July 12, 2020
"We now see the Great Attractor as the downtown region of the supercluster that we live in — an overall entity that our team has called the Laniakea Supercluster."
Said R. Brent Tully of the University of Hawaii, quoted in "Beyond the Milky Way, a Galactic Wall/Astronomers have discovered a vast assemblage of galaxies hidden behind our own, in the 'zone of avoidance'" (NYT).
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61 comments:
It is impossible for any human to really grasp this kind of scale.
The cool thing I got out of it is that we are moving at 400 miles/second, and yet my hair remains perfect.
I stopped reading when it said NYT. That's all you need to know about that.
"“One might wonder how such a large and not-so-distant structure remained unnoticed,” Dr. Pomarède mused in a statement issued by his university.""
Ahh, the Milky Way was in the way.
Now I'm going to have to get their paper. I should have access via the UW library, but they mess with the interface constantly and it's always a pain to figure out.
As it happens, I just started reading "Cosmology's Century", P.J.E. Peebles, and am currently reading about the work done to establish the correctness of Einstein's Cosmological Principle, which is that the universe is homogeneous and isotropic. Close to home (several hundred million light years) the universe is very much NOT homogeneous, as evidenced by the galaxy clusters discussed in this article.
The entire conglomeration is behind the Milky Way, in what astronomers quaintly call the zone of avoidance.
Nothing an Illudium Q-36 Explosive Space Modulator can't fix.
"The Bootes Void". Bootes is a big constellation. More then once I've been out observing and either I or my companions have commented on how "there's nothing in it". Not that amateur telescopes can probe to the depths that the phrase "The Bootes Void" refers to, but Bootes is strikingly empty. Seems like a waste of sky.
Amateur telescopes can see the brightest galaxies in the closest galaxy clusters. Great fun!
The two best lines from the Times’ story:
“a group of astronomers who called themselves the Seven Samurai . . .”
“We are like swimmers attempting to swim upstream but being carried downstream faster.”
My cardiologist has a PhD in Astrophysics from MIT. Then she went to medical school. That is pretty interesting stuff and I wonder why someone would give that up. We had a troll post some Trump hate stuff yesterday whose profile says he is an astronomer. Why get excited about politics when you have better things to think about ?
Think about the Voyagers. I would have loved to work for JPL. My wife's father did.
Makes brane hurt.
Could we please get a quote from Carl Sagan as to these new billions and billions of newly-found galaxies?
While we wait for a recent comment, the old ones still apply. I guess,
https://www.youtube.com/watch?v=HZmafy_v8g8&feature=youtu.be
Astronomers have discovered that there is a vast wall across the southern border of the local cosmos.
Even astronomy articles somehow relate back to Trump.
"My cardiologist has a PhD in Astrophysics from MIT. Then she went to medical school. That is pretty interesting stuff and I wonder why someone would give that up."
No jobs. I was in the astrophysics program at Wisconsin but changed to straight physics when I considered my job prospects. That was decades ago, but I imagine the situation has gotten worse rather than better.
"It is impossible for any human to really grasp this kind of scale."
That, and the age of earth, or even just of human life. I try to think about it, but I just can't really. Even the last 10,000 years of the neolithic.
You really need to find a meaning in it or it'll drive you crazy.
Amateur telescopes can see the brightest galaxies in the closest galaxy clusters. Great fun!
My youngest daughter saw the Sombrero Galaxy, when she was 10 through a 16 inch telescope.
"We had a troll post some Trump hate stuff yesterday whose profile says he is an astronomer."
I'd put money on "astrologer."
Bubba : Anyway, like I was sayin', galaxy is the fruit of the universe. You can barbecue it, boil it, broil it, bake it, saute it. Dey's uh, galaxy-kabobs, galaxy creole, galaxy gumbo. Pan fried, deep fried, stir-fried. There's pineapple galaxy, lemon galaxy, coconut galaxy, pepper galaxy, galaxy soup, galaxy stew, galaxy salad, galaxy and potatoes, galaxy burger, galaxy sandwich. That- that's about it.
