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Researchers are breaking through the difficulties of robotic recognition of various common, yet complex, items. Their layered sensor is equipped with material detection at the surface and pressure sensitivity at the bottom, with a porous middle layer sensitive to thermal changes. An efficient cascade classification algorithm rules out object types in order, from easy to hard, starting with simple categories like empty cartons before moving on to orange peels or scraps of cloth.

A study revealed that a simple thermal reaction of gallium nitride with metallic magnesium results in the formation of a distinctive superlattice structure. This represents the first time researchers have identified the insertion of 2D metal layers into a bulk semiconductor. By carefully observing materials through various cutting-edge characterization techniques, the researchers uncovered new insights into the process of semiconductor doping and elastic strain engineering.

A study revealed that a simple thermal reaction of gallium nitride with metallic magnesium results in the formation of a distinctive superlattice structure. This represents the first time researchers have identified the insertion of 2D metal layers into a bulk semiconductor. By carefully observing materials through various cutting-edge characterization techniques, the researchers uncovered new insights into the process of semiconductor doping and elastic strain engineering.

Crater 2, located approximately 380,000 light years from Earth, is one of the largest satellite galaxies of the Milky Way. Extremely cold and with slow-moving stars, Crater 2 has low surface brightness. How this galaxy originated remains unclear. A team of physicists now offers an explanation.

In facing life's many challenges, we often opt for complex approaches to finding solutions. Yet, upon closer examination, the answers are often simpler than we expect, rooted in the core "essence" of the issue. This approach was demonstrated by a research team in their publication on addressing the inherent issues of solid-state batteries.

Physicists have calculated how suitable molecules can be stimulated by infrared light pulses to form tiny magnetic fields. If this is also successful in experiments, the principle could be used in quantum computer circuits.

Physicists have calculated how suitable molecules can be stimulated by infrared light pulses to form tiny magnetic fields. If this is also successful in experiments, the principle could be used in quantum computer circuits.

A computer program based on data from nearly a half-million tissue images and powered by artificial intelligence can accurately diagnose cases of adenocarcinoma, the most common form of lung cancer, a new study shows.

A new computer vision technique developed by engineers significantly speeds up the characterization of newly synthesized electronic materials. Such materials might be used in novel solar cells, transistors, LEDs, and batteries.

A new computer vision technique developed by engineers significantly speeds up the characterization of newly synthesized electronic materials. Such materials might be used in novel solar cells, transistors, LEDs, and batteries.

A while back, the paper by Anderson et al. appeared in PLOS One, and caused a bit of a stir in the press because of its claims that women contributed far more to hunting in various societies than anthropologists thought.  The metrics involved what proportion of foraging societies women participated in hunting (79%) and in what proportion of societies women hunted “large game” (33%). This was seen as surprising, but was also sold in the media as showing that women had been unfairly denigrated as the “weaker sex”, doomed to stay home and take care of babies, gathering plants and roots, and only rarely doing the “man’s work” of killing animals.  (Of course a sexual division of labor says nothing about inferiority or superiority of the sexes only that they do different things, which are equally important in keeping society going.)

Click the title to read this paper if you haven’t already:

But then a group headed by Vivek Venkataraman (he’s at the University of Calgary) carefully scrutinized the data used and conclusions advanced by Anderson et al.,  and published a paper in bioRχiv which showed that the Anderson et al. paper was shoddy, containing a number of methodological and numerical errors, all of which conspired to make Anderson’s conclusions false: women appeared to hunt much less than men in both senses. (Note that the rebuttal is very polite, a model of how rebuttals should be written.

Here, for example, is a tweet I posted then listing the many problems with Anderson et al.

I wrote about Venkataraman’s paper on this site, but of course then it was a preprint that had not yet been published, so it didn’t have the imprimatur of publication. Now it has appeared, which i found after reader djc mentioned in a comment that it was accepted in a respectable journal, Evolution and Human Behavior.  The paper, which is essentially the same as the preprint, can be found in published version (well, as a corrected proof in press) by clicking on the link below, or accessing the pdf here:

I’m not going to reproduce all the criticisms I and others leveled at Anderson et al.  What’s new in the published paper is a figure that summarizes all the issues that Venkataraman et al. find with Anderson et al.’s data (click to enlarge):

The conclusions, if the second paper is right, is that women hunted far less often than Anderson et al. concluded, both in the frequency of foraging societies in which women hunted and the frequency of such societies in which women hunted large game.  The related conclusion is that the Anderson et al. paper was not thoroughly reviewed (I’ll give the reviewers a break here: it would be a lot of trouble to look up some of the original data), and at the very least Anderson et al. were inexcusably sloppy. At the most they could have even been tendentious, tweaking and massaging the data so it looks like women hunted more than they did. Here are two paragraphs from the second paper showing the problems of the first:

Insufficient search for source material:

Fourth, though Anderson et al. (2023) investigated each society “by searching through the original references cited in D-PLACE (Binford, 2023; Kirby et al., 2016), and by searching digitized databases and archives,” there are instances in which well-known authoritative sources were not consulted. For example, Anderson et al. (2023) coded the Batek of Malaysia as having female hunters based on Endicott (Endicott, 1984). However, a more recent book by the same author provides quantitative information on female contributions. Endicott and Endicott (2008) wrote: “Still, women procured 2 percent by weight of the animals hunted by nonblowpipe methods and 22 percent of all bamboo rats.” Women procured no animals using the blowpipe (Table 4.1, p. 76) (Endicott and Endicott, 2008). The!Kung were also coded by Anderson et al. (2023) as having female hunters. Yet in her famous ethnography Nisa: The Life and Words of!Kung Woman, Shostak (1981, p. 220) wrote: “!Kung women cannot be considered hunters in any serious way…” A similar case prevails for the Tsimane horticulturalists of Bolivia. The authors cite Medinaceli and Quinlan (Medinaceli and Quinlan, 2018), but they ignore a recent case study on Tsimane women hunting (Reyes-García et al., 2020).

Pseudoreplication:

The fifth issue concerns pseudoreplication, in which the same case is counted more than once. This leads to inflated and inaccurate estimates. There are several examples. The!Kung and Ju/’hoansi are treated as independent points, but these terms refer to the same population (Lee, 1979). The same holds for the Agta and Ayta of the Philippines (Goodman et al., 1985). Moreover, the Efe, Sua, Mbuti (BaMbuti), and Bambote, and the Mardujara and Martu (Martu), are each counted independently despite being members of closely related groups (Bahuchet, 2012; Myers, 1979). We recognize that these errors by Anderson et al. (2023) are not deliberate. Indeed, in at least one case it may be valid to count these as independent data points. The Efe and Mbuti live nearby but are known to have divergent hunting strategies. The Efe are traditionally bow hunters, whereas the Mbuti are traditionally primarily net hunters (Bailey and Aunger Jr., 1989). However, due to the potential for cultural autocorrelation to inflate the frequency of women’s hunting, such decisions should be acknowledged and justified.

These are just two of many problems, and I’d be really embarrassed if I were an author on the first paper. But perhaps Anderson et al. will reply, though I think Venkataraman, given that they use quotes, have them dead to rights.

But really, the Anderson et al. paper got a lot of publicity because it was considered “feminist,” showing that women did more hunting than previously thought, with the implication that anthropologists, because of an anti-female bias, unduly neglected women’s hunting.  Unfortunately, that kind of popular analysis is misguided, since women, even if they hunt less often than men, are not inferior: they just have a different role, and one that is essential in preserving societies and cultures.

And I predict that the rebuttal of that paper will probably be ignored by the press, simply because it dismantles a conclusion that was considered “progressive”.  I hope not, but we shall see.  But anyone calling the second paper “anti-feminist” is dead wrong; it’s just correcting the science, and it says nothing about how we regard women’s rights and value.

UPDATE: Prediction verified: see comment #2 below by one of the authors of the second paper.

h/t: David

Are points of infinite curvature, where general relativity breaks down, always hidden inside black holes? An audacious attempt to find out is shedding light on the mystery of quantum gravity

The largest collection yet of detailed medical data and tissue samples from astronauts should help researchers better understand the impacts of space flight on health

Earth is lagging behind other worlds with its single moon, so on this episode of Dead Planets Society we are giving it more – and giving those moons moonmoons to orbit them

My co-deplatformee Maarten Boudry has announced in Quillette that he’s written an open letter (with coauthor Prof. Mark Elchardus) against the growing worldwide call to boycott Israeli universities. Although it’s called a “faculty open letter”, you don’t have to be an academic to sign it, though the signatures will be vetted to keep out trolls. You can read about the letter at the first link (it presents an earlier version of the letter), and then click the second headline to actually sign the latest and most comprehensive letter if you agree with its sentiments.

From Maarten’s introduction in Quillette (I won’t reproduce the whole thing):

Universities across the world are facing pressure—from students but also from academic staff—to cut ties with Israeli institutions over the war in Gaza. In the US, a dozen universities have struck agreements with activists and partly conceded to their demands, including divestment from Israeli companies. In Europe, dozens of Spanish universities and five Norwegian universities have resolved to sever all ties with Israeli partners deemed “complicit” in the war in Gaza. Several Belgian universities have now suspended all collaborations with Israeli universities because of their collaborations with the IDF. Even without a formal boycott, pressure from anti-Israel protests and the BDS movement has already led to pervasive exclusion of Israeli scientists and students. In the liberal Israeli newspaper Haaretz, over 60 academics have testified what this amounts to: cancelled invitations to lectures and committees, desk rejections of papers on political grounds, freezing of ongoing collaborations, disrupted guest lectures, and withdrawn co-authorships.

