Your new home address: Laniakea

September 4, 2014 • 5:13 am

by Matthew Cobb

When you were a kid you probably wrote your address out, adding after your country ‘Earth, The Solar System, The Milky Way, Space, Near More Space’ or some such. Well with that final bit you were WRONG. A paper just out in Nature shows that the Milky Way is part of what is called a supercluster of galaxies, which has been given a name: Laniakea, which in Hawaiian means ‘immeasurable heaven’.

I won’t pretend I understand the whole of the article (“It has been shown that with a random Gaussian field, the optimal Bayesian estimator of the field given the data is the Wiener filter minimal variance estimator” – I understand the words, and I know who Gauss, Bayes and Wiener were, but still…), but thankfully Nature has made a fantastic 4-minute video that explains how they did the analysis, and how they defined the existence of these superclusters of galaxies. Watch the video, and be awed:

One of the ways that they did the study was to track the movement of galaxies towards what is known ominously as The Great Attractor – a zone of the sky about 250 million light years away, which seems to be pulling us (and everything else) towards it at around 700 km/second, which is pretty damn slow in space terms, so we aren’t going to be crushed any time soon.

According to WikipediaThe Great Attractor is a gravity anomaly in intergalactic space’ which sounds like something out of Star Trek, but is true. (The Wiki elves have acted quickly and have already added Laniakea…) xkcd had this touching cartoon about what might be at the heart of the Great Attractor a few years back:

Dark Flow

Looking the immense scale of the universe portrayed in the video, and the fact that not only is our solar system on the non-descript edge of our galaxy, but our galaxy is in a dull suburb of Laniakea, it is hard to feel that there’s anything special about where we are. And even less that any supernatural being should have been particularly interested in us. I am even tempted to feel that there really must be life elsewhere out there, even if I know that, for the moment, we only have evidence that life appeared once, in our boring fractal surbubia, nearly 4 billion years ago.

More info:

Nature News article explaining the discovery in more detail.

The original article: R. Brent TullyHélène Courtois, Yehuda Hoffman & Daniel Pomarède (2014) ‘The Laniakea supercluster of galaxies’ Nature 513:71–73  ($$$)

60 thoughts on “Your new home address: Laniakea

  1. ” but our galaxy is in a dull suburb of Laniakea, it is hard to feel that there’s anything special about where we are.”

    If God made all that for us, you’d at least expect some kind of arrow pointing at us, no?

    Of course, in a godless universe, being in a dull place is a prediction. We wouldn’t be able to live in a cosmic hotbed of activity, or we’d simply get fried. There are many such dull places, so special it is not…

    1. Creationists will say that this proves intelligent design: God in His Wisdom put us here so we wouldn’t get fried.

      Honestly, how can anyone doubt intelligent design after this evidence?

  2. Obviously, the center of Laniakea is where the concentration of consciousness resides and is the focal point of quantum awareness.

    Can I haz the Deepak science explanatory award now?

  3. I’ll bet that if more religious fundamentalists studied astronomy, there would be a theory that describes the great attractor as god.
    There probably already is one anyway, in some circles.

  4. Well now I feel less than insignificant. Thanks a lot, science!
    Actually, that was beautiful and now I feel that I understand what the Great Attractor is. What should be mentioned is that all those galaxies are sprinkled in more massive streams and globs of dark matter. I do not think that the Great Attractor is unusual anomaly, but is instead just a big glob of dark matter holding galaxies that formed before some other local big globs of dark matter.

  5. “I am even tempted to feel that there really must be life elsewhere out there”

    Funny, I got exactly the opposite impression! As probabilities go, it’s interesting that we live in the largest galaxy in our local cluster, in the most populated part of this new super-cluster. If you’d expect to find life somewhere, that’s where where you’d expect to find it! By extension, therefore, you’d expect life (at least sentient, multi-cellular life) to be not common, but rare! In contrast, if we lived in a small galaxy, in a less-dense part of Laniakea, wouldn’t probability lead you to expect that life is more common in the universe?

    1. I think you would have to first show good reason why galaxy size or cluster size have anything to do with the probability of life arising, and that bigger is for some reason better. It seems better, given the nearly complete lack of hard data on the actual frequency of life and the lack of ability to even collect such data (may be getting close though), to assume that if life occured in our solar system that very generally similar life should be possible in any other very generally similar environments. Of which there are uncountable numbers of in our observable universe.