Blogger Michael K said...
My cardiologist has a PhD in Astrophysics from MIT. Then she went to medical school.
MD's get jobs. PhD's often never do.
Science, schmience!
On the largest cosmic scales, these structures are only apparent and not real. Unless bound together by gravity 8 billion years ago, all of these superclusters, including our Laniakea, will, due to the dominance of dark energy, dissolve into lonely galactic islands as the universe expands.
When you stop to figure that Laniakea contains over 100,000 galaxies like ours, each of which is made up of many billions of solar systems all formed in the 18.5 billion years since the Big Bang, it is inconceivable that the 300,000 year existence of homo sapiens is all there is to life in the universe.
The Milk Way may ultimately end up as a lonely outpost in some otherwise dark corner of the universe, we can rejoice that we have BLM and their fellow Marxists to keep us warm and safe and well-fed. In saying that, I am not making a racist correlation between them and dark energy.
- Krumhorn
does the drake equation matter did it ever, the universe is more vast than our understanding,
I'm confused. Are we supposed to avoid the supercluster, or is the supercluster avoiding us?
"That motion away from Earth causes their light to be shifted to longer, redder wavelengths and lower frequencies, like retreating ambulance sirens."
Worst explanation of Doppler effect. If the reader knows what it is, they don't need the explanation. If they don't know, switching from talking about light to sound won't make sense. At least include "Doppler" so people who don't know can look it up. I wonder if there was more there originally but an editor struck it out as unnecessary.
A downtown, and a no-go zone. Rioters? Statues?
"Could we please get a quote from Carl Sagan"
Not a chance. According to the latest Washington state update, Sagan died of COVID-19 24 years ago.
HA! Got my grubby little hands on the paper! And the interactive data visualizations actual work!!!!
Thanks for this, Althouse!
The zone of avoidance is my happy place.
The "video tour of the South Pole Wall" referenced in the NYT article "is restricted from playing on your current domain." Not sure what that means. Do I have to be physically on a UW computer?
The Sombrero is really close. Virgo Cluster. Sixteen inches shows it well.
NYT made no mention of Farnsworth's boundary-breaking work with the Smelloscope?
Figures! I shan't read further.
Narr
Zone of avoidance indeed
Just think, if you had a spaceship that could accelerate to just under the speed of light, you could make the round-trip to see what they look like now, and then get back to Earth to find, umm, what would you find? That your species has been extinct for millions of years?
Except for any other travelers such as yourself, perhaps.
"You really need to find a meaning in it or it'll drive you crazy."
Or you just let it go.
The South Pole Wall is behind the "zone of obscuration".
If you look at this YouTube video, which is from the actual paper, then you can see the actual shape. And I don't why they call it a wall, since it doesn't seem very wall like to me.
Our view is being blocked by the Chamaeleon Cloud Complex, which is a star-forming molecular dust cloud quite close to us, and the large and small Magellanic clouds, which are two dwarf galaxies, in addition to the main disc of the Milky Way.
They show a 3D visualization of the structure at 1:13 minutes into the video.
Velikovsky's "Worlds In Collision",1950, is highly entertaining, as is Ambrose Bierce's "OIL of Dog"!
Outer space will be the next landfill, maybe it will create enough methane to fire up another batch of primordial soup, sorta like a sourdough culture. We can just keep making new planets with our waste. Earth Mamma to kambucha baby!
well he wasn't tenured, unlike wornstrum,
Yes, if you are going to use sound as the analogy for light, you really should first explain the differences between the sounds at long wavelength vs those of shorter wavelength, and only then describe light.
"On the largest cosmic scales, these structures are only apparent and not real. Unless bound together by gravity 8 billion years ago, …
They ARE bound by gravity. Gravity is WHY they're clustered.
Kevin said...
