The universe is expanding at an accelerating rate. This is a generally accepted scientific understanding, the discovery of which yielded a Nobel prize in 2011. But what exactly is the speed of that expansion? 
 
 According to new research, soon to be published in the Astrophysical Journal, the rate of expansion, or the Hubble constant, is about 73.24 kilometers per second per megaparsec (a unit equivalent to 3.26 million light-years): somewhere between five and nine percent faster than we thought. 
 
 A multitude of reasons has been put forth for this discrepancy, including the possibility that these new calculations are inaccurate. But if they continue to withstand scrutiny, they could challenge some of the basic precepts surrounding the functioning of our universe. 
 
 "If you really believe our number – and we have shed blood, sweat and tears to get our measurement right and to accurately understand the uncertainties – then it leads to the conclusion that there is a problem with predictions based on measurements of the cosmic microwave background radiation, the leftover glow from the Big Bang," co-author Alex Filippenko, an astronomy professor at the University of California, Berkeley, said in a press release. 
 
 "Maybe the universe is tricking us, or our understanding of the universe isn't complete," he added. 
 
 If the science is correct, then one possible explanation has to do with the mere 95 percent of the universe constituted of mysterious elements that do not emit light, such as dark matter, dark energy, and dark radiation. 
 
 Dark energy, thought to be responsible for the acceleration of our expanding universe, could be pushing galaxies apart with even greater vigor than scientists believed. Or dark matter, the "backbone of the universe," in NASA's words, could have some as-yet undiscovered oddities. 
 
 And then there's dark radiation: subatomic particles that travel at velocities approaching the speed of light. Maybe one such particle exists, or existed, that is unknown to science, perhaps the much-hypothesized "fourth flavor of neutrino." 
 
 Aside from all that darkness, there is another possible explanation: Einstein's theory of relativity could be inaccurate. 
 
 "You start at two ends, and you expect to meet in the middle if all of your drawings are right and your measurements are right," study leader and Nobel Laureate Adam Riess, an astrophysicist at Johns Hopkins University and the Space Telescope Science Institute, said in a NASA press release. "But now the ends are not quite meeting in the middle and we want to know why." 
 
 The new numbers are based upon the team's efforts to acquire a more precise understanding of the universe's current expansion rate. Using data from the Hubble Space Telescope and Hawaii's Keck I telescope, they refined that to an uncertainty of only 2.4 percent. 
 
 The new data were gleaned by analyzing two types of star: Cepheids and Type la supernovae. Cepheid stars allow astronomers to determine how far they are from us, and thereby how distant their galaxy is, by analyzing two characteristics: their true brightness, gleaned from the rate at which they pulsate, versus their apparent brightness as seen from Earth. Type la supernovae, a kind of exploding star, can be detected even further away. 
 
 The researchers measured about 2,400 Cepheid stars occupying 19 nearby galaxies, compared the apparent brightness of both types of star, and were able to determine the true brightness of the Type la supernovae. 
 
 Armed with this information, they could calculate the distance to some 300 Type la supernovae in distant galaxies. 
 
 "We've done the world's best job of decreasing the uncertainty in the measured rate of universal expansion and of accurately assessing the size of this uncertainty," Dr. Filippenko said in the Berkeley release, "yet we find that our measured rate of expansion is probably incompatible with the rate expected from observations of the young universe, suggesting that there's something important missing in our physical understanding of the universe." 
 
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 Some scientists uninvolved with this study urge caution, including NASA astrophysicist John Mather, Princeton astrophysicist David Spergel, and California Institute of Technology physicist Sean Carroll, who said that the most likely explanation is a mistake in the most recent calculations. 
 
 "It's far too early to jump up and down to say the universe is messing with us," Dr. Carroll told The Washington Post, but he conceded that the research was carried out by scientists both solid and careful. ||||| Measurements taken by Hubble space telescope conflict with studies of radiation left over from Big Bang – fuelling theories of ‘dark energy’ and mystery particles 
 
 The universe is expanding faster than anyone had previously measured or calculated from theory. This is a discovery that could test part of Albert Einstein’s theory of relativity, a pillar of cosmology that has withstood challenges for a century. 
 