      Given what we know of life here (it’s everywhere, tough, ubiquitous), and given that life did occur here, and given what we know about here (no good reasons to think here is uniquely special for life in some way), I’ve never been convinced by any of the arguments for life having uniquely arisen on Earth, or that it is spectacularly rare.

      Yes, we only have one example. But having only one example in a vast parameter space is not the same as having only one example in a vast parameter space that you do not have any information about, or even have the ability to search. The actual situation is the latter. And that, restated, amounts to looking in only one spot out of billions and billions, and finding life there.

      1. I’m not saying that galaxy or cluster size has anything to do with the probability of life arising. What I’m saying is that the probability of finding life is greater in a larger galaxy/cluster, just because there are more places to look. Probability is cumulative, to the chances of finding life in a large galaxy is greater than the chances of finding life in a small galaxy. Therefore, since we live in a large galaxy, a logical (but not certain) conclusion is that life is rare (perhaps one in a hundred billion). If we lived in a small galaxy, the probability would be greater (perhaps one in a billion).

        And, just for the record, I’m not saying that life is rare per se. Bacteria (or analogous life-forms) are just complex chemical reactions (biochemistry, anyone?) as far as I am concerned, so there’s nothing fancy about them. Bacteria (or similar) are therefore probably (very) common in the universe. However, when it comes to multi-cellular, complex, even sentient life, I’m much more skeptical. Not because we’re special in any way; it’s just that the chances of multi-cellular life arising in the first place are pretty small and associated with multiple bottlenecks (the acquisition of mitochondria was, as far as I know, quite a traumatic event!). Although I’m not convinced by all of his arguments, I quite like Nick Lane’s take on the matter (see here for links to papers, if you’re interested: http://www.nick-lane.net/Nick%20Lane%20Publications.htm).

        1. “I’m not saying that galaxy or cluster size has anything to do with the probability of life arising. ”

          Good, because our current knowledge tells us that being in the goldilocks zone is the key predictor here.

          Thanks to the observations made by the Kepler Space Telescope we now know that our galaxy has at least 100 billion planets.

        2. Putting aside the issue of where life is more probable, there is the other issue about the probability of our being able to find life outside of our solar system. 99.999..% of the volume of our galaxy is simply out of reach of us even finding smallish rocky planets. There is 0 chance of our being able to detect such planets outside of our own galaxy. A galaxy is just too big, and they are very very far apart.

          1. Kepler was extremely successful at finding “smallish rocky planets”, and the future telescopes will only be more so.

        3. I understand your reasoning better now, thanks. But, I still don’t think your proposed conclusion necessarily follows, or is even particularly likely. If the frequency of life were very low, perhaps. If it were moderate then the size of different search spaces would matter little or not at all. The same amount of time searching in the same ways would, on average, yield the same rate of hits regardless of the overall size of the spaces. Assuming of course that the spaces are similar environments.

          RE Nick Lane, his arguments, and similar ones, are precisely the kind I find unconvincing. For example, bottlenecks are not convincing. They make for very interesting history, but to assume that without those bottlenecks life could not have occurred seems like a non squitur to me. The most you could say, it seems to me, is that life as we know it would not have occurred.

          I have the same problem with nearly all of the “rare earth” kind of arguments. They focus on particular aspects of the evolutionary history of our solar system, planet, abiogenesis and life, and claim that life could not have occurred here unless these things happened. And these events are very unlikely to occur so therefore life is very unlikely. Doesn’t seem like sound reasoning to me. Unlikely, even unique, events happen a gazillion times every day. They are positively mundane.

          Just to be clear, I don’t think the paltry evidence we have warrants claiming that life must be common everywhere either. Though I do think that the paltry evidence so far available is more favorable to life being somewhat common than to life being extremely rare. But I would say that that ain’t saying much because the data is very sparse.

          RE intelligent life. I think the arguments against it are definitely better than life in general. But I have no strong confidence in that conclusion either, for the same reasons. Lack of data and the teeny tiny ratio of space searched vs the total space. And I don’t find the common drop dead killer arguments, like von Neumann probes, particularly convincing. Way too many assumptions involved there to warrant the confidence many people place in such arguments.

          1. What I’ve always thought of as sad is that civilizations could mature and thrive and then wink out and we’d never know they existed or we’d learn about them only too late because the space between us is so vast. In other words, we probably have a poor chance of meeting up with an advanced civilization because of the timing. It would be nice to calculate the probabilities but I suspect we don’t have enough variables to do so with enough accuracy.

