476 Romulus Augustulus, the last Western Roman Emperor, abdicates after forces led by Odoacer invade Rome, traditionally ending the Western Roman Empire
1609 Navigator Henry Hudson is the first European to discover the island of Manhattan [or September 11]
1781 Los Angeles is founded by 44 Spanish-speaking mestizos in the Bahía de las Fumas (Bay of Smokes)
1862General Lee begins the Maryland Campaign, invading the North with 50,000 Confederate troops (U.S. Civil War)
1957 Governor of Arkansas, Orval Faubus, calls out the National Guard to prevent nine Black students from entering Little Rock Central High School
1972 US 4 x 100 m medley relay team of Mike Stamm, Tom Bruce, Mark Spitz, and Jerry Heidenreich sets a world record of 3:48.16 to win gold at the Munich Olympics; Mark Spitz becomes the first athlete to win seven Olympic gold medals at a single Games
Fun Fact About September 4
A “magic carpet” that can help prevent falls among the elderly by warning them of unusual footsteps is developed by researchers at the University of Manchester
Wandering magnetic fields would have had noticeable effects for humans. Credit: Maximilian Schanner (GFZ Helmholtz Centre for Geosciences, Potsdam, Germany)
Weak magnetic fields once exposed humans to radiation. People adapted with shelter, clothing, and mineral protection.
When we first got together, we wondered whether our unconventional project, linking space weather and human behavior, could actually bridge such a vast disciplinary divide. Now, two years on, we believe the payoffs – personal, professional and scientific – were well worth the initial discomfort.
Our collaboration, which culminated in a recent paper in the journal Science Advances, began with a single question: What happened to life on Earth when the planet’s magnetic field nearly collapsed roughly 41,000 years ago?
Weirdness when Earth’s magnetic shield falters
The event is known as the Laschamps Excursion, a short but intense geomagnetic disruption named after volcanic deposits in France where it was first discovered. Near the end of the Pleistocene epoch, Earth’s magnetic poles did not undergo a full reversal, as they typically do every few hundred thousand years. Instead, they shifted erratically across thousands of miles, while the strength of the magnetic field fell to less than 10% of its present level.
Aurors in the skies above Europe could have been breathtaking, terrifying or both for ancient humans. Credit: The Conversation
Under normal conditions, Earth’s magnetic field behaves like a stable dipole, similar to a bar magnet. During the Laschamps Excursion, however, it broke apart into several weaker poles scattered across the globe. This fragmentation weakened the magnetosphere, Earth’s natural shield that normally blocks much of the solar wind and harmful ultraviolet radiation from reaching the surface.
With the magnetosphere compromised, models suggest that a variety of near-Earth effects would have occurred. Auroras, which today are usually confined to the polar regions, likely appeared much closer to the equator, and the planet was exposed to significantly higher levels of solar radiation than we experience now.
The skies some 41,000 years ago may therefore have been both dazzling and dangerous. Recognizing this, we as geophysicists began to wonder how such conditions might have influenced human populations of the time.
From an archaeological perspective, the answer was clear: they were indeed affected.
Human responses to ancient space weather
For people living during this period, the auroras would likely have been the most visible and dramatic consequence, perhaps provoking awe, fear, ritual practices, or other responses that are difficult to trace. The archaeological record rarely preserves direct evidence of such emotional or cognitive reactions.
The physiological consequences of heightened ultraviolet exposure, however, are easier to assess. With the magnetic field weakened, more harmful radiation reached the surface, increasing the risks of sunburn, vision damage, birth defects, and other health concerns.
Naturally occurring ochre can act as a protective sunscreen if applied to skin. Credit: Museo Egizio di Torino
In response, people may have adopted practical measures: spending more time in caves, producing tailored clothing for better coverage, or applying mineral pigment “sunscreen” made of ochre to their skin. As we describe in our recent paper, the frequency of these behaviors indeed appears to have increased across parts of Europe, where effects of the Laschamps Excursion were pronounced and prolonged.
During this time, both Neanderthals and Homo sapiens inhabited Europe, though their ranges likely overlapped only in certain regions. Archaeological findings indicate that these populations responded differently to environmental pressures, with some relying more heavily on shelter or material culture as forms of protection.
It is important to emphasize that the research does not claim space weather alone drove these changes in behavior, nor that the Laschamps event was responsible for Neanderthal extinction—a common misinterpretation. Instead, it may have been one of several factors, an unseen but influential force shaping human adaptation and innovation.
Cross-discipline collaboration
Collaborating across such a disciplinary gap was, at first, daunting. But it turned out to be deeply rewarding.
Archaeologists are used to reconstructing now-invisible phenomena like climate. We can’t measure past temperatures or precipitation directly, but they’ve left traces for us to interpret if we know where and how to look.
But even archaeologists who’ve spent years studying the effects of climate on past behaviors and technologies may not have considered the effects of the geomagnetic field and space weather. These effects, too, are invisible, powerful and best understood through indirect evidence and modeling. Archaeologists can treat space weather as a vital component of Earth’s environmental history and future forecasting.
