{"id":398333,"date":"2026-04-26T10:53:10","date_gmt":"2026-04-26T10:53:10","guid":{"rendered":"https:\/\/www.newsbeep.com\/nz\/398333\/"},"modified":"2026-04-26T10:53:10","modified_gmt":"2026-04-26T10:53:10","slug":"largest-3d-map-of-the-universe-is-adding-serious-fuel-to-the-cosmology-crisis","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/nz\/398333\/","title":{"rendered":"Largest 3D Map of the Universe Is Adding Serious Fuel to the Cosmology Crisis"},"content":{"rendered":"

Last week, the Dark Energy Spectroscopy Instrument<\/a> (DESI) concluded its first official survey. Over the past five years, the experiment recorded more than 47 million galaxies and 20 million stars over 11 billion years of cosmic history.<\/p>\n

The idea of a big, important observatory wrapping up a \u201cfinal run\u201d suggests that, as the phrase implies, the experiment is done. But for scientists, that couldn\u2019t be further from the truth. The conclusion of a major survey is, in many ways, the start of exciting science, as hundreds of hungry scientists dissect the new data in detail. That process can take anywhere from a couple of months to several years\u2014especially for data collected by an instrument as capable as DESI.<\/p>\n

\u201cAs soon as you have a galaxy survey like that, it\u2019s a real gold mine of information,\u201d DESI co-spokesperson Will Percival<\/a> told Gizmodo during a video call. \u201cThere\u2019s a lot of physics encoded in the distribution of galaxies and a whole wealth of science and analysis still to come.\u201d<\/p>\n

It takes a lot to explain the cosmos <\/p>\n

If you follow cosmology, you might remember a big DESI announcement in 2025 that took a swipe at a static cosmological constant<\/a>. The investigation suggested dark energy was evolving, not constant. According to Percival, an astrophysicist at the University of Waterloo in Canada, this finding came from studying DESI observations from its first three years of operations\u2014a giant dataset that scientists are still investigating.<\/p>\n

\"CirclesStar trails over the Kitt Peak National Observatory in Tucson, Arizona, where DESI is installed. Credit: DESI Collaboration <\/p>\n

So, if last year\u2019s analysis was a tiny preview into what DESI data could uncover, the observatory\u2019s first completed run\u2014the \u201cfull\u201d dataset\u2014will certainly do much more. Then again, the stakes are high. After all, the relevant questions here concern how the universe came to be, how it\u2019s growing\u2014and, perhaps most importantly, how it might end.<\/p>\n

\u201cWith data that\u2019s as good as you get from DESI, we really need to do a careful and robust analysis,\u201d Percival explained. Just preparing the data for scientific analysis is a huge task in itself, he said, adding, \u201cWe have to do things like creating mock universes and mock catalogues of galaxies, and then we look at how our observations impact the original physics that [dictate] these fake universes.\u201d<\/p>\n

Confirmed, but not really <\/p>\n

This level of precaution ensures the data is ready to investigate ideas like Einstein\u2019s cosmological constant, lambda (\u039b). This metric drives an accelerated expansion of the recent universe, as Andrew Liddle<\/a>, an astrophysicist at the University of Lisbon in Portugal, explained to Gizmodo. The standard cosmological model uses lambda to assume that whatever causes this acceleration\u2014typically represented as dark energy\u2014\u201cmaintains a perfectly constant energy density while the universe is expanding,\u201d said Liddle, who isn\u2019t directly involved with DESI.<\/p>\n

\u201cIt is a tug of war between the universe and established physics.\u201d <\/p>\n

Most observations thus far have affirmed this account of the universe\u2019s evolution, which is why suggesting otherwise\u2014as DESI\u2019s 2025 analysis did\u2014would be a \u201chuge discovery that would overturn the standard model of cosmology,\u201d noted Kev Abazajian<\/a>, an astrophysicist at the University of California, Irvine, also uninvolved with DESI.<\/p>\n

\u201cHowever, the statistical significance of the result is not yet that significant,\u201d Abazajian said, \u201cand it would need to be detected by an independent survey as well for it to be taken as truly credible.\u201d<\/p>\n

