The world, it seems, is soon to see the first picture of a black hole. On Wednesday, astronomers across the globe will hold “six major press conferences” simultaneously to announce the first results of the Event Horizon Telescope (EHT), which was designed precisely for that purpose. It has been a long wait. Of all the forces or objects in the Universe that we cannot see — including dark energy and dark matter — none has frustrated human curiosity so much as the invisible maws that shred and swallow stars like so many specks of dust. Astronomers began speculating about these omnivorous “dark stars” in the 1700s, and since then indirect evidence has slowly accumulated. “More than 50 years ago, scientists saw that there was something very bright at the centre of our galaxy,” Paul McNamara, an astrophysicist at the European Space Agency and an expert on black holes, told AFP. “It has a gravitational pull strong enough to make stars orbit around it very quickly — as fast as 20 years.” To put that in perspective, our Solar System takes about 230 million years to circle the centre of the Milky Way. Eventually, astronomers speculated that these bright spots were in fact “black holes” — a term coined by American physicist John Archibald Wheeler in the mid-1960s — surrounded by a swirling band of white-hot gas and plasma. At the inner edge of these luminous accretion disks, things abruptly go dark. “The event horizon” — a.k.a. the point-of-no-return — “is not a physical barrier, you couldn’t stand on it,” McNamara explained. “If you’re on the inside of it, you can’t escape because you would need infinite energy. And if you are on the other side, you can — in principle.” – A golf ball on the moon – At its centre, the mass of a black hole is compressed into a single, zero-dimensional point. The distance between this so-called “singularity” and the event horizon is the radius, or half the width, of a black hole. The EHT that collected the data for the first-ever image is unlike any ever devised. “Instead of constructing a giant telescope — which would collapse under its own weight — we combined several observatories as if they were fragments of a giant mirror,” Michael Bremer, an astronomer at the Institute for Millimetric Radio Astronomy in Grenoble, told AFP. In April 2017, eight such radio telescopes scattered across the globe — in Hawaii, Arizona, Spain, Mexico, Chile, and the South Pole — were trained on two black holes in very different corners of the Universe to collect data. Studies that could be unveiled next week are likely to zoom in on one or the other. Oddsmakers favour Sagittarius A*, the black hole at the centre of our own elliptical galaxy that first caught the eye of astronomers. Sag A* has four million times the mass of our sun, which means that the black hole is generates is about 44 million kilometres across. That may sound like a big target, but for the telescope array on Earth some 26,000 light-years (or 245 trillion kilometres) away, it’s like trying to photograph a golf ball on the Moon. – Testing Einstein – The other candidate is a monster black hole — 1,500 times more massive even than Sag A* — in an elliptical galaxy known as M87. It’s also a lot farther from Earth, but distance and size balance out, making it roughly as easy (or difficult) to pinpoint. One reason this dark horse might be the one revealed next week is light smog within the Milky Way. “We are sitting in the plain of our galaxy — you have to look through all the stars and dust to get to the centre,” said McNamara. The data collected by the far-flung telescope array still had to be collected and collated. “The imaging algorithms we developed fill the gaps of data we are missing in order to reconstruct a picture of a black hole,” the team said on their website. Astrophysicists not involved in the project, including McNamara, are eagerly — perhaps anxiously — waiting to see if the findings challenge Einstein’s theory of general relativity, which has never been tested on this scale. Breakthrough observations in 2015 that earned the scientists involved a Nobel Prize used gravitational wave detectors to track two black holes smashing together. As they merged, ripples in the curvatures of time-space creating a unique, and detectable, signature. “Einstein’s theory of general relativity says that this is exactly what should happen,” said McNamara. But those were tiny black holes — only 60 times more massive than the Sun — compared to either of the ones under the gaze of the EHT. “Maybe the ones that are millions of times more massive are different — we just don’t know yet.” Source: AFP AH