An artistic rendering of how far into lower latitudes the aurora might have been visible during the Laschamps Excursion. Credit: Maximilian Schanner (GFZ Helmholtz Centre for Geosciences, Potsdam, Germany)
Likewise, geophysicists, who typically work with large datasets, models and simulations, may not always engage with some of the stakes of space weather. Archaeology adds a human dimension to the science. It reminds us that the effects of space weather don’t stop at the ionosphere. They can ripple down into the lived experiences of people on the ground, influencing how they adapt, create and survive.
The Laschamps Excursion wasn’t a fluke or a one-off. Similar disruptions of Earth’s magnetic field have happened before and will happen again. Understanding how ancient humans responded can provide insight into how future events might affect our world – and perhaps even help us prepare.
Our unconventional collaboration has shown us how much we can learn, how our perspective changes, when we cross disciplinary boundaries. Space may be vast, but it connects us all. And sometimes, building a bridge between Earth and space starts with the smallest things, such as ochre, or a coat, or even sunscreen.
Reference: “Wandering of the auroral oval 41,000 years ago” by Agnit Mukhopadhyay, Sanja Panovska, Raven Garvey, Michael W. Liemohn, Natalia Ganjushkina, Austin Brenner, Ilya Usoskin, Mikhail Balikhin and Daniel T. Welling, 16 April 2025, Science Advances. DOI: 10.1126/sciadv.adq7275
Adapted from an article originally published in The Conversation.
Agnit Mukhopadhyay has received funding from NASA Science Mission Directorate and the University of Michigan Rackham Graduate School.
Raven Garvey and Sanja Panovska do not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and have disclosed no relevant affiliations beyond their academic appointment.
Scientists say childhood vaccines may protect for life, making adult tetanus and diphtheria boosters unnecessary — a change that could save $1 billion a year. Credit: Shutterstock
New evidence suggests that adults may not need routine tetanus and diphtheria booster shots after all, potentially saving the U.S. around $1 billion annually.
The protection from childhood vaccinations appears to last for decades, matching findings from the U.K., where boosters haven’t been given since the 1950s, yet disease rates remain extremely low.
Potential Billion-Dollar Savings
A new review led by scientists at Oregon Health & Science University suggests the United States could safely eliminate routine tetanus and diphtheria booster shots for adults and save roughly $1 billion every year.
The researchers stressed that these savings and safety depend on keeping childhood vaccination rates consistently high.
“By maintaining high childhood vaccination coverage, we not only protect kids, but we may actually be able to reduce adult booster vaccinations,” said lead author Mark Slifka, Ph.D., professor of microbiology and immunology in the OHSU School of Medicine and the Oregon National Primate Research Center. “That would save $1 billion a year in the U.S. while maintaining the safety and protection of the general population.”
Slifka added that ending the 10-year booster schedule would bring U.S. practices more in line with recommendations from the World Health Organization.
Decades of Immunity Confirmed
The review builds on earlier OHSU studies published in 2016 and 2020, which found that the combined tetanus and diphtheria vaccine provides immunity lasting at least 30 years. That protection far exceeds the current guidance from the U.S. Centers for Disease Control and Prevention, which advises adults to receive a booster every 10 years. The vaccine is most often administered as the combination shot for tetanus, diphtheria, and pertussis, known as DTaP.
In the United States, children are scheduled to receive six doses of this vaccine between infancy and age 12.
According to the review, eliminating routine adult boosters would be safe as long as childhood vaccination coverage remains strong. Boosters could still be given in specific situations, such as after serious injuries like workplace accidents or car crashes, where tetanus exposure is a concern.
Natural Experiment in Europe
Published recently in the journal Clinical Microbiology Reviews, the review highlights a comparison between two industrialized countries just 21 miles across the English Channel: France and the United Kingdom. Both countries have excellent childhood vaccination coverage, similar to the U.S.
“This represents sort of an experiment of nature,” Slifka said. “We have one country with over 60 million people that for decades has continued to vaccinate adults throughout their lifetime and another nearby country that also has over 60 million people, but over the past 50 years, they have never recommended adult booster vaccinations.
“The question we asked is, ‘What happens if we don’t vaccinate the adults? Are there more cases of disease or are these people protected after completing their childhood vaccination series?’”
France vs. United Kingdom Outcomes
Similar to the United States, France has a recommended booster vaccination schedule for adults. In contrast, except during pregnancy or for wound management, the United Kingdom hasn’t recommended boosters for tetanus and diphtheria beyond age 14 since the 1950s.
Yet, despite decades of adult booster vaccination, the review found that France had virtually no advantage over the U.K. in the rates of tetanus or diphtheria. In fact, the review found that the UK had a slightly lower rate overall.
Herd Immunity Holds Strong
In addition, “herd immunity” held strong even in 2022 when the U.K. reported an outbreak of 73 imported diphtheria cases among immigrants seeking asylum. This spike in cases was almost equal to the total number of diphtheria cases reported in the entire country over the previous 20 years combined.
“Remarkably, despite this proportionally large influx of imported diphtheria cases, there was no evidence of transmission reported among other asylum seekers who arrived by other routes or among staff or health care workers,” the authors write.
The U.K. Health Security Agency concluded that the country’s current childhood-focused vaccination program is sufficient for preventing the spread of diphtheria and that the risk to the general UK population remains low.
Vaccines’ Life-Saving Impact
The findings highlight the remarkable durability of protection following childhood vaccination against a pair of diseases that were once all but a death sentence.
