Scientists have just published in Nature that they have completed the entire connectome of a fruit fly: Network statistics of the whole-brain connectome of Drosophila. The map includes 140,000 neurons and more than 50 million connections. This is an incredible achievement that marks a milestone in neuroscience and is likely to advance our research.
A “connectome” is a complete map of all the neurons and all the connections in a brain. The ultimate goal is to map the entire human brain, which has 86 billion neurons and about 100 trillion connections – that’s more than six orders of magnitude greater than the drosophila. The human genome project was started in 2009 through the NIH, and today there are several efforts contributing to this goal.
Right now we have what is called a mesoscale connectome of the human brain. This is more detailed than a macroscopic map of human brain anatomy, but not as detailed as a microscopic map at the neuronal and synapse level. It’s in between, so mesoscale. Essentially we have built a mesoscale map of the human brain from functional MRI and similar data, showing brain regions and types of neurons at the millimeter scale and their connections. We also have mesoscale connectomes of other mammalian brains. These are highly useful, but the more detail we have obviously the better for research.
We can mark progress on developing connectomes in a number of ways – how is the technology improving, how much detail do we have on the human brain, and how complex is the most complex brain we have fully mapped. That last one just got its first entry – the fruit fly or drosophila brain.
The Nature paper doesn’t just say – here’s the Drosophila brain. It does some interesting statistics on the connectome, showing the utility of having one. The ultimate goal is to fully understand how brains process information. Learning such principles (which we already have a pretty good idea of) can be applied to other brains, including humans. For example, the study finds that the Drosophila brain has hubs and networks, which vary in terms of their robustness. It also reflects what is known as rich-hub organization.
Rich-hub organization means that there are hubs of neurons that have lots of connections, and these hubs have lots of connections to other hubs. This structure allows brains to efficiently integrate and disseminate information. This follows the same principle as with any distribution system. Even Amazon follows a similar model, with distribution centers serving as hubs. Further, the researchers identified specific subsets of the hubs that serve as integrators of information and other subsets that serve as broadcasters.
The connectome also includes synapse and neurotransmitter level data, which is critical to asking any questions about function. A connectome is not just a map of wiring. Different neurons use different neurotransmitters, which have different functions. Some neurotransmitters, for example, are excitatory, which means they increase the firing rate of the neuron in which they synapse. Some neurotransmitters are inhibitory, which means they decrease firing rate. So at the very least we need to know if a connection is increasing or decreasing the activity of the neurons it connects to.
Now that the model is complete, they are just getting started examining the model. This is the kind of research that is primarily meant to facilitate other research, so expects lot of papers using the Drosophila connectome as its subject.
Meanwhile scientists are working on completing the connectome of the mouse, which will likely be the first mammalian brain connectome. We already have mesoscale connectomes, and detailed connectomes of small sections of mouse brain. A completed mouse brain connectome is likely 10-15 years off (but of course, could be longer). That would be a huge milestone, as all mammalian brains share a lot of anatomy in common. With the Drosophila brain we can learn a lot about network principles, but the anatomy evolved completely independently from mammals (beyond the very rudimentary brain of our common ancestor).
One type of research that I would love to see is not just mapping a connectome, but emulating it in a computer. This information may be out there somewhere, but I have not found it so far – do we have a computer powerful enough to emulate the functioning of a Drosophila brain in real time? That would be a good test of the completeness and accuracy of our connectome – does it behave like an actual fruit fly?
Creating this would likely require more than just the connectome itself. We need, as I referenced above, some biological data as well. We need to know how the neurons are behaving biologically, not just as wires. We need to know how the neurotransmitters are behaving chemically. And we need to know how other cells in the brain, other than neurons, are affecting neuronal function. Then we need to give this virtual brain some input simulating a body and an environment, and simulate the environment’s response to the virtual fruit fly. That sounds like a lot of computing power, and I wonder how it compares to our current supercomputers. Likely we will be able to do this before we can do it in real time, meaning that a second of the life of our virtual Drosophila may take a day to compute (that is just a representative figure, I have no idea what the real current answer is). Then over time, our virtual Drosophila will go faster and faster until it catches up to real time.
Eventually the same will be true for a human. At some point we will have a full human connectome. Then we will be able to emulate in a computer, but very slowly. Eventually it will catch up to real time, but why would it stop there? We may eventually have a computer that can simulate a human’s thought processes 1000 times faster than a human.
There is another wrinkle to this whole story – the role of our current and likely short term future AI. We are already using AI as a tool to help us make sense of the mesoscale connectomes we have. Our predictions of how long it will take to have complete connectomes may be way off. What if someone figures out a way to use AI to predict neuron level connectomes from our current mesoscale connectomes? We are already seeing, in many contexts, AI being used to do literally years of research in days or weeks, or months of research in hours. This is especially true for information-heavy research questions involving highly complex systems – exactly like the connectome. It would therefore not surprise me at all if AI-boosted connectome research suddenly progresses orders of magnitude faster than previous predictions.
Another potential area of advance is using AI to figure out ways to emulate a mammalian or even human brain more efficiently. We don’t necessarily need to emulate every function of an entire brain. We can probably cheat our way to make simple approximations of the functions we are not interested in for any particular emulation or research project. Then dedicate the computing power to what we are interested in, such as higher level decision-making.
And of course I have to mention the ethical considerations of all of this? Would a high fidelity emulation of a human brain be a human? I think the answer is either yes, or very close to yes. This means we have to consider the rights of the emulated human. For this reason it actually may be more useful to emulate a mouse brain. We already have worked out ethical considerations for doing mouse research, and this would be an extension of that. I can imagine a future where we do lots of behavioral research on virtual mice in simulated environments. We could run millions of trials in a few minutes, without having to care for living creatures. We can then work our way evolutionarily toward humans. How far will we go? Would virtual primate research be OK? Can we guarantee our virtual models don’t “suffer”. Does it matter that they “exist” for just a fraction of a second? We’ll have to sort all this out eventually.
The post Fruit Fly Connectome Completed first appeared on NeuroLogica Blog.
Antivax is more ideology and conspiracy than science. The recent accusation that antivax influencers are running "limited hangouts" as part of "controlled opposition helps illustrate this characteristic, in which the insufficiently radical are portrayed as useful idiots for the enemy or even heretics.
The post Antivax as ideology: “Limited hangouts” run by “controlled opposition” first appeared on Science-Based Medicine.I’ve been struggling to understand the new articles in Nature on the fly brain, and it’s not easy! I will write about the issue, but not until I have something clear and interesting to impart to readers.
When I look at my draft posts, I see that many of them are about Israel, which prompted me to call Malgorzata and whine, “Everything I’m writing is about Israel; people are going to think I’m obsessed.” Malgorzata responded that. as with her, I likely have two reasons. First, I’m a Jew and am naturally concerned with an existential crisis threatening the Jewish state. Second, she said, both she and I have been worried about the new rise in anti-Semitism that goes by the name of “anti-Zionism”.
