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SETI: The Casino Perspective

I like George Johnson’s approach toward SETI. In The Intelligent-Life Lottery, he talks about playing the odds in various ways, and that of course gets us into the subject of gambling. What are the odds you’ll hit the right number combination when you buy a lottery ticket? Whenever I think about the topic, I always remember walking into a casino one long ago summer on the Côte d’Azur. I’ve never had the remotest interest in gambling, and neither did the couple we were with, but my friend pulled a single coin out of his pocket and said he was going to play the slots.

“This is it,” he said, holding up the coin, a simple 5 franc disk (this was before the conversion to the Euro). “No matter what happens, this is all I play.”

He went up to the nearest slot machine and dropped the coin in. Immediately lights flashed and bells rang, and what we later calculated as the equivalent of about $225 came pouring out. Surely, I thought, he’ll take at least one of these coins and play it again — it’s how gambling works. But instead, he headed for the door and we turned the money into a nice meal. $225 isn’t a huge hit, to be sure (not in the vicinity of Monte Carlo!), but calculating the value of the 5 franc coin at about a dollar, he did OK. As far as I know,none of us has ever gone back into a casino.


Image: The Palais de la Méditerranée in Nice. It’s possible to drop a lot of money in here fast, but we got out unscathed.

The odds on winning the grand prize in a lottery are formidable, and Johnson notes that a Powerball prize of $90 million, the result of hitting an arbitrary combination of numbers, went recently to someone who picked up a ticket at a convenience store in Colorado. The odds on that win were, according to Powerball’s own statistics, something like one in 175 million.

Evolutionary biologist Ernst Mayr probably didn’t play the slots, but he used his own calculations of the odds to argue against Carl Sagan’s ideas on extraterrestrial civilizations. No way, said Mayr, intelligence is vanishingly rare. It took several billion years of evolution to produce a species that could build cities and write sonnets. If you’re thinking of the other inhabitants of spaceship Earth, consider that we are one out of billions of species that have evolved in this time. What slight tug in the evolutionary chain might have canceled us out altogether?

Johnson likewise quotes Stephen Jay Gould, who argued that so many chance coincidences put us where we are today that we should be awash in wonder at our very existence. We not only hit the Powerball numbers, but we kept buying tickets, and with each new ticket, we won again and got an even larger prize. Some odds!

For Gould, the fact that any of our ancestral species might easily have been nipped in the bud should fill us “with a new kind of amazement” and “a frisson for the improbability of the event” — a fellow agnostic’s version of an epiphany.

“We came this close (put your thumb about a millimeter away from your index finger), thousands and thousands of times, to erasure by the veering of history down another sensible channel,” he wrote. “Replay the tape a million times,” he proposed, “and I doubt that anything like Homo sapiens would ever evolve again. It is, indeed, a wonderful life.”

A universe filled with planets on which nothing more than algae and slime have evolved? Perhaps, but of course we can’t know this until we look, and I think Seth Shostak gets it right in an essay on The Conversation called We Could Find Alien Life, but Politicians Don’t Have the Will. Seth draws the distinction between searching for life per se, as we are engaged in on places like Mars, and searching for intelligent beings who use technologies to communicate. He’s weighing evolution’s high odds against the sheer numbers of stellar systems we’re discovering, and saying the idea of other intelligence in the universe is at least plausible.

And here the numbers come back into play because, despite my experience in the Nice casino, we’re unlikely to hit a SETI winner with only a few coins. Shostak points out that the proposed 2015 NASA budget allocates $2.5 billion for planetary science, astrophysics and related work including JWST — this encompasses spectroscopy to study the atmospheres of exoplanets, another way we might find traces of living things on other worlds, though not necessarily intelligent species. And while this figure is less than 1/1000th of the total federal budget in the US, the combined budgets for the SETI effort are a thousand times less than what NASA will spend.