In 1948, the U.S. mortality rate for tetanus was 91%. Before the introduction of antibiotics and vaccines, the mortality rate for diphtheria was roughly 50%. To this day, diphtheria kills roughly one out of 10 people who aren’t vaccinated against it.
Childhood Vaccinations Keep Us Safe
Today, the public health threat is diminished thanks to childhood vaccinations as well as booster shots recommended in pregnancy.
“Thanks to childhood vaccinations, these diseases are incredibly rare,” Slifka said. “In fact, you’re 10 to 1,000 times more likely to be struck by lightning than to be diagnosed with tetanus and diphtheria in the United States.”
Reference: “Lessons learned from successful implementation of tetanus and diphtheria vaccination programs” by Mark K. Slifka, Archana Thomas, Lina Gao, Ian J. Amanna and Walter A. Orenstein, 15 July 2025, Clinical Microbiology Reviews. DOI: 10.1128/cmr.00031-25
In addition to Slifka, co-authors include Archana Thomas and Lina Gao, Ph.D., of OHSU; Ian J. Amanna, Ph.D., of Najít Technologies, and Walter A. Orenstein, M.D., of the Emory Vaccine Center at Emory University.
Research reported in this publication was supported by the Office of the Director of the National Institutes of Health, award number P51OD011092. The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.
Jan Bartek – AncientPages.com – A new study by a Utah anthropologist, using genetic studies, has concluded that Sahul colonizers arrived later than the commonly held 65,000-year timeframe.
Gwion Gwion rock paintings in the Kimberley region of Western Australia, taken at a site off Kalumburu Road near the King Edward River. Image c redit: TimJN1 -Source –Bradshaw Art
Aboriginal Australian culture is regarded as humanity’s oldest continuous living culture. Existing scientific literature estimated their arrival on the continent of Australia at 65,000 years ago as a group known as the Sahul peoples. However, recent genetics research led by the University of Utah that analyzes traces of Neanderthal DNA in Homo sapiens suggests the actual origination date was no more than 50,000 years ago.
In collaboration with a colleague from Australia’s La Trobe University, James O’Connell, Distinguished Professor Emeritus in the Department of Anthropology, reported new findings in a study in the journal Archaeology in Oceania. The team highlights conclusions from previous studies that argue Homo sapiens and Neanderthals interbred only once, over a period of several thousand years—between 43,500 and 51,500 before present, or BP.
Most modern humans, including Indigenous Australians, carry 1–4% Neanderthal DNA. The logic follows that modern Aborigine ancestors’ arrival on the continent could not have predated this time range.
Moreover, the dating of most archaeological sites across Australia points to a range between 43,000 and 54,000 years. “The colonization date falls within that interval,” O’Connell said. “That puts it in the same time range as the beginning of the displacement of Neanderthal populations in western Eurasia by anatomically modern humans.”
Other hominids, such as Homo erectus, had lived in Southeast Asia for more than a million years, but had not crossed overseas in large enough numbers to create a stable population in Australia. That is an important measure of the significance of Homo sapiens’ arrival.
Dating archaeological sites using OSL
One important Australian outlier among archaeological sites, O’Connell notes, is Madjedbebe, a site dated within a range of 59,000 to 70,000 years ago. The dating technique used in a 2017 study of Madjedbebe published in Nature was optically stimulated luminescence, or OSL. The technique reads minerals, typically quartz or feldspar, recovered at the site like a “clock” by measuring the energy they store. Radiation accumulates when these minerals are buried, then released when they are exposed to light. Measurements of the amount released determine when the minerals were last exposed to light.
The site has been subject to sand deposition, which may explain the estimated age of the artifacts. “The question for us has not been about the validity of the date. It’s about the relationship between the date and material evidence of human presence—that is, artifacts. In that part of Australia, many older archaeological sites are in situations where the depositional environment is a sand sheet. Material can move down through those deposits over time.”
Artifacts that are heavier than sand could settle through the sand deposit over time, and as a result, the dating process may have accurately analyzed the age of the sand deposits but not the artifacts they come to contain.
O’Connell also reviewed the hurdles the first Sahul peoples to arrive in Australia would have faced. The Sahul likely relied on rafts or canoes for exploration from Southeast Asia and colonization of Australia. But several challenges existed: first, they would need to engineer marine-capable watercraft that could pass through a “formidable ecological barrier,” the Wallacean archipelago, spanning 1,500 kilometers. Island-hopping through the archipelago, now comprising the nation of Indonesia, to Australia would involve at least eight separate crossings, the longest being 90 kilometers.
Early colonizers arrived in at least four groups
Moreover, these journeys would need to support a sizable population. Citing mitochondrial data, O’Connell noted: “Genomic analysis shows that early human colonizing populations included at least four separate mitochondrial lineages. Simple modeling exercises show that establishing each lineage on Sahul required the presence of at least five–10 women of reproductive age, which implies census populations of at least 25–50 individuals per lineage among the founders.”
The analysis indicates that these founding populations arrived within a short timeframe, lasting just a few centuries.
“This strongly suggests that colonizing passage was deliberate, not accidental,” O’Connell said,” and that it required sturdy rafts or canoes capable of holding, say, 10 or more people each plus the food and water needed to sustain those folks on open ocean voyages of up to several days, and of making headway against occasionally contrary ocean currents.”
