Category: 7. Science

The Arctic has always seemed like the perfect place to hide secrets. Thick ice, biting winds, and months of darkness. For years, people believed that during the coldest ice ages, the Arctic Ocean vanished beneath an enormous ice shelf, one as thick as a skyscraper is tall.

That idea has stuck around for decades. A slab of ice, nearly a kilometer deep, covering the entire Arctic? It sounded dramatic. But not every dramatic story survives forever. A new study now shatters this icy myth.

In a study published in the journal Science Advances, scientists explain why this old theory no longer holds up. Their findings suggest something else happened during the last 750,000 years.

The Arctic, even in its most brutal days, wasn’t entirely sealed under thick ice. Instead, it had patches of open water. Life kept going. The sea ice came and went with the seasons.

Ancient mud shows open Arctic seas

The researchers dug deep. They drilled into the seafloor of the Arctic-Atlantic gateway and the Nordic Seas. There, buried in the mud, they found tiny fingerprints left by algae.

Some of these algae bloom only in open waters. Others live under seasonal sea ice, the kind that melts and freezes every year. These ancient traces told a clear story.

“Our sediment cores show that marine life was active even during the coldest times,” said Jochen Knies, lead author of the study from UiT The Arctic University of Norway, Tromsø.

“That tells us there must have been light and open water at the surface. You wouldn’t see that if the entire Arctic was locked under a kilometre-thick slab of ice.”

That’s not all they found. A molecule called IP25 showed up again and again in the sediments. This molecule comes from algae that thrive in seasonal sea ice. Its steady presence revealed a world where sea ice wasn’t permanent. It came. It melted. It returned again.

Arctic life survived through ice ages

Sea ice wasn’t the only thing that moved with the seasons. The ocean itself stayed alive. Phytoplankton, the tiny floating plants of the sea, kept growing, even when the cold hit hard.

Biomarkers of phytoplankton like epi brassicasterol and dinosterol showed up consistently in the sediment cores. These tiny clues pointed to a surprising fact. Life did not vanish during glaciations. It slowed down, but it never stopped.

Even during the Last Glacial Maximum, around 21,000 years ago, the sea ice still followed a seasonal rhythm. The same thing happened about 140,000 years ago during an even colder spell.

The Arctic breathed. It froze in winter. It opened in summer. And where light could sneak through, life flourished.

Some giant icebergs also roamed the seas during these cold spells. They were like wandering giants, breaking free from Greenland and the Canadian Arctic.

The icebergs sometimes got stuck on shallow shelves, leaving deep marks on the seafloor. Yet, these icebergs were visitors, not rulers. They never formed a permanent lid over the entire ocean.

Arctic ice was not permanent

To double-check their findings, the scientists turned to climate models. They used the AWI Earth System Model, a detailed computer simulation of ancient climates.

These simulations showed the same thing the sediments revealed. Even during extreme cold, warm Atlantic waters kept sneaking into the Arctic. This flow of water stopped the ocean from freezing solid.

“The models support what we found in the sediments,” said Knies. “Even during these extreme glaciations, warm Atlantic water still flowed into the Arctic gateway. This helped keep some parts of the ocean from freezing over completely.”

The models also captured the restless movement of sea ice. It spread in winter. It melted back in summer. It drifted along powerful ocean currents like the Transpolar Drift and the Beaufort Gyre.

A glimpse of the Arctic at its coldest

There was one chapter in this icy story that stood out. It happened during Marine Isotope Stage 16, about 650,000 years ago. That’s when the biomarkers nearly vanished.

It looked as if the Arctic locked itself down for a brief time. No sign of open water. No hint of seasonal ice. Just endless cold.

This period lines up with the coldest known stretch of the Quaternary period. Carbon dioxide levels dropped to their lowest point, around 180 parts per million. Everything about this time screams extreme cold.

“There may have been short-lived ice shelves in some parts of the Arctic during especially severe cold phases,” said Knies. “But we don’t see any sign of a single, massive ice shelf that covered everything for thousands of years.”