 Nasa and the European Space Agency jointly announced the universe is expanding 5% to 9% faster than predicted, a finding they reached after using the Hubble space telescope to measure the distance to stars in 19 galaxies beyond theMilky Way. 
 
 The rate of expansion did not match predictions based on measurements of radiation left over from the Big Bang that gave rise to the known universe 13.8bn years ago. 
 
 Milky weigh: our galaxy has the mass of 700bn suns, say scientists Read more 
 
 Physicist and lead author Adam Riess said: “You start at two ends, and you expect to meet in the middle if all of your drawings are right and your measurements are right. 
 
 “But now the ends are not quite meeting in the middle and we want to know why.” 
 
 The researchers arrived at a new expansion rate of 73.2 kilometres per second per megaparsec. A megaparsec is 3.26 million light years. The consequence of this adjustment in difficult-to-imagine speeds over unthinkable distances is that the distance between cosmic objects will double in another 9.8 billion years. The catch is that such speeds do not match predictions for an expansion rate from other observations made by Nasa’s Wilkinson microwave anisotropy Probe, or the European Space Agency’s Planck satellite. Both went into orbit to study the afterglow of the Big Bang, in which time, space and matter were created. And both delivered lower – and in each case slightly different – predictions for cosmic expansion, the first 5% and the second 9% lower. 
 
 The latest discovery also stirs hypotheses about what fills the 95% of the cosmos that emits no light and no radiation, scientists said on Thursday. 
 
 One possibility for the discrepancy is that the universe has unknown subatomic particles, similar to neutrinos, that travel nearly as fast as the speed of light, about 186,000 miles (300,000km) per second. 
 
 Facebook Twitter Pinterest From left: Hubble is used to measure the distances to stars called Cepheid variables. Their brightness means they can be used as cosmic yardsticks to measure distances to galaxies. Astronomers then look for galaxies that contain Cepheids (centre) and Type Ia supernovae, and determine their distance. They then look for supernovae in more remote galaxies. The brightness of distant supernovae are compared to measure out to the distance where the expansion of the universe can be seen (right). Those measurements are compared with how light from the supernovae is stretched by the expansion of space. Illustration: A. Riess (STScI/JHU) and A. Feild (STScI)/NASA/ESA 
 
 Another idea is that so-called “dark energy”, a mysterious, anti-gravity force discovered in 1998, may be shoving galaxies away from one another more powerfully than originally estimated. 
 
 “This may be an important clue to understanding those parts of the universe that make up 95% of everything and that don’t emit light, such as dark energy, dark matter and dark radiation,” said Riess, with the Space Telescope Science Institute in Baltimore, Maryland. 
 
 Riess shared the 2011 Nobel prize in physics for the discovery that the expansion of the universe was speeding up. 
 
 The speedier universe also raises the possibility that Einstein’s general theory of relativity, which serves as the mathematical scaffolding for calculating how the basic building blocks of matter interact, is slightly wrong, or at least incomplete. 
 
 “We know so little about the dark parts of the universe, it’s important to measure how they push and pull on space over cosmic history”, said one of the team, Lucas Macri of Texas A&M University. 
 
 Such research has a long history of revision and updates. Einstein’s original calculations for general relativity seemed to predict that the universe was expanding and – in what he is supposed to have described later as his greatest blunder – he confected a cosmological constant to correct what he thought was an error. In 1923, the great American astronomer Edwin Hubble stared through what was then the world’s biggest telescope at what he thought was a nebula - cloud of dust – in the night sky and realised that he was observing another distant star system: the island universe of the Andromeda galaxy. And within two years he had observed the light signature of a receding galaxies, and proposed that everywhere in the universe, galaxies were rushing away each other, the farthest away at a greater rate. 
 