Altogether, this technological progression adds more weight to a post-50,000-year arrival date, with other innovations and behavioral shifts—including cave art, tools, and ornaments—emerging in that timeframe.
The 50,000-year hypothesis has been a focus of the Australian anthropological debate since 2018. Four separate genetics studies have outlined the DNA ancestries of modern Indigenous New Guineans and Australians, concluding they could not have arrived earlier than 55,000 years ago. The other side of the debate continues to favor a 65,000-year date, which O’Connell disputes.
“I would expect in the next five years or so, the pendulum is going to swing back to general agreement for an under 50,000-year date for Australian colonization. It links up with the broader Eurasian record of an out-of-Africa population wave that spreads across Eurasia—a process that occurs over several thousand years. That raises all kinds of questions about why it happens, what it involves, what prompts it, and what changes in behavior are indicated in greater detail than they are now.”
Scientists at the University of Duisburg-Essen have developed Datavzrd, an open-source tool that transforms complex tables into interactive, easy-to-use reports. This breakthrough promises to make massive datasets clearer and more accessible across scientific disciplines. Credit: Shutterstock
Datavzrd makes complex datasets interactive and easy to use. It works across scientific fields without programming knowledge.
Tabular data is central to scientific research, whether in medicine, the social sciences, or archaeology. Yet transforming raw tables into something clear and usable is often labor-intensive, especially when the datasets are large or complicated.
To address this, the Institute for Artificial Intelligence in Medicine (IKIM) at the University of Duisburg-Essen has created Datavzrd, an open-source tool that converts ordinary tables into interactive and visually engaging HTML reports. Importantly, it requires no programming skills or additional software. The development was recently described in the open-access journal PLOS One.
Raw tables are often hard to interpret and can quickly become overwhelming. Typically, data points cannot be sorted, filtered, or connected, and when tables are shared, much of their context is lost. Existing solutions, such as R Shiny, provide useful visualization and interactivity but usually demand advanced technical expertise or specialized software.
User-friendly solution at IKIM
Datavzrd, designed at IKIM, avoids these drawbacks. Reports generated with the tool can be viewed directly in a web browser, attached to manuscripts, or sent by email. They stay fully interactive even when handling massive datasets with millions of rows. “The big advantage of Datavzrd is that it is particularly user-friendly and low-maintenance,” explains Felix Wiegand, a computer scientist involved in its development.
Wiegand, a member of Prof. Dr. Johannes Köster’s research group at IKIM, emphasizes the tool’s simplicity. “The reports are not programmed, but simply described in an easy-to-understand text file – similar to a profile that specifies which data should be displayed and in what way. This allows even users without programming experience to prepare their data quickly and clearly.” He adds that the tool can also represent complex relationships across multiple tables, enabling users to explore hierarchies or link related entries. A tutorial further streamlines its use, making it accessible to a wide range of researchers.
Wide applications in research
The IKIM team demonstrates the versatility of Datavzrd in the publication using various examples, including these two: In a molecular tumor board, genetic findings and therapy options are presented interactively on a patient-specific basis – just as required in medical practice. And in an archaeological study, decorated clothing elements from various archaeological sites are prepared in a comparable manner and presented in a linked format.
“Datavzrd makes data-based results intuitive, flexible, and sustainable,” says Felix Wiegand, summarizing the advantages. “It is suitable for almost all disciplines and scientific fields – from research and teaching to evaluation.”
Reference: “Datavzrd: Rapid programming- and maintenance-free interactive visualization and communication of tabular data” by Felix Wiegand, David Lähnemann, Felix Mölder, Hamdiye Uzuner, Adrian Prinz, Alexander Schramm and Johannes Köster, 22 July 2025, PLOS ONE. DOI: 10.1371/journal.pone.0323079
The Dark Energy Spectroscopic Instrument is mounted on the U.S. National Science Foundation’s Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory—a program of NSF NOIRLab—in Arizona. Credit: KPNO/NOIRLab/NSF/AURA/B. Tafreshi
DESI observations suggest black holes may generate dark energy by consuming stellar matter. The idea resolves puzzles about neutrino mass and cosmic expansion.
These are remarkable times for probing some of the most profound mysteries in physics, made possible by advanced experiments and increasingly precise measurements. One of the most compelling questions centers on dark energy, the term given to the unknown force driving the accelerated expansion of the universe.
A study published in Physical Review Letters presents new evidence suggesting that dark energy’s role in cosmic evolution—long assumed to remain constant—may actually vary over time. According to the researchers and their collaborators, the results can be interpreted as a sign that ordinary matter is gradually being transformed into dark energy.
This work is based on observations from Iolkam Du’ag, a mountain in southern Arizona where the Tohono O’odham Nation oversees Kitt Peak National Observatory. At the site, the Dark Energy Spectroscopic Instrument (DESI) scans deep into the history of the universe with 5,000 robotic eyes, each capable of locking onto a different galaxy every 15 minutes.
Data from DESI is mapping the large-scale distributions of millions of galaxies throughout the universe. DESI’s measurements also enable new calculations for the mass of the universe’s neutrinos through different lenses provided by different theoretical frameworks. Credit: DESI Collaboration
Black holes as dark energy bubbles
Operating nearly every night, DESI has already charted millions of galaxies and other luminous objects, many dating back to when the universe was less than half its current age.
