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Thread: [47 Tucanae]

  1. #1

    [47 Tucanae]

    On the subject of evidence, anybody knows what happened with that alleged signal caught coming from 47 Tucanae?

  2. #2
    *cough* 47 Tucanae *cough* .... anyone?

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    Posts above moved from : http://www.bautforum.com/showthread....but-not-proven.

    Please don't repeat questions ("bump") just because nobody has answered according to your schedule.
    Thank you, members of cosmoquest forum, you are a part of my life I value.

  4. #4
    Quote Originally Posted by pzkpfw View Post
    Posts above moved from : http://www.bautforum.com/showthread....but-not-proven.

    Please don't repeat questions ("bump") just because nobody has answered according to your schedule.
    I thought I was ignored. Why are they moved anyway? They had everything to do with the topic.

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    Quote Originally Posted by NeptuneRise View Post
    I thought I was ignored. Why are they moved anyway? They had everything to do with the topic.
    These posts were moved to give them higher visibility, and because they are about a much more specific topic than the OP. In my opinion, they weren't ignored, but you did not supply enough information or link to make it easy for most viewers to comment. I personally don't know about this alleged signal, and was not intrigued enough to look it up myself, and hence had no comment... but I certainly would have followed a link, or have been interested in your synopsis of what that signal was.
    Forming opinions as we speak

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    i think its the australian seti laser signal right?

    theres a thread on here about it... bit of a nothing story if thats what they are talking about

    http://www.bautforum.com/showthread....hlight=Bhathal

  7. #7
    Quote Originally Posted by antoniseb View Post
    These posts were moved to give them higher visibility, and because they are about a much more specific topic than the OP. In my opinion, they weren't ignored, but you did not supply enough information or link to make it easy for most viewers to comment. I personally don't know about this alleged signal, and was not intrigued enough to look it up myself, and hence had no comment... but I certainly would have followed a link, or have been interested in your synopsis of what that signal was.
    Oh, okay then, thanks for that.

    I'm not sure where I read it, it just clicked to me as the topic dealt with evidence (direct/indirect) of extraterrestrials in space, and I remembered reading somewhere about this signal (and another one from M67, claimed by a Ukranian astronomer), but at the time it was a fresh news, so I never looked it up to see a follow up to where the investigation has went since then.

    It seems from my search that the signal was not confirmed again (I guess they thought they could catch it again, or a third time, even though everything in space moves and that is virtually impossible, unless the signal was directed). It was caught by Dr. Ragbir Bhathal from the Optical SETI Network based in Australia. It was indicated in the Astrobiology Conference Australia 2010 paper. The description is the following "In December 2008 a sharp laser look alike signal emanating from 47 Tucanae was detected."

    Bhathal's team detected an unusual strong laser signal that could not have been identified nor did it re-occur since: "It may be a glitch in our equipment, or some astrophysical phenomena (e.g an optical pulsar) or some unknown source. We are still investigating it", told Bhathal to the German online-newsmagazine "Grenzwissenschaft-aktuell.de".

    Even if still unidentified, the signal's discovery seems to have created enough enthusiasm within the team to mark it with a "Was t ET?"-comment - not unlike the famous "Wow"-Mark next to the detection of a strong, narrowband radio signal detected by Dr. Jerry R. Ehman on August 15, 1977, while working on a SETI project at the Big Ear radio telescope of Ohio State University.
    04836.jpg
    04840.jpg

    ^ ^ ^ The signal, now dubbed "Is it ET?"

    Another set of sources.

    I find it curious that in one research paper, they say they had this anomalous data, indicating that 47 Tucanae could be well over 20 billion years old, which goes contrary to the standard accepted theories on the age of the universe. And considering it has metal-rich stars, it would indicate that its from a "new" enough generation.

    Any thoughts guys?

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    47 Tucanae is a globular cluster 16700 light years away. Any light signal from that distance would not receive an answer for 33 thousand years. I think that, if they really wanted converse at that distance, they should probably have sent a slightly longer message than one lasting a few seconds.

    In a conversation that consists of only a few seconds of data transmission every thirty thousand years or so, not a great deal of information is exchanged.

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    i forget the detail, but the good folk at seti seemed to think that you would expect to see an attention attracting simple beacon in the first instance. that dosnt mean to say they would wait for a return signal before sending a greeting, but you wouldnt necessarily expect to see them at the same time.