        4. I would say that Lane is the complement to Valentine when one wants to understand why life evolved three “domains”. E.g. Valentine predicts that Archaea is low energy specialists (due to evolving less permeable membranes – lower proton, redox energy, leakage) and Lane predicts that Eukaryota is high energy specialists (due to evolving mitochondria small genome energy plants – “more proteins for the bucks”).

          Else there are a lot of technical problems in your comment, which underlies a basic confusion: life is not the same as language capable life, e.g. us. For observing the latter but not the former, we live with selection bias (we use the traits that define us alone to demarcate what to observe).

          Bacteria (which we clade within) are not just “complex chemical reactions”, cellular life forms are disequilibrium membrane bound redox systems of a kind that we don’t see in nature on the current Earth. But there were similar geophysical systems on the Hadean/Archean Earth that we likely descend from. That is a planet that astrobiologists now look at as an “alien planet” type case to study alongside the type case of today’s Earth.

          So far, we haven’t seen similar systems on other planets. (But there are high hopes that early Mars and Europa had them.)

          To get to the likelihood of life, we can look at the rate of the process. It was fast, we see early life. If anything like it is possible elsewhere it should be among the commonest such processes, since it was fast. Hence life should be common.

          Since you gave a probability, I’ll make my own estimate. By the above, using a simplest possible Poisson process as crude estimate for such geophysical systems that evolves life, and noting that life likely appeared within 1 billion year of Earth age, there is ~ 100 % probability that habitable planets 7 billion years old has life. That means habitable superEarths around long lived M stars, most habitable planets, will fester with life within another 3-4 billion years. (Due to the delay of the galactic habitable zone establishing similar metallicity, IIRC there is another 1-2 billion years before the fringes of Milky Way catch up with the Sun’s habitability.)

          Now we get to the selection bias part, where the technical problems stack up.

          – We are not alone among sentient life, most animals are sentient (have subjective experiences), many are self-aware (experience embarrassment), we are language capable. And it is unique, so perhaps rare. But last week a study reported that animal vocalization is a lot like ours, because we have context free grammars, same grammar between sentences, and they have non-markovian sound generation, their ‘vocabulary’ has memory too. I.e. if they find a fancy sound that say attract the opposite sex, they keep it for a while. So language isn’t tricky to evolve, making one wonder why it is rare.

          – Of multicellular life the are some 30 independently evolved types. Complex multicellularity isn’t rare either, evolved 6 or 7 times independently. It is the eukaryote cell that is required for the latter that is rare. (Evolved once.)

          – Milky Way isn’t the largest nearby galaxy, that prize goes to Andromeda. A few years back the question was open. But lately consistently and by several ways the mass ratio has been observed to be ~2.

          – The Local Group isn’t situated in “the most populated part” of Laniakea, on the contrary! Watch the video: we are at the fringe furthest away from the most populated part, the Great Attractor, just between a void and a moderately dense part of the supercluster.

          More pertinent, a selection bias statistic must look at the dynamics. We are relatively late compared to the first stars, but there are many more planetary systems that will age the required 2-4 billion years before large complex multicellular, oxygen dependent, life can appear. And as per above, a few more billion years will establish more biospheres in naive models.

          With such a dynamic, and accepting the selection bias, language capability is not the rarest of things.

          1. cellular life forms are disequilibrium membrane bound redox systems of a kind that we don’t see in nature on the current Earth.
            But of course we do, everywhere. I guess you didn’t say what you meant, there.

            last week a study reported that animal vocalization is a lot like ours, because we have context free grammars, same grammar between sentences, and they have non-markovian sound generation, their ‘vocabulary’ has memory too.
            You mean Kershenbaum et al.? (Not loading for me for some reason, but I’ll check back later.) Or was it something else?

    2. As far as I know Andromeda – with its approx. trillion stars – is the biggest galaxy in our local cluster. BTW, when we collide with it in about 5bn years, we will most probably form a bigger elliptical galaxy.

  6. Fools, do you not realise that The Great Attractor is Satan and only by accepting Jesus as our Saviour can the plans of the Great Attractor be thwarted?