In this study, the team examined the idea that black holes act as tiny reservoirs of dark energy. Since black holes form when massive stars burn through their fuel and collapse, this concept—known as the cosmologically coupled black hole (CCBH) hypothesis—implies that stellar material is converted into dark energy.
This framework naturally ties the rate of dark energy production and the depletion of matter to a well-studied quantity: the rate of star formation, measured for decades with instruments such as the Hubble Space Telescope and now the James Webb Space Telescope.
“This paper is fitting the data to a particular physical model for the first time and it works well,” said DESI collaboration member Gregory Tarlé, professor emeritus of physics at the University of Michigan and corresponding author of the new report.
Left: A key figure from the report, exploring what the cosmologically coupled black holes, or CCBH, hypothesis implies about the mass of neutrinos, or “ghost particles.” Right: An annotation of this figure simplifying its main ideas. Credit: Graph: SA Ahlen at al. Phys. Rev. Lett. 2025 DOI:10.1103/yb2k-kn7h Annotation: Claire Lamman/DESI Collaboration
Another central aspect of the research involves neutrinos—extremely light, ghost-like particles that are the second most abundant in the universe after photons. Physicists know neutrinos must have a small but nonzero mass, meaning they contribute to the universe’s overall matter content, though their exact masses remain uncertain.
By analyzing DESI’s findings within the CCBH framework, the team obtained values greater than zero for neutrino mass. This outcome aligns with current scientific understanding and improves upon earlier interpretations that had pointed to zero or even negative values.
Developing the CCBH hypothesis
“It’s intriguing at the very least,” Tarlé said. “I’d say compelling would be a more accurate word, but we really try to reserve that in our field.”
DESI is a global collaboration of more than 900 scientists from over 70 institutions. The project is led by Lawrence Berkeley National Laboratory, with construction and operations funded by the U.S. Department of Energy Office of Science. The instrument is installed on the Nicholas U. Mayall 4-meter Telescope at Kitt Peak National Observatory, operated by NSF NOIRLab in Arizona.
The CCBH model was proposed about five years ago by study co-authors Kevin Croker, assistant research scientist at Arizona State University, and Duncan Farrah, a professor at the University of Hawaii. The idea builds on decades of theoretical work exploring black holes as droplets of dark energy rather than destructive “spaghettifying” singularities wrapped in one-way boundaries.
Although the suggestion that dark energy within black holes could influence the cosmos as a whole was unconventional, it proved mathematically viable. This attracted a small group of researchers who began testing how well the hypothesis matched existing observations and large-scale cosmological data.
“Historically, this is the way physics is done. You come up with as many ideas as you can and you shoot them down as fast as you can,” said DESI researcher Steve Ahlen, emeritus professor of physics at Boston University and an early collaborator on the CCBH development.
“You don’t shy away from ideas that are new and different, which is clearly what we need to come up with these days when there are so many mysteries.”
Linking dark energy to star formation
The first data to bolster the CCBH hypothesis came from the unexpected growth of supermassive black holes at the centers of dormant elliptical galaxies, relative to the growth of those galaxies’ stellar populations. But it was data from the first year of DESI, which showed the dark energy density tracking the rate of star formation, that convinced Croker and Farrah to join forces with the DESI Collaboration.
“Working with DESI on the three-year data, it’s been a game-changer,” Croker said of working as a DESI external collaborator on this project. “You’ve got some of the sharpest and most creative researchers in the field lending their hands and hearts. It’s an absolute privilege.”
Other than packets of light called photons, neutrinos are the most abundant particles in the universe. In the time it takes you to read this sentence, hundreds of trillions of neutrinos will pass through your body. But neutrinos rarely interact with their surroundings, meaning they’re constantly zipping through other matter, completely undetected, which is why they’re sometimes referred to as ghost particles.
Scientists know neutrinos have mass, but precisely how much is challenging to measure on account of their ethereal nature. While enormous experiments currently running on Earth work to pin down these numbers, the night sky offers a powerful and complementary avenue for answers.
DESI’s galactic maps contain information on how fast the universe has grown over the past 10 billion years, in turn providing a cosmic inventory of matter and dark energy. But matter comes in three types: cold dark matter, baryons and neutrinos. Early universe measurements from the afterglow of the Big Bang measure the amount of dark matter and baryons long ago. But according to DESI, it seems like there is less matter today when compared to the ancient past. This leaves little room for the neutrinos.
“The data would suggest that the neutrino mass is negative and that, of course, is likely unphysical,” said Rogier Windhorst, Regents’ Professor at ASU’s School of Earth and Space Exploration and co-author of the new study.
CCBH model resolves the neutrino puzzle
Interpreted with the CCBH hypothesis, however, that unphysical issue disappears. Because stars are made of baryons, and black holes convert dead star matter into dark energy, the amount of baryons today has decreased relative to the Big Bang measurements. This allows neutrinos to contribute to the matter budget in the way expected from other measurements.
“You find that the neutrino mass probability distribution points to not only a positive number, but a number that’s entirely in line with ground-based experiments,” Windhorst said. “I find this very exciting.”
While this result gets top billing, the work also highlights other helpful features of the CCBH model.
“The CCBH hypothesis quantifiably links phenomena you would not initially expect to be related,” Farrah said. “It is the mixing of scales, large and small, that runs so counter to our trained linear intuition.”