Before 1880, anti-Semitism was called “Jew hatred,” but that was deemed too crass, so “anti-Semitism”, coined by Wilhelm Marr, arose as a softer, more scientific euphemism. Now with the rise of Jew and Israel hatred, and the reluctance of liberals to say they are “antisemitic”, we have yet another euphemism: “anti-Zionism”. But at bottom they’re all the same thing, softened variants of “Jew hatred.” And that hatred, expressed as approbation for eliminating the existence of Israel, threatens not only the Jewish state, but the West as a whole, for the sentiments are more than “Jew hatred”: they’re “West hatred.”
Or so Malgorzata said, and sent me a video, saying that I would get a better explanation by watching the section of this video between 9:15 to 22:30. I’ve pasted it in so it starts at 9:15. The speaker is Dr. Einat Wilf, “former Knesset member and expert on Israel’s foreign policy,” and she’s quite eloquent. Wikipedia notes that “Wilf describes herself as a Zionist, a feminist and an atheist.”
At any rate, that’s her take, and I guess I have no choice about the topics I cover, since they just issue from the determined molecular movements going on inside my head. So here’s my post.
The BBC, accused repeatedly of biased reporting, has formed a division called “BBC Verify”, dedicated to fact checking and preventing misinformation. The announcement of its inception says this:
We’ve brought together forensic journalists and expert talent from across the BBC, including our analysis editor Ros Atkins and disinformation correspondent Marianna Spring and their teams. In all, BBC Verify comprises about 60 journalists who will form a highly specialised operation with a range of forensic investigative skills and open source intelligence (Osint) capabilities at their fingertips.
They’ll be fact-checking, verifying video, countering disinformation, analysing data and – crucially – explaining complex stories in the pursuit of truth.
This is a different way of doing our journalism. We’ve built a physical space in the London newsroom, with a studio that BBC Verify correspondents and experts will report from, transparently sharing their evidence-gathering with our audiences. They will contribute to News Online, radio and TV, including the News Channel and our live and breaking streaming operation, both in the UK and internationally.
But investigative journalist David Collier, who has investigated “Verify,” cannot verify that it’s fulfilled its mission. In fact, on this post on his website (click to read), he calls for this BBC unit to be shut down.
One example: Verify purported to verify that the Iranian missiles raining down on Israel last week were aimed solely at military targets. (Regardless of what they were aimed at, of course, it was an attack unprovoked by any Israeli attack on Iran.) But some elementary fact-checking showed that Verify dissimulated:
On Tuesday evening, 1 October 2024, Iran fired approximately 180 ballistic missiles at Israel. Many were intercepted, but several sites were hit. On Wednesday evening BBC Verify published a 1 minute 20 second video – titled ‘where Iran’s missiles struck in Israel’.
The BBC Verify team tells us they have been looking at ‘where Iran’s missiles have landed’ and the video is to counter ‘a lot of false imagery’ being circulated online. They say they managed to verify strikes in the vicinity of three key locations – all of them military sites:
Here’s the figure from “Verify”, showing the verified Iranian missile strikes:
More from Collier:
This creates an immediate problem. Why only these three? For example, a verified strike by Ramat Gan shopping mall has not been included. The BBC had reported on this – and so were well aware of it – but for some reason, BBC Verify left the shopping mall strike out of their analysis.
It is difficult to escape the conclusion that BBC Verify were deliberately pushing a pro-Iranian propaganda line that the missiles were fired only at military targets.
But it gets a lot, lot worse.
Having told us that the three targets verified were ‘in the vicinity’ of military targets, we are then shown the evidence. The first we see are several apparent strikes on Nevatim airbase, but it is when the journalist turns her attention to the attack on the Tel Nof base that things become surreal.
We find the base was not hit at all. This is the script:
Location two is the Tel Nof airbase. In this video you can see a crater where a missile has landed. It is not the airbase itself, but a school a few miles away”:
And Collier makes a clever analogy:
What? So the Iranian’s didn’t hit Tel Nof airbase with this missile – they hit a school. So why isn’t the school listed in the original map. How on earth can BBC Verify know that the intended target of this missile was an airbase? They can’t.
The school that was hit is the Shalhavot Chabad school in Gadera. About 5 miles from the place BBC verify tells us was the target.
. . . . To put this into context. Below on the map are two marks, Gaza City Centre and Jabalia camp. The distance between them is approximately the same distance as between the school and the airbase. Can you imagine Israel hitting a school in Jabalia camp and BBC Verify virtually forgiving them by suggesting it was a close call on a Hamas military target 5 miles away.
There is no excuse for this – and it appears to be a deliberate attempt to whitewash an Iranian ballistic missile strike on a school. Why on earth didn’t the BBC put the school as one of the verified strikes on the map at the start? We all know why. For the same reason they didn’t mention the strike on the shopping mall. It doesn’t fit the propaganda story they are seeking to tell.
Yes, this is of course biased reporting, made worse that it was made by the “Verify” team. This is just one more incident in the Beeb’s history of biased anti-Israel reporting. I’ve written before about the Asserson Report that accused the Beeb of violating its own journalistic guidelines 1500 times during the Gaza War, and you can see my collection of pieces on the BBC’s bias here. The Beeb is the British equivalent of the NYT, and it’s doing exactly what the NYT does—passing off biased reporting as if it were unbiased.
Collier discusses the author of this “verified” piece, Verify correspondent Nawal Al-Maghafi, showing that she has a history of reporting for anti-Israeli publications like Middle East Eye, Al-Jazeera, and even for PRESS TV, the state media outlet of Iran! This is hardly the person for Verify to choose as author of a piece that tries to exonerate Iran of trying to kill civilians! He concludes that BBC Verify should be shut down (indeed, the Beeb needs a top-to-bottom housecleaning). Check out the numbered links.
The BBC has spent decades demonising Israel – but since Oct 7, the situation has become blatant and inexcusable (a few examples 1, 2, 3, 4, 5, 6, 7, 8, 9). Two damning reports have recently been published on BBC Bias (Asserson, Cohen)
The BBC has gone completely off the rails. It isn’t just that it is incapable of putting together proper impartial coverage of Israel’s conflict with its neighbours – it is that it doesn’t think it is doing anything wrong. The inability to even begin to identify the problem it has – means it cannot be salvaged in its current form. No public funds should ever be used to finance something so deeply and irredeemably flawed.
Well, so much for that. Nobody claimed that the liberal MSM media, whether in the US or UK, was objective when it came to the Gaza war.
After reading that, I immediately came upon Tom Gross’s newsletter, which said this:
No surprise here. Just a publicly-funded BBC journalist leaving today after 4.5 years to go and officially work as an anti-Zionist influencer.
Check out the Palestine Media Centre yourself; I’m not sure it’s a mouthpiece for anti-Zionism, but there are suggestions of that in its mission, for how many Palestinians dare speak against their rulers?
The Britain Palestine Media Centre connects media professionals with Palestinians – from academics and artists, to human rights activists and ordinary people with extraordinary stories.
An independent non-profit, the Centre is an invaluable resource for journalists, editors, and producers seeking expert opinion, information, and contacts in a timely and reliable manner.
How we can help:
Looking for Palestinian experts to talk to for an article or report? We can connect you with the right person for your topic.
We can provide quick turnaround Palestinian guests for TV, radio or online broadcasting, to respond to breaking news.