“Of course, if you don’t ante up, you will never win the jackpot,” Shostak concludes, yet another gambling reference in a field that is used to astronomical odds and how we might defeat them. I have to say that Mayr’s analysis makes a great deal of sense to me, and so does Gould’s, but I’m with Shostak anyway. The reason is simple: We have no higher calling than to discover our place in the universe, and to do that, the question of whether or not other intelligent species exist is paramount. I’m one of those people who want to be proven wrong, and the way to do that is with a robust SETI effort working across a wide range of wavelengths.

And working, I might add, across a full spectrum of ideas. Optical SETI complements radio SETI, but we can broaden our SETI hunt to include the vast troves of astronomical data our telescopes are producing day after day. We have no notion of how an alien intelligence might behave, but we can look for evidence not only in transmissions but in the composition of stellar atmospheres and asteroid belts, all places we might find clues of advanced species modifying their environment. It is not inconceivable that we might one day find signs of structures, Dyson spheres or swarms or other manipulations of a solar system’s available resources.

So I’m with the gamblers on this. We may have worked out the Powerball odds, but figuring out the odds on intelligent life is an exercise that needs more than a single example to be credible. I’ll add that SETI can teach us a great deal even if we never find evidence of ETI. If we are alone in the galaxy, what would that say about our prospects as we ponder interstellar expansion? Would we, as Michael Michaud says, go on from this to ‘impose intention on chance?’ I think so, for weighing against our destructive impulses, we have a dogged need to explore. SETI is part of our search for meaning in the cosmos, a meaning we can help to create, nurture and sustain.


Comments on this entry are closed.

  • Hiro August 26, 2014, 20:32

    About the Fermi Paradox:

    Probably every single advanced civilizations had their own type of alien writers who wrote some kind of similar version to “The Killing Star” >_< ! But instead of the relativistic rockets or spacecrafts, it's more reasonable to send thousands of vehicle which contain +1000 tons nanobots or killer viruses. This is the main reason why our galaxy is very quiet because nobody wants to become dumb matter.

  • Joëlle B. August 27, 2014, 1:32

    Our imaginations have probably served us well and will more than likely continue to do so. So long as we keep our minds on the probability of alien lifeforms from different worlds, the chances of preparedness for encounters increases. If we throw it under the rug and forget all of the progress so far we have made, though once in hypothetically experimental stages, vulnerability will decrease that preparedness for generations to come who will call the encounters visitations from on high–gods visiting man… A “devolving” would be an apathetic response, much like how if an alien culture identical to humanity came to Earth and interacted with animals–some exciting predation and diseases may be in store, but other than that we can confidently say it’d be pretty boring, especially since that identical culture would have tools to defend itself.

    If I encountered a stone age culture and had access to Type III Kardeshev knowledge and technology (or something equally as advanced), I may find myself in a tempting situation to make my presence advantageous. In fact, as you have observed, Hiro, who is to say that even tens of thousands of years ago this couldn’t have already happened? An alien culture touches down, stays just long enough to do what they want, and leaves before things get iffy after cultural contamination. Sounds practical enough.

    Or better yet, touches down, sets all of the necessary processes in motion to steer us in a direction they planned, only to return at a later time when things appear more favorable, flavorful or effable? :)

    There are a plethora of human cultures who believe they are the result of extraterrestrial origin and intervention. One interesting example is the Dogon people of Mali, who believe they are the descendants of a fish-like species from the Sirius system. Carl Sagan, in his book Broca’s Brain: Reflections on the Romance of Science, criticized claims of two French anthropologists who were allegedly informed by the Dogon of their beliefs and knowledge related to the system. http://en.wikipedia.org/wiki/Nommo

    Our problems communicating ideas to one another and other terrestrial species may mirror how communicating to extraterrestrials may pan out. I remember asking my dog what the purpose of the universe was; as of yet I am unable to decipher his silent response. On the other hand, closer relatives such as Hominidae (Great Apes) show more promising results; but let’s not forget that the relationship is comparable to a godlike/dependency dynamic: in the wild I doubt a Gorilla would be patient enough to let you walk up to it and teach it to sign.

    I predict that the more adaptable an independent species is, combined with its resource management, will affect the way it is willing to communicate with others, regardless of its “intelligence”.