Matter slows down the growth of the universe, whereas dark energy speeds it up. Because matter is converted to dark energy in the CCBH hypothesis, accelerated expansion happens earlier and so the expansion rate today, the Hubble rate, is a bit larger. This extra boost brings the cosmological measurement of the Hubble rate closer to other measurements, like those from distant exploding stars called supernovae.
The CCBH hypothesis also explains the observed amount of dark energy: It’s not just some magical number set when the universe was born. Dark energy comes from dead stars, so there isn’t any until you have stars, and stars do not form until the universe has grown sufficiently large and cool. Once stars are produced, the amount of dark energy made is directly related to how many stars are made.
Looking forward with DESI
“Working on this project has been both challenging and incredibly fun,” said study co-author Gustavo Niz, a researcher at the University of Guanajuato, Mexico. “This is just another milestone in establishing CCBH as a viable theory. It will take more data, rigorous analysis, and broader scrutiny to determine whether it can become a new paradigm for explaining our universe. Of course, it could also be ruled out as new data emerges.”
Croker said the hypothesis performs well when looking at the universe in the rough, “but data from other experiments that study individual black holes isn’t as compelling. That’s why the hypothesis is interesting. Many different observers can actually test it, hammer it out in real time.”
According to Ahlen, that’s the way science goes. But for scientists who have been working on DESI from the beginning, it’s exciting to see that data coming in is enabling researchers to test new and different hypotheses.
“This is so cool, to be at this point after working on an experiment for so long, to be coming up with exciting results,” said Tarlé, who led the team that built DESI’s robotic eye system. “It’s just wonderful.”
Reference: “Positive Neutrino Masses with DESI DR2 via Matter Conversion to Dark Energy” by S. P. Ahlen, A. Aviles, B. Cartwright, K. S. Croker, W. Elbers, D. Farrah, N. Fernandez, G. Niz, J. W. Rohlf, J. W. Rohlf, G. Tarlé, R. A. Windhorst, J. Aguilar, U. Andrade, D. Bianchi, D. Brooks, T. Claybaugh, A. de la Macorra, A. de Mattia, B. Dey, P. Doel, J. E. Forero-Romero, E. Gaztañaga, S. Gontcho A. Gontcho, G. Gutierrez, D. Huterer, M. Ishak, R. Kehoe, D. Kirkby, A. Kremin, O. Lahav, C. Lamman, M. Landriau, L. Le Guillou, M. E. Levi, M. Manera, R. Miquel, J. Moustakas, I. Pérez-Ràfols, F. Prada, G. Rossi, E. Sanchez, M. Schubnell, H. Seo, J. Silber, D. Sprayberry, M. Walther, B. A. Weaver, R. H. Wechsler and H. Zou, 21 August 2025, Physical Review Letters. DOI: 10.1103/yb2k-kn7h
In addition to its primary support from the DOE Office of Science, DESI is also supported by the National Energy Research Scientific Computing Center, a DOE Office of Science user facility. Additional support for DESI is provided by the NSF; the Science and Technology Facilities Council of the United Kingdom; the Gordon and Betty Moore Foundation; the Heising-Simons Foundation; the French Alternative Energies 2 and Atomic Energy Commission; the National Council of Humanities, Sciences, and Technologies of Mexico; the Ministry of Science and Innovation of Spain; and by the DESI member institutions.
The DESI collaboration is honored to be permitted to conduct scientific research on Iolkam Du’ag (Kitt Peak), a mountain with particular significance to the Tohono O’odham Nation.
On the evening of 21 July 1973, in the quiet Norwegian town of Lillehammer, a couple walked home from the cinema. The woman was seven months pregnant and was walking slowly when a grey Volvo stopped nearby. Two hitmen from Mossad, the Israeli foreign intelligence agency, emerged and shot the man in the torso and head before leaving as quickly as they had come.
The man killed that night was Achmed Bouchiki, a Moroccan waiter and cleaner, who – apart from looking similar to the alleged terrorist Ali Hassan Salameh – had nothing to do with Middle Eastern terrorism. Mossad initially thought that they had achieved a major success as part of ‘Operation Wrath of God’, a retribution campaign initiated by the Israeli government in reaction to the 1972 Munich Olympics Massacre, in which members of the Palestinian terrorist group Black September abducted and then killed 11 Israeli athletes. But instead of killing the alleged mastermind behind the Munich attack, they had committed one of Mossad’s worst blunders, embarrassing the agency for years to come and triggering an international crisis known as the Lillehammer affair.
How did this happen? The assassination mission was approved in haste and based on a single picture of Ali Hassan Salameh, which Mossad officers had held up to Bouchiki before deciding to go ahead with the assassination. The picture had been given to Mossad by the British domestic intelligence agency MI5. Since 1971 the two agencies had been part of the Club de Berne, a covert intelligence-sharing group, established in 1969 by the heads of eight Western European domestic intelligence agencies. Throughout the 1970s the Club de Berne hosted an encrypted telecommunication channel that established a straight line directly between 18 agencies, including extra-European partners such as Mossad and the FBI. The codeword used for this secret correspondence was ‘Kilowatt’. To date some 40,000 documents from the Kilowatt files have been released and are accessible to the public in the Swiss Federal Archives. These include finished analytical products but also so-called ‘raw intelligence’, reports that came straight from an agency’s sources, most often spies or other informants. The files show that Kilowatt members shared large amounts of information about Palestinians. Not only did this help to anticipate and thwart terrorist plots, but it also supported Mossad’s covert assassination operation.
