Latest news with #Laschamps
Yahoo
23-04-2025
- Science
- Yahoo
Stone Age SPF: How An Ancient Mineral May Have Helped Humans Survive The Sun
Long before beach bags and bottles of SPF, early humans may have reached for something far more basic to protect themselves from the sun: dirt. That's according to experts who have a new theory about how our ancestors may have survived a serious spike in ultraviolet radiation thousands of years before sunblock (as we know it today) was invented. Let's rewind the tape to about 41,000 years ago when Earth's magnetic field had a bit of a crisis. Scientists at the University of Michigan, in a new study published in Science Advances, reconstructed what happened during the infamous Laschamps geomagnetic excursion, a two-millennia-long episode where Earth's magnetic field plummeted to just 10% of its usual strength and the poles began to, for lack of a better word, wander. (MORE: Were Earth's First Oceans Green?) During the Laschamps, Earth's magnetic field, which shields us from solar radiation, became multipolar, with zones popping up unpredictably. Auroras were no longer Arctic exclusives; they moved into much lower latitudes. The weakened magnetic field meant more ultraviolet radiation was leaking through the atmosphere, and some of our ancestors quickly adapted. Both Neanderthals and anatomically modern humans were living across Europe when this chaos kicked off. Evidence suggests both groups had richly pigmented skin, hair, and eyes—but it turns out, even that wasn't enough. Groups of anatomically modern humans started using ochre, a yellow mineral loaded with iron oxide, in greater quantities, possibly as a prehistoric sunscreen. They also began crafting tailored clothing that may have acted as additional protection. These weren't just random upgrades, they were survival tools in their new radiation-filled environment. (MORE: New Telescope Captures Blasts From The Sun) Neanderthals, by contrast, mostly stuck to draped cloaks and simpler tech, with no evidence that they used anything for sun protection. While their extinction was likely due to a blend of factors, it's possible this played a part. You could say pants and sunscreen might've saved humanity. Now, here's the kicker: Earth's magnetic field has been weakening again. Not to Laschamps levels, but it's declined by about 1% every 20 years for the last 180 years. And the poles? They're not sitting still either. (MORE: Scientists Link Centuries-Old Mystery To Weather Patterns) If a modern-day Laschamps like event occurred, it wouldn't just fry your skin—it would wreak havoc on satellites, communication networks, GPS, and international flights. So, next time you're gazing up at the aurora or slathering on sunscreen, just remember: we've been here before. Only this time, our survival might depend less on ochre. lead editor Jenn Jordan explores how weather and climate weave through our daily lives, shape our routines and leave lasting impacts on our communities.
Telegraph
16-04-2025
- Science
- Telegraph
Sunscreen helped Homo sapiens outlive Neanderthals, study suggests
Cave dwelling, clothing and sunscreen may be the reason Homo sapiens outlasted the Neanderthals, a new study suggests. Neanderthals became extinct about 40,000 years ago, leaving modern humans as the sole-surviving hominin left on Earth. Now a new theory suggests that the replacement could have been down to how the two groups responded to an increase in harmful UV radiation from space, sparked by an unusual flipping of the magnetic poles. About 41,000 years ago, a temporary reversal of the poles occurred – known as the Laschamps excursion. It lasted about 1,000 years and weakened Earth's magnetic field to about 10 per cent of its current strength. Earth's magnetic field protects the planet from harmful solar radiation and cosmic rays. Without it, populations can be dangerously exposed. Scientists from the University of Michigan modelled the regions that were most vulnerable during the period and found they tallied with human activity in Europe and Asia. Archaeological evidence shows that around the same time, Homo sapiens started making tailored clothes, dwelling in caves and using ochre as body paint – all of which would have screened them from the increased radiation. 'Having protection against solar radiation (from clothing) would have conferred significant advantage to anyone who possessed it,' said Dr Raven Garvey, associate professor of anthropology at the University of Michigan. '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. 'Its increased production and its association primarily with anatomically modern humans during the Laschamps is also suggestive of people having used it for this purpose as well.' While clothing, ochre and cave dwelling could have protected Home sapiens, there is little evidence that Neanderthals had the same practices. At sites associated with modern humans, archaeologists have found hide-scraping stones, as well as needles and awls, which were probably used for sewing, but these were absent from Neanderthal sites. Tailored clothing, as well as protecting from UV rays, also brought warmth, meaning people could travel farther from their hearths and shelters in search of food. Homo sapiens also probably stepped up their use of ochre, a naturally occurring pigment comprising iron oxide, clay and silica that has been used by many species to paint objects, cave walls and decorate their bodies 'I think it's important to note that these findings are correlational,' Dr Garvey added. 'But I think it is a fresh perspective on the data in light of the Laschamps excursion.' Earth's magnetic field is created by the rotation of its molten iron core, which generates an electric field that forms around the globe. This magnetic field has a north and south orientation, the North and South poles, but occasionally these poles wander from their traditional geographic positions, known as excursions. The Laschamps excursion caused Earth's magnetic poles to drop down near the Equator and would have caused aurora to be seen all over Europe and into northern Africa. It coincided with a big shift for humanity. '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 into the ground,' said Dr Agnit Mukhopadhyay, a climate, space sciences and engineering expert at the University of Michigan. 'Prehistoric sunscreen' '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.' Dr Mukhopadhyay added: 'If such an event were to happen today, we would see a complete blackout in several different sectors. 'Our communication satellites would not work. Many of our telecommunication arrays, which are on the ground, would be severely affected by the smallest of space weather events, not to mention the human impacts, which would also play a pretty massive role in our day-to-day lives.'
