Latest news with #ScienceAlert
Yahoo
2 days ago
- Science
- Yahoo
An Astrophysicist Proposes We Send a Spacecraft to Visit a Black Hole
Black holes are some of the most mysterious objects in the Universe – a reputation not helped by the difficulty of studying them. Because these ultra-dense objects emit no light we can detect, we have to study them based on the effect they have on the space around them, from large distances across space-time. But there could be another way to get the skinny on these cosmic heavyweights. "I was looking for some completely new way to study black holes," astrophysicist Cosimo Bambi of Fudan University in China told ScienceAlert, "and I realized that an interstellar mission to the closest black hole is not unrealistic – but nobody had ever proposed it." Related: Physicists Simulated a Black Hole in The Lab, And Then It Began to Glow Black holes generate the strongest gravitational fields in the Universe, so strong that not even light is fast enough to achieve escape velocity from its powerful hold. Although we know a fair bit about how they behave, the measure of what we don't know about them is far greater than what we do. Additionally, the black hole gravitational regime would be one of the best in the Universe for testing general relativity, offering extreme conditions not found anywhere else that would really push the theory to its absolute limits. A probe orbiting a black hole would be able to perform tests, and take measurements of the black hole, that we can't do from Earth. "We do not know the structure of a black hole, namely of the region inside the event horizon. General relativity makes clear predictions, but some of them are certainly incorrect," Bambi said. "Black holes are therefore ideal laboratories to find possible deviations from the predictions of general relativity." In his proposal, Bambi lays out the physical feasibility of a black hole exploration mission, focusing on the two first hurdles that would need to be addressed: firstly, the identification of a suitable target; and secondly, the technology. To be clear, this is long-term planning. The technology we have now is not ready for such a mission, and the distances involved would mean a travel time of decades. But each journey begins with a single step – and without that step, the journey cannot take place. Finding a suitable black hole to visit is the first major hurdle. Currently, the closest known black hole to Earth resides at a distance of about 1,565 light-years. That's too far, really. There could, however, be black holes much closer. If they're just hanging out in space, not doing anything, black holes are hard to spot, but astronomers are getting better at finding them based on the way their gravitational field warps the space-time around them. Finding such a black hole nearby within the next decade or so isn't outside the realm of possibility. "I think we just need to be 'lucky' and have a black hole within 20 to 25 light-years. This is not under our control, of course. If there is a black hole within 20 to 25 light-years of the Solar System, we can develop the technology for such a mission," Bambi explained. "If the black hole is not within 20 to 25 light-years, but still within 40 to 50 light-years, the technological requirements are more challenging. If the black hole is at more than 40 to 50 light-years, I am afraid we have to give up." The next step would be how to get there. This would require the development of a craft that can travel at speeds up to a third of the speed of light, powered initially by Earth-based lasers, then by solar (or stellar) power as it makes its way to its destination – a journey of 70 years or so. "Two or more probes orbiting around the black hole would be the best option," Bambi said. "Generally speaking, we need that the probe gets as close as possible to the black hole, then it separates into a main probe (mothership) and many small probes. If these probes can communicate with each other through the exchange of electromagnetic signals, we can determine their exact trajectories around the black hole and how electromagnetic signals propagate around the black hole." Any data sent from the probe would then travel at light-speed to get back to Earth; at a distance of 20 light-years, that would mean an additional 20 years before data comes in, for a total mission duration of around a century or so. That's a long time, but it's worth thinking about now, even before a nearby black hole has been found, because such a mission would require a great deal of planning. And the results would absolutely be worth it, Bambi said. "I would hope to observe deviations from the predictions of general relativity and some clues to develop a theory beyond general relativity," he told ScienceAlert. In a statement, he adds, "It may sound really crazy, and in a sense closer to science fiction. But people said we'd never detect gravitational waves because they're too weak. We did – 100 years later. People thought we'd never observe the shadows of black holes. Now, 50 years later, we have images of two." The proposal has been published in iScience. Related News You're More Likely to Die From an Asteroid Than Rabies, Scientists Find Scientists Have Brewed a 'Super Alcohol' Theorized to Exist in Deep Space Earth Spun Faster Today. Here's How We Know. Solve the daily Crossword
