\u201cUnstable solutions in physics and science are considered not physical,\u201d Blake Temple, the study\u2019s co-author and a mathematician at University of California, Davis (UC Davis), said in a statement<\/a>. \u201cYou\u2019ll never observe them in nature.\u201d<\/p>\n Temple and the UC Davis team instead explore an alternative model of expansion that is reportedly simpler and \u201cbased entirely within the framework of Einstein\u2019s original theory\u201d of general relativity.<\/p>\n Some cosmic lore When Albert Einstein first introduced the cosmological constant lambda (\u039b), he did so with the assumption that the universe was static, an idea he later discarded when Edwin Hubble showed that it was actually expanding. Then in 1998, a Nobel-winning discovery found<\/a> that the universe\u2019s expansion rate was accelerating.<\/p>\n It was around this time that cosmologists revived lambda as a metric to characterize the universe\u2019s accelerated expansion. Hence, the standard cosmological model came to be known as the lambda-cold dark matter model<\/a>. The force driving this accelerated expansion was dubbed dark energy and is often associated<\/a> with the cosmological constant.<\/p>\n The math is not mathing <\/p>\n A key component of the standard model is Friedmann spacetimes, which \u201cdescribe a uniform three-dimensional universe of galaxies\u201d that expand at a rate \u201cdetermined by Einstein\u2019s field equations,\u201d according to the paper. But for the team, the math \u201cdidn\u2019t add up.\u201d<\/p>\n \u201cOur first idea was that maybe the universe was expanding because there was a shockwave, and the anomalous acceleration was the expanding wave behind that shockwave,\u201d Temple said.<\/p>\n Specifically, the team explored whether Friedmann spacetimes generated by the Big Bang\u2019s instability could by themselves \u201caccount for the anomalous acceleration of the galaxies,\u201d the authors noted in the study. They derived a self-similar version of Einstein\u2019s field equation to evaluate the stability of Friedmann spacetimes during the \u201cradiation epoch of the Big Bang,\u201d Temple explained.<\/p>\n Steady or not <\/p>\n According to the team\u2019s framework, Friedmann spacetimes were unstable both at small and large length scales at the Big Bang. What this means is that, even before dark energy comes anywhere near the equations, the \u201cset of possible accelerations induced by the instability is rich enough to mimic the effects of dark energy at all orders, even consistent with a variable acceleration,\u201d the paper noted.<\/p>\n That is, there\u2019s a way to do the math to derive acceleration directly from the initial frameworks set forth by Einstein and Leonhard Euler. It\u2019s too early to tell whether cosmologists will choose to adopt this alternative, but it\u2019s an intriguing idea nonetheless.<\/p>\n","protected":false},"excerpt":{"rendered":"Dark energy has been a mysterious element of cosmological equation since it was proposed three decades ago, but…\n","protected":false},"author":2,"featured_media":999943,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_share_on_mastodon":"0"},"categories":[3845],"tags":[23755,9828,46122,74,70,5638,16,15],"class_list":["post-999942","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-albert-einstein","tag-cosmology","tag-general-relativity","tag-physics","tag-science","tag-the-universe","tag-uk","tag-united-kingdom"],"share_on_mastodon":{"url":"","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/999942","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/comments?post=999942"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/999942\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/999943"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=999942"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=999942"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=999942"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}![\"Albert](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2026\/06\/Albert-Einstein-1921-by-F-Schmutzer-portrait.jpg\")
Credit: Ferdinand Schmutzer\/Historiches Museum Bern <\/p>\n![\"Universe](\"https:\/\/www.europesays.com\/uk\/wp-content\/uploads\/2026\/06\/universe-timeline-1280x877.jpg\")
The evolution of the universe, according to \u039bCDM. Credit: NASA\/LAMBDA Archive\/WMAP Science Team <\/p>\n