    Viruses are the most abundant biological entity on Earth and play an important role in horizontal gene transfer. They aren’t necessarily “intelligent” and we don’t like to recognize them as “life”, but they seem to be doing the best job in evolution and communication if one adheres to the S&D method. Something we should perhaps note.

  • Holger August 27, 2014, 10:20

    “Recall that with few exceptions, for most of human civilization the idea of beings on other worlds was considered fantasy and even dangerous thinking.”

    I don’t think that’s true. Since humanity has known/believed that other worlds similar to Earth exist (i.e. since Copernicus/Galilei), aliens have been considered or even expected to exist, e.g. by Galilei himself. Even before, aliens on the Moon or the Sun were considered e.g. in 1440 by Cardinal Cusa (http://www.space.com/10663-astronomy-religion-cosmos-intersection-part2.html). Mars and Venus being inhospitable was quite a surprise in the 1960s to many…

    With our technical instruments, we can nowadays perceive everything an alien (or terrestrial animal) conceivably could, unless one considers metaphysical or quantum life.

  • Joëlle B. August 28, 2014, 1:12

    ‘The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. II. Framework, Strategy, and First Result’
    Abstract: “We describe the framework and strategy of the \^G infrared search for extraterrestrial civilizations with large energy supplies, which will use the wide-field infrared surveys of WISE and Spitzer to search for these civilizations’ waste heat. We develop a formalism for translating mid-infrared photometry into quantitative upper limits on extraterrestrial energy supplies. We discuss the likely sources of false positives, how dust can and will contaminate our search, and prospects for distinguishing dust from alien waste heat. We argue that galaxy-spanning civilizations may be easier to distinguish from natural sources than circumstellar civilizations (i.e., Dyson spheres), although Gaia will significantly improve our capability to identify the latter. We present a “zeroth order” null result of our search based on the WISE all-sky catalog: we show, for the first time, that Kardashev Type III civilizations (as Kardashev originally defined them) are very rare in the local universe. More sophisticated searches can extend our methodology to smaller waste heat luminosities, and potentially entirely rule out (or detect) both Kardashev Type III civilizations and new physics that allows for unlimited “free” energy generation.” http://arxiv.org/abs/1408.1134

  • ljk August 28, 2014, 9:51

    To clarify, a few intellectuals in the early history of human civilization seriously considered the concept of life on other worlds, but most people did not. And when the masses did consider it, they usually went with and still go along the lines of science fiction absurdities or UFO legends.

    This is similar to the heliocentric theory. Until Copernicus came along, few seriously considered the idea that Earth goes around Sol. Even today, though the concept is generally accepted, there are people who do not think about such matters, others who still think Earth is the center of everything, and some who outright reject it.

    If anything typical human thought on alien life still has it worse: I rarely come across a discussion of the subject on the Internet which does not bog down into alien abduction stories and other nonscientific fluff, no matter how hard the ones who start the talk try to keep things on a scientific level.
    Aliens are still monsters and a punch line to many people on this planet.

  • Joëlle B. August 28, 2014, 12:41

    Posted these links with their abstracts above the comment I made on August 28, 2014 at 1:12, but are not showing up?

    The Ĝ Infrared Search for Extraterrestrial Civilizations with Large Energy Supplies. I. Background and Justification

    Quantum Tunnelling to the Origin and Evolution of Life

  • Joëlle B. August 28, 2014, 13:12

    “Aliens are still monsters and a punch line to many people on this planet.”

    I think this is changing and only find this amongst an older generation of folks, particularly Westerners, due to the psychological and sociological relationships “abductants” show between peers as observed via media. I also don’t think the laughter is directed solely at the idea of extraterrestrial life, rather the “monster” hovering over your cornfield with the aim of beaming you up into an ominous laboratory to run tests on you and send you back home once experiements are completed.