Need information or data for a Palestine-related story? Let us know what you’re researching, and we’ll be happy to help.
********
Finally, something that I read today in the Times of Israel: a report on a woman who used to be “a vocal supporter of the Islamic Republic” but now heads a pro-Israel group that accuses the BBC of war coverage biased towards Hamas (this, of course, is not a new accusation).
When Catherine Perez-Shakdam took the helm of Britain’s biggest grassroots pro-Israel campaign group this summer, she inherited a bulging inbox .
Aside from the continuing domestic fallout from the conflict between Israel and Hamas, the UK’s new Labour government has made a string of decisions that have dismayed and infuriated large elements of the country’s Jewish community and supporters of Israel.
Since taking the helm in July, Labour has restored funding for the UN’s Palestinian refugee agency, UNRWA; pulled out of a legal case opposing the International Criminal Court application for arrest warrants for Prime Minister Benjamin Netanyahu and Defense Minister Yoav Gallant; and partially suspended arms exports to Israel.
The last paragraph surprised me, though I knew about the suspension of arms exports. But I thought Labour had purged itself of its anti-Israelism and anti-Semitism. In this case, we have the reverse of the case of Karishma Patel (above), for Perez-Shakdam was once a talking head for Iran and is now excoriating the Beeb for its anti-Israel bias. The article continues:
Born to Jewish parents in Paris whose own parents had fled Nazi persecution, Perez-Shakdam lived as a Muslim while studying in the UK after marrying a Muslim man from Yemen. She later spent years as a journalist and commentator in the Middle East and began appearing on Iranian state media. Increasingly trusted and valued by the regime, Perez-Shakdam was granted an audience with Supreme Leader Ayatollah Ali Khamanei; interviewed the late Ebrahim Raisi during his initial, unsuccessful 2017 bid for the presidency (he would succeed in 2021 and serve as president until his death this year); and was invited to a pro-Palestinian conference in Tehran attended by Hamas terror chief Khaled Mashaal.
That was then; this is now. Influenced by her “Zionist” daughter, Perez-Shakdam did a 180°:
Perez-Shakdam’s journey was capped by her appointment last month as director of We Believe In Israel. She replaces Luke Akehurst, who was elected as a Labour MP in the July general election. The campaign group seeks to counter the well-organized pro-Palestinian lobby by mobilizing grassroots support for the Jewish state.
For years, I was motivated by a kind of self-hate. But you realize that you can’t deny who you are
The group’s latest campaign has the BBC firmly in its crosshairs.
The new report into the BBC led by British-Israeli lawyer Trevor Asserson says the public service broadcaster’s coverage associated Israel with war crimes, genocide, and international law violations far more often than it did Hamas. It claims that the BBC downplayed Hamas terrorism, and finds that the BBC’s Arabic service was among the most biased global media outlets in covering the Israel-Hamas conflict.
. . . . Perez-Shakdam says her organization’s campaigning is not driven by hostility to the BBC, which is prevalent in the opposition Conservative party and its media allies, as well as on the far left. “It’s not a witch hunt. This is not an effort to bring down the BBC,” she says. “It’s just to elevate the level of journalism and to make sure that ethic [of impartiality] is at the forefront of it all.”
“The BBC has a lot of answering to do and I don’t think that it’s willing to do that; it [has] already doubled down,” she says. She believes the government may have to take action. “Taxpayers’ money is being used, through the vehicle of the TV license. The government needs to do something about it. This is not a case of free speech. It’s a case of holding the BBC accountable for a service that it is not providing in violation of its own [guidelines].”
You can read the Asserson Report here. But if you’ve followed the Beeb’s coverage of the war you hardly need to Just think of all those British Jews who have to pay for a television license to listen to the distortions of the BBC.
Small primordial black holes (PBHs) are one of the hot topics in astronomy and cosmology today. These hypothetical black holes are believed to have formed soon after the Big Bang, resulting from pockets of subatomic matter so dense that they underwent gravitational collapse. At present, PBHs are considered a candidate for dark matter, a possible source of primordial gravitational waves, and a resolution to various problems in physics. However, no definitive PBH candidate has been observed so far, leading to proposals for how we may find these miniature black holes.
Recent research has suggested that main-sequence neutron and dwarf stars might contain small PBHs in their interiors that are slowly consuming their gas supply. In a recent study, a team of physicists extended this idea to include a new avenue for potentially detecting PBHs. Basically, we could search inside objects like planets and asteroids or employ large plates or slabs of metal to detect PBHs for signs of their passage. By detecting the microchannels these bodies would leave, scientists could finally confirm the existence of PBHs and shed light on some of the greatest mysteries in cosmology today.
The research was conducted by De-Chang Dai, a physicist at National Dong Hwa University in Taiwan and the Center for Education and Research in Cosmology and Astrophysics (CERCA) at Case Western Reserve University, and Dejan Stojkovic, a physicist from High Energy Physics and Cosmology group at the State University of New York Buffalo. The paper that details their findings recently appeared online and is being reviewed for publication in the journal Physics of the Dark Universe.
How we might discover primordial black holes and help solve the dark matter mystery. Credit: ESAScientists have been fascinated by PBHs for decades since Russian scientists Igor D. Novikov and Yakov Zeldovich predicted their existence in 1966. They were also a source of interest for Stephen Hawking, whose work on PBHs led to his breakthrough discovery in 1974 that black holes can evaporate over time. While larger and intermediate black holes would take longer to evaporate than the current age of the Universe (ca. 13.8 billion years), smaller PBHs may have already or could be in the process of doing so.
However, interest in PBHs has experienced a renaissance in recent years because they serve as dark matter candidates, a source of primordial gravitational waves (GWs), and more. Like Dark Matter, their existence could help resolve some major cosmological mysteries, but no confirmed observations have been made yet. As De-Chang and Stojkovic told Universe Today via email, this is what motivated them to propose novel detection methods:
“If an asteroid, or a moon, or a small planet (planetoid) has a liquid core surrounded by a solid crust, then a small PBH will consume the dense liquid core relatively quickly (within weeks to months). The crust will remain intact if the material is strong enough to support gravitational stress. Thus, we will end up with a hollow structure. If the central black hole is ejected (due to collisions with other objects), the density will be lower than the usual density of a rocky object with a liquid core.”
In addition, De-Chang and Stojkovic calculated the gravitational stress small PBHs would generate. They then compared this to the compressive strength of materials that make up a planet’s crust – such as silicate minerals (rock), iron, and other elements. They also considered the strongest manufactured materials, such as multiwall carbon nanotubes. “We found, for example, that granite can support hollow structures up to the radius of 1/10 of the Earth’s radius,” said Stojkovic. “That is why we should concentrate on planetoids, moons, or asteroids.”
