimes appears in the media, which at times tends to treat this serious topic in a sensationalist manner.

“In other words, I hope the students will see that science and scientific method, good, careful scholarship and thought in a variety of disciplines, can provide significant insights into this very complex topic. In fact, I hope they will come to realize that this is true in regard to many other issues, including those that the public learns about chiefly from entertainment TV and popular journals.”

Who knew those little green men were so erudite?

Contact: Michael Crowe at 574-631-6212 or Crowe.1@nd.edu

ljk October 20, 2008 at 23:45

A Numerical Testbed for Hypotheses of Extraterrestrial Life and Intelligence

Authors: Duncan Forgan

(Submitted on 13 Oct 2008)

Abstract: The search for extraterrestrial intelligence (SETI) has been heavily influenced by solutions to the Drake Equation, which returns an integer value for the number of communicating civilisations resident in the Milky Way, and by the Fermi Paradox, glibly stated as: “If they are there, where are they?”. Both rely on using average values of key parameters, such as the mean signal lifetime of a communicating civilisation. A more accurate answer must take into account the distribution of stellar, planetary and biological attributes in the galaxy, as well as the stochastic nature of evolution itself.

This paper outlines a method of Monte Carlo realisation which does this, and hence allows an estimation of the distribution of key parameters in SETI, as well as allowing a quantification of their errors (and the level of ignorance therein). Furthermore, it provides a means for competing theories of life and intelligence to be compared quantitatively.

Comments: 22 pages, 24 figures, accepted by the International Journal of Astrobiology

Subjects: Astrophysics (astro-ph)

Cite as: arXiv:0810.2222v1 [astro-ph]

Submission history

From: Duncan Forgan [view email]

[v1] Mon, 13 Oct 2008 12:33:50 GMT (94kb)

http://arxiv.org/abs/0810.2222

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