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While the 20th century saw rapid rises in average life expectancy at birth, more recent years have seen a slowdown, suggesting we may be reaching the limit of human lifespan

A pair of ctenophores, or comb jellies, can fuse their bodies together, merging their digestive and nervous systems, without any issues with immune rejection

Daniele Oriti’s pursuit of a theory of quantum gravity has led him to the startling conclusion that the laws of nature don’t exist independently of us – a perspective shift that could yield fresh breakthroughs

Some environmental phenols are known to have cardiac toxicities. Now, a new study is revealing their adverse impact on the heart's electrical properties.

Planet-forming disks, maelstroms of gas and dust swirling around young stars, are nurseries that give rise to planetary systems, including our solar system. Astronomers have discovered new details of gas flows that sculpt those disks and shape them over time.

New experimental results suggest that sprinkling boron into a tokamak could shield the wall of the fusion vessel and prevent atoms from the wall from getting into the plasma. A new computer modeling framework shows the boron powder may only need to be sprinkled from one location.

New experimental results suggest that sprinkling boron into a tokamak could shield the wall of the fusion vessel and prevent atoms from the wall from getting into the plasma. A new computer modeling framework shows the boron powder may only need to be sprinkled from one location.

Researchers conducted innovative simulations of spinning black holes grounded in general relativity, which clarified that the ultraluminous accretion disk (i.e., gaseous spiral surrounding a black hole) exhibits a precessional motion driven by the black hole's spin. This finding underscores the potential of this spin to be the primary driver of the periodic fluctuations in luminosity observed within these ultraluminous accretion disks.

Researchers have developed a novel method using facet-selective, ultrafine cocatalysts to efficiently split water to create hydrogen -- a clean source of fuel.

Researchers have created a high-performance polymer that can be chemically recycled without compromising its heat and chemical resistance. The revolutionary design includes a directing group that allows links in the polymer to be broken easily with a catalyst and the original polymer to be reformed in few steps. The directing group could be included in many polymers, potentially providing a new generation of high-performance plastics that can be recycled indefinitely.

Researchers have discovered the most distant Milky-Way-like galaxy yet observed. Dubbed REBELS-25, this disc galaxy seems as orderly as present-day galaxies, but we see it as it was when the Universe was only 700 million years old. This is surprising since, according to our current understanding of galaxy formation, such early galaxies are expected to appear more chaotic.

Global warming could increase the threat posed to whale sharks from large ships, according to a new study.

Motion sensors in smartphones can be turned into makeshift microphones to eavesdrop on conversations, outsmarting security features designed to stop such attacks

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.

The 2024 Nobel prize in physiology or medicine has gone to Victor Ambros and Gary Ruvkun for their discovery that tiny pieces of RNA called microRNAs play a key role in controlling genes

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: ESA

Scientists 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 Structures

Tully’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 Universe

Where 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: NASA

As 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 Attractors

The 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 Information

Identification 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)

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