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    Quote Originally Posted by NeptuneRise View Post
    I find it curious that in one research paper, they say they had this anomalous data, indicating that 47 Tucanae could be well over 20 billion years old, which goes contrary to the standard accepted theories on the age of the universe.
    I'm seeing estimates of about 13 billion years. What research paper was this from, and when was it written? If it's an older paper, that wouldn't be a surprising age estimate. The universe age estimates have narrowed down considerably in recent years, and some technical issues involved with estimates have been resolved. If it's recent, I'd be curious about provenance (as in, was this study peer reviewed, and if so, where?).


    It seems from my search that the signal was not confirmed again (I guess they thought they could catch it again, or a third time, even though everything in space moves and that is virtually impossible, unless the signal was directed).
    At that distance, if it were real it would have to be directed unless it was extremely powerful (significant compared to a star's output), but even if directed the beam spread would be considerable. Relative motion of the sun versus any possible source there would only be an issue over long periods, and if it were real, I can't imagine why someone would only send one short message.

    "The problem with quotes on the Internet is that it is hard to verify their authenticity." Abraham Lincoln

    I say there is an invisible elf in my backyard. How do you prove that I am wrong?

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    Quote Originally Posted by Van Rijn View Post
    At that distance, if it were real it would have to be directed unless it was extremely powerful (significant compared to a star's output), but even if directed the beam spread would be considerable. Relative motion of the sun versus any possible source there would only be an issue over long periods, and if it were real, I can't imagine why someone would only send one short message.
    alien hunters seem to think laser beacons are by far the most likely method that would be used. They say you can use a directed beam with far less energy than any other method known to us. A concentrated beam having the apparent brightness of a supernova. This would be to grab attention.
    Because it needs to be directed, you would not expect to see it continuosly - presumably ET would have many potential targets it would cycle through.
    Any message would use a different method once it had got you looking in that direction...something like free electron lasers.
    seth shostak has been an advocate of seti turning its attention to this kind of search for some time now.

    From what i gather, the chances of ever being able to decipher a message are extremely small, possibly so low that one wouldnt be sent. The only expectation might be that you would flash back at them when you had the means.
    Last edited by mutleyeng; 2012-Apr-27 at 11:20 PM.

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    I see it's already pretty much covered, but to add.. It appears to have been beaten up by the Daily Mail, who tangled up two different things for a story.. The Daily Mail doesn't need a slow news day to do that sort of thing..

    World of Weird Things article
    The Australian news article

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    Quote Originally Posted by mutleyeng View Post
    i forget the detail, but the good folk at seti seemed to think that you would expect to see an attention attracting simple beacon in the first instance. that dosnt mean to say they would wait for a return signal before sending a greeting, but you wouldnt necessarily expect to see them at the same time.
    Sending out messages and not waiting for an answer is as pointless as shouting into a bucket.

    I can call spirits from the vasty deep.
    Why so can I, and so can any man- but will they come when you do call for them?

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    Quote Originally Posted by eburacum45 View Post
    Sending out messages and not waiting for an answer is as pointless as shouting into a bucket.

    I can call spirits from the vasty deep.
    Why so can I, and so can any man- but will they come when you do call for them?
    again, the point is, a beacon gets you looking at the right point in the sky... which as has been pointed out might not even be that close to their star.. relatively speaking. A light beacon is not thought to be more than a means of pin pointing a place to look.
    The assumption is that they will have done their own Kepleresque searches and identified thousands of potentials.
    They would have their own optical searches to see if they got a responce ...which dosnt require much energy at all.
    Like i said, this is what the folk at seti think would be a likely method used by an advanced race seeking to answer the same questions we have.
    There has also been folk thinking about whether we would have any chance to decipher alien messages .. unless they had some knowledge of us, then a random signal not specifically intended for us would probably be impossible to crack.

  15. #15
    Quote Originally Posted by Van Rijn View Post
    I'm seeing estimates of about 13 billion years. What research paper was this from, and when was it written? If it's an older paper, that wouldn't be a surprising age estimate. The universe age estimates have narrowed down considerably in recent years, and some technical issues involved with estimates have been resolved. If it's recent, I'd be curious about provenance (as in, was this study peer reviewed, and if so, where?).
    Well yes, the research paper has been peer reviewed, but as you guessed, you were right, its an older one, from 1999. It has been conducted by the "American Astronomical Society", and I found it on the http://iopscience.iop.org website, titled as "The Spectroscopic Age of 47 Tucanae".