Giant ice shelf theory now disproved

For years, scientists pointed to strange patterns on the seafloor as proof of an ancient Arctic ice shelf. Deep scours, ridges, and grooves looked like evidence of ice pressing down on the ocean floor.

But this study offers a new explanation. Those marks may have come from huge icebergs drifting through the Arctic. These giants could easily gouge the seafloor during their journeys.

The researchers also stress a crucial difference. Sea ice is not the same as ice shelves. Sea ice forms and melts every year. Ice shelves are thick, massive slabs of ice that grow from glaciers on land.

If the Arctic ever had an ice shelf, it likely existed long ago – perhaps during the Mid Pleistocene transition between 950,000 and 790,000 years ago. Since then, the Arctic has danced between ice and water, never staying frozen solid for long.

Arctic’s past shows it may survive future

This isn’t just a story about ancient ice. It’s also a warning for today. The Arctic is changing fast. The more we understand its past, the better we can predict its future.

“These past patterns help us understand what’s possible in future scenarios,” said Knies. “We need to know how the Arctic behaves under stress and what tipping points to watch for as the Arctic responds to a warming world.”

The Arctic has shown time and again that it doesn’t like to sit still. Even at its coldest, it found ways to stay partly open. It allowed life to hold on.

Today, the Arctic faces a new kind of challenge. Warming is accelerating faster than anything in the past. But this study reminds us that the Arctic has always been more dynamic than we thought. It has never been just a frozen wasteland.

Its icy history tells a story of change, survival, and resilience. The future may still surprise us, just like its hidden past has done.

The study is published in the journal Science Advances.

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Antarctic sea ice used to advance and retreat with seasonal regularity, but the rhythm has faltered. Scientists counted three record‑low summer ice seasons between 2017 and 2023, a run without precedent in four decades of satellite observations.

Dr. Edward Doddridge of the Institute for Marine and Antarctic Studies, University of Tasmania, has described the wider fallout of Antarctic sea ice loss in the journal PNAS Nexus.

“Antarctic sea ice appears to be changing; in the last decade, we have observed both record highs and record lows in Antarctic sea ice coverage. This article addresses the impacts of extreme lows in Antarctic summer sea ice coverage,” wrote Dr. Doddridge.

Sea ice loss impacts global climate

Sea ice is bright, and its high albedo bounces much of the Sun’s energy back to space. When dark ocean replaces that mirror, extra heat soaks in and lingers beneath the surface, nudging global temperatures upward.

The frozen cover also braces the coastline. Pack ice and the more stationary land‑fast variety absorb the punch of storm waves that would otherwise flex and crack vulnerable ice shelves, slowing the feed of inland glaciers into the sea.

How fast sea ice is shrinking

Dr. Doddridge’s team combined satellite records, Argo float profiles, and high‑resolution climate models.

The researchers showed that a single summer loss of 100,000 square miles of ice correlates with roughly six extra tabular icebergs that year, a figure the oceanographer calls “strikingly linear for a system famous for surprises.”

“With Antarctic sea ice providing climate and ecosystem services on regional and planetary scales, sustained and long‑term observations to accurately predict and potentially mitigate the impacts of climate change on this region should be a global scientific priority,” said Dr. Doddridge.

Model runs also revealed heat anomalies that persisted for three to four summers after the 2016‑17 plunge. That lingering warmth slows winter refreezing and suggests thresholds beyond which recovery is not quick or guaranteed.

Melting ice triggers ocean heating

Open water absorbs more solar energy, stratifying the upper ocean. Sensors show warming and freshening down to 1,300 feet after recent low‑ice summers, altering the formation of Antarctic Intermediate Water that helps lock away excess atmospheric heat and carbon.

Less sea ice also means fewer brine‑rich plumes sinking to ventilate the ocean interior. If that overturning slows, climate sensitivity could climb as the deep Pacific takes up less anthropogenic heat.

For many species, sea ice is both dining room and nursery. Larval krill feed on sea‑ice algae and hide from predators in its under‑surface; years with scant winter ice yield poor recruitment the following spring.

Emperor penguins suffered near‑total breeding failure in parts of the Bellingshausen Sea when the 2022 ice broke up before chicks had grown waterproof feathers.