\u201cThese kinds of questions really depend on how well we know the errors in the data,\u201d Percival explained. \u201cSo we spend a lot of time making sure they\u2019re as accurate as we can make them.\u201d<\/p>\n

Why even ask the question? <\/p>\n

It might seem odd that, if observational results are compliant with lambda, scientists are even considering different options. This has to do with major complications on the theoretical side of cosmology and physics at large, according to Marina Cort\u00eas<\/a>, an astrophysicist at the University of Portugal.<\/p>\n

\u201cIt is so difficult to insert lambda into the century-old body of theoretical physics that no one knows how or where to even begin to change that edifice [\u2026] due to unsolvable discrepancies with particle physics,\u201d Cort\u00eas, who was involved with DESI\u2019s earliest stages, told Gizmodo. \u201cRegardless of the increased ingenuity, complexity, and collaborative effort of surveys, the universe has remained firm [that lambda is correct]. It is a tug of war between the universe and established physics.\u201d<\/p>\n

As for the cosmological model as a whole, there were some discrepancies regarding the diversity of galaxy densities, as well as the infamous \u201cHubble tension<\/a>\u201d surrounding the expansion rate of the universe, added Abazajian.<\/p>\n

\u201cIt is here where the DESI survey plays a vital role by suggesting possible dark energy evolution,\u201d Cort\u00eas said. \u201cIf verified, this provides new quantitative properties of dark energy to diagnose its true nature. Even if DESI ultimately verifies [lambda] once more, it will have done so with substantially greater accuracy\u2026 leaving no maneuver space for lazy theorists to delay moving on with [devising new models].\u201d<\/p>\n

What now? <\/p>\n

Both Abazajian and Cort\u00eas anticipate we\u2019ll get some answers with DESI and also Euclid<\/a>, another space telescope launched to explore all things dark in the universe. The latter is slated to publish its first data release in October this year.<\/p>\n

\u201cIf evolving dark energy is seen in both and with the same features, this is on the path to becoming a major discovery,\u201d Abazajian said.<\/p>\n

\u201cIt\u2019s a really exciting time to be working in cosmology, because we\u2019re working with things we don\u2019t understand.\u201d <\/p>\n

Cort\u00eas, who recently visited DESI members, told Gizmodo that the team is considering a collaborative supernova survey<\/a> with Rubin Observatory, another major institution with monster-level capabilities<\/a>. Other teams are already planning for successor projects<\/a> to both DESI and Rubin, too, she said.<\/p>\n

Meanwhile, the DESI team reportedly has six batches of five to ten scientific papers on different topics, all planned to come out later this year, Percival told Gizmodo. Again, this comes from the dataset up to DESI\u2019s third year of operations. It\u2019s worth noting that the instrument itself hasn\u2019t physically turned off and will run supplementary surveys until around 2028.<\/p>\n

As of now, the team is working on processing the five-year data dump for scientific analysis, which Percival predicts will take about two to four months.<\/p>\n

\u201cAnd hopefully, by that point, the team will have finished with the [data up to the third year] and will be ready to move on,\u201d Percival mused. \u201cIt\u2019s a really exciting time to be working in cosmology, because we\u2019re working with things we don\u2019t understand. I\u2019m biased, but I think getting more information is really key. It\u2019s really exciting science that\u2019s happening now.\u201d<\/p>\n","protected":false},"excerpt":{"rendered":"Last week, the Dark Energy Spectroscopy Instrument (DESI) concluded its first official survey. Over the past five years,…\n","protected":false},"author":2,"featured_media":380954,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[7],"tags":[399,401,402,111,139,69,147],"class_list":{"0":"post-398333","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-science","8":"tag-astrophysics","9":"tag-cosmology","10":"tag-dark-energy","11":"tag-new-zealand","12":"tag-newzealand","13":"tag-nz","14":"tag-science"},"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/398333","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/comments?post=398333"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/posts\/398333\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media\/380954"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/media?parent=398333"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/categories?post=398333"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/nz\/wp-json\/wp\/v2\/tags?post=398333"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}