Latest news with #AgnitMukhopadhyay
Economic Times
22-06-2025
- Science
- Economic Times
They survived ice ages and hunted mammoths; so why did the Neanderthals suddenly disappear? Now a physicist blames something in the sky
Live Events Radiation as a Hidden Killer? A Caution Against Oversimplification (You can now subscribe to our (You can now subscribe to our Economic Times WhatsApp channel Neanderthals have long puzzled scientists. These ancient relatives of modern humans thrived across Europe and parts of Asia for hundreds of thousands of years. But around 40,000 years ago, they disappeared, just as Homo sapiens spread across the same regions. What really caused their extinction remains one of human evolution's biggest a new and unusual theory suggests that space weather, not climate, competition, or disease, may have played a decisive role.A recent study by Dr. Agnit Mukhopadhyay, a space physicist from the University of Michigan , proposes that a powerful cosmic event known as the Laschamp excursion might have played a part in the Neanderthals' decline. The findings were published in the journal Science Laschamp event occurred about 41,000 years ago, when the Earth's magnetic poles temporarily flipped. During this brief reversal, the planet's magnetic field, which normally protects us from cosmic radiation, dramatically weakened for several argues that this weakening may have exposed the Earth's surface to much higher levels of ultraviolet (UV) and cosmic radiation, particularly in some parts of the core of the hypothesis is that Neanderthals, already living in small, isolated populations, may have been more vulnerable to this radiation than Homo sapiens. The study claims that Homo sapiens had tighter clothing, used red ochre as UV protection, and took shelter in caves helping them survive the radiation. Neanderthals, in contrast, might have lacked these simulations in the study even show that auroras, a sign of increased solar activity, might have been visible across much of the world during this time, proof, the author argues, of the heightened radiation the theory is bold and imaginative, many experts are José-Miguel Tejero and Montserrat Sanz Borràs, writing for The Conversation, point out that the idea rests on shaky archaeological example, it assumes that Neanderthals didn't wear fitted clothing. While it's true that no sewing needles have been found at Neanderthal sites, there is clear evidence that they processed animal hides and likely wore functional garments using other techniques, such as tying hides with leather cords or fact, genetic studies of lice suggest that humans, possibly including Neanderthals, were already wearing clothes over 200,000 years ago. The absence of needles doesn't prove the absence of study also claims that Homo sapiens used red ochre as sunblock. While experiments show that ochre can somewhat block UV rays, this claim is also disputed. Ochre was widely used by both Neanderthals and modern humans, often for symbolic or cosmetic reasons. There is no solid evidence that either group used it primarily for sun are known to have used ochre for over 100,000 years. In one example, a painted scallop shell found in a Neanderthal cave in Spain shows their symbolic use of pigments long before Homo sapiens arrived in scientists believe that multiple factors caused the Neanderthals' disappearance. These include, interbreeding with Homo sapiens (evident in modern DNA), smaller populations that were more vulnerable to decline, limited long-range hunting tools, unlike the projectile weapons used by sapiens, Changing climate, and possibly, competition for this broader context, Mukhopadhyay's theory appears too narrow. Critics note that there is no archaeological evidence of a sudden, global collapse of Neanderthal populations tied to the Laschamp event. If radiation were such a major factor, it would have also harmed Homo sapiens populations living outside caves in sunny Africa, which doesn't seem to have Neanderthal story is complex. These early humans were not primitive brutes. They developed tools, built shelters, made symbolic objects, and survived in extreme climates for hundreds of thousands of years. They even lived through earlier magnetic reversals, such as the Blake event 120,000 years theory adds an intriguing piece to the puzzle, but it's far from did a shift in Earth's magnetic field doom the Neanderthals?Probably not. While the Laschamp event may have had some environmental impact, there's no strong evidence that it caused Neanderthal extinction . The theory suggests that the disappearance of Neanderthals was likely due to a mix of climate, biology, and human interaction.