    As with the Dogon, the idea of extraterrestrial life has sacred underpinnings in most human cultures; and though may be scientifically questionable to the skeptic, holds respectable, often times complex clout to said cultures. When people try to make a joke out of something sacred for the sake of entertainment, then you begin to see attitudes of the program change. This can also have other side effects on the programmed psyche, being unable to define the simple fact that an ‘alien’ simply implies any lifeform foreign to planet Earth. This would of course include many deities people may take for granted as being supernatural or transcendant of all material realizations (metaphysical). By definition, if not originally from Earth, that’s still an extraterrestrial–an alien. Furthermore, if said deity is the result of extraterrestrial intervention (say some type of hybridized form of alien and non-alien) then this is still an alien phenomena–albeit panspermic.

  • ljk August 28, 2014, 14:05

    ​How Escaped Chunks of Earth May Be Seeding Life Throughout the Solar System

    August 27, 2014 // 12:25 PM EST


    The notion that life can hitchhike its way through space via comets and asteroids has captured the human imagination for over a century. The concept, called lithopanspermia, is probably best known from its appearances in science fiction: A space rock that delivers alien life to Earth is one of the genre’s most beloved tropes.

    But did alien rocks bring life to Earth, or was it the other way around? Rather, is it Earth rocks bringing life to alien planets?

    “If it can survive the transfer, it’s likely that life from Earth has already been brought to other planets,” said Rachel Worth, a PhD candidate at Penn State University and lead author of a recent paper published in Astrobiology addressing this very question.

    Full article here:


    The paper here:


  • ljk August 28, 2014, 15:00

    The Dogon were probably heavily influenced by Western visitors to their region. Note how their knowledge of the Sol system seems both rather dated and limited if it came from beings who actually observed the various celestial neighbors.

    That being said, I certainly agree that the heavens have influenced humanity since the dawn of our existence. Remember that our ancestors had a view of the night skies virtually unclouded by light pollution, so just that vista alone could have a major impact on them and their resulting culture without requiring visitors to enhance things.

    Don’t worry, I have no intention of saying that no ETI ever came to Earth or met up with at least some groups of humans and educated them. It is possible, but I am waiting for better evidence than a few stories. Our ancestors had good imaginations, too. They often certainly had us beat in the crazy deities department, to be sure.





  • Hiro August 28, 2014, 18:50

    @ LJK:

    “If anything typical human thought on alien life still has it worse: I rarely come across a discussion of the subject on the Internet which does not bog down into alien abduction stories and other nonscientific fluff, no matter how hard the ones who start the talk try to keep things on a scientific level.”

    At least we don’t invade the land where Earthworms live, not sure about taking away the “females” part, but wasting lots of resource just for these silly thoughts is kinda strange. I believe some advanced civilizations would wipe us out only if we become the big threat to their existences in far future.

    Anyway, this map (http://www.atlasoftheuniverse.com/2billion.html) always reminds me that we aren’t alone in this universe even though this line of reasoning is totally biased; it’s extremely hard to believe that we are the only one around the region of 2 billion ly radius.

  • Joëlle B. August 29, 2014, 1:27

    ljk said on August 28, 2014 at 15:00
    “The Dogon were probably heavily influenced by Western visitors to their region. Note how their knowledge of the Sol system seems both rather dated and limited if it came from beings who actually observed the various celestial neighbors.”

    I am totally against conjecturing a culture’s belief system without actually having any contact with the said practitioners. Various apologetic and/or counter arguments can be made from hearsay, so I’m not in a place to criticize knowledge, even the knowledge of the ‘Nommo’ who may or may not exist and may or may not have had accurate knowledge of a star system foreign to their own when or not when human interaction ensued.

    I’m not defending the notion of whatever the Dogon may believe, but let’s not forget that bias, misinformation, and ignorance are bound to be shared by other forms of intelligent life if we ever come across them.

    Some of those websites you shared, ljk, come across very offensive, doing exactly what I said influences people’s attitudes of life outside of our own experience trying “to make a joke out of something sacred for the sake of entertainment.” A lot of the occurrences of cultural mythologies contain symbolic meaning and deep cosmological/environmental representation of how those people viewed their place in the universe. Some of those belief systems even helped cultures thrive and dominate their environments.