    At first I thought maybe I misinterpreted something, as I don't always understand the technical/scientific jargon there (and I may have still, confused something about it, I'm not denying that), but this is what confused me and out of curiosity, thought I would share so somebody can explain if its what I thought it was:

    "Because of its weak series of Balmer lines relative to model spectra, our results imply a spectroscopic age of 47 Tuc well in excess of 20 Gyr, which is at odds with the color-magnitude diagram age of 14 1 Gyr. The derived metal abundance, however, is consistent with the known value. Although the observational constraints are restrictive, existing data cannot entirely exclude emission "fill-in" of the Hγ line as the source of the discrepancy."

    I'm interested what the last sentence means?

    Quote Originally Posted by Van Rijn View Post
    At that distance, if it were real it would have to be directed unless it was extremely powerful (significant compared to a star's output), but even if directed the beam spread would be considerable. Relative motion of the sun versus any possible source there would only be an issue over long periods, and if it were real, I can't imagine why someone would only send one short message.
    Well, if its really aliens in question, we can only play guesswork as to why they would sent just a short message. If they think different then us (logically, as they are aliens), maybe it would make sense that for us, it would seem illogical thing to do.

    Then again, this could very well be what the team also suspected - an optical pulsar, was something they said I believe. Or some other cosmic phenomena, we are yet to define, that doesn't have to mean - extraterrestrials.

    Quote Originally Posted by mutleyeng View Post
    alien hunters seem to think laser beacons are by far the most likely method that would be used. They say you can use a directed beam with far less energy than any other method known to us. A concentrated beam having the apparent brightness of a supernova. This would be to grab attention.
    Because it needs to be directed, you would not expect to see it continuosly - presumably ET would have many potential targets it would cycle through.
    Any message would use a different method once it had got you looking in that direction...something like free electron lasers.
    seth shostak has been an advocate of seti turning its attention to this kind of search for some time now.

    From what i gather, the chances of ever being able to decipher a message are extremely small, possibly so low that one wouldnt be sent. The only expectation might be that you would flash back at them when you had the means.
    Yes. I'm not sure why there has to be three consecutive hits, in order to be deemed the "real deal". Two would be enough, heck, even one hit, if studied enough, could be reveling enough if its extraterrestrial in origin.

    I guess the scientific community has this fear of confirming anything, then later be proven wrong (damaging credibility etc.).

    I agree though, that we would not be able to be hit with it continuously, as I also think that there would be better targets closer by then our star system. It would suck if in 16.700 light years radius, we are the only other form of intelligent life (assuming this is indeed from an extraterrestrial origin, it could very well be something else).

    But I seriously doubt the other explanation, that it could be an equipment malfunction.

    Quote Originally Posted by chrlzs View Post
    I see it's already pretty much covered, but to add.. It appears to have been beaten up by the Daily Mail, who tangled up two different things for a story.. The Daily Mail doesn't need a slow news day to do that sort of thing..

    World of Weird Things article
    The Australian news article
    Yes, there was some connection with this guy, and some stupid claim that he detected the signal not from 47 Tucanae, but from Gliese 581. I tried explaining this, but people were too hyped up about it, they stuck with the original story, done by some journalist who either did it on purpose, to gain more readership/views, or they confused together two separate events.

    This is why I think astronomy news should be only reported by astronomers, not anyone else.



    Thanks for the comments guys. I just thought that even if this is not an extraterrestrial signal case, that it may spark some discussion, and ponder on the ideas of what an actual event like this might bring to the table, purely on speculative means, from the detection, the place of detection, form of the signal, the deciphering, the contents, the public reaction, aftermath etc.

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    Quote Originally Posted by NeptuneRise View Post

    But I seriously doubt the other explanation, that it could be an equipment malfunction.
    why?
    With seti radio search these are 10 a penny.
    As seth often says, the only thing that stood out about the Wow signal was that someone wrote "wow" next to it.

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    The assumption is that they will have done their own Kepleresque searches and identified thousands of potentials.
    They would have their own optical searches to see if they got a response ...which doesn't require much energy at all.
    If they really are in 47 Tucanae then they would need to wait a very long time for an answer; but perhaps they have a different subjective experience of time to humans, in which case they probably don't have much in common with us at all.

