<\/p>\n
Almost a century ago, famous astronomer Edwin Hubble determined that the universe was expanding at an accelerating rate. He discovered that the farther a galaxy is from Earth, the faster it appears to be moving away from us.<\/p>\n
It was an elegant observation that underpins much of today’s cosmology. But determining the exact relationship between the distance of a celestial object and the speed with which it moves away from us remains one of the most important challenges in modern astronomy. Specifically, the exact rate of expansion of the universe, known as the Hubble constant, is a major issue, and attempts to solve it continue to yield widely varying numbers.<\/p>\n
One problem is that when scientists calculate the Hubble constant, should<\/em> Perhaps it doesn’t quite match observations of the real universe. To make matters worse, the various sensitive devices designed to measure it don’t match each other. This problem is so significant that it has its own name: the Hubble tension.<\/p>\n Now, an international team of astronomers say they have made one of the most accurate measurements of the Hubble constant to date, which they say brings them a step closer to addressing this apparent discrepancy and could potentially answer some of the most fundamental questions surrounding the nature of the universe, including its true age.<\/p>\n As detailed in a paper published in the journal astronomy and astrophysics<\/em>the team determined that the specific value of the Hubble constant is about 73.5 kilometers per second (about 3.26 million light-years) per megaparsec. While this may be a step in the right direction, the latest findings also help highlight how hard leading scientists are struggling to resolve the tension. It’s a quagmire that raises the possibility that we have deeply misunderstood something, or that the universe is governed by yet-to-be-discovered physical laws.<\/p>\n “Popular cosmological models predict that the Hubble constant should be 10 percent smaller than what we directly measure,” said lead author Stefano Casertano, a scientist at the Space Telescope Science Institute. Phys.org<\/em>. “This is known as the Hubble tension, and the difference is more than five times the uncertainty in both the model and measurements combined.”<\/p>\n Previous attempts to arrive at an exact value for the Hubble constant have yielded mixed results. To integrate these measurements into one number, the team “developed a statistical framework to properly combine all of these measurements and identify possible discrepancies,” co-author Adam Rees, a scientist at the Space Telescope Science Institute, told the publication.<\/p>\n “This is the most accurate measurement to date and the first to achieve 1 percent accuracy,” Casertano added. “We also found that no single measurement or thread was important for this result; any component could be removed completely and the value of the Hubble constant would remain essentially unchanged.”<\/p>\n Focusing on a more precise value for the Hubble constant is an important step forward, but much work remains.<\/p>\n “Confirming the Hubble tension makes it even more important to reconsider the foundations of current cosmological models and identify new phenomena that could change the evolution of the universe,” Rees said. Phys.org<\/em>.<\/p>\n “This study effectively rules out explanations for the Hubble tension that rely on a single overlooked error in local distance measurements,” the scientists conclude in their paper. “If this tension is real, as growing evidence suggests, it could point to new physics beyond standard cosmological models.”<\/p>\n Learn more about Hubble tension:<\/strong> Our entire galaxy appears to be embedded in a giant sheet of dark matter<\/em><\/p>\n<\/div>\n #Physicists #big #problems #universe<\/p>\n","protected":false},"excerpt":{"rendered":" Almost a century ago, famous astronomer Edwin Hubble determined that the universe was expanding at an accelerating rate. He discovered that the farther a galaxy is from Earth, the faster it appears to be moving away from us. It was an elegant observation that underpins much of today’s cosmology. But determining the exact relationship between … Read more<\/a><\/p>\n","protected":false},"author":1,"featured_media":765,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[],"tags":[1700,1695,1696,1698,1286,1701,1697,1699,789],"class_list":["post-764","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","tag-big","tag-edwin-hubble","tag-hubble-constant","tag-measured-value","tag-physicists","tag-problems","tag-space-telescope-science-institute","tag-stefano-casertano","tag-universe"],"_links":{"self":[{"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/posts\/764","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hyokal.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=764"}],"version-history":[{"count":0,"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/posts\/764\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/hyokal.com\/index.php?rest_route=\/wp\/v2\/media\/765"}],"wp:attachment":[{"href":"https:\/\/hyokal.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=764"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hyokal.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=764"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hyokal.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=764"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}