Seals that haul out to molt face a similar squeeze as large floes fragment into smaller rafts with little room to rest or escape orcas.

Sea ice loss reshapes the food chain

Recent satellite and float data confirm that changes in ice extent are linked to shifts in phytoplankton bloom timing and intensity.

These microscopic plants form the foundation of the Antarctic food web, supporting everything from krill to whales, but the bloom response to ice loss is inconsistent across regions.

Some areas saw higher chlorophyll-a levels, signaling stronger blooms, especially near the coast where ice retreat was early and meltwater brought nutrients.

In other regions, despite longer open water seasons, blooms were weaker – likely due to deeper mixed layers or cloudier skies that reduced light for growth.

More than 4 million square kilometers of sea ice may support under-ice blooms, according to BGC‑Argo float measurements. These hidden blooms affect not only the carbon cycle but also cloud formation, altering how the region cools or warms the atmosphere.

Shipping, tourism, and fishing

The wave‑exposed coastlines calve more icebergs, rerouting shipping lanes and occasionally blocking access to research bases.

Tourism operators, less constrained by thick pack ice, have already logged more high‑latitude port calls during low‑ice summers, widening the footprint of black‑carbon emissions and invasive species risk.

Commercial krill fisheries may also chase pole‑ward stocks, complicating conservation plans around the Antarctic Peninsula.

Meanwhile, national programs are rethinking resupply windows as land‑fast ice, once a sturdy seasonal highway, thins and breaks weeks earlier than it did in the 1990s.

What happens if ice keeps shrinking

Dr. Doddridge and colleagues list circumpolar ice‑thickness monitoring as the single biggest data gap. Without it, models cannot pin down when volume, not just area, might cross a tipping point.

Public interest is already reacting; online searches for “Antarctic sea ice” hit a record peak in July 2023, a pulse researchers link to rising climate anxiety.

Better forecasts could temper fear with facts, but only if satellites, floats, and shore stations keep streaming year‑round measurements.

For now, the Southern Ocean’s frozen skin appears to be sliding toward a leaner state. Whether that new normal stabilizes or spirals depends on how fast the world reins in greenhouse‑gas emissions, a decision that will be felt from Hobart laboratories to emperor penguin rookeries.

The study is published in the journal PNAS Nexus.

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Gel manicures have turned into a tiny luxury that fits between lunch breaks and school runs. The ultraviolet or near‑ultraviolet lamps that harden glossy manicure coatings do the job in about four minutes, so the routine feels harmless.

The dryers bathe fingertips in swift pulses of light, but until recently few people asked what those pulses do to the skin that holds the nails. A new laboratory study brings unsettling answers.

The new work was led by photochemist Dr. María Laura Dántola at the Institute of Theoretical and Applied Physical‑Chemical Research (INIFTA), part of Argentina’s National Scientific and Technical Research Council (CONICET).

Studying manicure lamps

Serrano’s team placed common skin molecules, including tyrosinase, inside a chamber that mimicked a salon lamp and zapped them for the same four‑minute cycle used in most gel services.

All targets, from amino acids to lipids, emerged chemically altered and less able to perform their jobs.

“These devices are used without any controls or regulations requiring manufacturers to report on the potential risks of frequent exposure,” cautioned Dántola and colleagues.

One of the starkest changes hit tyrosinase, the enzyme that drives production of melanin, a pigment that shields DNA from solar radiation.

The researchers also measured how fast the altered molecules sparked oxidative stress reactions that can shred cell membranes. Reaction rates jumped within seconds, confirming that harm starts long before a hand is removed from the booth.

Why photosensitization matters

Photosensitization happens when a molecule absorbs light then transfers that energy to oxygen, creating reactive species. Those species slice through DNA, proteins, and lipids with no regard for cell repair cycles.

Because tyrosinase sits at the start of melanin synthesis, even small interruptions amplify downstream damage. Losing melanin’s natural sunscreen effect makes every future dose of sunlight or lamp light more hazardous.