  7. So…the Fertile Crescent is just a minor spot on the edge of the Eurasian landmass, which is just one of a few such landmasses on Earth, which is just a minor part of the surface of the Earth, and the surface is a tiny fraction of the whole of the Earth, and the Earth would just be a small fraction of just the eye of a storm on Jupiter, and Jupiter itself is the fringes of relevance to the Solar System, and the Sun isn’t even measurable on the scale of the distances of the Oort Cloud, and the Solar System is an unnoticeable speck of dust at the outer edge of the Milky Way, and the Milky Way doesn’t even register on the radar of Laniakea, which itself is an imperceptible fraction of the size of our Hubble Volume, which in turn is only one of an infinite many such in a multiverse so vast that it’s not even possible in principle for each Hubble Volume to observe another….

    Anybody else feel like you’ve just stepped into the Vortex?

    https://www.youtube.com/watch?v=kSnJl7B_TVs

    Cheers,

    b&

    1. The whole infinite Universe, the infinite suns, the infinite distances between them and yourself, an invisible dot on an invisible dot… 🙂

    1. First, I literally laughed out loud; this isn’t meant as a criticism of the joke, but rather a serious riff inspired by it.

      And that’s that I wholeheartedly approve of appropriating mythic and especially religiously mythic themes for modern scientific identification. I think the poetry of it all is wonderful, and the choice in this particular case is perfect.

      I’d especially like to see today’s popular religions included in the act. If, for example, Webb discovers a first-generation galactic supercluster filled with the earliest stars to ignite after the Big Bang, that by all rights should be named the Virgin Mary Supercluster.

      …not that that would ever happen….

      b&

      1. The trouble with using religious imagery in science is that religious types will claim that you are proving the Bible. When scientists stated that all humanity is descended from a mitochondrial “Eve” who lived 100,000–200,000 years ago, literalists were claiming that science had proven the existence of Adam & Eve. Take that, Darwin!

        Unfortunately, with the lack of understanding of science and widespread belief in the Bible in this country, we should be leery of adding to the confusion by bringing in religious themes. Naming planets after mythological figures is different because–I assume–no-one believes in the Roman gods any more (Otherwise people would be claiming that “Scientists prove the existence of the god Neptune!”)

  8. The copernican principle wins again! I always felt it was funny that the Local Group was peculiar in that it wasn’t a member of a supercluster.

    Of course, with the new (and IMHO better) definition of supercluster, there are only those and voids…

    “It has been shown that with a random Gaussian field, the optimal Bayesian estimator of the field given the data is the Wiener filter minimal variance estimator” – I understand the words, and I know who Gauss, Bayes and Wiener were, but still…

    The gist is, I think, that they don’t assume any model (“Bayesian”) more detailed than that there are random velocity fields (“random Gaussian fields”) modulated by gravitational attraction.

    The Wiener filter stuff is the stochastic process technique in which you do the quantitative analysis.

  9. As I watch this, and see the expanse of this ‘immeasurable heaven’ of which we are an infinitesimal speck, the TV shows a documentary on the murder of Dr. George Tiller.

    What tiny creatures we are. What arrogance thinking we are central to anything.

    There are more things in the heavens and on earth, believers, than are dreamt of in your philosophy. With apologies to William Shakespeare.

  10. There is a theory out there called Dark Flow which suggests that this so-called Great Attractor is really gravitational attraction from a nearby, more dense universe which is expanding toward us and causing this flow of galactic clusters in our universe to a single point in space. If so, that would constitute evidence for the multiverse. Ran across this a few years back on one episode of “Through the Wormhole with Morgan Freeman.” Don’t know how popular this theory is these days.

  11. At the risk of coming across as smug and pedantic, but Matthew falls himself for the common canard of “science was wrong! Previous theory radically overturned!! ZOMG!”

    Not quite. We knew for a while that Earth’s address contained a “local cluster” and a “local supercluster” (as the article mentions, the Virgo Supercluster).

    The only thing that has changed is the definition, in a way, of what a supercluster is. That’s great but I don’t know whether we’ve really /discovered/ anything new.

    This is news along the same line as “you thought Pluto was a planet? Well, think again because you’re wrong”. That’s not because Pluto suddenly shrunk.

    Not saying it isn’t awesome though – the cosmos always is =).

    Sour pedant out 😛

    1. I’ll defend this as a legitimate discovery. If an improvement in surveying techniques revealed that a small town in North Dakota was actually part of Saskatchewan, that would be a new fact worth knowing.

      Similarly, the fact that Pluto turns out to be just the most visible member of a previously unknown class of trans-Neptunian objects counts as a real discovery, not just a change in terminology.

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