 But all astronomical observations depend on being able to calculate distances, and from that make ever more precise estimates of galactic recession. When the Hubble space telescope was first launched in 1990, estimates of the rate of cosmic expansion varied by a factor of two. Continuous observations seemed to narrow the range to ever more precise estimates. 
 
 Until 1998, astronomers thought they had got the big picture. The universe was expanding at a steady rate, but it might still be possible that expansion could halt, or even that the universe could contract. A team of astronomers staring at a class of stars called type 1a supernovae across enormous distances realised that the furthest were not just receding at the predicted rate: they were accelerating as if being driven by a mysterious force briefly dubbed “antigravity”. 
 
 It was the first hint of what, for want of a better term, is called dark energy: a so-far inexplicable force that is likely to keep the universe expanding forever. And it was at that point that cosmologists began to realise that all the gas, dust, planets, stars, galaxies and black holes they could account for added up to only about 4% of the universe. 
 
 Stunning Hubble Bubble Nebula image marks telescope's 26th birthday Read more 
 
 It also raised the possibility that, an unimaginable number of years from now, all the other galaxies will have receded over some cosmic horizon, leaving the Milky Way alone in the visible universe, and with no distant objects to provide any evidence at all of accelerating cosmic expansion. 
 
 The latest advance on the speed of universal expansion builds on all these elements in a century of cosmological discovery. Riess and colleagues made their discovery by building a better cosmic yardstick to calculate distances. They used the Hubble Space Telescope to measure a particular type of star, known as Cepheid variables – the stars that gave Edwin Hubble and and his colleagues the first hint of an expanding universe - in 19 galaxies beyond our own Milky Way galaxy. 
 
 How fast these stars pulse is directly related to how bright they are, which in turn can be used to calculate their distances, much like a 100-watt light bulb appears dimmer the farther away it is. They also used the type 1a supernovae as “standard candles” and it had been this class of objects that had illuminated not just another advance in speed but speculation about dark energy. 
 
 The research will be published in an upcoming edition of the Astrophysical Journal. ||||| Astronomers using NASA's Hubble Space Telescope have discovered that the universe is expanding 5 percent to 9 percent faster than expected. 
 
 "This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything and don't emit light, such as dark energy, dark matter, and dark radiation," said study leader and Nobel Laureate Adam Riess of the Space Telescope Science Institute and The Johns Hopkins University, both in Baltimore, Maryland. 
 
 The results will appear in an upcoming issue of The Astrophysical Journal. 
 
 Riess' team made the discovery by refining the universe's current expansion rate to unprecedented accuracy, reducing the uncertainty to only 2.4 percent. The team made the refinements by developing innovative techniques that improved the precision of distance measurements to faraway galaxies. 
 
 The team looked for galaxies containing both Cepheid stars and Type Ia supernovae. Cepheid stars pulsate at rates that correspond to their true brightness, which can be compared with their apparent brightness as seen from Earth to accurately determine their distance. Type Ia supernovae, another commonly used cosmic yardstick, are exploding stars that flare with the same brightness and are brilliant enough to be seen from relatively longer distances. 
 
 By measuring about 2,400 Cepheid stars in 19 galaxies and comparing the observed brightness of both types of stars, the accurately measured their true brightness and calculated distances to roughly 300 Type Ia supernovae in far-flung galaxies. 
 
 The team compared those distances with the expansion of space as measured by the stretching of light from receding galaxies. They used these two values to calculate how fast the universe expands with time, or the Hubble constant. 
 
 The improved Hubble constant value is 73.2 kilometers per second per megaparsec. (A megaparsec equals 3.26 million light-years.) The new value means the distance between cosmic objects will double in another 9.8 billion years. 
 
 This refined calibration presents a puzzle, however, because it does not quite match the expansion rate predicted for the universe from its trajectory seen shortly after the Big Bang. Measurements of the afterglow from the Big Bang by NASA's Wilkinson Microwave Anisotropy Probe (WMAP) and the European Space Agency's Planck satellite mission yield predictions which are 5 percent and 9 percent smaller for the Hubble constant, respectively. 
 