Yahoo
3 days ago
- Science
- Yahoo
Ancient Tools Suggest Indonesian 'Hobbits' Had a Mysterious Neighbor
The ancestors of the ancient 'hobbits' who once lived on the Indonesian island of Flores were not the only early hominins to cross deep ocean barriers more than a million years ago. A team of archaeologists from Indonesia and Australia has now discovered the tools of a mysterious neighbor who resided on the island of Sulawesi to the north around the same time, if not earlier. "It's highly unlikely these early hominins had the cognitive capacity (especially the ability for advanced planning) required to invent boats," archaeologist and co-lead of the expedition, Adam Brumm, told ScienceAlert. "It is more likely that hominins got to Sulawesi by accident, most probably as a result of 'rafting' on natural vegetation mats. It's thought rodents and monkeys made overwater crossings from the Asian mainland to reach Sulawesi in this way." Related: The seven flaked stones on Sulawesi were found at different depths below ground, but according to the dating of local sandstone and a nearby pig fossil, the tools range in age from 1.04 million years to 1.48 million years. If correct, the artifacts could represent the earliest evidence of human activity in Wallacea – a string of mainly Indonesian islands that has separated the Asian and Australian continents for millions of years. The identity of the isolated toolmakers remains a mystery. Brumm has been studying early hominins in the region for decades, and he co-led the recent archaeological expedition on Sulawesi with Budianto Hakim from the National Research and Innovation Agency of Indonesia (BRIN). Archaeologist Debbie Argue, who was not involved in the discovery, told ScienceAlert the findings are "most important", because they add to the startling fact that early Pleistocene hominins could somehow make sea crossings. "With evidence for hominins on three islands that have never been attached to a mainland – Flores, Luzon, and now Sulawesi – island Southeast Asia is shaping up to be an extraordinary frontier for human evolution," said Argue. Until now, the earliest evidence of stone tools in Wallacea – which are thought to be 1.02 million years old – came from the island of Flores. Flores is the same place where archaeologists discovered the short-statured Homo floresiensis – also known as the 'hobbit' – in a cave in 2003. This meter-high hominin (3.3 feet) with a brain the size of grapefruit took the world by surprise when it was found, because it didn't look like any other early human. The remains of H. floriensis date up to 100,000 years ago, but its presumed ancestors on the island date back 700,000 years. The 1.02 million-year-old stone tools on Flores were probably made by those ancestors – whether descended from Homo erectus or another hominin species on the Asian mainland. According to a 2021 interview with archaeologist Lucy Timbrell, Brumm accidentally happened upon the Flores tools while "nursing an appalling hangover" due to a local village ceremony the night before. "Whilst stumbling about in the sweltering heat, in a bewildered state, I found some heavily patinated stone tools eroding out from a fluvial conglomerate exposed at the base of a gully," Brumm recalled in the interview. "I have since tried to make major archaeological discoveries while hungover, but it only worked that one time." Archaeologists have yet to uncover hominin fossils on Sulawesi, but the evidence of stone tools indicates their existence. It's unknown if the Sulawesi population was related to hominins on Flores, but the late Mike Morwood, one of the co-discoverers of the 2003 'hobbit', was convinced that Sulawesi was the key to understanding where H. floresiensis came from. "We had always suspected that hominins were established on Sulawesi for a very long period of time, but until now we had never found clear evidence," Brumm told ScienceAlert. Influenced by Morwood's thinking, Brumm suspects that Sulawesi was once a stepping stone to Flores from mainland Asia (which once stretched as far as Java and