{"id":427466,"date":"2025-12-05T22:59:09","date_gmt":"2025-12-05T22:59:09","guid":{"rendered":"https:\/\/www.europesays.com\/us\/427466\/"},"modified":"2025-12-05T22:59:09","modified_gmt":"2025-12-05T22:59:09","slug":"this-telescopes-final-data-release-just-killed-30-cosmological-theories","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/us\/427466\/","title":{"rendered":"This Telescope’s Final Data Release Just Killed 30 Cosmological Theories"},"content":{"rendered":"

The Atacama Cosmology Telescope (ACT) in Chile spent nearly two decades studying how the universe began, what it\u2019s made of, and how it evolved to its current state. The observatory was decommissioned<\/a> in 2022, but its last batch of data is still sending shockwaves through the cosmological community.<\/p>\n

A recent study published in the Journal of Cosmology and Astroparticle Physics<\/a> used this data to test about 30 \u201cextended\u201d models of the universe\u2019s evolution\u2014alternatives to the standard model of cosmology. These alternatives attempt to explain certain cosmological phenomena that the standard model can\u2019t, such as the Hubble tension<\/a>, a discrepancy between different measurements of the universe\u2019s expansion rate.<\/p>\n

The researchers ruled out every extended model they tested. Alongside another JCAP-published study<\/a> that used ACT\u2019s final data to confirm the Hubble tension, the findings deepen this cosmological mystery, leaving experts with even more questions about what\u2019s driving the expansion of the universe.<\/p>\n

\u201cWe assessed them completely independently,\u201d Erminia Calabrese, a Cardiff University cosmologist and co-author of the study that tested the extended models, said in a statement<\/a>. \u201cWe weren\u2019t trying to knock them down, only to study them. And the result is clear: The new observations, at new scales and in polarization, have virtually removed the scope for this kind of exercise. It does shrink the theoretical \u2018playground\u2019 a bit.\u201d<\/p>\n

A deepening cosmological mystery <\/p>\n

There are two main ways to measure the universe\u2019s expansion rate, also known as the Hubble constant. One method involves looking at the radiation leftover from the Big Bang (the cosmic microwave background), and the other looks at galaxies and supernovae in the local universe.<\/p>\n

According to the standard model of cosmology, both methods should produce the same value. The problem is, they don\u2019t. This, in essence, is the Hubble tension.<\/p>\n

Researchers have spent years trying to explain this discrepancy, and they\u2019ve come up with many interesting hypotheses<\/a>. Others have found<\/a> evidence to suggest the Hubble tension may not actually exist. The latest ACT data strengthen the case for this cosmological conundrum but bring experts no closer to resolving it.<\/p>\n

More questions, but a clearer path to answers <\/p>\n

So, \u201cWhat\u2019s the big deal?\u201d you ask. Well, for one thing, confirming the Hubble tension with ACT\u2019s observations means we can be pretty darn sure this problem is real.<\/p>\n

The telescope measured the cosmic microwave background with unprecedented precision, producing polarization maps that complement the temperature maps created<\/a> by the European Space Agency\u2019s Planck spacecraft. By comparison, the ACT maps\u2014published<\/a> in a third JCAP study\u2014have much higher resolution than Planck\u2019s. This is largely owed to the fact that ACT\u2019s primary mirror is much larger than Planck\u2019s, with a diameter of about 20 feet (6 meters).<\/p>\n

\u201cWhen we compare [the maps], it\u2019s a bit like cleaning your glasses,\u201d Calabrese said. As such, the ACT data fill several gaps in our understanding of the CMB.<\/p>\n

\u201cOur new results demonstrate that the Hubble constant inferred from the ACT CMB data agrees with that from Planck\u2014not only from the temperature data, but also from the polarization, making the Hubble discrepancy even more robust,\u201d Colin Hill, a cosmologist at Columbia University and co-author of the study that used ACT data to confirm the Hubble tension, said in the statement.<\/p>\n

ACT\u2019s observations also allowed Calabrese and her colleagues to rule out many of the extended models that attempt to explain the Hubble tension. While this narrows the range of possibilities, it provides a clear path forward. If these models are dead ends, it\u2019s time to stop pursuing them and look for answers elsewhere.<\/p>\n

ACT\u2019s operational lifespan may be over, but its final data release marks a new beginning for cosmologists working to resolve the Hubble tension. Experts will continue using the data for years to come, inching their way closer to a better understanding of our expanding universe.<\/p>\n","protected":false},"excerpt":{"rendered":"The Atacama Cosmology Telescope (ACT) in Chile spent nearly two decades studying how the universe began, what it\u2019s…\n","protected":false},"author":3,"featured_media":427467,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[8],"tags":[28891,45482,159,48147,198905,67,132,68],"class_list":{"0":"post-427466","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-science","11":"tag-telescopes","12":"tag-the-hubble-tension","13":"tag-united-states","14":"tag-unitedstates","15":"tag-us"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@us\/115669445771309276","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/427466","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/comments?post=427466"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/posts\/427466\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media\/427467"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/media?parent=427466"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/categories?post=427466"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/us\/wp-json\/wp\/v2\/tags?post=427466"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}