 "If we know the initial amounts of stuff in the universe, such as dark energy and dark matter, and we have the physics correct, then you can go from a measurement at the time shortly after the big bang and use that understanding to predict how fast the universe should be expanding today," said Riess. "However, if this discrepancy holds up, it appears we may not have the right understanding, and it changes how big the Hubble constant should be today." 
 
 Comparing the universe's expansion rate with WMAP, Planck, and Hubble is like building a bridge, Riess explained. On the distant shore are the cosmic microwave background observations of the early universe. On the nearby shore are the measurements made by Riess' team using Hubble. 
 
 "You start at two ends, and you expect to meet in the middle if all of your drawings are right and your measurements are right," Riess said. "But now the ends are not quite meeting in the middle and we want to know why." 
 
 There are a few possible explanations for the universe's excessive speed. One possibility is that dark energy, already known to be accelerating the universe, may be shoving galaxies away from each other with even greater -- or growing -- strength. 
 
 Another idea is that the cosmos contained a new subatomic particle in its early history that traveled close to the speed of light. Such speedy particles are collectively referred to as "dark radiation" and include previously known particles like neutrinos. More energy from additional dark radiation could be throwing off the best efforts to predict today's expansion rate from its post-big bang trajectory. 
 
 The boost in acceleration could also mean that dark matter possesses some weird, unexpected characteristics. Dark matter is the backbone of the universe upon which galaxies built themselves up into the large-scale structures seen today. 
 
 And finally, the speedier universe may be telling astronomers that Einstein's theory of gravity is incomplete. 
 
 "We know so little about the dark parts of the universe, it's important to measure how they push and pull on space over cosmic history," said Lucas Macri of Texas A&M; University in College Station, a key collaborator on the study. 
 
 The Hubble observations were made with Hubble's sharp-eyed Wide Field Camera 3 (WFC3), and were conducted by the Supernova H0 for the Equation of State (SH0ES) team, which works to refine the accuracy of the Hubble constant to a precision that allows for a better understanding of the universe's behavior. 
 
 The SH0ES Team is still using Hubble to reduce the uncertainty in the Hubble constant even more, with a goal to reach an accuracy of 1 percent. Current telescopes such as the European Space Agency's Gaia satellite, and future telescopes such as the James Webb Space Telescope (JWST), an infrared observatory, and the Wide Field Infrared Space Telescope (WFIRST), also could help astronomers make better measurements of the expansion rate. 
 
 Before Hubble was launched in 1990, the estimates of the Hubble constant varied by a factor of two. In the late 1990s the Hubble Space Telescope Key Project on the Extragalactic Distance Scale refined the value of the Hubble constant to within an error of only 10 percent, accomplishing one of the telescope's key goals. The SH0ES team has reduced the uncertainty in the Hubble constant value by 76 percent since beginning its quest in 2005. 
 
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 The Hubble Space Telescope is a project of international cooperation between NASA and the European Space Agency. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope Science Institute (STScI) in Baltimore, Maryland, conducts Hubble science operations. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C. 
 
 For images and more information about the Hubble Constant finding and Hubble, visit: 
 
 http://hubblesite. org/ news/ 2016/ 17 ||||| BALTIMORE, June 2 (UPI) -- A discrepancy between galactic distances in the infant universe and more modern measurements suggests the universe is expanding at a faster pace than previously predicted. 
 
 Astronomers recently used the Hubble Space Telescope to measure the distance between 19 galaxies with unprecedented accuracy. The numbers suggest the universe is expanding between 5 and 9 percent faster than the rate derived from galactic distances measured in the early universe, just after the Big Bang. 
 
 Researchers believe the discrepancy may offer insights into the nature of dark matter. 
 
 "This surprising finding may be an important clue to understanding those mysterious parts of the universe that make up 95 percent of everything and don't emit light, such as dark energy, dark matter, and dark radiation," Adam Riess, an astronomer with the Space Telescope Science Institute and Johns Hopkins University, said in a news release. 
 