    Remember, we are the result of the universe, of nature–our cultural evolution represents the entirety of creation, abiogenically propagated or otherwise. Mythologies and religions should be respected, sought to be understood on the deepest levels and preserved as we continue to evolve. We don’t necessarily have to adhere to any beliefs, but we can’t act like they are some type of joke, because they’re not–even if generated to simulate parody; for it still represents a human condition, based wholly in cosmology.

  • Joëlle B. August 29, 2014, 5:44

    Hiro said on August 28, 2014 at 18:50
    “I believe some advanced civilizations would wipe us out only if we become the big threat to their existences in far future.”

    It takes far less than that among terrestrial species, even inter-species, to display genocidal tendencies. ET could wipe us out for whatever reason they wanted, even one that would not make sense to us. Think about genocides among human populations to an outsider looking in–it would probably not make any sense, considering the level of cooperation needed among species to successfully traverse foreign, hostile environments i.e. space, using tools. Humans can not yet say they are at a logical state of advancement; we are (seemingly) very much still in a dark age of our evolution if there exists any enlightenment at the end of the tunnel. A eusocial mentality would probably be the most efficient in a Kardashev scheme of resource management for humanoids–but it would become very easy for extinction to happen since eusocial states tend to stagnate unless reversion to a more solitary state is possible.

    Solitary species would probably develop in a way where space colonization wouldn’t be as dire, except for maybe finding a mate and warring over territory if their population grew to substantial numbers. They’d evolve with their home planet and probably be in less danger of extinction, and I’d assume their intelligence would be much more complex than social/hive lifeforms given enough time, due to the complicated inter-species competition. In such a case, your statement may fit for these types of organizations (the majority on this planet). They’d probably develop smarter plans for survival and expansion that wouldn’t require going star system to star system, galaxy to galaxy to gather resources. I predict that such an organism would be a perfect predator of extreme stealth, stability, efficiency and environmental flexibility.

    And then there’s inclusive fitness theory, whereby evolution is driven by reproduction and altruistic social behavior, of which I suggested to ljk in an earlier comment in this topic.

    This is all of course based on Earth’s ecology–who knows what other stellar cradles can and will produce?

    An article worth keeping an eye on regarding some of the above: Risk management of solitary and eusocial reproduction http://arxiv.org/abs/1407.0290

  • ljk August 29, 2014, 13:56

    Back on the Rails with OSETI

    Planetary Society OSETI Going Strong

    Posted by Bruce Betts

    2014/08/29 00:06 UTC

    Topics: Planetary Society Projects, life, SETI

    Sometimes the most advanced space observations, like looking for laser pulse communications from alien civilizations, get interrupted by rather mundane issues. The optical SETI (Search for Extraterrestrial Intelligence) search carried out by Paul Horowitz’s group at Harvard University using The Planetary Society All-Sky Optical SETI Telescope had just such a hiccup awhile back: it literally ran off the rails.

    Full article and images here:


    One thing I find frustrating with The Planetary Society’s Optical SETI program is that they seldom give updates on what is happening, especially when it comes to regular reports. I am not just waiting for them to report an alien signal: I would like to see the regular output as well. If they run into anything unusual, they should alert other observatories to double check their find.

    Apparently now the project is running on automatic, operated by someone in California (the observatory is in Harvard, Massachusetts, near Boston). How quickly can interesting finds be responded to, even with today’s computer technology?

    When their Project BETA broke down due to a windstorm in 1999, nothing was formally announced about this until I kept prodding people for answers. They tried to repair the radio telescope but it proved too expensive and the venerable instrument was dismantled in 2007.


    I don’t know if they can do anything resembling live streaming, but one would think that considering TPS members have donated funds for their OSETI project that something other than an occasional news update they could provide some kind of regular reports.

    I know that TPS has never been quite as enthusiastic about SETI since cofounder Carl Sagan passed in 1996, but so long as they keep declaring they have “the only continual operating SETI search in the world” perhaps TPS should let us members and others in on news and events about it a bit more often.