    On the other hand they might experience time just like we do- in which case these interstellar pings will almost certainly be forgotten in 33 thousand years time. we have, for our part, almost completely forgotten about the Arecibo Message, sent in 1974 to a different globular cluster but one which is very much like 47 Tucanae in most characteristics;
    http://en.wikipedia.org/wiki/Arecibo_Message

    On the gripping hand the ping might have come from another star near 47 Tuc in the sky, but much closer to Earth (maybe Zeta Tucanae, for example) - in which case the transmission wasn't much good as a directional beacon, really...

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    whats 33k to a civilisation that may have been around for millions.
    Optical beacons dont need much energy... once you are a space going civilisation you can just let the experiment run with very little cost to the society. The same cannot be said for sending radio waves that can be detectable hundreds of light years away.
    The other advantage is that the ability to send and recieve such greetings would be available to civilisations in their very early stages of technological progression.
    The location of the source isnt so tough once you looking in the right direction.
    It just depends i guess on whether you think seti is worthwhile in the first place.
    If i were paying for it, id say go the full hog optical. The chances of recognising radio signals traveling light years are just not worth the effort IMO.
    We have seen in our own short experience that it dosnt take long for a planet to go quiet, unless it is deliberately announcing itself.

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    The idea of a galactic society of civilisations all happily conversing by optical laser is a good one with quite a long pedigree, and is one of the more optimistic solutions to the Fermi Paradox. There could be thousands of civilisations out there exchanging data and even uploaded mindstates freely across the light years without ever coming into physical contact. Some call it the Interstellar Internet.
    http://www.darkmattermag.com/july03/dark_science.html

    There are two things that strike me about this scenario; in a society where no-body ever meets each other, it is very possible for a civilisation to lie about its characteristics; the Daleks could present themselves as being like cuddly Ewoks, and so on. This would only be a danger if we ever met them, or if they have very-long-range weapon systems (neither of which are impossible).

    ...secondly an interstellar internet would work best between stars a few tens of light years apart; those poor saps out there in 47 Tucanae probably feel a bit left out, and wonder why everyone ignores their friend requests...

  20. #20
    Quote Originally Posted by mutleyeng View Post
    whats 33k to a civilisation that may have been around for millions.
    Optical beacons dont need much energy... once you are a space going civilisation you can just let the experiment run with very little cost to the society. The same cannot be said for sending radio waves that can be detectable hundreds of light years away.
    The other advantage is that the ability to send and recieve such greetings would be available to civilisations in their very early stages of technological progression.
    The location of the source isnt so tough once you looking in the right direction.
    It just depends i guess on whether you think seti is worthwhile in the first place.
    If i were paying for it, id say go the full hog optical. The chances of recognising radio signals traveling light years are just not worth the effort IMO.
    We have seen in our own short experience that it dosnt take long for a planet to go quiet, unless it is deliberately announcing itself.

    One of the notions that I tend to not agree here is that the beacons of which you speak would need to be much energetic. The distance that you quote (~ 16000 ly) is very far in terms of how the beacon that you mention would broaden and how the intervening ISM would disperse the beam.

    The notion to me is creative but not very analytical enough to make any scientific sense. That is just my opinion.

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    oh i wouldnt suggest for a moment that the signal from 47 Tucanae was in any way ET,
    i was just supporting the principle of optical seti as a rational search method...if you are going to be doing seti searches at all.

  22. #22
    Quote Originally Posted by mutleyeng View Post
    oh i wouldnt suggest for a moment that the signal from 47 Tucanae was in any way ET,
    i was just supporting the principle of optical seti as a rational search method...if you are going to be doing seti searches at all.
    I'm not advocating that it is either - but from a viewpoint of evidence, this might constitute one, right? You said this is what we should expect, if we are taking the whole interstellar communication thing seriously enough.

    But, my question is - if this is an ET signal, would that imply that there is no intelligent life besides us in these 16.700 light years?

    What's your view from that aspect?

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    Quote Originally Posted by NeptuneRise View Post
    I'm not advocating that it is either - but from a viewpoint of evidence, this might constitute one, right? You said this is what we should expect, if we are taking the whole interstellar communication thing seriously enough.

    But, my question is - if this is an ET signal, would that imply that there is no intelligent life besides us in these 16.700 light years?