European partners helped Mossad locate terrorist suspects, initially – as becomes clear from Kilowatt correspondence – without knowing that Israel was planning to kill them. After every assassination in Europe, the respective intelligence agencies then reported to the Club de Berne about the case, shared detailed police reports, and provided regular updates about the ongoing criminal investigations.
Achmed Bouchiki, killed by Mossad in 1973. NTB/Alamy Stock Photo.
That intelligence agencies such as the French Direction de la surveillance du territoire (DST) or Italian Servizio Informazioni Difesa (SID) were willing to send police findings to the very intelligence agency that had committed the crime sent a message that Europe would continue to ‘look the other way’ and tacitly accept Mossad eliminating Palestinians on their territory. For instance, after the assassination by car bomb of Mohamed Boudia, a key figure in Palestinian terrorism, in Paris in June 1973, the DST sent a report to its European and Israeli partners. In it, they mentioned various possibilities for Boudia’s death, including an accidental explosion and a possible Palestinian feud – with no mention of Mossad, even though by this point their involvement was known to most people; the day following the assassination, the French newspaper Le Monde blamed Mossad. Furthermore, Swiss intelligence had been particularly useful in the planning of Boudia’s assassination: it had helped to identify his routine, cover names he travelled under, addresses in Paris, and, crucially, details about the car he was driving. Mossad was then able to place a bomb in the car. Wrath of God is often seen as an Israeli operation, but it could not have succeeded without the European agencies that actively supported it.
Following the Lillehammer affair, Operation Wrath of God was suspended for several years. The incident and public trial of the six Mossad officers involved caused an outpouring of international outrage and hostile press towards Israel, and diplomatic relations with Western Europe were embittered. While Norway publicly showed outrage and refused to cover up the story, it also showed relative leniency towards Israel. In February 1974 the Norwegian court ruled that Mossad was responsible for the murder. Five of the six agents were sentenced to prison, with terms ranging from one to five and a half years. However, after 22 months all were pardoned, probably through a secret Israeli-Norwegian deal.
Other Western European states also showed solidarity with Israel. During the course of the trial in 1974 the Palestine Liberation Organization (PLO) demanded that investigations into the unresolved murders of Palestinians in France and Italy be reopened, but both governments ignored these requests. In Kilowatt intelligence exchanges, cooperation continued unchanged even though their governments faced an official diplomatic crisis and despite the obvious truth that their intelligence had facilitated Mossad’s killing mission. The exposure of Operation Wrath of God had no effect among the Kilowatt group.
The files thus give insights into a parallel security order. Away from public scrutiny and oversight, intelligence agencies were free to pursue their own foreign political agenda. In the 1970s, for example, while MI5 exchanged information daily with Mossad about Palestinian groups, including the whereabouts of Palestinians who could be put on an Israeli kill list, Whitehall applied a very critical foreign policy towards Israel. During the October 1973 ‘Yom Kippur’ War, prime minister Edward Heath refused to supply spare parts for Israel’s Centurion tanks or to provide landing rights to US military supply planes on their way to Israel. Since the early 1970s the UK’s Middle Eastern policy has had the explicit aim of providing ‘a “personality” for the Palestinian people’ – a policy that would ensure the Palestinians had a stake in a future Middle East settlement without clearly mentioning an independent state. Yet when it is assumed that an action can be kept secret and plausibly denied, agencies can, and do, act in disregard of political or ethical considerations.
Aviva Guttmann is Lecturer in Strategy and Intelligence at Aberystwyth University and the author of Operation Wrath of God: The Secret History of European Intelligence and Mossad’s Assassination Campaign (Cambridge University Press, 2025).
Facetotectans (aka y-larvae) have been a mystery since their discovery in the 1800s. Scientists are unsure of what they grow up to become, but we now know where these crustaceans fit in the tree of life. This image shows a cypris larvae, or y-cyprid. Credit: Niklas Dreyer
Y-larvae, mysterious crustaceans related to barnacles, may be parasitic and are key to understanding barnacle evolution.
When most people think of barnacles, they imagine shell-like organisms clinging to boats, docks, or even whales. Yet some barnacles go far beyond passive attachment — they can actually invade and take over their hosts.
“Instead of gluing themselves to a rock or something, they glue themselves to a host, often a crab, and they inject themselves into that host, and live their entire life as a root network growing through their host. It’s almost like a fungal network or plant root system. They have no real body in the way that we think of animal bodies,” explains James Bernot, an assistant professor in the Department of Ecology and Evolutionary Biology at UConn.
Bernot and an international team of collaborators — including lead author Niklas Dreyer from the Natural History Museum of Denmark and Biodiversity Research Center Academia Sinica in Taiwan, Jørgen Olesen from the Natural History Museum of Denmark, Gregory Kolbasov from Moscow University, Jens Høeg from the University of Copenhagen, and Ryuji Machida and Benny Chan from the Biodiversity Research Center Academia Sinica — recently published a study in Current Biology on a puzzling group of crustaceans that may help resolve one of marine biology’s enduring mysteries.