Bubba : Anyway, like I was sayin', galaxy is the fruit of the universe. You can barbecue it, boil it, broil it, bake it, saute it. Dey's uh, galaxy-kabobs, galaxy creole, galaxy gumbo. Pan fried, deep fried, stir-fried. There's pineapple galaxy, lemon galaxy, coconut galaxy, pepper galaxy, galaxy soup, galaxy stew, galaxy salad, galaxy and potatoes, galaxy burger, galaxy sandwich. That- that's about it.
***************
He left out sous vide.
Kevin said...
Bubba : Anyway, like I was sayin', galaxy is the fruit of the universe. You can barbecue it, boil it, broil it, bake it, saute it. Dey's uh, galaxy-kabobs, galaxy creole, galaxy gumbo. Pan fried, deep fried, stir-fried. There's pineapple galaxy, lemon galaxy, coconut galaxy, pepper galaxy, galaxy soup, galaxy stew, galaxy salad, galaxy and potatoes, galaxy burger, galaxy sandwich. That- that's about it.
***************
He left out sous vide.
"We now see the Great Attractor as the downtown region of the supercluster that we live in — an overall entity that our team has called the Laniakea Supercluster"
...in the 'zone of avoidance.
Sounds like "CHOP."
@Krumhorn:
When you stop to figure that Laniakea contains over 100,000 galaxies like ours, each of which is made up of many billions of solar systems all formed in the 18.5 billion years since the Big Bang, it is inconceivable that the 300,000 year existence of homo sapiens is all there is to life in the universe.
According to the Drake Equation, it is certain that there are other intelligent lifeforms in just the Milky Way, never mind the universe.
The problem with the Drake equation is that it provides discrete estimates to each of the factors.
To quickly see the problems point estimates can cause, consider the following toy example. There are nine parameters (f1, f2, . . .) multiplied together to give the probability of intelligent life arising at each star.
Suppose that our true state of knowledge is that each parameter could lie anywhere in the interval [0, 0.2], with our uncertainty being uniform across this interval, and being uncorrelated between parameters.
In this example, the point estimate for each parameter is 0.1, so the product of point estimates is a probability of 1 in a billion. Given a galaxy of 100 billion stars, the expected number of life-bearing stars would be 100, and the probability of all 100 billion events failing to produce intelligent civilizations can be shown to be vanishingly small: 3.7 × 10−44. Thus in this toy model, the point estimate approach would produce a Fermi paradox: a conflict between the prior extremely low probability of a galaxy devoid of ETI and our failure to detect any signs of it.
Instead, the authors account for our uncertainty by applying a Monte Carlo simulation — randomly assigning a probability in the range [0, 0.2] for each factor, then combining the values for each of the factors.
The result?
More than 22% of the simulations produce a galaxy devoid of even one ETI.
But wait, there's more.
If, instead of assigning point probabilities to each factor, model each factor as itself a combination of factors. Take the existence of life as an example. Abiogenesis is a transition from non-life to life that "… occurs at some rate per unit time per unit volume of a suitable prebiotic substrate." Using informed guesses about rate, volume, protein folding, etc, yields a range of estimates for the existence of life on suitable planets spanning 20 orders of magnitude. (There is much more to this than I am presenting, btw.)
Applying uncertainty distributions reflecting current knowledge to each of the factors in the Drake Equation, what do you suppose the likelihood is that we are alone, not just in the galaxy, but in the entire observable universe?
Nearly 38%.
Unknown said...
Blogger Michael K said...
My cardiologist has a PhD in Astrophysics from MIT. Then she went to medical school.
MD's get jobs. PhD's often never do.
Better pay, too. Cliff Stoll was an astronomer who ended up teaching high school. His book, "The Cuckoo's Egg" is still fun reading.
"On the largest cosmic scales, these structures are only apparent and not real. Unless bound together by gravity 8 billion years ago, …
They ARE bound by gravity. Gravity is WHY they're clustered.