An image based on a supercomputer simulation of the cosmological environment where primordial gas undergoes direct collapse to create black holes. Credit: Aaron Smith/TACC/UT-Austin.These calculations offer a means to search for evidence of PBHs in space and here on Earth. Possible candidate planetoids, moons, or asteroids could be identified in our Solar System by observing their mass and radius to provide estimates of their density. This would allow astronomers to identify potentially hollow objects for follow-up studies by probes, landers, and other robotic space missions. Alternatively, they recommend that sensors be built to search for PBHs by detecting their passage. Said Stojkovic:
“If a small PBH passes through some solid material, it will leave a straight long tunnel of the radius comparable to the PBH’s radius. For example, a 1023 g PBH should leave a tunnel with a radius of 0.1 micron. [The energies] that such PBHs can have are significant, but [the energies] which they deposit into the material are very low. In fact, such a PBH can even pass through a human body, and we would not even notice because human body tissue has a very low tension.”
In this vein, scientists can scan for micro tunnels in commonplace materials we find lying around (like glass or rocks). At the same time, say De-Chang and Stojkovic, large slabs of polished metal could be prepared for this purpose. Similar to neutrino detection, these slabs would need to be isolated so that any sudden change in their properties could be recorded. “The expected flux of these PBHs is very small and we may end up finding nothing, but a possible payoff of finding a PBHs will be huge, especially since such experiments will be very cheap,” said Stojkovic.
As De-Chang added, it has been proposed in recent years that some primordial black holes may be hidden in stars. Stephen Hawking once proposed the idea, which became the basis of two studies, one released in 2019 and another this past year. “It is also proposed that primordial black holes may radiate Gamma rays. Strong gamma rays in the Milky Way’s dark matter halo can be a good hint for the existence of primordial black holes,” said De-Chang. “Gravitational microlensing can be another way to identify the primordial black holes.”
Further Reading: arXiv
The post Primordial Holes Could be Hiding in Planets, Asteroids, and Here on Earth appeared first on Universe Today.
I can aways count on John Avise to provide weekly bird photos, and today we feature the first part of a four-part series. John’s captions are indented, and you can enlarge the photos by clicking on them.
Birds in Hawaii, Part 1
This week we begin a stop at yet another overseas (albeit not foreign) destination. In 2008, I went on an invited seminar trip to Oahu and Kauai. My hosts graciously showed me around these beautiful islands and patiently indulged my passion for bird photography. So, here is Part 1 of a 4-part series on birds I photographed on these Hawaiian Islands.
Before the arrival of humans, the Hawaiian Islands had a species-rich endemic avifauna, much of which subsequently went extinct through direct or indirect human actions. Today, birds found on the Hawaiian Islands comprise a potpourri of a few surviving native species, plus some natural migrants, plus various other species that have been intentionally or accidentally introduced from disparate locations around the world. The net result is that bird-watching in the Hawaiian Islands has somewhat the aura of viewing birds in a tropical outdoor pet store. For this reason, I’ve indicated the native range of each species that I photographed.
Apapane (Himatione sanguinea) (native to the Hawaiian Islands):
Black Francolin (Francolinus francolinus) (introduced from India or the Middle East):
Black-crowned Night Heron, adult (Nycticorax nycticorax) (this species has a nearly worldwide distribution):
Black-crowned Night Heron, juvenile flying:
Black-necked Stilt (Himantopus mexicanus) (native to Hawaii and throughout the Americas):
Bristle-thighed Curlews (Numenius tahitiensis) (breeds in upland tundra locations but winters in Hawaii and other tropical sites):
Bristle-thighed Curlew flying:
Cattle Egret (Bubulcus ibis) (originally native to Africa and Asia but has spread nearly worldwide):
Cattle Egret flying:
Common Moorhen (Gallinula chloropus) (native to Africa and Eurasia):
Common Moorhen juvenile:
Common Myna (Acridotheres tristis) (native to Asia):
Common Myna in flight:
If you want to pinpoint your place in the Universe, start with your cosmic address. You live on Earth->Solar System->Milky Way Galaxy->Local Cluster->Virgo Cluster->Virgo Supercluster->Laniakea. Thanks to new deep sky surveys, astronomers now think all those places are part of an even bigger cosmic structure in the “neighborhood” called The Shapley Concentration.
Astronomers refer to the Shapley Concentration as a “basin of attraction”. That’s a region loaded with mass that acts as an “attractor”. It’s a region containing many clusters and groups of galaxies and comprises the greatest concentration of matter in the local Universe. All those galaxies, plus dark matter, lend their gravitational influence to the Concentration. There are many of these basins in the Universe, including Laniakea. Astronomers are working to survey them more precisely, which should help provide a more precise map of the largest structures in the Universe.
A slice of the Laniakea Supercluster, a local basin of attraction. This structure contains many galaxies and clusters, including our own Milky Way Galaxy. Credit: SDvision interactive visualization software by DP at CEA/Saclay, France.One group, led by astronomer R. Brent Tully of the University of Hawai’i measured the motions of some 56,000 galaxies to understand these basins and their distribution in space. “Our universe is like a giant web, with galaxies lying along filaments and clustering at nodes where gravitational forces pull them together,” said Tully. “Just as water flows within watersheds, galaxies flow within cosmic basins of attraction. The discovery of these larger basins could fundamentally change our understanding of cosmic structure.”
Cosmic Flows and Mapping StructuresTully’s team is called CosmicFlows and they study the motions through space of those distant galaxies. The team’s “redshift” surveys revealed a possible shift in the size and scale of our local galactic basin of attraction. We already know that we “live” in Laniakea, which is about 500 million light-years across. However, the motions of other clusters indicate there’s a larger “attractor” directing the cluster flow. The CosmicFlows data suggest that we could be part of the Shapley Concentration, which could be 10 times the volume of Laniakea. It’s about half the volume of the largest structure in space, known as “the Great Wall”, which is a string of galaxies stretching across 1.4 billion light-years.
Several superclusters were revealed by the 2dF Galaxy Redshift Survey. This contains the structure known as the “Sloan Great Wall”. Courtesy 2dF Galaxy Redshift Survey.The Shapley Concentration was first observed by astronomer Harlow Shapley in the 1930s as a “cloud” in the constellation Centaurus. This supercluster appears along the direction of motion of the Local Group of galaxies (where we live). Because of that, scientists speculated that it could be influencing our galaxy’s peculiar motion. Interestingly, the Virgo Supercluster (and the Local Group and Milky Way Galaxy) appears to be moving toward the Shapley Concentration. The surveys that Tully and others are doing should confirm that motion toward whatever is attracting them.
Exploring Ever-larger Structures in the UniverseWhere do these basins of attraction come from? In one sense, they’re as old as the Universe and its cosmic web of matter that Tully references. The seeds for the web and those basins of attraction were planted some 13.8 billion years ago. After the Big Bang, the infant Universe was in a hot dense state. As it expanded and cooled, the density of matter started to fluctuate. There were tiny differences in those density fluctuations. Think of them as the earliest “seeds” of galaxies, galaxy clusters, and even vaster structures that we see in today’s Universe.
This detailed map of the cosmic microwave background is created from seven years worth of data. It shows the “seed” structures of galaxies in the infant Universe. Image Credit: NASAAs astronomers survey the sky, they find evidence for all those different structures. Now, they have to explain them. The idea that the Shapley Concentration is the large basin that our Laniakea belongs to means that current cosmological models don’t quite explain its existence.