    Here is the TPS page on their SETI efforts:


  • ljk August 29, 2014, 15:04

    Hiro said on August 28, 2014 at 18:50:

    [LJK] “If anything typical human thought on alien life still has it worse: I rarely come across a discussion of the subject on the Internet which does not bog down into alien abduction stories and other nonscientific fluff, no matter how hard the ones who start the talk try to keep things on a scientific level.”

    [Hiro] “At least we don’t invade the land where Earthworms live, not sure about taking away the “females” part, but wasting lots of resource just for these silly thoughts is kinda strange.”

    Um… what?

    Hiro then said:

    “I believe some advanced civilizations would wipe us out only if we become the big threat to their existences in far future.”

    If such ETI were of that mindset, are you sure they would wait until we were vast and powerful? Why not hedge the bet and conduct a preemptive strike while we are still vulnerable?

    See here and scroll down about halfway to the section “The Killing Star”:


    Hiro then said:

    “Anyway, this map (http://www.atlasoftheuniverse.com/2billion.html) always reminds me that we aren’t alone in this universe even though this line of reasoning is totally biased; it’s extremely hard to believe that we are the only one around the region of 2 billion ly radius.”

    Likely true enough, but why go out 2 billion light years? The 400 billion star systems in the 100,000 light year wide Milky Way galaxy probably have a couple of ETI amongst them too.

  • ljk September 10, 2014, 13:23


    On the role of GRBs on life extinction in the Universe

    Tsvi Piran, Raul Jimenez

    (Submitted on 8 Sep 2014)

    As a copious source of gamma-rays, a nearby Galactic Gamma-Ray Burst (GRB) can be a threat to life. Using recent determinations of the rate of GRBs, their luminosity function and properties of their host galaxies, we estimate the probability that a life-threatening (lethal) GRB would take place.

    Amongst the different kinds of GRBs, long ones are most dangerous. There is a very good chance (but no certainty) that at least one lethal GRB took place during the past 5 Gyr close enough to Earth as to significantly damage life.

    There is a 50% chance that such a lethal GRB took place during the last 500 Myr causing one of the major mass extinction events. Assuming that a similar level of radiation would be lethal to life on other exoplanets hosting life, we explore the potential effects of GRBs to life elsewhere in the Galaxy and the Universe. We find that the probability of a lethal GRB is much larger in the inner Milky Way (95% within a radius of 4 kpc from the galactic center), making it inhospitable to life.

    Only at the outskirts of the Milky Way, at more than 10 kpc from the galactic center, this probability drops below 50%. When considering the Universe as a whole, the safest environments for life (similar to the one on Earth) are the lowest density regions in the outskirts of large galaxies and life can exist in only ~ 10% of galaxies.

    Remarkably, a cosmological constant is essential for such systems to exist. Furthermore, because of both the higher GRB rate and galaxies being smaller, life as it exists on Earth could not take place at z>0.5. Early life forms must have been much more resilient to radiation.

    Subjects: High Energy Astrophysical Phenomena (astro-ph.HE); Cosmology and Nongalactic Astrophysics (astro-ph.CO); Earth and Planetary Astrophysics (astro-ph.EP); Astrophysics of Galaxies (astro-ph.GA); Solar and Stellar Astrophysics (astro-ph.SR)

    Cite as: arXiv:1409.2506 [astro-ph.HE]
    (or arXiv:1409.2506v1 [astro-ph.HE] for this version)

    Submission history

    From: Raul Jimenez [view email]

    [v1] Mon, 8 Sep 2014 20:09:41 GMT (77kb,D)


  • ljk September 10, 2014, 13:24


    An Astrophysical Explanation for the Great Silence

    James Annis

    (Submitted on 22 Jan 1999)

    An astrophysical model is proposed to answer Fermi’s question. Gamma-ray bursts have the correct rates of occurrence and plausibly the correct energetics to have consequences for the evolution of life on a galactic scale.