Scientists have found an extraordinary snapshot of the fallout from the asteroid impact that wiped out the dinosaurs 66 million years ago. Excavations in North Dakota reveal fossils of fish and trees that were sprayed with rocky, glassy fragments that fell from the sky. The deposits show evidence also of having been swamped with water - the consequence of the colossal sea surge that was generated by the impact. The detail is reported in PNAS journal. Robert DePalma, from the University of Kansas, and colleagues say the dig site, at a place called Tanis, gives an amazing glimpse into events that probably occurred perhaps only tens of minutes to a couple of hours after the giant asteroid hit the Earth. When this 12km-wide object slammed into what is now the Gulf of Mexico, it would have hurled billions of tonnes of molten and vaporized rock into the sky in all directions - and across thousands of kilometers. And at Tanis, the fossils record the moment this bead-sized material fell back down and strafed everything in its path. Fish are found with the impact-induced debris embedded in their gills. They would have breathed in the fragments that filled the water around them. There are also particles caught in amber, which is the preserved remnant of tree resin. It is even possible to discern the wake left by these tiny, glassy tektites, to use the technical term, as they entered the resin. Geochemists have managed to link the fallout material directly to the so-called Chicxulub impact site in the Gulf. They have also dated the debris to 65.76 million years ago, which is in very good agreement with the timing for the event worked out from evidence at other sites around the world. From the way the Tanis deposits are arranged, the scientists can see that the area was hit by a massive surge of water. Although the impact is understood to have generated a huge tsunami, it would have taken many hours for this wave to travel the 3,000km from the Gulf to North Dakota, despite the likely presence back then of a seaway cutting directly across the American landmass. Instead, the researchers believe local water could have been displaced much more quickly by the seismic shockwave - equivalent to a Magnitude 10 or 11 earthquake - that would have rippled around the Earth. It is a type of surge described as a seiche, which would have picked up everything in its path and dumped it into the jumbled collection of specimens now being reported by the team. "A tangled mass of freshwater fish, terrestrial vertebrates, trees, branches, logs, marine ammonites and other marine creatures was all packed into this layer by the inland-directed surge," said Mr DePalma. "A tsunami would have taken at least 17 or more hours to reach the site from the crater, but seismic waves - and a subsequent surge - would have reached it in tens of minutes," he added. The PNAS paper, which will go online on Monday, includes among its authors Walter Alvarez, the Californian geologist who, with his father Luis Alvarez, is credited with helping to develop the impact theory for the demise of the dinosaurs. The Alvarez pair identified a layer of sediment at the boundary of the Cretaceous and Palaeogene geological periods that was enriched with iridium, an element commonly found in asteroids and meteorites. Iridium traces are also found to be capping the Tanis deposits. "When we proposed the impact hypothesis to explain the great extinction, it was based just on finding an anomalous concentration of iridium - the fingerprint of an asteroid or comet," said Prof Alvarez. "Since then, the evidence has gradually built up. But it never crossed my mind that we would find a deathbed like this." Phil Manning, from the University of Manchester, the only British author on the paper, commented: "It's one of the most important sites in the globe now. You know, if you truly wanted to understand the last day of the dinosaurs - this is it," he told BBC News. Source: BBC AH

One out of four people interviewed in eastern Congo last year believed Ebola wasn't real, according to a new study released Wednesday, underscoring the enormous challenges health care workers are now facing. The survey found that a deep mistrust of the Ebola response resulted in those people being 15 times less likely to seek medical treatment at an Ebola health center, according to the study published in The Lancet Infectious Diseases journal. The study was based on interviews conducted last September, about a month after the outbreak began. It comes as the number of probable and confirmed cases has exceeded 1,000. At least 639 people have died from Ebola since August in what is now the second deadliest outbreak in history, according to the World Health Organization. The outbreak's response has been hampered by a series of deadly attacks on Ebola health centers since the study was completed. As a result, Doctors Without Borders has stopped staffing two health centers at the outbreak's epicenter after violent attacks. Researchers said their study published Wednesday showed more precisely how individual people's misinformed views about Ebola were undermining the response and helping to spread the deadly virus. "It really helps us understand how central and fundamental community trust should be as part of the response," said Patrick Vinck of Harvard University, who led the research. Eva Erlach, the community engagement and accountability delegate for the International Federation of Red Cross and Red Crescent Societies, called the findings "absolutely interesting" and said they show how the level of trust correlates with preventative behaviors. The organization has had more than 800 trained volunteers working to get out prevention messages amid the region's security