“This discovery presents a challenge: our cosmic surveys may not yet be large enough to map the full extent of these immense basins,” said UH astronomer Ehsan Kourkchi. “We are still gazing through giant eyes, but even these eyes may not be big enough to capture the full picture of our universe.”
Measuring the AttractorsThe main actor in all these galaxies, clusters, and superclusters, is gravity. The more mass, the more gravity influences motions and matter distribution. For these basins of attraction, Tully’s research team examined their impact on galaxy motions in the region. The basins exert a sort of “tug of war” on galaxies that lie between them. That influences their motions. In particular, redshift surveys like Tully’s team is doing will map the radial motion (along the line of sight), velocities (how fast they’re moving), and other related motions. By mapping the velocities of galaxies throughout our local Universe, the team can define the region of space where each supercluster dominates.
Of course, these motions are tricky to define. That’s why the team does different types of measurements. They aren’t mapping just the luminous material in galaxies. They also have to take into account the inferred existence of dark matter. There are other complications as well. For example, not all galaxies are the same—that is, they differ in their shapes (morphology) and matter density. Astronomers can get around this by measuring something called “galaxy peculiar velocity”. That’s the difference between its actual velocity and the expected “Hubble flow” velocity (which reflects gravitational interactions between galaxies).
The results of the Tully team surveys should provide ever more precise 3D maps of these regions of space. That includes their structures as well as their motions and velocities. Those maps, in turn, should give greater insight into the distribution of all matter (including cold dark matter) throughout the Universe.
For More InformationIdentification of Basins of Attraction in the Local Universe (journal)
Identification of Basins of Attraction in the Local Universe (arXiv pdf)
The Shapley Supercluster: the Largest Matter Concentration in the Local Universe (PDF)
The post The Milky Way Might be Part of an Even Larger Structure than Laniakea appeared first on Universe Today.
The James Webb Space Telescope (JWST) has revealed magnificent things about the Universe. Using its sophisticated infrared optics, it has peered deeper into space (and farther back in time) than any observatory to date, gathering data on the first galaxies to form in our Universe. It has also obtained spectra from exoplanets, revealing things about the chemical composition of their atmospheres. In addition, Webb has provided some stunning views of objects within our Solar System, like Jupiter and its auroras, Saturn’s rings and moons, and Neptune and its satellites.
Recently, a team led by researchers from Southwest Research Institute (SwRI) used Webb Near-Infrared Spectrograph (NIRSpec) to closely examine the Pluto-Charon system. Their observations detected frozen carbon dioxide and hydrogen peroxide on the surface of Pluto’s largest moon for the first time. These discoveries add to what scientists learned about Charon’s chemical inventory from ground-based telescopes and the New Horizons mission. It also reveals more about the chemical composition of the many objects that make up the Kuiper Belt.
The team was led by Silvia Protopapa, a Principal Scientist with the SwRI Department of Space Studies and a co-investigator of the New Horizons mission. She was joined by members from the Space Telescope Science Institute (STScI), the Florida Space Institute, the Lowell Observatory, the SETI Institute, the Pinhead Institute, the Institut d’Astrophysique Spatiale, the Johns Hopkins University Applied Physics Laboratory (JHUAPL), the Association of Universities for Research in Astronomy (AURA), and NASA Goddard Space Flight Center. The paper that details their findings recently appeared in Nature Communications.
The observations were part of Webb’s Guaranteed Time Observation (GTO) program 1191, which relied on Webb’s Near Infrared Camera (NIRCam) to study Kuiper Belt Objects (KBO). Dr. John Stanberry, the program’s Principal Investigator, is an instrument scientist for Webb’s NIRCam at the Space Telescope Science Institute (STScI). The team used Webb’s NIRSpec to conduct four observations of the Pluto-Charon system between 2022 and 2023, which provided full coverage of Charon’s northern hemisphere.
Webb spectroscopic measurements revealed signatures of carbon dioxide, which the team compared with laboratory measurements and detailed spectral models of the surface. They concluded that carbon dioxide is present primarily as a surface veneer on a subsurface rich in water ice. As Dr. Protopapa explained in a recent SwRI press release:
“Charon is the only midsized Kuiper Belt object, in the range of 300 to 1,000 miles in diameter, that has been geologically mapped, thanks to the SwRI-led New Horizons mission, which flew by the Pluto system in 2015. Unlike many of the larger objects in the Kuiper Belt, the surface of Charon is not obscured by highly volatile ices such as methane and therefore provides valuable insights into how processes like sunlight exposure and cratering affect these distant bodies.
“Our preferred interpretation is that the upper layer of carbon dioxide originates from the interior and has been exposed to the surface through cratering events. Carbon dioxide is known to be present in regions of the protoplanetary disk from which the Pluto system formed.”
Pluto and Charon. Credit: NASA/JHUAPL/SwRIHydrogen peroxide forms when water ice is broken down at the atomic level through exposure to ultraviolet light, charged particles from the Sun (solar wind), and galactic cosmic rays. Its presence on the surface of Charon indicates that the water ice-rich surface is subject to photolysis. This is similar to how exposure to solar radiation causes methane to create tholins, which explains why bodies in the outer Solar System are ruddy in appearance. Said SwRI’s Dr. Ujjwal Raut, leader of the Cornell Laboratory for Accelerator-based ScienceS and Education (CLASSE) and second author of the paper:
“Laboratory experiments conducted at SwRI’s CLASSE (Center for Laboratory Astrophysics and Space Science Experiments) facility were instrumental in demonstrating that hydrogen peroxide can form even in mixtures of carbon dioxide and water ice under conditions analogous to those at Charon.”
The team’s findings demonstrate Webb’s ability to uncover complex surface signatures, which can tell astronomers more about the chemical composition, formation, and evolution of bodies in our Solar System and beyond. These same capabilities allow astronomers to characterize exoplanets’ atmospheres to see if they have the necessary ingredients to support life (as we know it).
“The new insights were made possible by the synergy between Webb observations, spectral modeling, and laboratory experiments and are possibly applicable to other similar midsized objects beyond Neptune,” said Protopapa.
Further Reading: SWRI, Nature Communications
The post Webb Detects Carbon Dioxide and Hydrogen Perodixe on Pluto’s moon Charon appeared first on Universe Today.
UPDATE: For another splenetic take on scientism, read David Brin’s post, “The dangerous chimera called ‘scientism.” An excerpt:
The crusade to discredit all fact-using professions is an existential threat to us all — a deliberate effort to lobotomize-away any influence by folks who actually know stuff.
One of the core elements of this campaign is to deride modern science as a ‘mere religion’. A religion called “scientism’. That cult incantation – aiming to cancel out all nerds and every kind of ‘expert’ – is promoted in this article.
One raver, denouncing Scientific America’s endorsement of pro-fact candidates, said:
“…worshippers at this new altar seem determined to usher in a new post-modern utopia in which science and religion are fused once again. In that light, they cannot help but endorse Kamala Harris because their consciences won’t allow them to do otherwise. It’s not a choice dictated by science, but by theology.”
Parse it. The fundamental goal is to demean fact-professions by their own standards, by calling them (without any hint of evidence, or irony) mere boffin-lemmings, yelping in unison as they worship the current paradigm and repress dissenting views.