Many over‑the‑counter skincare ingredients, including retinoids and some antibiotics, can enhance photosensitization.

People who use them may face higher risks because their skin already carries extra light‑reactive compounds.

Tyrosinase, melanin and lost defense

Tyrosinase flips the chemical switches that turn the amino acid tyrosine into melanin granules. When the lamp’s photons broke those switches, the team saw melanin output stall.

Without melanin the skin compensates poorly for incoming ultraviolet, so photo‑aging and cancer risk rise. The altered enzyme also disrupts color balance, explaining reports of blotchy pigmentation after frequent gel sessions.

Manicure lamps are very bright

Bench measurements showed the lamp delivered a dose of UVA radiation around 368–400 nanometers, the same band blamed for tanning and wrinkles.

A separate American study in 2023 reported that a 20‑minute session killed up to 70 percent of cultured human skin cells and stamped permanent mutations on the survivors.

Sensor data from the Argentine team indicate the lamp’s irradiance peaks at 7 milliwatts per square centimeter, nearly matching the noon sun in Buenos Aires during spring.

Weekly visits translate into roughly three and a half hours under that intensity each year, more than many people spend sunbathing.

A systematic review in 2024 concluded that while the absolute cancer risk appears low, the evidence remains weak and long‑term users should be told the data gaps.

Short bursts, long shadows

Gel clients often repeat the service every two to three weeks, layering dose upon dose across years. Cumulative exposure matters because photochemical injuries add rather than heal, especially when they trigger oxidative stress and DNA breaks.

A 2023 test on human keratinocytes showed sunscreen with SPF 50 cut cell death by more than one‑third during the same four‑minute irradiation used in salons.

Protective gloves that leave only the nail plate visible can block over 90 percent of the rays, yet they remain optional accessories.

“These are processes that, in one way or another, result in cell death,” added Dántola and colleagues after monitoring the altered enzyme profiles.

The comment echoes warnings from dermatology societies that link chronic UVA to premature aging and certain skin cancers.

Keeping nails and skin safe

Dermatologists at the American Academy of Dermatology urge customers to apply a broad‑spectrum SPF 30 or higher on their hands before every gel manicure and to choose LED lamps that cure polish faster and with lower UV output.

Salons can switch to newer hybrid lacquers that air‑dry or set under visible blue light, trimming exposure further. At home, limiting sessions and spacing them at least a month apart reduces cumulative dose.

For clients unwilling to give up the chip‑free finish, simple habits help: wear fingertip‑less UPF gloves, time the lamp cycles carefully, and keep moisturizer handy because dry skin amplifies light penetration.

Regulators have yet to issue binding standards for consumer nail lamps, so the burden falls on users and technicians.

Serrano’s group believes clear warning labels and pre‑packed barrier gloves would let people enjoy the beauty trend while understanding the trade‑offs.

Manicure lamps: Speed vs. safety

The beauty business around gel nails is sizable. Analysts estimate the global UV gel polish segment alone was worth almost six billion dollars in 2024 and could double within a decade.

Social media trends and influencer tutorials push fans to redo manicures every week rather than once a month, increasing exposure well beyond the study’s four‑minute baseline. Convenience encourages at‑home kits, yet those kits often ship without detailed safety instructions.

Dántola stresses that the project sits in basic science, aimed at mapping chemical events rather than legislating behavior.

Still, sharing data allows dermatologists, engineers, and regulators to design larger trials that measure real skin after repeated consumer‑level doses.

Applied research may soon test glove fabrics, lamp filters, or polish formulas that polymerize under visible light. Until such options become standard, informed choice remains the safest tool on the manicure table.

The study is published in Chemical Research in Toxicology.

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Earth formed about 4.6 billion years ago, during the geological eon known as the Hadean. The name “Hadean” comes from the Greek god of the underworld, reflecting the extreme heat that likely characterized the planet at the time.

By 4.35 billion years ago, the Earth might have cooled down enough for the first crust to form and life to emerge.

However, very little is known about this early chapter in Earth’s history, as rocks and minerals from that time are extremely rare. This lack of preserved geological records makes it difficult to reconstruct what the Earth looked like during the Hadean Eon, leaving many questions about its earliest evolution unanswered.