challenges. "There is still a part of the community who do not believe that Ebola is real and we definitely still need to continue focusing on community engagement," said Erlach, who was not part of the study. "And this is why this report is so helpful even if it's from September." WHO Director-General Tedros Adhanom Ghebreyesus said earlier this month he was encouraged "to see the communities accepting the response more and more." Wednesday's study highlights just how pervasive misinformation has been in places in eastern Congo like Beni and Butembo, where in-person interviews were conducted with 961 people. Some 25.5 percent of those interviewed did not believe Ebola was real. In addition, nearly 45.9 percent of people thought the Ebola outbreak was being fabricated to destabilize the region or for financial gain. Additionally 18.2 percent believed all three of those statements, the study found. Those who didn't believe Ebola was real were far less likely to agree to agree to the Ebola vaccine or to go to a treatment center. Ebola is spread through the bodily fluids of the sick, and isolation of those infected is key to stopping transmission. This outbreak has been uniquely challenging because of the volatile security situation in the region. Eastern Congo is home to numerous armed groups and the Ebola epidemic has deepened the political and economic grievances of many in the area. The fact that people in Ebola affected areas were excluded from the December presidential election has only heightened conspiracy theories. Tariq Riebl, of the International Rescue Committee, who is currently working in eastern Congo, said the findings released Wednesday mirror what he and his colleagues are seeing on the ground. Concern remains about how Ebola prevention efforts are going because new cases are still emerging. "Once you reach a wider outbreak zone, especially urban zones, the community engagement and prevention side of things is almost more important than the treatment side," Riebl said. "If you can't have those messages out successfully, it doesn't matter if you have all the treatment options available because no one is ever arriving to take advantage of that," he said. Source: AP AH

Cities are all but shutting down across the US Midwest as the region shivers through a record-breaking and deadly cold snap known as a "polar vortex". At least six people are reported to have been killed across several states as a result of the arctic weather, reports BBC. Temperatures have dropped as low as -30C (-22F) in Chicago and -37C in North Dakota. Freezing weather will chill 250 million Americans, and 90 million will experience -17C (0F) or colder temperatures. Twenty million people in the continental US will experience temperatures of -28C or lower by the week's end. Snow is expected to fall throughout Wednesday, from the Great Lakes region into New England. As much as 24in (60cm) is forecast in the state of Wisconsin, and 6in in Illinois. States of emergency have been declared in Midwestern Wisconsin, Michigan and Illinois, and even in the Deep South states of Alabama and Mississippi. "This could possibly be history-making," said Ricky Castro, a National Weather Service meteorologist in Illinois. Multiple deaths have been confirmed across the Midwest, including a man killed by a snow plough in Chicago and another found frozen to death in a Milwaukee garage. An 82-year-old man died from hypothermia outside his home in Pekin, Illinois, NBC News reported. Roads made dangerous by ice and snow have also caused fatal accidents - a young couple died after a collision on snowy roads in northern Indiana. Hundreds of schools have been closed in the affected states. At least 1,300 flights were grounded early on Wednesday, mainly out of Chicago O'Hare and Chicago Midway international airports, said FlightAware.com. Amtrak, the US inter-city train operator, has cancelled all rail services to and from Chicago on Wednesday. The US Postal Service has called a halt to mail deliveries in parts of 10 states in the Great Plains and Midwest. With wind chill, Chicago will feel more like -45C. Grand Forks, North Dakota, has so far seen the lowest wind chill at -54C on Wednesday morning. Even beer deliveries in Wisconsin have been hit by the cold, as brewers delay shipments over fears their beverages will freeze in the trucks. The National Weather Service is warning that frostbite is possible within just 10 minutes of being outside in such extreme temperatures. Residents of the city of Chicago in Illinois, long used to freezing winters, have been warned to expect an unusually deep and dangerous period of cold. Chicago mayor Rahm Emanuel has urged people not to venture outdoors if possible. Dozens of "warming centres" for the estimated 80,000 rough sleepers there, including buses. But at least one homeless Chicago man said he preferred to take his chances with the deadly weather, rather than go into a shelter. Tony Neeley told the New York Times: "A lot of us don't go to the shelters because of bedbugs. We don't go because people steal from you. "We don't go because you can't even really sleep in the shelter." Chicago landmarks including the Lincoln