Time of India
22-06-2025
- Science
- Time of India
They survived ice ages and hunted mammoths; so why did the Neanderthals suddenly disappear? Now a physicist blames something in the sky
Neanderthals have long puzzled scientists. These ancient relatives of modern humans thrived across Europe and parts of Asia for hundreds of thousands of years. But around 40,000 years ago, they disappeared, just as Homo sapiens spread across the same regions. What really caused their extinction remains one of human evolution's biggest mysteries. Now, a new and unusual theory suggests that space weather, not climate, competition, or disease, may have played a decisive role. A recent study by Dr. Agnit Mukhopadhyay, a space physicist from the University of Michigan , proposes that a powerful cosmic event known as the Laschamp excursion might have played a part in the Neanderthals' decline. The findings were published in the journal Science Advances. by Taboola by Taboola Sponsored Links Sponsored Links Promoted Links Promoted Links You May Like If You Eat Ginger Everyday for 1 Month This is What Happens Tips and Tricks Undo The Laschamp event occurred about 41,000 years ago, when the Earth's magnetic poles temporarily flipped. During this brief reversal, the planet's magnetic field, which normally protects us from cosmic radiation, dramatically weakened for several centuries. Mukhopadhyay argues that this weakening may have exposed the Earth's surface to much higher levels of ultraviolet (UV) and cosmic radiation, particularly in some parts of the world. Live Events Radiation as a Hidden Killer? The core of the hypothesis is that Neanderthals, already living in small, isolated populations, may have been more vulnerable to this radiation than Homo sapiens. The study claims that Homo sapiens had tighter clothing, used red ochre as UV protection, and took shelter in caves helping them survive the radiation. Neanderthals, in contrast, might have lacked these protections. Computer simulations in the study even show that auroras, a sign of increased solar activity, might have been visible across much of the world during this time, proof, the author argues, of the heightened radiation environment. While the theory is bold and imaginative, many experts are skeptical. Researchers José-Miguel Tejero and Montserrat Sanz Borràs, writing for The Conversation, point out that the idea rests on shaky archaeological evidence. For example, it assumes that Neanderthals didn't wear fitted clothing. While it's true that no sewing needles have been found at Neanderthal sites, there is clear evidence that they processed animal hides and likely wore functional garments using other techniques, such as tying hides with leather cords or splinters. In fact, genetic studies of lice suggest that humans, possibly including Neanderthals, were already wearing clothes over 200,000 years ago. The absence of needles doesn't prove the absence of clothes. The study also claims that Homo sapiens used red ochre as sunblock. While experiments show that ochre can somewhat block UV rays, this claim is also disputed. Ochre was widely used by both Neanderthals and modern humans, often for symbolic or cosmetic reasons. There is no solid evidence that either group used it primarily for sun protection. Neanderthals are known to have used ochre for over 100,000 years. In one example, a painted scallop shell found in a Neanderthal cave in Spain shows their symbolic use of pigments long before Homo sapiens arrived in Europe. Most scientists believe that multiple factors caused the Neanderthals' disappearance. These include, interbreeding with Homo sapiens (evident in modern DNA), smaller populations that were more vulnerable to decline, limited long-range hunting tools, unlike the projectile weapons used by sapiens, Changing climate, and possibly, competition for resources. In this broader context, Mukhopadhyay's theory appears too narrow. Critics note that there is no archaeological evidence of a sudden, global collapse of Neanderthal populations tied to the Laschamp event. If radiation were such a major factor, it would have also harmed Homo sapiens populations living outside caves in sunny Africa, which doesn't seem to have happened. A Caution Against Oversimplification The Neanderthal story is complex. These early humans were not primitive brutes. They developed tools, built shelters, made symbolic objects, and survived in extreme climates for hundreds of thousands of years. They even lived through earlier magnetic reversals, such as the Blake event 120,000 years ago. Mukhopadhyay's theory adds an intriguing piece to the puzzle, but it's far from conclusive. So, did a shift in Earth's magnetic field doom the Neanderthals? Probably not. While the Laschamp event may have had some environmental impact, there's no strong evidence that it caused Neanderthal extinction . The theory suggests that the disappearance of Neanderthals was likely due to a mix of climate, biology, and human interaction.