Gravitational forces took advantage of very slight (on a scale of 0.003%)imperfections in the distribution of energy-matter right after the Big Bang 18.5 billion years ago to create the structures we see, but 8 billion years ago, dark energy began to dominate and all of these galactic structures are disintegrating before our eyes and will continue to drift apart over cosmic time scales.
This is why the universe is expanding and not contracting as gravitational forces would dictate. As a result, Laniakea is dissolving and will never merge with the Virgo cluster or any other cluster larger than ours.
- Krumhorn
"My cardiologist has a PhD in Astrophysics from MIT. Then she went to medical school. That is pretty interesting stuff and I wonder why someone would give that up."
There are no jobs except for university positions. Astrophysicists generally work as postdocs funded with government money on three year contracts that do not renew. Two years after a postdoc position is started, the PhD must spend the next year applying for the next grant. The applications are full-bore scientific papers on the work and the next postdoc position will inevitably be in another country. That's fun for awhile, but by the time the scientist is in their thirties, they have no roots and no time to start a family.
Most of them leave hard science and become data analysts for private companies or forex trades for a large bank where they can make some money and have stability. Many banks and large companies openly advertise for astrophysicists not only because they are smart, but because they have expertise in managing massive volumes of data and writing the code necessary to evaluate the data. The life of an astrophysicist is less about the actual science and more about data management and analysis.
- Krumhorn
it is inconceivable that the 300,000 year existence of homo sapiens is all there is to life in the universe.
Then why haven't any of them managed to get in touch with us? Surely some of them would millions of years ahead of us technologically, just by chance.
"dark energy began to dominate and all of these galactic structures are disintegrating before our eyes and will continue to drift apart over cosmic time scales."
There's nothing inconsistent with the fact that they are gravitational bound now but may be pulled apart by dark energy in the future.
"This is why the universe is expanding and not contracting as gravitational forces would dictate."
The universe would have been expanding from the Big Bang even if there were no dark energy. And, depending upon its mass density, could have expanded forever without dark energy.
Signals, nothing but signals, of unknown fidelity and origin, and inference from patterns in the data, a conflation of logical domains.
Hey Skipper@2:49PM/
From one flyboy (Viet Vet ex AF zoomie) to another, you might want to check out the work along similar lines by two geologists (of all things) in a book entitled Rare Earth:Why complex life is uncommon in the universe (2003)
When I started to read sci-fi as a pre-teen in the late 1940's (the stuff I was reading often went back to the '30's or earlier), we could accept the idea that there might be Martians living on the desert world of Mars and Venusians living on the oceans of Venus. The damned scientists took that away from us. So we had to transfer our Mars fantasies to interplanetary realms -- e.g. Dune. Even when we chose to ignore Einstein and imagine faster-than-light travel on Star Trek, etc., we knew we were fooling ourselves.
This stuff about the whole frigging UNIVERSE is intellectually challenging, but if they ever prove that flying saucers and Area 51 are phony, a lot of folks are going to lose interest.
Then they better find those gazillion dollar asteroids to keep up interest in a space program.
I've still never seen a really convincing refutation of the Rare Earth Hypothesis. It seems most likely that evolution of a species that is capable of producing a technological civilization is very, very rare. The huge scale of the universe does seem to guarantee that other such species must nevertheless exist, but then that same huge scale works against the likelihood that we can ever even verify their existence, let along establish any kind of communication with them. Life on a sort of green slime level, on the other hand, is almost certainly commonplace.
And galaxies beyond the wall are moving outward more slowly than they otherwise should be, reined in by the gravitational drag of the wall.
No, they'd just resume the speed they'd normally have had.
Nothing prevents them from producing garbage from data once they get into inferring what can't be checked.
It's hard to imagine that earth is the only place in the universe overrun with fake news.
it is inconceivable that the 300,000 year existence of homo sapiens is all there is to life in the universe.
Then why haven't any of them managed to get in touch with us? Surely some of them would millions of years ahead of us technologically, just by chance.