And then, since Maarten is a philosopher, he goes into the arguments for and against such a boycott.

On the “con” side he criticizes the Netanyahu government and its policy of settlement on the West Bank, but in the end, as you must have guessed, he concludes that a blanket boycott of Israeli universities is counterproductive, not just for Israel but for the liberal Western values that universities are supposed to represent.

In liberal democracies such as Israel, universities are indispensable parts of civil society, which facilitate the critical examination and questioning of government policies. Despite the country’s flaws, such criticism is still very much possible in Israel. Those who oppose the policies of Benjamin Netanyahu and his far-right coalition partners will find numerous allies among Israeli academics. Many of them took the lead in the protests against Netanyahu’s dangerous judicial reforms of 2023, which threatened Israel’s democratic character. Finally, Israeli universities enrol tens of thousands of Palestinian and Arab students, often supported by government programs. They too will be targeted by a blanket boycott of Israeli universities, which will in no way contribute to peace, but will instead further weaken the constructive and liberal forces in Israeli society.

Let me add that Bob Zimmer, the late President of the University of Chicago, was pressured to divest from Israel and also engage in an academic boycott against its country’s universities He responded in 2016 by issuing this statement:

The University of Chicago will not divest from companies for doing business in Israel and opposes academic boycotts aimed at specific nations, including Israel. The University is restating its policy to address questions regarding its institutional position.

The University does not take social or political stances on issues outside its core mission. Using investments or other means to advance a social or political position held by some segment of the University community would only diminish the University’s distinctive contribution – providing a home and environment for faculty and students to engage freely and openly on the widest range of issues. The Kalven Report outlines this approach and the values behind it, concluding that preserving the freedom of individual scholars to argue for or against any issue of political controversy requires “a heavy presumption against” collective political action by the University itself.

The University has been consistent in its opposition to proposed academic boycotts, issuing statements in 2007 and again in 2013. The University has from its founding held as its highest value the free and open pursuit of knowledge. Faculty and students must be free to pursue their research and education around the world, and to form collaborations both inside and outside the academy, encouraging engagement with the widest spectrum of views. For this reason, the University continues to strongly oppose boycotts of academic institutions or scholars in any region of the world, including recent actions to boycott Israeli institutions.

QED.  Now click below to go to the letter itself, and then, if you want to append your name, click again on the “sign the open letter” boxes at top right or bottom—or just click here.

Of course I asked Maarten what would become of the letter so that readers who sign it aren’t simply engaging in a performative gesture. Maarten said this:

What will become of it? Obviously we want to send a signal to universities across the world that plenty of academics firmly oppose any form of boycott, so that the cowards won’t follow the path of least resistance and cave into the loudest protestors (as my uni had done already). I like to think that our well-publicized letter in Dutch (in two newspapers) played some role in the public announcement by the Dutch rectors that they reject a boycott, two weeks later. The more people sign, especially academics, the stronger the signal. JAC: Note that the anti-boycott announcement in the Netherlands involved 15 Dutch universities, including the University of Amsterdam.  These comprise the totality of the Association of Universities of the Netherlands, so it’s a very strong signal of opposition to boycotts. But this is only one country, not the world, and, as Maarten notes in his Quillette piece, calls for academic boycotts of Israel are numerous and ubiquitous.

The plastic-digesting capabilities of the fungus Parengyodontium album could be harnessed to degrade polyethylene, the most abundant type of plastic in the ocean

Reader Divy, who runs a Florida vet operation with her husband Ivan (Mobile Veterinary Services; Instagram page here), produced this wonderful collage of animal eyes. Your job: guess the animals.  Divy’s notes:

All these animals have been seen by us in one capacity or another, either as patients, or part of a collection check.

The answers are below the fold.

Click “continue reading” to see the answers:

Starting from top, left to right: Albino gator Eclectus parrot (female) Snail eating turtle Macklot’s python Water monitor (juvenile) Moluccan cockatoo Catalina Macaw Albino water monitor (adult) Australian freshwater crocodile (juvenile) Dwarf rabbit Crested gecko Ring-tailed lemur Aldabra giant tortoise Eclectus parrot (male) Scarlett Macaw Keel-billed Toucan African-crowned crane Eurasian eagle-owl African grey parrot Panther chameleon

Would anyone like a tour of the ATLAS and CMS experiments, the general purpose particle detectors at the Large Hadron Collider that were used to discover the particle known as the Higgs boson? A live, virtual tour is being given today (Tuesday June 11) on YouTube, https://www.youtube.com/watch?v=askq7-9CzrU, at 1700 CERN time — that’s 1600 London time, 11:00 New York time, 8:00 San Francisco time. Find out how these enormous, complex, magnificent devices are constructed, and learn how their various parts work together, 25 million times every second, to allow scientists to track the tiniest objects in the universe. Includes a Q&A at the end for participants.