Yahoo
19-06-2025
- Science
- Yahoo
Neanderthal extinction: a space physicist reopens the debate
Neanderthals have long been the subject of intense scientific debate. This is largely because we still lack clear answers to some of the big questions about their existence and supposed disappearance. One of the latest developments is a recent study from the University of Michigan, published in the journal Science Advances. It proposes that Neanderthals went extinct for astrophysical reasons. The work was led by Agnit Mukhopadhyay, an expert in space physics, a discipline that studies natural plasmas, especially those found within our own solar system. Plasma is the state of matter that dominates the universe: the Sun and stars are huge balls of plasma, as are the northern lights. Mukhopadhyay's research suggests that a shift in the Earth's magnetic poles around 41,000 years ago, known as the Laschamp event, may have contributed to the extinction of Neanderthals. According to his work, the extreme weakening of the Earth's magnetic field during that event allowed for greater penetration of cosmic and ultraviolet radiation. This would have generated more aggressive environmental conditions that Neanderthals could not withstand, giving our own species, Homo sapiens, an edge. In this context, sapiens would have had an advantage over Neanderthals thanks to their presumed use of close-fitting clothing, ochre – a mineral with protective properties against the sun – and taking shelter in caves. Caves which, by the way, on numerous occasions were inhabited by both Neanderthals and our own species. The hypothesis is interesting, and is based on innovative three-dimensional models of the Earth's geospatial system during this period. However, as with many hypotheses that attempt to explain complex phenomena on the basis of a single variable, its scope and some of the assumptions on which it is based need to be examined more closely. One of the pillars of this hypothesis is that Neanderthals did not wear tight-fitting clothing, and would therefore have been more exposed to the harmful effects of solar radiation. It is true that sewing needles have not been definitvely linked to Neanderthals. The first needles documented in Eurasia are associated with either Denisovan or sapiens populations around 50,000 years ago, and in western Europe they did not appear until around 23,000 years ago. But this does not mean that Neanderthals did not wear clothing. In fact, the Homo sapiens who lived during episodes of extreme cold (such as the Heinrich 4 event, which occurred some 39,600 years ago) did not have sewing needles either, but they did have enough technology to make garments, and possibly tents and footwear. There is ample archaeological evidence of Neanderthals processing hides, such as the systematic use of scrapers and other tools associated with the tanning process. However, the use of fur or clothing has much older origins. In fact, the genetic study of lice has revealed that humans were already wearing clothing at least 200,000 years ago. Furthermore, in cold environments such as those they inhabited in Europe, it would have been unfeasible to survive without some form of body protection. Even if they did not have needles, it is very plausible that they used alternative systems such as ligatures or bone splinters to adapt animal hides to the body. The absence of needles should not be confused with the absence of functional clothing. The study also highlights the use of ochre by Homo sapiens, which it says offered protection against solar radiation. Although experiments have been carried out to demonstrate certain blocking capacities of ochre against ultraviolet (UV) rays, its use by human populations is not limited to a single group. In fact, evidence of pigment use during the same period has been found in Africa, the Near East and the Iberian Peninsula, and among different human lineages. The use of ochre has been documented in Neanderthal contexts for more than 100,000 years, both in Europe and in the Levant. Its application may have had multiple purposes: symbolic, therapeutic, cosmetic, healing, and even an insect repellent. There are no solid grounds for claiming that its use for protective purposes was exclusive to Homo sapiens, especially when both species shared spaces and technologies for millennia. Nor can we be sure that it was used as a protective sunscreen. Leer más: One of the most significant factors may have been the marked difference in population size. There were fewer Neanderthals, meaning they would have been assimilated by the much more numerous populations of Homo sapiens. This assimilation is reflected in the DNA of current populations, suggesting that, rather than becoming extinct, Neanderthals were absorbed into the evolutionary process. Technology also played a part– as far as we