Of course this is the masturbation-incantation of morons who know nothing about how science works, but desperately seek to justify their war against it.
Whenever I hear the word “scientism”, I know that there will follow a discourse about either how science is deficient, or about how “other ways of knowing” are as good as modern science at discerning truths about the universe. The subject of my book Faith versus Fact is in fact a long defense of science (“construed broadly,” as I explain in the book) as the only way to know truths about the universe, so it’s no surprise that I’m wary of the word “scientism” and how it’s used.
If you think that the U.S. has largely been immune to the type of anti-modern-science attitudes pervading New Zealand, you might want to look at the Scientism Workshop that will take place at the University of Chicago next week. This is apparently a part of The Scientism Project, a multi-university and somewhat multinational consortium of philosophers and historians of science researching scientism, which they define this way:
Scientism, as an epistemic position, is the view that the sciences and their methods are the best (or only) way of obtaining genuine knowledge of reality. As a social ideology, scientism is the view that the sciences alone can be trusted with the task of bringing about social progress. These two aspects of scientism, while distinct, are related: It is by virtue of revealing ‘the way the world really is’ that we acquire the ability to effectively and reliably direct society towards progress.
I am not referring to scientism as a “social ideology,” but concentrating on the first definition. Clearly making social progress requires more than just science, and no scientists would say otherwise. One needs politics, tactics, money, empathy, and so on. But let’s stick with the first definition.
The Scientism Project is holding a two-day conference next week. It’s across the street from me, and I’m not yet sure if I’ll go. Some of the talks look interesting, some boring, others don’t seem to be very science-dissing, but some make me concerned. The printed summaries of two talks from the last group are below. Here are the dates (The Franke Institute is inside the Regenstein Library at its east end).
Date: 11-12 October 2024.
Time: 9.30 am to 5.30 pm.
Location: Franke Institute for the Humanities, University of Chicago.
The Program is given as a whole, with talk summaries; here are two: (I’ve provided links to the speakers. The first in particular is almost identical to what we hear from New Zealand. Bolding in the summaries is mine. I’ve addressed the contentions of the first talk many times with respect to “ways of knowing” of the Māori of New Zealand, and reader will be familiar with my beefs:
“Rethinking Expertise: How Indigenous Science Expands the Limits of Scientism for a Better Understanding of the World and Improved Decision Making”
Heather Sauyaq Jean Gordon, Sauyaq Solutions and University of Alaska Fairbanks
Indigenous Sciences (IS) offer distinct ways of knowing derived from Indigenous cosmologies, epistemologies, ontologies, and axiologies, that often seem to stand in contrast to scientism. While scientism elevates scientific methods as the sole valid approach to knowledge, Indigenous Knowledge systems are holistic, integrating spiritual, cultural, ecological, and relational understandings of the world. Scientism focuses on the scientific method that is typically traced to the 16th and 17th centuries, ignoring the Indigenous processes of observation, hypothesis, and experimentation developed millennia ago. In addition to IS offering millennia of the scientific method, IS bring in more comprehensive approaches to science (what in mainstream science may be referred to as systems science or sustainability science) that includes place, culture, and community, recognizing that data cannot be understood without contextualization, and that humans cannot exist without the nonhuman world. IS also contextualize [sic] through relationality, generational knowledge, lived experiences, and oral traditions (nearly all religious texts are also based on oral tradition in dominant society. It is important to note that when scientism makes claims about what is science and what is evidence, it attempts to delegitimize other ways of knowing, engaging in epistemic injustice and intellectual colonialism, and creating a space where decisions can only bemade on what is “evidence” according to scientism. Epistemic pluralism recognizes multiple ways of knowing and creates space to co-produce new knowledge from multiple ways of knowing coming together. IS offers scientism a new way to see the world, through sustainable 7 generations thinking of over 800 years back and 800 years into the future, focusing on the long term instead of the short term. Indigenous approaches also create outcomes recognizing the interconnectedness between all things, removing silos between disciplines, and seeking to benefit future generations. IS exist for practice and life, they are not restricted to those with degrees and the ability to read. It is vital to decolonize scientism so that IS can be seen as both evidence and knowledge in collaborative decision making. ************ “Science-Envy and the Current Science Crisis” Matthew J. Brown, Southern Illinois University CarbondaleOne feature of or type of scientism can be described somewhat disparagingly as “science-envy.” Scientism in this sense seeks to take the methods, practices, and results of science as the model or criteria for another field, such as philosophy. But contemporary science is not a worthy object of envy, due to a contemporary crisis in science. This crisis has two parts: internally, there is what we might call a quality control crisis, while externally, there is what we might call a crisis of expertise. Accordingly, fields like philosophy should not take science uncritically as a model or standard for success.
I can’t help defending science here against this calumny. Yes, science is imperfect: there are failures to replicate, and even Nobel Prizes have been given for things that were later shown to be wrong. But every bit of understanding about the universe that we’ve eked out of observation and experiment has come from science construed broadly. Despite the “contemporary crisis” that Dr. Brown touts, we have discovered black holes, gravity waves, mRNA vaccines for covid, golden rice, and, just this week, the structure of the fly brain, including all the neurons and their connections (and in some cases how the brain interacts with the fly body), a discovery that promises to promote huge leaps in understanding one of the great mystery of science: how the brain works. (I’ll write about that soon.) How dare any tyro say that “science is not a worthy object of envy?”
Religion in the twenty-first century is alive and well across the world, despite its apparent decline in North America and parts of Europe. Vigorous competition between and within religious movements has led to their accumulating great power and wealth. Religions in many traditions have honed their competitive strategies over thousands of years. Today, they are big business; like businesses, they must recruit, raise funds, disburse budgets, manage facilities, organize transportation, motivate employees, and get their message out. In The Divine Economy, economist Paul Seabright argues that religious movements are a special kind of business: they are platforms, bringing together communities of members who seek many different things from one another—spiritual fulfilment, friendship and marriage networks, even business opportunities. Their function as platforms, he contends, is what has allowed religions to consolidate and wield power.
This power can be used for good, especially when religious movements provide their members with insurance against the shocks of modern life, and a sense of worth in their communities. It can also be used for harm: political leaders often instrumentalize religious movements for authoritarian ends, and religious leaders can exploit the trust of members to inflict sexual, emotional, financial or physical abuse, or to provoke violence against outsiders. Writing in a nonpartisan spirit, Seabright uses insights from economics to show how religion and secular society can work together in a world where some people feel no need for religion, but many continue to respond with enthusiasm to its call.
Paul Seabright is a Professor of Economics in the Industrial Economics Institute and Toulouse School of Economics and the University of Toulouse, France. He earned his graduate degrees in economics from the University of Oxford. He was Assistant Director of Research and a Reader in Economics at the University of Cambridge until 2001. He has also been a consultant to private sector firms, governments and international organizations including the European Bank for Reconstruction and Development, the World Bank, the European Commission and the United Nations. He is the author of The War of the Sexes: How Conflict and Cooperation Have Shaped Men and Women from Prehistory to the Present, The Company of Strangers: A Natural History of Economic Life, and his new book The Divine Economy: How Religions Compete for Wealth, Power, and People.