We are part of a research team that has confirmed the oldest known rocks on Earth are located in northern Québec. Dating back more than four billion years, these rocks provide a rare and invaluable glimpse into the origins of our planet.

Remains from the Hadean Eon

The Hadean Eon is the first period in the geological timescale, spanning from Earth’s formation 4.6 billion years ago and ending around 4.03 billion years ago.

The oldest terrestrial materials ever dated by scientists are extremely rare zircon minerals that were discovered in western Australia. These zircons were formed as early as 4.4 billion years ago, and while their host rock eroded away, the durability of zircons allowed them to be preserved for a long time.

Studies of these zircon minerals has given us clues about the Hadean environment, and the formation and evolution of Earth’s oldest crust. The zircons’ chemistry suggests that they formed in magmas produced by the melting of sediments deposited at the bottom of an ancient ocean. This suggests that the zircons are evidence that the Hadean Eon cooled rapidly, and liquid water oceans were formed early on.

Other research on the Hadean zircons suggests that the Earth’s earliest crust was mafic (rich in magnesium and iron). Until recently, however, the existence of that crust remained to be confirmed.

In 2008, a study led by one of us — associate professor Jonathan O’Neil (then a McGill University doctoral student) — proposed that rocks of this ancient crust had been preserved in northern Québec and were the only known vestige of the Hadean.

Since then, the age of those rocks — found in the Nuvvuagittuq Greenstone Belt — has been controversial and the subject of ongoing scientific debate.

‘Big, old solid rock’

The Nuvvuagittuq Greenstone Belt is located in the northernmost region of Québec, in the Nunavik region above the 55th parallel. Most of the rocks there are metamorphosed volcanic rocks, rich in magnesium and iron. The most common rocks in the belt are called the Ujaraaluk rocks, meaning “big old solid rock” in Inuktitut.

The age of 4.3 billion years was proposed after variations in neodymium-142 were detected, an isotope produced exclusively during the Hadean through the radioactive decay of samarium-146. The relationship between samarium and neodymium isotope abundances had been previously used to date meteorites and lunar rocks, but before 2008 had never been applied to Earth rocks.

This interpretation, however, was challenged by several research groups, some of whom studied zircons within the belt and proposed a younger age of at most 3.78 billion years, placing the rocks in the Archean Eon instead.

Confirming the Hadean Age

In the summer of 2017, we returned to the Nuvvuagittuq belt to take a closer look at the ancient rocks. This time, we collected intrusive rocks — called metagabbros — that cut across the Ujaraaluk rock formation, hoping to obtain independent age constraints. The fact that these newly studied metagabbros are in intrusion in the Ujaraaluk rocks implies that the latter must be older.

The project was led by masters student Chris Sole at the University of Ottawa, who joined us in the field. Back in the laboratory, we collaborated with French geochronologist Jean-Louis Paquette. Additionally, two undergraduate students — David Benn (University of Ottawa) and Joeli Plakholm (Carleton University) participated to the project.

We combined our field observations with petrology, geochemistry, geochronology and applied two independent samarium-neodymium age dating methods, dating techniques used to assess the absolute ages of magmatic rocks, before they became metamorphic rocks. Both assessments yielded the same result: the intrusive rocks are 4.16 billion years old.

The oldest rocks

Since these metagabbros cut across the Ujaraaluk formation, the Ujaraaluk rocks must be even older, placing them firmly in the Hadean Eon.

Studying the Nuvvuagittuq rocks, the only preserved rocks from the Hadean, provides a unique opportunity to learn about the earliest history of our planet. They can help us understand how the first continents formed, and how and when Earth’s environment evolved to become habitable.

A new brain imaging study published in Current Biology has uncovered surprising neural activity in people with aphantasia—a condition where individuals report being unable to form mental images. Although they describe a complete absence of visual imagery, their brains still show patterns of activity in the early visual cortex when they attempt to imagine visual stimuli. However, this activity differs in important ways from what’s seen in people who do experience vivid mental imagery, offering insight into how consciousness might be linked to sensory representations in the brain.