know, Neanderthals did not use hunting weapons at a distance. The invention and use of projectiles associated with hunting activities – first in stone and later in hard animal materials – appear to be an innovation specific to Homo sapiens. Their development may have given them an adaptive advantage in open environments, and a greater capacity to exploit different prey and environments. Leer más: Associating the Neanderthal 'extinction' to their supposed failure to adapt to increased solar radiation during the Laschamp excursion oversimplifies a phenomenon that remains the subject of heated debate. Put simply, the archaeological record does not support Mukhopadhyay's hypothesis. There is no evidence of an abrupt demographic collapse coinciding with this geomagnetic event, nor of a widespread catastrophic impact on other human or animal species. Moreover, if solar radiation had been such a determining factor, one would expect high mortality also among populations of sapiens that did not wear tight clothing or live in caves (in warm regions of Africa, for instance). As far as we know, this did not happen. When trying to explain the disappearance of Neanderthals, it is vital that we integrate multiple lines of archaeological, paleoanthropological and genetic evidence. These humans were not simply victims of their own technological clumsiness or of a hostile environment that they failed to cope with. They were an adaptive and culturally complex species that, for more than 300,000 years, survived multiple climatic changes – including other geomagnetic shifts such as the Blake event, which occurred about 120,000 years ago. Neanderthals developed sophisticated tools, dominated vast territories and shared many more traits with us than was assumed for decades. So did the magnetic reversal of the Earth's magnetic poles wipe out the Neanderthals? The answer is: probably not. Este artículo fue publicado originalmente en The Conversation, un sitio de noticias sin fines de lucro dedicado a compartir ideas de expertos académicos. Lee mas: Neanderthals: the oldest art in the world wasn't made by Homo sapiens Modern human DNA contains bits from all over the Neanderthal genome – except the Y chromosome. What happened? How Neanderthal language differed from modern human – they probably didn't use metaphors Las personas firmantes no son asalariadas, ni consultoras, ni poseen acciones, ni reciben financiación de ninguna compañía u organización que pueda obtener beneficio de este artículo, y han declarado carecer de vínculos relevantes más allá del cargo académico citado anteriormente.
Yahoo
25-04-2025
- Science
- Yahoo
Ancient Body Paint May Have Been Prehistoric Sunscreen, Study Says
Ochre body paint may have been a form of prehistoric sunscreen that helped early humans survive a sudden increase in ultraviolet (UV) radiation around 41,000 years ago. That's a fascinating new hypothesis recently put forward by an international team of geoscientists and anthropologists, led by researchers at the University of Michigan. Their study reconstructs the global space environment during the end of the Last Glacial Period, and it finds that when Earth's magnetic field suddenly hiccuped all those millennia ago, it had a profound impact on our planet's protective solar shield. Scientists already knew of this distinct geomagnetic tantrum in Earth's history, called the Laschamp event, when the poles suddenly and briefly went haywire and underwent a partial flip before settling back into their original positions. But the new model is more detailed than ever before, and it shows that over the course of thousands of years, while the event was underway, the strength of Earth's geomagnetic field plummeted, reaching just 10 percent of what it is today. At the same time, the poles where magnetic field lines meet expanded and tilted by over 75 degrees relative to Earth's rotational axis. The South Pole shifted away from Antarctica and settled over Australia and New Zealand, while the North Pole wandered out of the Arctic into Western Eurasia, Northern Africa, and the northwestern Sahara. "Vast expanses of both hemispheres were enveloped by expansive open field line regions, unleashing a substantial barrage of auroral precipitation on a global scale," the authors write. That's where the sunscreen comes in handy. Auroras are caused by charged particles from the Sun, which are guided along Earth's magnetic field lines to the poles, where they are dumped out and interact with our planet's atmosphere. If the magnetic field lines are weakened, though, all that cosmic radiation enters the atmosphere earlier and deeper, which can be disastrous for the ozone layer below. As this protective layer weakens, it in turn admits more harmful UV light. During the Laschamp weakening, if some parts of the world let in more UV radiation, then early humans, including our