Shermer and Seabright discuss:
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Although Biden (and now Harris) have proclaimed an ironclad commitment to Israel’s well-being, they’re acting very wonky about Israel’s behavior. First they withheld 2000-pound bombs from Israel (you know, the kind that were used on the targeted strike that killed the leader of Hassan Nasrallah, the leader of Hezbollah), though the U.S. rations some of these bombs to Israel.
But now the U.S. is trying to tell Israel how to run a war that is an existential thread to Israel’s existence, for the tiny Jewish nation is fighting on seven fronts at once (Gaza, Lebanon, Yemen, Iran, Iraq, Syria, and the West Bank). But the U.S. has been trying to control how Israel responded to Hamas’s October 7 attack from the very beginning. First Biden told Israel not to invade Gaza. When they did, Biden told Israel not to go into Gaza City. When they did, Biden told Israel not to go into Khan Younis. When they did, Biden told Israel in no uncertain terms not to go into Rafah, for that was “crossing a red line.” Kamala Harris backed up Bided then, asserting that she had “studied the maps.” Israel did go into Rafah and got some hostages, along the way destroying much of Hamas’s military capabilities. All the while Secretary of State Anthony Blinken was waffling, especially about negotiations, for he is the lever Biden uses to try to push Israel in his direction. Had the U.S. followed Biden’s wishes, then, Hamas would still be in control of Gaza, and the dangers of another October 7 would remain.
Now that Israel has made pretty short work of Gaza—granted, I don’t know what will happen “the day after”—and Israel is engaged with both Hezbollah and Iran, Biden is still trying to control Israel, telling the country not to do this and not to do that in response to the Iranian ballistic missile attack. “This” is “not going after Iran’s nukes”, and “that” is not going after Iran’s oil and gas fields. The former could possibly scuttle Iran’s nuclear program, while the latter would eliminate Iran’s major domestic source of income. (If I had my way, I’d say “get the nukes,” hard as that may be, for if Israel doesn’t do that, the country is doomed.)
The article from the Times of Israel below just reprises what I said, and what we know, about Biden’s response to Iran’s attack, and the headline tells the tale (click on it to read):
An excerpt:
US President Joe Biden says Israel has not yet decided how it’s going to respond to Iran’s ballistic missile strike.
“If I were in their shoes, I’d be thinking about other alternatives than striking oil fields,” Biden says during a rare appearance at the White House daily press briefing where one reporter after another asks leading questions goading him to criticize Israel.
Earlier this week, Biden said he opposed Israel targeting Iranian nuclear sites as well.
Asked whether he thinks Prime Minister Benjamin Netanyahu is rejecting diplomatic agreements in Gaza and Lebanon to influence the upcoming presidential election, Biden responds, “No administration has helped Israel more than I have. None, none, none, and I think Bibi should remember that.
“As for whether he’s trying to influence the election or I don’t know, but I’m not counting on that,” Biden adds.
Biden says he assumes he will speak to Netanyahu when Israel decides on how it wants to respond to Iran.
Another reporter suggests Biden does not influence Israel. The president rejects the premise, saying he receives regular briefings and that his team is in constant contact with their Israeli counterparts.
“It’s the High Holidays… They’re not going to make a decision immediately. And so, we’re going to wait to see when they want to talk,” he adds.
Pressed again on how Israel should respond to Iran, Biden declines to offer further details. “That’s between me and them.”
Asked if he’s considering imposing sanctions against Iran, the president says the matter is under discussion.
Another reporter asks if there is anything the US can do to prevent an all-out war in the Middle East.
“There’s a lot we are doing. The main thing we can do is try to rally the rest of the world, our allies into participating — like the French are in Lebanon and other places — to tamp this down, but when you have proxies as irrational as Hezbollah and the Houthis and it’s a hard thing to determine,” Biden says.
No attacks on oil facilities, no attacks on bomb-building or uranium-enrichment sites. So what does Biden want Israel to do? All the progress Israel has made in defeating its enemies has involved ignoring Biden’s advice and “orders.” And if Biden really wants to tamp down the war, he should just let Israel respond the way it wants. (Remember none of these seven wars were started by Israel.) Why is he waffling so much, and trying to order Israel how to behave?
Well, there’s the election of course, for an Israeli attack on Iranian oil may drive up the price of gas at the American pump, and the U.S. would blame that on Biden. As for the attack on nukes, Biden may be considering the Muslim vote, for while there are more Jews than Muslims in America, the Muslims tend to live in swing states.
But Malgorzata has another credible theory, which is hers. In her view, Biden is determined to carry on the legacy of Obama, who was strongly invested in “balancing” the Middle East, believing that peace would obtain if the power of Shiite states (e.g., Iran) remained appreciable compared to the power of Sunni states. To maintain this balance of power, then, Obama favored a strong Iran, and that meant largely ignoring Iran’s progressing nuclear program while refusing to put sanctions on Iran. (Trump did put sanctions on Iran, but Biden removed them upon taking office). Biden has continued Obama’s Middle East strategy since taking office.
So there we have a couple of speculations about why Biden is telling Israel not to retaliate against Iran by going after either oil or nukes. Of course we don’t know what Biden is really thinking, but what is clear is that Biden is constantly trying to stop Israel from retaliating against attacks from Iran and Gaza, and also asking for a very limited response in Lebanon. Biden’s “orders” are, in effect, orders to Israel to stop retaliating and, in the end, lose these wars, remaining perpetually subject to Islamist terrorism. Biden sure wouldn’t behave that way if, say, Canada started attacking the U.S. with ballistic missiles.
There is no doubt in my mind that Harris will continue to pressure Israel if she’s elected, except she’ll put the screws on tighter than did Biden. Apparently the election is a big factor in BIden’s foreign policy towards Israel, and he may have forgotten that most Israelis regard themselves as being in a war for the existence of their country. It’s 1948 all over again.
***********
Oh, I almost forgot. Since I get flak from both sides, here’s a comment that came in yesterday from a peeved reader who doesn’t like me dissing Trump. The reader’s handle on his attempted comment was “Robert Peters,” and his attempted comment (posted here but not at the site) was meant to address this post: “An anonymous post at the Elder of Ziyon site: The Harris/Walz’s (and Biden/Harris’s) abysmal record on Israel, Jews, and the war.” The comment:
Your contention that Trump is mentally ill is utter nonsense and diminishes everything else you have to say.
This made me laugh, because first of all, it seems likely to me that Trump really is mentally ill, at least with a diagnosable pattern of symptoms that fit into narcissistic personality disorder:
Narcissistic personality disorder involves a pattern of self-centered, arrogant thinking and behavior, a lack of empathy and consideration for other people, and an excessive need for admiration. Others often describe people with NPD as cocky, manipulative, selfish, patronizing, and demanding. This way of thinking and behaving surfaces in every area of the narcissist’s life: from work and friendships to family and love relationships.
People with narcissistic personality disorder are extremely resistant to changing their behavior, even when it’s causing them problems. Their tendency is to turn the blame on to others. What’s more, they are extremely sensitive and react badly to even the slightest criticisms, disagreements, or perceived slights, which they view as personal attacks. For the people in the narcissist’s life, it’s often easier just to go along with their demands to avoid the coldness and rages.