Commenter Lal asks in the topic suggestions:

“Media reports that light has been travelling from that distant galaxy for 13 and a half billion years, which I assume is true, but this neither represents the original nor the current distance to that galaxy in terms of light years. I would be interested to know where we lie in the expanding universe compared to these distant galaxies.”

This is a good question, and is challenging to grasp. We need experts who have been thinking about this for decades and who actually understand what’s happening and who can explain it well. Here, I think, is an excellent discussion of this very question. I’ll give a quick summary, but for those interested, you may want to read the full article.

The basic background is that, according to modern cosmological theory, which includes the Big Bang, the universe was a singularity – one point that contained all of spacetime and all matter and energy – about 13.7 billion years ago. This point underwent rapid expansion, at first very rapid, called the inflationary period. Then it continued to rapidly expand, although at a much slower pace, although this rate of expansion has been increasing over time due to dark energy. What happens to the universe when it expands? It’s important to note first that the universe is not expanding into space – space-time itself is expanding.

Matter in the universe gets less dense and hot as the universe expands. At first matter was too hot for particles to exist. Once it cooled enough for protons and neutrons to exist, they mostly formed into hydrogen, but that was still too hot to hold onto electrons so the matter was all plasma. That eventually cooled enough for hydrogen (and some helium and a tiny bit of lithium) atoms to exist – at about 380,000 years after the Big Bang. Since then the matter in the universe has continued to cool and become less dense. However, it was also able to form stars, galaxies, heavier elements, and then lots of interesting things like people.

Radiation, including light, in the universe also became less dense as the universe expanded. However, something else interesting happens to radiation when spacetime itself expands – it’s wavelength also expands. In terms of light, this means it becomes red shifted. This further means that distant objects become fainter than they would purely because of distance. According to the inverse square law, when something is twice as far away any light or waves emanating from it will be 2 squared or one fourth as intense. Sound will be one quarter the volume and light will be one quarter the brightness. But in the universe distant object are more dim than can be accounted for by mere distance, because of light’s redshift.

Energy density in the universe, however, remains constant even when the universe expands. This is because the universe is not expanding into empty space – space itself is expanding. In a sense more space is being created, keeping the energy density of space constant.

This brings us to the core question above – how do we account for all this when measuring the distance to a distant object. If we think about two galaxies in the early universe, about 500 million years after the Big Bang – as the universe expanded these two galaxies would become farther and farther apart. Light leaving one galaxy would have to catch up with the other galaxy as it moves away with the expansion of space. So it takes longer than the original distance of the galaxies, the distance apart at the moment that light leaves one headed for the other, would indicate. The farther apart the galaxies were initially, the longer it will take to catch up.

The time the light has been traveling to get from one galaxy to the other is called the “lookback time”. This is not the same as the actual current distance, which is much greater. For a lookback time of about 13 billion years, that would correspond to a current distance of about 40 billion light years. This also means that if there has not been enough time yet in the age of the universe for light from an object to catch up to an observer, that object is outside the visible universe for that observer. Our visible universe, therefore, corresponds to the age of the universe, 13.78 billion years, which equals a current distance of 41.6 billion light years. Actually I think it’s a bit less than this, the age at which it became transparent to light.

Beyond 41 billion light years, or a look back time of 13.7 billion years, there is more universe but it is outside our visible universe. Interestingly, as the universe expands the percentage of the total universe that is within the visible range of any observer will decrease. Eventually future astronomers will only be able to see our local group of galaxies and that’s it. This will happen in about 100 billion years. What is the percentage of the total universe that is currently visible? We have to make some cosmological assumptions to give a precise answer, but according to some estimates only about 1.5%.

There is a lot more complexity to this question, but this is a quick summary to at least give a basic idea of the structure of the universe over time. The currently view is also evolving as we gather more information. It was only relatively recently that astronomers realized the expansion of the universe is accelerating, for example. So the precise numbers are likely to change, but these basics are fairly reliable.

 

The post Light and Distance in an Expanding Universe first appeared on NeuroLogica Blog.

People taking semaglutide, also called Ozempic and Wegovy, either for weight loss or type 2 diabetes, were less likely to become addicted to alcohol