Park Zoo, Field Museum and Art Institute are closed. Those braving the cold on Wednesday will also be hard pressed to find a warming cup of coffee - La Colombe has shut all five of its Chicago cafes, as have other local shops. Delivery pizza - a traditional bad-weather food in the US - has also been affected. Chicago's famous deep dish pizza chain Lou Malnatis and other regional restaurants are closing early on Tuesday and Wednesday. Chicago police say people are being robbed at gunpoint of their coats, especially those wearing Canada Goose jackets, which can cost as much as £900 ($1,100). Weather officials in the state of Iowa have warned people to "avoid taking deep breaths, and to minimise talking" if they go outside. Animal rights organisation Peta has warned people to bring animals indoors. Farmers across the Midwest have been taking measures to protect their livestock, including building igloos for chickens. In North Dakota, cattle ranchers Joey Myers and Scott Bailey told Reuters news agency they planned on staying up with their animals during the cold snap to prevent fatalities. Frigid weather could cause pregnant cows to deliver ahead of schedule, the farmers said, and newborn calves cannot survive such conditions. Meanwhile, police in McLean, Illinois, some 150 miles (240km) from Chicago, had some fun with the freeze, announcing that Elsa, from Disney movie Frozen, had been arrested over the extreme cold. The bitterly cold conditions are the result of a spinning pool of cold air known as the polar vortex. It normally circles the stratosphere over the North Pole, but its current has been disrupted and it is now moving south into the US. Forecasters are attributing this to a sudden warming above the North Pole, caused by a blast of hot air from Morocco last month. This weather system split the polar vortex and caused it to drift south, Judah Cohen, a winter storm expert for Atmospheric Environmental Research, told AP news agency. President Donald Trump, who has questioned whether humans are responsible for climate change, tweeted about the conditions. "What the hell is going on with Global Waming [sic]?" he said. "Please come back fast, we need you!" But one of the US government's own meteorological agencies, the National Oceanic and Atmospheric Administration, posted what was widely interpreted as a rebuttal to the president. But one of the US government's own meteorological agencies, the National Oceanic and Atmospheric Administration, posted what was widely interpreted as a rebuttal to the president. The world's leading scientists have said that climate change is primarily human-induced and can lead to harsher winters. MHK

Met Office researchers expect to record one of the biggest rises in atmospheric concentrations of CO2 in 2019. Every year, the Earth's natural carbon sinks such as forests soak up large amounts of CO2 produced by human activities. But in years when the tropical Pacific region is warmer like this year, trees and plants grow less and absorb smaller amounts of the gas. As a result, scientists say 2019 will see a much bigger CO2 rise than 2018. Since 1958, the research observatory at Mauna Loa in Hawaii, has been continuously monitoring and collecting data on the chemical composition of the atmosphere. In the years since they first started recording, the observatory has seen a 30% increase in the concentration of CO2 in the atmosphere caused by emissions of fossil fuels and deforestation. Scientists argue that the increase would have been even larger without the ability of the forests, land and seas to soak up around half of the gas emitted by human activities. This ability however, varies with the seasons. In the summer, CO2 levels in the atmosphere fall as the trees and plants soak up more of the carbon as they grow. In the winter, when they drop their leaves, they soak up less and atmospheric levels rise. But when temperatures are warmer and drier than normal, trees and plants grow less and absorb less. This natural variation is compounded in years when there's an El Niño event, which sees an upwelling of heat from the Pacific into the atmosphere. "The warm sea surface conditions now will continue over the next few months and that will lead into the vegetation response," said Dr Chris Jones from the Met Office. "Around the world this heat has different impacts, in some places it's hotter and drier and you get more forest fires, in a tropical rainforest for instance you reduce the natural growth of the vegetation." According to the Met Office, these limits on the ability to absorb CO2 will see a rise in concentrations this year of 2.75 parts per million, which is higher than the 2018 level. They are forecasting that average CO2 concentrations in 2019 will be 411ppm. Carbon dioxide concentration exceeded 400ppm for the first time in 2013. This year's predicted rise won't be as big as in the El Niño years of 2015-16 and 1997-98. However there have only been increases similar to this year's, about half a dozen times since records began. Researchers say the long-term trend is only going in one direction. "The year-on-year increase of CO2 is getting steadily bigger as it has done