The speed of light is a limiting factor. Any radio transmission would have to travel at the speed of light. We don't have any way to capture a signal that could exceed that limit. The point of the article is that massive clusters of galaxies that contain hundreds of thousands of galaxies, each of which has billions of solar systems are hidden to us behind the Milky Way. The South Pole Wall is 500 million light years away.
If it helps to conceptualize the enormity of the number of galaxies in the universe,
check out this Hubble Legacy Field photo. It has extraordinary depth of field and it covers a part of the sky that would be roughly covered by the thumb on your outstretched arm. And that thumb would be nowhere near the direction of the South Pole. There are an extraordinary number of galaxies in this photo, most of which cannot be seen without zooming into any particular location. Most are hundreds of millions of light years away.
The mind of man cannot possibly calculate the odds of life elsewhere among those quintillions (billions of billions)of solar systems. Life on earth began roughly 4 billion years ago when some amino acids interacted in the primordial goo. Homo sapiens didn't arrive until yesterday, relatively speaking.
Andromeda is the closest galaxy to ours. It is 2.5 million light years away and is a quarter of a million light years across. Even assuming that intelligent life developed in Andromeda in orders of magnitude faster than here on earth so that some intelligent beings were able to broadcast signals we could receive, they would have had to do so 3 million years ago in order to traverse the distance. The Virgo cluster is 65 million light years away. They would have had to send us a signal back when the dinosaurs became extinct in order for us to receive it today.
The possibility should not be overlooked that intelligent life prospered and blew itself up or was destroyed like the dinosaurs. If they had BLM Marxist types, they undoubtedly withered and died.
- Krumhorn
@Krumhorn:
The possibility should not be overlooked that intelligent life prospered and blew itself up or was destroyed like the dinosaurs.
Alternatively, the near certainty that intelligent life only transmits significant signals for a very, very, brief period.
Earth didn't start emitting radio waves until, what, the mid-1930s? Less than 100 years later — 100/4*10^ is a very small number — there is scarcely any need for powerful radio transmitters. The odds of us happening to look in the right direction at a vanishingly brief period are near as dammit to nil.
The assumed likelihood of life of any kind, never mind intelligent, is almost certainly wildly overblown. But even if it isn't, the result is the same: there could be a thousand advanced civilization in the Milky Way alone, and we'd never know about any of them.
@virgil xenophon
... you might want to check out the work along similar lines by two geologists (of all things) in a book entitled Rare Earth:Why complex life is uncommon in the universe (2003)
Just added to my read list.
It's a good thing we are way out in the galactic boonies. If were in the downtown area the radiation would be so intense we would never have arisen.
I remember reading The Search for the Great Attractor at least two decades ago. I remember one detail was that they had a guy who had a photographic memory, which greatly sped up their work since he could identify star fields from photos instantly, allowing them to put the big picture together. I think that this was about the time they were first using electronic sensors instead of photographic plates. Now they would do it with software and such intellectual gifts are rendered meaningless curiosities.
The problem with finding other intelligent life is that everything in the universe is rushing away from everything else at such a high speed that it’s a huge hurdle to overcome without some new physics that enables “warp speed.”
Wasn’t the warp drive in Star Trek discovered around 2020? So many disappointments.
Eleven years more recent than Rare Earth is David Waltham's Lucky Planet: Why Earth is Exceptional--And What That Means for Life in the Universe. I read it a while ago and liked it. It also has a nice page and a half Further Reading at the end.
"I remember one detail was that they had a guy who had a photographic memory, which greatly sped up their work since he could identify star fields from photos instantly, allowing them to put the big picture together."
Not so much anymore, but in the hunt for supernovae in other galaxies (which led to the claim of dark energy) there were amateurs who memorized the appearance of hundreds of galaxies and would search them nightly for a new star. When they saw one they reported it so that the research teams could get the crucial early stages of their light decay curve.
around 2060 in the adjusted time line,
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