    If one assumes that they are in fact lethal to land based life throughout the galaxy, one has a mechanism that prevents the rise of intelligence until the mean time between bursts is comparable to the timescale for the evolution of intelligence.

    Astrophysically plausible models suggest the present mean time between bursts to be ∼108 years, and evolutionarily plausible models suggest the rise of intelligence takes ∼108. Hence, this model suggests that the Galaxy is currently undergoing a phase transition between an equilibrium state devoid of intelligent life to a different equilibrium state where it is full of intelligent life.

    Comments: Appeared in JBIS Jan 1999. Since media reports of it are appearing as well, I guess it should appear here too

    Subjects: Astrophysics (astro-ph)

    Cite as: arXiv:astro-ph/9901322
    (or arXiv:astro-ph/9901322v1 for this version)

    Submission history

    From: James Annis [view email]

    [v1] Fri, 22 Jan 1999 20:34:04 GMT (20kb)


  • ljk September 11, 2014, 14:05


    Space ethics to test directed panspermia

    Maxim A. Makukov, Vladimir I. shCherbak

    (Submitted on 20 Jul 2014 (v1), last revised 26 Aug 2014 (this version, v2))

    The hypothesis that Earth was intentionally seeded with life by a preceding extraterrestrial civilization is believed to be currently untestable.

    However, analysis of the situation where humans themselves embark on seeding other planetary systems motivated by survival and propagation of life reveals at least two ethical issues calling for specific solutions.

    Assuming that generally intelligence evolves ethically as it evolves technologically, the same considerations might be applied to test the hypothesis of directed panspermia: if life on Earth was seeded intentionally, the two ethical requirements are expected to be satisfied, what appears to be the case.

    Comments: 6 pages. Accepted in Life Sciences in Space Research. Keywords: astrobiology, directed panspermia, SETI, genetic code, space ethics

    Subjects: Popular Physics (physics.pop-ph); Earth and Planetary Astrophysics (astro-ph.EP)

    Journal reference: Life Sciences in Space Research 3 (2014) 10-17

    DOI: 10.1016/j.lssr.2014.07.003

    Cite as: arXiv:1407.5618 [physics.pop-ph]
    (or arXiv:1407.5618v2 [physics.pop-ph] for this version)

    Submission history

    From: Maxim Makukov [view email]

    [v1] Sun, 20 Jul 2014 05:50:02 GMT (178kb)

    [v2] Tue, 26 Aug 2014 03:44:16 GMT (177kb)


  • ljk September 12, 2014, 10:43

    Mathematicians Say It’s Probable That Alien Probes Have Reached Earth

    By Paul Darin, Epoch Times | July 28, 2014

    he universe is full of mysteries that challenge our current knowledge. In “Beyond Science” Epoch Times collects stories about these strange phenomena to stimulate the imagination and open up previously undreamed of possibilities. Are they true? You decide.

    NASA’s Voyager 1 space probe reached beyond our solar system’s boundary last year, and it’s set to rendezvous with a star named AC+79 3888—in about 40,000 years. It may seem like a long time, but imagine an alien race that’s 40,000 years ahead of us in technological development.

    What if that race sent out a probe 40,000 years ago? Could we be at the receiving end of similar attempts at space exploration? What if that race had a million-year head start on humanity?

    University of Edinburgh professors Arwen Nicholson and Duncan Forgana have pondered such questions and formulated some related theories.

    They published an article in the International Journal of Astrobiology last year explaining techniques that could dramatically cut down the time needed to send probes far and wide. They also said it is not only possible that aliens could reach our solar system with such probes, but they may have even done so a very long time ago. And this may be ongoing, with several different alien cultures sending probes at the same time.

    Furthermore, the probes could be so advanced we would not even be able to detect them. Just because we haven’t seen the probes, said the mathematicians, doesn’t mean they haven’t arrived.

    According to Albert Einstein’s relativity theory, it is impossible to travel faster than the speed of light, and this has led some to question how aliens could reach our planet within any reasonable amount of time if they live so many light-years away.