    What's your view from that aspect?
    as john pointed out, 1600 light years is a long way... i would need to refer how possible that is to a physicist working in this field.
    Regarding this particular signal, i would not begin to start thinking anything of it until further observations were made. While i did say you would expect it to disappear, you would also expect it to return if you carried on looking at that point for long enough...who knows how long "long enough" is.
    If it were ET, i would just take it that they were the first signal we managed to identify. Actually, as a bit of a skeptic, i would think closer ETs were a lot more likely than before...at least i would know it had happened twice simutaniously in our galaxy

    edit, or our region of universe..(sorry, had brain fade...forgot how big MW was there)
    Last edited by mutleyeng; 2012-Apr-28 at 06:01 PM. Reason: my ignorance again

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    There can be false alarms even with lasers.
    http://forgetomori.com/2010/science/...laser-planets/
    http://sci.tech-archive.net/Archive/.../msg00266.html

    First pulsars, now this.

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    Quote Originally Posted by publiusr View Post
    Well, this thread has gone very quiet since publiusr made this post ! (The sound of crickets !)

    Thanks for the post, publius ! Very interesting.

    The following quote about 'laser stars' summarises the typical conditions quite nicely:

    Laser emission lines are very strong, broad and dominate the spectra. Maximum laser gain occurs in a narrow range of plasma parameters which depends on the ion and the transition. The maximum gain for the 4686 He II transition occurs at 2.5e15 electrons/cm3 and 2.05e4 Kelvin.
    This sensitivity to initial conditions leads to the wide variety of
    laser emission lines found in emission line stars.
    So, we're talking about energies and ion densities produced by stellar magnitude processes. Also, the sensitivity to initial conditions, would suggest that the specific characteristics of the phenomenon, is likely to be unpredictable across the obs. universe.

    Just looking at the planetary atmospheric 'laser' effect, I notice:
    The process is self-limiting, however, since an increase in the intensity of the incident radiation causes the medium to approach local thermodynamic equilibrium. However, as long as the energy is 'diluted', some sort of laser action will occur.
    From this, it seems that it would be unlikely to observe a laser type emission for any lengthy periods, also.

    The 'take home' point here is the unexpected phenomenon itself. Prior to the discovery (some 35 years ago ?), who would've thought such a phenomenon could have been generated naturally ?

    How many other phenomena are out there, of which we are entirely oblivious about?
    (Eg: like non-biogenic processes, which might sustain large quantities of atmospheric O2 ?)

    Regards

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    Quote Originally Posted by Selfsim View Post
    How many other phenomena are out there, of which we are entirely oblivious about? (Eg: like non-biogenic processes, which might sustain large quantities of atmospheric O2 ?)
    We already know albout at least one possible non-biological source of oxygen - on waterworlds photodissociation of water will produce sufficient quantity to be persisent for Gyears and detectable from distance.
    You sure try a lot to preemptively strike out future discoveries in exoplanet spectra...

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    Quote Originally Posted by MaDeR
    Quote Originally Posted by Sefsim
    How many other phenomena are out there, of which we are entirely oblivious about? (Eg: like non-biogenic processes, which might sustain large quantities of atmospheric O2 ?)
    You sure try a lot to preemptively strike out future discoveries in exoplanet spectra...
    Do I ?

    In my words above, I was specifically acknowledging that which is undiscovered.

    How does this constitute 'preemptively striking out future discoveries' ?

    Regards

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    Quote Originally Posted by MaDeR View Post
    We already know albout at least one possible non-biological source of oxygen - on waterworlds photodissociation of water will produce sufficient quantity to be persisent for Gyears and detectable from distance.
    I wonder what percentage of our oxygen atmosphere is produced in this way. We are 71% waterworld. Then there's the formation of an ozone layer blocking out some
    UV.

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    Quote Originally Posted by Paul Wally View Post
    I wonder what percentage of our oxygen atmosphere is produced in this way. We are 71% waterworld. Then there's the formation of an ozone layer blocking out some UV.
    I do not know/remember details, but AFAIK without life on earth oxygen would be removed from atmosphere in geological blink of eye, so abiological production cannot be very much present on Earth. I think reason is that having 29% of land give disproportionally large effect... plus plethora of other reasons (different atmosphere, temperature, geological history etc) that render untrue speculations like "waterworld produces x oxygen abiologically, so planet with 71% water cover would produce 71% of this x". It is not that simple...

    Quote Originally Posted by Selfsim View Post
    How does this constitute 'preemptively striking out future discoveries' ?
    Say we discover planet with oxygen in atmosphere where according to our knowledge it would be very unstable on geological scale (like our). You can (and did already) then argue this does not consitute proof of live, because there can be some unknown abiological processes imitiating effcts of life. While this concern is certainly valid, your position give me impression of being unfairly biased against extraterrestial life.

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