Aphantasia is a relatively newly defined condition in which people are unable to form mental images voluntarily. While those with aphantasia can describe objects and scenes using words or concepts, they report no visual “pictures” in the mind’s eye. Since much of what is known about mental imagery comes from people who can generate vivid images, the researchers wanted to know what happens in the brain when someone with aphantasia tries to visualize something. Do they engage the same brain regions, or are there deeper differences in how their brains represent imagined information?

To answer these questions, the research team compared people with aphantasia to individuals with typical visual imagery using functional magnetic resonance imaging (fMRI). The goal was to examine how both groups activated early visual brain regions—especially the primary visual cortex—during attempts to visualize simple stimuli. The researchers focused on whether the brain could still represent specific content in people who lack a subjective visual experience.

The study involved 14 participants with verified aphantasia and 18 control participants with typical imagery. All were right-handed and had normal or corrected vision. Participants completed the Vividness of Visual Imagery Questionnaire to assess their subjective imagery, and their imagery ability was further validated using an objective task called the binocular rivalry paradigm. This method measures how imagining a visual pattern affects what people perceive shortly afterward. As expected, those with aphantasia scored near the floor on the vividness questionnaire and showed little or no sensory bias in the binocular rivalry task, confirming that they lacked typical imagery experience.

In the main experiment, the researchers used fMRI to measure brain activity while participants either viewed or attempted to imagine simple visual patterns—specifically colored Gabor patches—at specific locations on a screen. Each participant completed several types of scans: imagery generation, passive viewing, retinotopic mapping to define visual areas, and region-of-interest localization to pinpoint the parts of the brain involved in processing the stimuli. During the imagery task, participants received a visual cue indicating which pattern to imagine and where to place it in the visual field. After each attempt, they rated how vivid their imagery had felt.

Although people with aphantasia gave extremely low vividness ratings—averaging around 1 on a 1-to-4 scale—their brain activity told a more complex story. In both groups, fMRI signals from early visual areas could be used to decode what kind of pattern a person was trying to imagine. In other words, the brain still encoded specific information about the content of the imagery—even in the absence of subjective experience.

But there were clear differences in how that information was represented. In people with typical imagery, activity in the visual cortex showed expected patterns: stronger responses in the hemisphere opposite to the side of the visual field where the stimulus was imagined. In contrast, people with aphantasia showed the reverse: stronger responses in the same-side hemisphere (ipsilateral) instead of the opposite (contralateral). This suggests a different functional organization of visual activity during imagery attempts.

While the imagery content could be decoded in both groups, only in the control group did the patterns of brain activity overlap between imagery and actual perception. In the control group, algorithms trained on imagery-related brain data could accurately identify visual stimuli seen during passive viewing—and vice versa. This kind of cross-decoding failed in the aphantasia group. Their visual cortex did encode information about imagery attempts, but those patterns did not match those generated during real visual perception.

This mismatch might explain why people with aphantasia experience no visual imagery even though their brains generate structured representations during imagery tasks. According to the researchers, the results point to a difference not just in the strength of visual signals, but in their format. The activity in the visual cortex of people with aphantasia appears to be “less sensory,” meaning it may lack the specific qualities that give rise to conscious visual experience.

The researchers also looked at broader brain networks. During imagery attempts, people with aphantasia showed stronger activity in brain regions associated with language and auditory processing, such as the superior temporal gyri. They also had weaker functional connections between these regions and visual areas. This could indicate that when people with aphantasia try to visualize, they may rely more on verbal or conceptual strategies rather than generating vivid internal images.

To test whether differences in attention or effort might explain the results, the researchers ran a follow-up study with control participants. These individuals were asked to imagine either a clear or blurry version of the same visual patterns. Their reported effort levels and brain activation were similar across both conditions, suggesting that differences in subjective clarity do not necessarily reflect differences in cognitive effort. This makes it less likely that the patterns seen in aphantasia are simply due to lower motivation or task engagement.