That seems to describe Trump pretty well. Of course I’m not a shrink, and everybody is some sort of mental outlier, but I think my view is reasonable. But beyond that, Mr. Peters is showing his own misguided petulance, saying that because I made one statement about Trump that he dislikes (he seems to be a Trump lover), it therefore “diminishes everything else I have to say.” Peters, in other words, is being irrational, showing the tendency of many to dismiss everything coming from a person—or a source—that has made one offensive statement. Too bad for him.
h/t: Norm
For the past ten years, Australia’s ARC Centre of Excellence in All Sky Astrophysics in 3 Dimensions (ASTRO 3D) has been investigating star formation, chemical enrichment, migration, and mergers in the Milky Way with the Anglo-Australian Telescope (AAT). Their work is part of the GALactic Archaeology with HERMES (GALAH) project, an international collaboration of more than 100 scientists from institutes and universities worldwide. These observations have led to the highest spectral resolution multi-dimensional datasets for over a million stars in the Milky Way.
Previous GALAH data releases have led to many significant discoveries about the evolution of the Milky Way, the existence of exoplanets, hidden star clusters, and many more. In the fourth data release (DR4), the GALAH team released the chemical fingerprints (spectra) for almost 1 million stars. This data is the pinnacle of the 10-year project and was released during the 50th anniversary celebration of the AAT. According to the study that accompanied the release, the data will inform decades of research into the formation and evolution of our galaxy.
The study was led by Sven Buder, a research fellow at ASTRO 3D and the Australian National University (ANU). He was joined by an international team of researchers from ANU’s Research School of Astronomy and Astrophysics, ASTRO 3D, ACCESS-NRI, the UNSW Data Science Hub, the Sydney Institute for Astronomy, Astrophysics and Space Technologies Research Centre, Space Telescope Science Institute (STScI), the Stellar Astrophysics Centre, the International Space Science Institute, and multiple universities. The paper describing the data release recently appeared in the Publications of the Astronomical Society of Australia.
The GALAH survey relies on the High Efficiency and Resolution Multi-Element Spectrograph (HERMES) working in conjunction with the 2-degree field (2dF) positioner. Both instruments are part of the Anglo-Australian Telescope (AAT) located at the Siding Spring Observatory in Coonabarabran, New South Wales. The 2dF positioner places a fiber at a star’s location in order for the light to pass to the HERMES instrument, which obtains detailed spectra of 392 objects at a time over two degrees of the sky. As Dr. Buder explained in a recent Science in Public news release:
“Our work is focused on collecting as much quality data as we can,” said ASTRO 3D’s Sven Buder, a research fellow at the Australian National University. GALAH has shown us which chemical elements make up the stars of the Milky Way. This dataset now helps further our ability to accurately age the stars in our neighborhood and understand where they came from. This data becomes a powerful tool for astronomers to test new theories and make new scientific discoveries about the Universe.”
The project scientists also rely on data from the Gaia, Kepler, and CoRoT missions, which have gathered optical data on countless stars in our galaxy. The GALAH project aims to determine the ages of these stars via their chemical signatures to get a clearer picture of the assembly of the Milky Way. This will allow astronomers to estimate a timeline of the Galaxy’s chemical and dynamical evolution and to investigate changes in the rate of star formation rate over time.
“We have measured the elements within these stars, like carbon, nitrogen, oxygen, as well as heavy elements found in our smartphones and electric vehicles,” added Dr. Buder. “This data will help us figure out how these elements are produced in stars, which is fundamental to explaining the origins of the building blocks of life.”
The spectral data consists of the visible spectrum with overlapping barcodes that indicate at which wavelengths light is being absorbed. These are the “chemical fingerprints” of the star, revealing their overall composition. This data will also help astronomers understand how the elements were formed and distributed throughout the Universe, offering hints about cosmic evolution. As if that wasn’t enough, the spectra can also be used for potentially detecting signatures of planetary systems.
The colorful spectra taken at Siding Spring Observatory with the element barcode of the pointer stars alpha Centauri, our Sun, and stars with very little elements. Credit: Sven Buder, ANU/ASTRO 3DIn the past, GALAH data has shown stars that may have consumed planets as the Milky Way developed. Said co-author Professor Daniel Zucker of Macquarie University:
“The GALAH survey has detected signs that some stars may have ‘eaten’ planets that were orbiting them. This can be observed by looking at the chemical composition of the star, as the elements from the consumed planet would show up as markers in the star’s spectrum.”
The GALAH datasets have had a profound impact on the global astronomical community and led to 290 scientific studies to date. The previous data release (DR3) paper covered 300,000 stars and became the most cited work of the year for the journal responsible. With data on almost 1,000,000 stars, the scientific impact of this latest release is expected to be tremendous. The GALAH dataset is also expected to play a vital role in training the next generation of machine-learning tools, which are increasingly important to astronomy.
“We are really looking towards an incredibly exciting period over the next few years where all of these discoveries about what’s happening in our Universe are going to flow from the data that we’ve collected right here in Australia using Australian telescopes and building on Australian research,” said Associate Professor Sarah Martell of UNSW, a key member of the project. Professor Emma Ryan-Weber, the Director of ASTRO 3D, added that the GALAH project is directly aligned with ASTRO 3D’s mission:
“It helps us understand how galaxies build mass over time. The chemical information the research team has gathered is like stellar DNA – we can use it to tell where each star has come from. We can also determine their ages and movements and gain a deeper understanding of how the Milky Way and other galaxies formed and have evolved. What’s more, as the ASTRO 3D mission comes to a close, the GALAH project will leave a lasting legacy of Australian science informing astronomical discoveries about the Universe’s origins and development for decades to come.”
The DR4 release can be found here, while the entire list of GALAH datasets can be found here.
Further Reading: Science in Public
The post The GALAH Fourth Data Release Provides Vital Data on One Million Stars in the Milky Way. appeared first on Universe Today.
The 2024 Presidential Election Survey is a representative (by age, race, sex and educational attainment) sample of 3,023 Americans, collected between September 5, 2024, to September 29, 2024. Substantively, the survey covers timely and controversial topics including: voting intentions and perceptions of election legitimacy, willingness to sever relationships because of political disagreement/support for violence if one’s preferred party loses the election, attitudes towards free speech, mental health, trust in journalism and other U.S. institutions, as well as various questions assessing peoples’ attitudes towards (and understanding of) abortion, immigration, crime, race, climate change, economic, gun control and war-related issues.
For additional information, please feel free to contact the Skeptic Research Center by email: research@skeptic.com.
MethodologyQuick note: two powerful solar flares occurred in the last 72 hours, creating high spikes in the rate of X-rays from the Sun.
Each flare created a coronal mass ejection that could arrive in a couple of days at Earth, potentially creating a geomagnetic storm. Consequently there’s a good probability this weekend, especially Saturday night into Sunday morning (in Europe and the US), of seeing northern and southern lights (auroras). [See this post for some advice as to how to infer whether the storms have started and/or are ongoing.]