throughout the whole of the 20th century," said Dr Jones. "What we are seeing for next year will be one of the biggest on record and it will certainly lead to the highest concentration of CO2." Other researchers say the Met Office findings are worrying. "The increases in CO2 are a function of our continued reliance on fossil fuels," said Dr Anna Jones, from the British Antarctic Survey (BAS). "Some tempering in the rate of increase arise from the Earth's ability to absorb CO2 from the atmosphere, but that can change year-on-year as the Met Office forecast shows." "What's critical, however, is that the persistent rise in atmospheric CO2 is entirely at odds with the ambition to limit global warming to 1.5C. We need to see a reduction in the rate of CO2 emissions, not an increase." The Met Office scientists say that it doesn't always follow that a record CO2 concentration will lead to a record global temperature in 2019, as there are many natural factors that can impact the final figure. The researchers there are pleased that observations over the past four years show that their model is accurate. They believe it can be used in the future to help countries accurately attribute increases in emissions to their actions or to natural factors.   MHK  

A keystone prey species in the Southern Ocean is retreating towards the Antarctic because of climate change. Krill are small, shrimp-like creatures that swarm in vast numbers and form a major part of the diets of whales, penguins, seabirds, seals and fish. Scientists say warming conditions in recent decades have led to the krill contracting poleward. If the shift is maintained, it will have negative ecosystem impacts, they warn. Already there is some evidence that macaroni penguins and fur seals may be finding it harder to get enough of the krill to support their populations. "Our results suggest that over the past 40 years, the amount of krill has, on average, gone down, and also the location of the krill has contracted to much less of the habitat. That suggests all these other animals that eat krill will face much more intense competition with each other for this important food resource," Simeon Hill from the British Antarctic Survey told BBC News. It focuses on the Scotia Sea and the Antarctic Peninsula - the places where the crustaceans are most abundant. Scientists have been gathering data in these areas since the 1920s. Initially, krill catches were recorded to understand the environmental consequences of commercial whaling, but the information has continued to be collected through to the present. Dr Hill and colleagues say the change in the distribution and density of the crustaceans is a clear signal that emerges in the data from the late 1980s onwards. It coincides with a phase change in a climate oscillation known as the Southern Annular Mode. The SAM essentially describes the dominant pattern of pressure zones in the southern hemisphere outside of the tropics. The mode's switch in state in the late 80s produced warmer, cloudier, windier weather, and much less sea-ice in those areas where the krill had tended to congregate. The larval stage of the crustaceans in particular has been strongly associated with the presence of a sea-ice habitat. The team's analysis indicates the centre of krill distribution has now moved to where more favourable conditions are found, tracking southward towards the Antarctic continent by about 440km, or four degrees of latitude. "The average size of krill has lengthened over this period of time as well," said Dr Hill. "And that's because the population has increasingly become dominated by older and larger animals. This is a result of a decline in the number of krill entering the population - what we call juvenile recruitment." Margaret McBride, from the Norwegian Institute of Marine Research in Bergen, has written a comment article on the research in the same edition of Nature Climate Change. She said models had predicted that krill would shift southwards in the future, whereas the new research suggested this contraction was already under way. "It offers a profoundly adverse, but highly plausible, endgame for Antarctic krill that has serious implications for both the Southern Ocean food web and sustainable management of fisheries targeting this species," she wrote. The campaign group WWF-UK said the study showed "the need to protect the waters off the Antarctic Peninsula with an effective network of marine protected areas - placing conservation above fishing interests."   MHK

State Minister for Information and Communication Technology Junaid Ahmed Palak said internet prices will be reduced in this year. He said this in a post on his verified Facebook page on Monday morning. In his status, Palak wrote, “A few days ago, VAT on internet services were reduced to 5% from 15%. VAT reduction on ITC, IIG and NTTN by 5% will reduce the cost of internet services.” Thanking Prime Minister Sheikh Hasina, Palak also wrote, "Thank you, honorable Prime Minister Sheikh Hasina, thanks to Mr. Sajeeb Wajed Joy, honorable advisor, architect of Digital Bangladesh, for utilising the power of youth, another step towards building a prosperous Bangladesh.” MHK