Although the findings shed new light on the neural basis of aphantasia, the authors note several limitations. The sample size was relatively small, especially given the rarity of aphantasia, and most participants in both groups were women. Also, while the study focused on low-level visual features, it did not examine whether similar results would hold for more complex images, such as faces or scenes. The absence of eye-tracking during scanning means researchers could not fully rule out whether subtle eye movements influenced the neural signals.

But the results still offer evidence that people with aphantasia can generate structured, content-specific activity in the visual cortex, even though they lack a conscious image. This dissociation between brain activity and experience challenges long-held assumptions that activity in early visual areas is directly tied to visual awareness. Instead, it suggests that not all neural representations are created equal—some may carry enough sensory information to generate conscious images, while others may not.

The study opens new avenues for understanding the neural basis of mental imagery and visual consciousness. Future research could explore what kinds of information are encoded in the brain during imagery attempts in aphantasia, and whether different feedback connections in the brain might account for the altered representations.

The study, “Imageless imagery in aphantasia revealed by early visual cortex decoding,” was authored by Shuai Chang, Xinyu Zhang, Yangjianyi Cao, Joel Pearson, and Ming Meng.

The Neanderthals are our closest extinct relatives, and they continue to fascinate as we peer back through tens of thousands of years of history.

In a new discovery about this mysterious yet often familiar species, researchers have found ancient evidence of a Neanderthal “fat factory” in what is now Germany.

Operational around 125,000 years ago, the factory would’ve been a place where Neanderthals broke and crushed the bones of large mammals to extract valuable bone marrow and grease, used as a valuable extra food source.

Related: Neanderthal DNA Exists in Humans, But One Piece Is Mysteriously Missing

According to scientists, this is the earliest evidence yet for this type of sophisticated, large-scale bone processing, including both bone marrow and grease: the first confirmation Neanderthals were also doing this some 100,000 years before our species made it to Europe.

“This was intensive, organised, and strategic,” says archaeologist Lutz Kindler from the MONREPOS Archaeological Research Center in Germany.

“Neanderthals were clearly managing resources with precision – planning hunts, transporting carcasses, and rendering fat in a task-specific area. They understood both the nutritional value of fat and how to access it efficiently – most likely involving caching carcass parts at places in the landscape for later transport to and use at the grease rendering site.”

The researchers found their evidence on a site called Neumark-Nord in eastern Germany, not far from the city of Halle. They uncovered more than 100,000 bone fragments from what are thought to be at least 172 large mammals, including horses and deer.

A good proportion of the bones showed cut marks and signs of intentional breakage, pointing to deliberate butchering – these weren’t just leftovers from a hunt. There were also indications of tool use and fires in the same location, all in a relatively small area.

Add all of that together, and it seems clear that some kind of systematic, organized bone processing was going on here. Similar processes have been linked to Neanderthal sites before, but not at this level of scale or sophistication.

“Bone grease production requires a certain volume of bones to make this labour-intensive processing worthwhile and hence the more bones assembled, the more profitable it becomes,” says archaeologist Sabine Gaudzinski-Windheuser from MONREPOS.

We can add this to the long list of studies that have revealed Neanderthals were much smarter than they’re often made out to be. Thanks to recent research we know they were adept swimmers, capable brewers, and abstract thinkers – who raised their kids and used speech patterns in a similar way to humans.

Ultimately though, Homo sapiens thrived and survived, while Neanderthals died out. That’s another story that archaeologists are busy investigating the whys and wherefores of, but all we have of the Neanderthals now are the remains and the sites they left behind – which will no doubt give up more revelations in the future.

“The sheer size and extraordinary preservation of the Neumark-Nord site complex gives us a unique chance to study how Neanderthals impacted their environment, both animal and plant life,” says computer scientist Fulco Scherjon from MONREPOS.

“That’s incredibly rare for a site this old – and it opens exciting new possibilities for future research.”

The research has been published in Science Advances.

• We are reliant on satellite services for modern life. We use them for communication, banking, navigation and so much more.
• In order to use satellites, we need to know exactly where they are. And that also depends on where Earth and the sun are, too.
• So astronomers use radio waves from distant black holes to help pinpoint our place in the universe. But the radio spectrum is getting crowded.