The mystery of y-larvae
Barnacles are crustaceans, like crabs and shrimp, and have evolved unusual survival strategies. After a free-swimming larval phase, they spend the rest of their lives permanently attached to a chosen surface.
One especially mysterious group, known as “y-larvae” or Facetotecta, looks like juvenile barnacles. They have been documented in plankton samples since the 1800s, but no one has ever identified their adult stage. Bernot notes that this unresolved question remains central, though the team’s new research brings science closer to an answer.
To investigate where y-larvae belong on the crustacean family tree, the researchers gathered more than 3,000 specimens and examined their genes by sequencing the transcriptome — the set of expressed RNA molecules that reflects which genes are active.
Genetic analysis and hidden lives
“We were finally able to confirm, in the realm of big data science, that they are, in fact, related to barnacles, but they aren’t closely related to any of the other parasitic barnacles. This was interesting to test by building a giant tree of life for all the crustaceans, then adding this little branch of y-larvae, this very unknown group, to that bigger tree, and we saw that they are related to barnacles, but more as distant cousins,” says Bernot.
Though not closely related to parasitic barnacles, these crustaceans are also likely parasitic because they have some structures in common with their parasitic cousins, says Bernot, including antennae with claws that may be used to hook onto their host.
This image shows the lifecycle of y-larvae from y-nauplius, to y-cyprid, to ypsigon (the last known stage), which is a worm-like stage that emerges from the previous larval stage if the y-cyprid is exposed to crustacean molting hormones. The researchers believet his worm-like stage is probably parasitic and would borrow into a host. Each is about 100 micrometers long (1/10 of a millimeter). Credit: Niklas Dreyer
“One of the best pieces of evidence we have that y-larvae become parasitic is that if we expose them to crustacean growth hormone, they will hatch out of their little swimming larval shape into a small slug-like body, which is similar to what parasitic barnacles do when they enter a host,” says Bernot. “The fact that if we give them hormones, they also molt into a slug-like thing, suggests they go on to be parasitic somewhere, but we still don’t know what host they end up in. Being hidden inside another animal’s body could explain why we haven’t found the adult stage of y-larvae yet.”
Although these crustaceans are unusual and largely unknown with only 17 species described so far, Bernot says some of his co-authors found more than 100 new and different species from a single harbor in Japan. There is more to learn about these enigmatic animals.
Evolutionary strategies and ecosystem roles
“We were finally able to confirm, in the realm of big data science, that they are, in fact, related to barnacles, but they aren’t closely related to any of the other parasitic barnacles. This was interesting to test by building a giant tree of life for all the crustaceans, then adding this little branch of y-larvae, this very unknown group, to that bigger tree, and we saw that they are related to barnacles, but more as distant cousins,” says Bernot.
Although they are only distantly related to parasitic barnacles, the evidence suggests y-larvae are also parasitic. They share certain traits with parasitic barnacles, including clawed antennae that may help them latch onto a host.
“One of the best pieces of evidence we have that y-larvae become parasitic is that if we expose them to crustacean growth hormone, they will hatch out of their little swimming larval shape into a small slug-like body, which is similar to what parasitic barnacles do when they enter a host,” says Bernot. “The fact that if we give them hormones, they also molt into a slug-like thing, suggests they go on to be parasitic somewhere, but we still don’t know what host they end up in. Being hidden inside another animal’s body could explain why we haven’t found the adult stage of y-larvae yet.”
Despite being poorly understood, with only 17 described species, y-larvae may be far more diverse than previously thought. Bernot points out that some of his colleagues identified more than 100 distinct species from just a single harbor in Japan, suggesting much remains to be discovered about these unusual animals.
Ingenious barnacle adaptations
Different species of barnacles use different strategies when they become sessile adults. Besides living on inanimate objects, those that live on animals like whales are not considered parasitic because they are essentially hitching a ride and do not feed on their host. Others attach to the host and have structures that they use to feed on the host. Understanding the evolution of these different strategies is important, and Bernot says that a project they are currently working on involves building the evolutionary tree of all barnacles to observe and understand some of the evolutionary patterns.
“A big question is, what is it about barnacles that has given them so much variability over evolutionary time to take on so many different shapes and forms and lifestyles? They have come up with incredibly ingenious strategies for making their ways of life, and often their ways of life seem very bizarre to us, but they have clearly been very successful,” says Bernot. “These animals have been around for hundreds of millions of years and there are several thousand species of them, so they have come up with some really amazing solutions to complex problems.”
Some of those solutions could also help humans. For example, Bernot says, there is a lot of interest in trying to better understand barnacle glues.
“They glue themselves to docks, they glue themselves to boats, and that is a problem. The Navy spends millions of dollars on additional fuel because barnacles on their ships cause additional drag. Also having more powerful glues that can dry underwater would be very useful for mechanical reasons, but maybe also for dentistry and things like that,” says Bernot. “There could be a lot of applications if we can better understand some of these amazing solutions that barnacles have evolved.”
Reference: “Phylogenomics of enigmatic crustacean y-larvae reveals multiple origins of parasitism in barnacles” by Niklas Dreyer, James P. Bernot, Jørgen Olesen, Gregory A. Kolbasov, Jens Thorvald Høeg, Ryuji J. Machida and Benny K.K. Chan, 21 July 2025, Current Biology. DOI: 10.1016/j.cub.2025.06.007
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