 Dark matter and the dark energy it carries may explain the acceleration of the universe's expansion. 
 
 The most recent calculation of the universe's rate of expansion, called the Hubble constant, is believed to be the most accurate ever -- with a margin of error, or rate of uncertainty, of just 2.4 percent. 
 
 Astronomers expected the new calculations to forge an agreeable link with those derived from observations of the Big Bang afterglow collected by NASA's Wilkinson Microwave Anisotropy Probe and the European Space Agency's Planck satellite. 
 
 "You start at two ends, and you expect to meet in the middle if all of your drawings are right and your measurements are right," Reiss said. "But now the ends are not quite meeting in the middle and we want to know why." 
 
 Astronomers are continuing to go over the data to try to reduce the margin for error even further, but it appears likely researchers will now be faced with the task of explaining the disagreement between the two Hubble constants. ||||| Add this to the list of existential fears that keep you up at night: the universe appears to be expanding faster than we thought. A lot faster. 
 
 
 
 That’s according to new, highly precise measurements of the distance between 19 faraway galaxies acquired by the Hubble Space Telescope. The new numbers indicate that the rate of expansion of our universe (the so-called “Hubble constant”) is approximately 45.5 miles per second per megaparsec. 
 
 In slightly less baffling terms, space is expanding fast enough to essentially double the distance between our galaxy and our nearest neighbors in about 10 billion years. The new Hubble constant is 5 to 9 percent higher than previous estimates. It might not seem like that much, but when it comes to the fate of the entire universe, it constitutes a major discrepancy. 
 
 The discovery, which will be detailed in a forthcoming issue of The Astrophysical Journal, presents a problem for cosmologists, because it does not match estimated expansion rates from the energetic leftovers of the Big Bang. Two missions—NASA’s Wilkinson Microwave Anisotropy Probe and the European Space Agency’s Planck satellite mission—have both yielded smaller Hubble constants by examining the so-called “afterglow” of the mega-explosion that birthed our universe. 
 
 The discrepancy still needs to be independently verified. But if it holds up, it implies that there are underlying physical processes pushing space apart which we haven’t fully accounted for. That’s not too surprising when you consider that some 95 percent of our universe is made up of dark energy, dark matter, and dark radiation, all of which emit no light and are barely understood at all. Alternatively, it could mean that Einstein’s theory of relativity is incomplete—which is also kind of understandable, given that the man single-handedly penned the laws of existence in his twenties without the aid of a computer. 
 
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 Either way, it’s an exciting reminder that the very fabric of reality is being shaped and stretched by forces we can barely comprehend. But one day, those forces will ensure that all of our atoms are dispersed across trillions of light years of vast nothingness. 
 
 [NASA]
– New calculations in the cosmos have revealed a surprise: The universe appears to be expanding faster than anyone thought. Using the Hubble Space Telescope, scientists measured the distance to stars in 19 galaxies and concluded that the universe is growing 5% to 9% quicker than expected, the researchers say in a press release. For the record, they calculate the rate to be 45.5 miles per second per megaparsec, the latter being the equivalent of 3.26 million light-years. It's surprising, UPI reports, because astronomers expected the calculations to jibe with previous ones conducted by NASA and the European Space Agency. If the new rate is confirmed, it could challenge some basic precepts about how the universe functions and challenge at least part of Einstein's theory of relativity, reports the Guardian. "If you really believe our number—and we have shed blood, sweat and tears to get our measurement right and to accurately understand the uncertainties—then it leads to the conclusion that there is a problem with predictions based on measurements of the cosmic microwave background radiation, the leftover glow from the Big Bang," says co-author Alex Filippenko of Berkeley, per the Christian Science Monitor. While 5% to 9% may not seem like a big deal, it constitutes a "major discrepancy" in this particular case, notes Gizmodo. Part of the answer around the discrepancy may lie in the "mysterious parts of the universe that make up 95% of everything and don't emit light, such as dark energy, dark matter, and dark radiation," says another of the project's researchers. Their findings will be published in Astrophysical Journal.