Borneo). In 2010, Morwood told The Guardian that he suspected tools on Sulawesi could date back two million years. "This is going to put the cat among the pigeons," he said at the time. No doubt he would have been thrilled by the recent work of Brumm's and Hakim's team. The archaeologists now plan to search Sulawesi for direct remains of the mysterious tool makers. "We are also working at much younger sites that we hope will provide insight into what happened to these early humans when our species arrived on the island at least 65,000 years ago," said Brumm. The study was published in Nature. Related News DNA Casts Doubt Over Theory on What Killed Napoleon's Forces Study Reveals How Many IVF Babies Have Been Born Worldwide Image on The Shroud of Turin May Not Belong to a Real Human Solve the daily Crossword
NDTV
4 days ago
- Science
- NDTV
Researchers Study Prehistoric CO2 Levels After Reconstructing Air From Dinosaur Teeth
Researchers have analysed the oxygen isotope ratios in fossilised dinosaur teeth, specifically the tooth enamel. The tooth has preserved traces of the ancient atmosphere. The researchers studied these isotopes to understand atmospheric CO2 levels during the Mesozoic era, when dinosaurs roamed the Earth. The CO2 levels were much higher during that time, with concentrations reaching up to 1,200 parts per million in the late Jurassic and 750 parts per million in the late Cretaceous. To understand it better, today's atmospheric CO2 levels are around 430 parts per million. The volcanic activity apparently played a significant role in shaping the prehistoric atmosphere. According to the researchers, some dinosaur teeth showed signs of high CO2 levels likely caused by large flood basalt eruption events. "Our findings provide a new research avenue to reconstruct a direct link between land-living vertebrates and the atmosphere they breathed," palaeontologist and geochemist Thomas Tutken of the Institute of Geosciences at Johannes Gutenberg Universitat, Mainz in Germany, told Science Alert. "Even after up to 150 million years, isotopic traces of the oxygen molecules of the Mesozoic atmosphere that the dinosaur inhaled are still preserved in fossil tooth enamel and can tell us something about the ancient atmosphere composition and global photosynthetic biomass production." Now, the team plans to apply this method to other geological periods, including the Permian-Triassic extinction event, to understand the Earth's climate history better. This innovative approach has shed new light on the prehistoric atmosphere and has the potential to revolutionise our understanding of Earth's climate history. "Overall, triple oxygen isotope analysis of fossil teeth of terrestrial amniotes can provide insights into past atmospheric greenhouse gas content and global primary productivity," the researchers wrote in the study.
NDTV
31-07-2025
- Science
- NDTV
892-Kilometres Megaflash From Texas To Kansas Shatters World Record For Longest Lightning Strike
A massive lightning bolt that lit up the sky from Texas to Kansas in October 2017 has been confirmed as the world's longest lightning flash, stretching an incredible 829 kilometres (515 miles) across the Great Plains of North America. This record-breaking megaflash surpassed the previous record by 61 kilometres. The World Meteorological Organisation (WMO) announced the discovery on Thursday. Though the strike occurred almost eight years ago, it was only recently discovered. As per Science Alert, researchers used data from the GOES East weather satellite, which orbits 22,236 miles above Earth's surface, to detect the enormous lightning strike. This satellite technology allowed scientists to track the megaflash, which wouldn't have been possible with conventional ground-based lightning detection networks that only detect ground strikes. "We call it megaflash lightning, and we're just now figuring out the mechanics of how and why it occurs. It is likely that even greater extremes still exist, and that we will be able to observe them as additional high-quality lightning measurements accumulate over time," said geographical scientist Randy Cerveny of Arizona State University and the World Meteorological Organisation. The WMO has established a new world record for the longest lightning flash – an incredible 829 km (515 miles) in a notorious storm hotspot in the United States of America. Details: — World Meteorological Organization (@WMO) July 31, 2025 A megaflash that occurred on April 29, 2020, previously held the record for the longest horizontal distance, covering 768 kilometres across Texas, Louisiana, and Mississippi. "This new record clearly demonstrates the incredible power of the natural environment. Additionally, WMO assessment