By Lucia McCallum, University of Tasmania. Edits by EarthSky.

Phones and wifi block our view of our place in the universe

The scientists who precisely measure the position of Earth are in a bit of trouble. We’re talking about geodesy, the science of accurately measuring and understanding the Earth’s geometric shape, orientation in space, and gravity field. These scientists’ measurements are essential for the satellites we use for navigation, communication and Earth observation every day.

But you might be surprised to learn that making geodetic measurements depends on tracking the locations of black holes in distant galaxies.

The problem is, the scientists need to use specific frequency lanes on the radio spectrum highway – where the available radio frequency spectrum is pictured as being divided into “lanes” or smaller bands, similar to lanes on a road – to track those black holes.

And with the rise of wifi, mobile phones and satellite internet, travel on that highway is starting to look like a traffic jam.

Why we need black holes

Satellites and the services they provide have become essential for modern life. From precision navigation in our pockets to measuring climate change, running global supply chains and making power grids and online banking possible, our civilization cannot function without its orbiting companions.

To use satellites, we need to know exactly where they are at any given time. Precise satellite positioning relies on the so-called global geodesy supply chain.

This supply chain starts by establishing a reliable reference frame as a basis for all other measurements. Satellites are constantly moving around Earth, Earth is constantly moving around the sun, and the sun is constantly moving through the galaxy. So this reference frame needs careful calibration via some relatively fixed external objects.

As it turns out, the best anchor points for the system are the black holes at the hearts of distant galaxies. Black holes spew out streams of radiation as they devour stars and gas.

And these black holes are the most distant and stable objects we know. Using a technique called very long baseline interferometry, we can use a network of radio telescopes to lock onto the black hole signals and disentangle Earth’s own rotation and wobble in space from the satellites’ movement.

Different lanes on the radio highway

We use radio telescopes because we want to detect the radio waves coming from the black holes. Radio waves pass cleanly through the atmosphere. And we can receive them during day and night and in all weather conditions.

But we also use radio waves for communication on Earth. This includes things such as wifi and mobile phones. There is close regulation on the use of different radio frequencies, or different lanes on the radio highway. And a few narrow lanes are reserved for radio astronomy.

However, in previous decades the radio highway had relatively little traffic. Scientists commonly strayed from the radio astronomy lanes to receive the black hole signals.

To reach the very high precision needed for modern technology, geodesy today relies on more than just the lanes exclusively reserved for astronomy.

Radio traffic on the rise

In recent years, human-made electromagnetic pollution has vastly increased. When wifi and mobile phone services emerged, scientists reacted by moving to higher frequencies.

However, they are running out of lanes. Six generations of mobile phone services (each occupying a new lane) are crowding the spectrum. Not to mention, a fleet of thousands of satellites directly send internet connections.

Today, the multitude of signals are often too strong for geodetic observatories to see through them to the very weak signals that black holes emit. This puts many satellite services at risk.

How to help find our place in the universe

To keep working into the future – to maintain the services on which we all depend – geodesy needs some more lanes on the radio highway. When international treaties at world radio conferences divide up the spectrum, geodesists need a seat at the table.

Other potential fixes might include radio quiet zones around our essential radio telescopes. Work is also underway with satellite providers to avoid pointing radio emissions directly at radio telescopes.

Any solution has to be global. For our geodetic measurements, we link radio telescopes together from all over the world, allowing us to mimic a telescope the size of Earth. Each nation individually primarily regulates the radio spectrum, making this a huge challenge.

But perhaps the first step is increasing awareness. If we want satellite navigation to work, our supermarkets to be stocked and our online money transfers arriving safely, we need to make sure we have a clear view of those black holes in distant galaxies. And that means clearing up the radio highway.

Lucia McCallum, Senior Scientist in Geodesy, University of Tasmania

We republished this article from The Conversation under a Creative Commons license. Read the original article.

Bottom line: Astronomers help us locate our place in the universe by analyzing the radio waves that come from black holes in the distant universe. But the radio spectrum is getting crowded with our everyday technology.