own species and Neanderthals, were likely affected. Scientists have previously suggested our species' adaptations to the Laschamp event may have allowed us to survive where other humans could not. The new study, led by space physicist Agnit Mukhopadhyay, adds to that idea. "In the study, we combined all of the regions where the magnetic field would not have been connected, allowing cosmic radiation, or any kind of energetic particles from the Sun, to seep all the way in to the ground," explains Mukhopadhyay. While speculative, the authors point out that many of the areas likely exposed to increased ultraviolet radiation matched closely with changes in human activity more than 40,000 years ago, including more tools for tailoring clothing, an increase in cave art, and the use of ochre, which some studies suggest is a natural prehistoric sunscreen. These behaviors may reflect humanity's attempt to minimize exposure to ultraviolet radiation. To this day, the Himba community in northern Namibia, for instance, use ochre as sunscreen, and Indigenous Australians have similar customs. "There have been some experimental tests that show [ochre] has sunscreen-like properties. It's a pretty effective sunscreen, and there are also ethnographic populations that have used it primarily for that purpose," confirms anthropologist Raven Garvey of the University of Michigan. "Its increased production and its association primarily with anatomically modern humans (during the Laschamp) is also suggestive of people's having used it for this purpose as well." The timing is certainly intriguing, but the fossil record is not a complete one, and it needs to be interpreted with caution. There are likely many factors that led to our species' survival – and to the demise of our cousins. The disappearance of the Neanderthals, for instance, largely coincides with the Laschamp event, which has led some to propose that it is what killed our early relatives. Today, however, there is now some archaeological evidence of Neanderthals making tools for clothing, using ochre, and making cave art. Perhaps they didn't do this to the same level of sophistication as our own species, but they may have been adapting to the times, too. Historically, scientists have tended to underestimate our ancient cousins and what they were capable of. In 2021, archaeologist Anna Goldfield wrote a piece for Sapiens that argued that "headlines trumpeting that a magnetic pole switch killed off our ancient relatives are vastly oversimplifying the tremendously complex system in which Neanderthals and our Homo sapiens ancestors lived." The new study was published in Science Advances. Scientists Discover First Probable Evidence of a Roman Fighter Mauled by a Lion Scientists Say They Found a New Color Humans Have Never Seen Before Mysterious Antikythera Mechanism May Actually Be a Toy, Study Says
Yahoo
21-04-2025
- Science
- Yahoo
Sunscreen may have contributed to ancient humans' survival
(NewsNation) — Research from the University of Michigan shows that ancient Homo sapiens may have benefitted from the use of a prehistoric sunscreen during the shifting of the magnetic North Pole over Europe. Ancient humans used ochre, a mineral with sun-protective properties when applied to the skin. Other ways they protected themselves from harmful solar radiation include tailored clothes and the use of caves. The research team found that the North Pole wandered over Europe when the magnetic field's poles started to flip positions, a natural process that has happened around 180 times over Earth's geological history. The magnetic reversal didn't occur, but the magnetic field weakened, allowing aurora to appear over most of the globe and increasing the amount of harmful UV light from space. Scientists find strongest evidence yet of life on an alien planet Researchers say the measures the ancient humans took may have contributed to their spread throughout Europe and Asia when the Neanderthal population was declining and eventually disappeared around 40,000 years ago. 'In the study, we combined all of the regions where the magnetic field would not have been connected, allowing cosmic radiation, or any kind of energetic particles from the sun, to seep all the way in to the ground,' lead researcher Agnit Mukhopadhyay said. 'We found that many of those regions actually match pretty closely with early human activity from 41,000 years ago, specifically an increase in the use of caves and an increase in the use of prehistoric sunscreen.' Researchers said their work highlighted that people were still able to survive on a planet whose atmosphere looked a lot different than ours today, and this has implications for the search for life on planets other than Earth. Copyright 2025 Nexstar Media, Inc. All rights reserved. This material may not be published, broadcast, rewritten, or redistributed.