of environmental extremes such as this lightning distance record testifies to the significant scientific progress in observing, documenting, and evaluating such events. It is likely that even greater extremes still exist, and that we will be able to observe them as additional high-quality lightning measurements accumulate over time," Professor Randall Cerveny, rapporteur of the WMO's Committee on Weather and Climate Extremes, said in a statement. How does lightning occur? Lightning is a spectacular natural phenomenon that occurs when atmospheric turbulence causes particles to collide and generate electrical charge. As the charge builds up, it eventually discharges in a massive burst of electricity, producing millions of volts across the sky. While most lightning bolts are short, typically less than 10 miles long and often striking vertically, some can travel horizontally through clouds, resulting in enormous bolts. When a lightning bolt exceeds 100 kilometres in length, it's classified as a megaflash, a rare and extraordinary event. Tracking a megaflash requires meticulous analysis, combining satellite and ground-based data to recreate the event's extent in 3D. However, due to clouds often obscuring part of the strike, these enormous lightning events can easily go undetected, making their measurement even more challenging.
Time of India
29-07-2025
- Health
- Time of India
Could a baby be born in space? Scientist explains the possibility and risks of space birth
As human space travel moves closer to long-duration missions to Mars and beyond, an intriguing and complex question emerges: could a baby be conceived, carried, and delivered in space? While it may sound like science fiction, researchers are beginning to seriously investigate what pregnancy and birth would look like in the extreme environment of outer space. According to Science Alert, the biological and technological hurdles are enormous—from the effects of microgravity on fetal development to the invisible threat of cosmic radiation. Arun Vivian Holden, emeritus professor of computational biology at the University of Leeds, explains that while space birth is theoretically possible, nearly every stage of reproduction would be impacted in unpredictable ways. Birth in space: pregnancy and childbirth challenges in microgravity In space, microgravity affects the body in countless ways, and pregnancy is no exception. While conception might still be physically possible, carrying a pregnancy in zero gravity introduces major complications. Although an embryo floating in the amniotic sac may resemble a microgravity environment, the absence of gravity during childbirth poses logistical challenges. Fluids, the baby, and even medical tools don't stay in place, making delivery much more difficult than on Earth. Additionally, caring for a newborn—feeding, cleaning, and simply holding—would be far more complex without the stabilizing effect of gravity. Space birth and the danger of cosmic radiation Space birth faces an even more critical hazard: cosmic radiation. Outside Earth's protective atmosphere and magnetic field, high-energy particles travel through space at nearly the speed of light. These cosmic rays can damage human DNA, destroy cellular structures, and increase the risk of cancer and miscarriage. During the earliest stages of pregnancy, when cells are rapidly dividing and forming key organs, a direct hit from a cosmic ray could cause fatal developmental errors. Though such hits are rare, their consequences could be severe. As the fetus grows larger, the risk increases. A more developed fetus and uterine environment offer a bigger target for radiation, which could trigger preterm labor or developmental abnormalities. Without advanced shielding, space remains an inherently dangerous environment for gestation. Once a baby is born in space, the challenges continue. Microgravity may interfere with the infant's physical development, including posture, balance, and coordination. These early milestones depend on gravity cues, and their absence could lead to delayed or altered motor skills. At the same time, a newborn's brain continues to grow rapidly after birth, leaving it vulnerable to radiation damage. This could affect cognition, learning ability, and long-term health. Although the idea of space birth is gaining traction, scientists emphasize that we are far from prepared. Before attempting reproduction in orbit or on another planet, humanity must solve the complex issues of radiation protection, fetal viability, and early development in weightless environments. Until then, space pregnancy remains a frontier of science best explored with caution, simulation, and ethical scrutiny—not premature real-world trials.