    Some scientists have begun questioning Einstein’s relativity theory, though it still provides the prevailing framework for understanding cosmic motion. Even within the bounds of this theory, said the researchers, space travel could be much quicker than previously thought.

    Nicholson and Forgana theorize that probes could slingshot themselves around cosmic bodies using the gravitational forces of those bodies. This slingshot maneuver, combined with an ability to self-replicate, could allow alien civilizations to probe the entire Milky Way galaxy within 10 million years without going faster than the speed of light, according to their calculations. Actually, the probes would only need to go 10 percent of the speed of light to accomplish this.

    It may seem that 10 million years is still a completely unreasonable time span, but considering the enormity of the galaxy and the great time span of all of cosmic history, it’s really quite short.

    The two professors built their theory upon the work of mathematician and physicist John Von Neumann, who first postulated the model of the self-replicating machine in the 1940s.

    The concept of the self-replicating, Voyager-like probe follows the idea that a probe is sent to a distant star system, and once it arrives, it collects the necessary resources needed to construct another probe. Once the new probe is finished, it would move onto another system while the parent would stay at its destination and complete its mission.


  • ljk September 17, 2014, 11:10

    Mysterious X-ray Signal Intrigues Astronomers

    For Release: June 24, 2014

    A mysterious X-ray signal has been found in a detailed study of galaxy clusters using NASA’s Chandra X-ray Observatory and ESA’s XMM-Newton. One intriguing possibility is that the X-rays are produced by the decay of sterile neutrinos, a type of particle that has been proposed as a candidate for dark matter.

    While holding exciting potential, these results must be confirmed with additional data to rule out other explanations and determine whether it is plausible that dark matter has been observed.

    Astronomers think dark matter constitutes 85% of the matter in the Universe, but does not emit or absorb light like “normal” matter such as protons, neutrons and electrons that make up the familiar elements observed in planets, stars, and galaxies. Because of this, scientists must use indirect methods to search for clues about dark matter.

    The latest results from Chandra and XMM-Newton consist of an unidentified X-ray emission line, that is, a spike of intensity at a very specific wavelength of X-ray light. Astronomers detected this emission line in the central region of the Perseus galaxy cluster using both Chandra and XMM-Newton. They also found the line in a combined study of 73 other galaxy clusters with XMM-Newton.

    “We know that the dark matter explanation is a long shot, but the pay-off would be huge if we’re right,” said Esra Bulbul of the Harvard-Smithsonian Center for Astrophysics (CfA) in Cambridge, Mass. who led the study. “So we’re going to keep testing this interpretation and see where it takes us.”

    The authors suggest this emission line could be a signature from the decay of a “sterile neutrino.” Sterile neutrinos are a hypothetical type of neutrino that is predicted to interact with normal matter only via gravity. Some scientists have proposed that sterile neutrinos may at least partially explain dark matter.

    “We have a lot of work to do before we can claim, with any confidence, that we’ve found sterile neutrinos,” said Maxim Markevitch, a co-author from NASA’s Goddard Space Flight Center in Greenbelt, Maryland. “But just the possibility of finding them has us very excited.”

    One source of uncertainty is that the detection of this emission line is pushing the capabilities of the two observatories in terms of sensitivity. Also, there may be explanations other than sterile neutrinos if this X-ray emission line is deemed to be real. There are ways that normal matter in the cluster could have produced the line, although the team’s analysis suggested that all of these would involve unlikely changes to our understanding of physical conditions in the galaxy cluster or the details of the atomic physics of extremely hot gases.

    The authors note that even if the sterile neutrino interpretation is correct, their detection does not necessarily imply that all of dark matter is composed of these particles.

    “Our next step is to combine data from Chandra and JAXA’s Suzaku mission for a large number of galaxy clusters to see if we find the same X-ray signal,” said co-author Adam Foster, also of CfA. “There are lots of ideas out there about what these data could represent. We may not know for certain until Astro-H launches, with a new type of X-ray detector that will be able to measure the line with more precision than currently possible.”

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