Yahoo
16-04-2025
- Science
- Yahoo
Sunscreen helped Homo sapiens outlive Neanderthals, study suggests
Cave dwelling, clothing and sunscreen may be the reason Homo sapiens outlasted the Neanderthals, a new study suggests. Neanderthals became extinct about 40,000 years ago, leaving modern humans as the sole-surviving hominin left on Earth. Now a new theory suggests that the replacement could have been down to how the two groups responded to an increase in harmful UV radiation from space, sparked by an unusual flipping of the magnetic poles. About 41,000 years ago, a temporary reversal of the poles occurred – known as the Laschamps excursion. It lasted about 1,000 years and weakened Earth's magnetic field to about 10 per cent of its current strength. Earth's magnetic field protects the planet from harmful solar radiation and cosmic rays. Without it, populations can be dangerously exposed. Scientists from the University of Michigan modelled the regions that were most vulnerable during the period and found they tallied with human activity in Europe and Asia. Archaeological evidence shows that around the same time, Homo sapiens started making tailored clothes, dwelling in caves and using ochre as body paint – all of which would have screened them from the increased radiation. 'Having protection against solar radiation (from clothing) would have conferred significant advantage to anyone who possessed it,' said Dr Raven Garvey, associate professor of anthropology at the University of Michigan. '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. 'Its increased production and its association primarily with anatomically modern humans during the Laschamps is also suggestive of people having used it for this purpose as well.' While clothing, ochre and cave dwelling could have protected Home sapiens, there is little evidence that Neanderthals had the same practices. At sites associated with modern humans, archaeologists have found hide-scraping stones, as well as needles and awls, which were probably used for sewing, but these were absent from Neanderthal sites. Tailored clothing, as well as protecting from UV rays, also brought warmth, meaning people could travel farther from their hearths and shelters in search of food. Homo sapiens also probably stepped up their use of ochre, a naturally occurring pigment comprising iron oxide, clay and silica that has been used by many species to paint objects, cave walls and decorate their bodies 'I think it's important to note that these findings are correlational,' Dr Garvey added. 'But I think it is a fresh perspective on the data in light of the Laschamps excursion.' Earth's magnetic field is created by the rotation of its molten iron core, which generates an electric field that forms around the globe. This magnetic field has a north and south orientation, the North and South poles, but occasionally these poles wander from their traditional geographic positions, known as excursions. The Laschamps excursion caused Earth's magnetic poles to drop down near the Equator and would have caused aurora to be seen all over Europe and into northern Africa. It coincided with a big shift for humanity. '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 into the ground,' said Dr Agnit Mukhopadhyay, a climate, space sciences and engineering expert at the University of Michigan. '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.' Dr Mukhopadhyay added: 'If such an event were to happen today, we would see a complete blackout in several different sectors. 'Our communication satellites would not work. Many of our telecommunication arrays, which are on the ground, would be severely affected by the smallest of space weather events, not to mention the human impacts, which would also play a pretty massive role in our day-to-day lives.' The study was published in the journal Science Advances. Broaden your horizons with award-winning British journalism. Try The Telegraph free for 1 month with unlimited access to our award-winning website, exclusive app, money-saving offers and more.
Yahoo
14-02-2025
- Science
- Yahoo
Earth's Flipping Magnetic Field Heard as Sound Is an Unnerving Horror
Earth's magnetic field dramatically flipped a little more than 40,000 years ago. We can now experience this epic upheaval, thanks to a clever interpretation of information collected by the European Space Agency's Swarm satellite mission. Combining the satellite data with evidence of magnetic field line movements on Earth, European geoscientists mapped the so-called Laschamps event and represented it using natural noises like the creaking of wood and the crashing of colliding rocks. The resulting compilation – unveiled in 2024 by the Technical University of Denmark and the German Research Center for Geosciences – is unlike anything you've ever heard. Generated by the swirling liquid metals in our planet's core, Earth's magnetic field reaches tens to hundreds of thousands of kilometers into space, protecting us all by deflecting atmosphere-stripping solar particles. In its current orientation, the field lines form closed loops that are directed south to north above the planet's surface, and then north to south deep within it. Yet every so often the field randomly flips its polarity. Were this to happen again today, our north-pointing compasses would point to the South Pole. The last such cataclysmic event occurred about 41,000 years ago, leaving a signature in the Laschamps lava flows in France. As the field weakened to only 5 percent of its current strength the reversal process allowed a surpluss of cosmic rays to pass into Earth's atmosphere. Ice and marine sediment preserve isotopic signatures of this higher-than-normal solar bombardment, with levels of beryllium-10 isotopes doubling during the Laschamps event, according to a study published last year. These altered atoms are formed when cosmic rays react with our atmosphere, ionizing the air and frying the ozone layer. With global climate change being a potential consequence, it's speculated the extinction of Australia's megafauna as well as changes in human cave use may have been associated with this event. "Understanding these extreme events is important for their occurrence in the future, space climate predictions, and assessing the effects on the environment and on the Earth system," German Research Center for Geosciences geophysics Sanja Panovska explained at the time. It took 250 years for the Laschamps reversal to take place and it stayed in the unusual orientation for about 440 years. At most, Earth's magnetic field may have remained at 25 percent of its current strength as the north polarity drifted to the south. Recent magnetic field anomalies like the weakening over the Atlantic ocean have led to questions about an impending reversal today, but recent research suggests these anomalies are not necessarily connected to flipping events. The South Atlantic anomaly is, however, exposing satellites in the area to higher levels of radiation. Since 2013, ESA's Swarm constellation has been measuring magnetic signals from Earth's core, mantle, crust, oceans, ionosphere, and magnetosphere so we can better understand our planet's geomagnetic field and predict its fluctuations. An earlier version of this article was published in October 2024. We Finally Know Why Ancient Roman Concrete Was So Durable Teleportation Achieved Between Quantum Computers in a World First Scientists Discover New Class of Quantum States in Graphene
