{"id":770930,"date":"2026-06-30T11:31:14","date_gmt":"2026-06-30T11:31:14","guid":{"rendered":"https:\/\/www.newsbeep.com\/ca\/770930\/"},"modified":"2026-06-30T11:31:14","modified_gmt":"2026-06-30T11:31:14","slug":"hubble-crisis-and-the-cosmic-cataclysm-lighting-up-our-knowledge-of-the-universe","status":"publish","type":"post","link":"https:\/\/www.newsbeep.com\/ca\/770930\/","title":{"rendered":"Hubble Crisis and the cosmic cataclysm lighting up our knowledge of the universe"},"content":{"rendered":"

\"AngusSave<\/p>\n

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Examine, a free weekly newsletter covering science with a sceptical, evidence-based eye, is sent every Tuesday. You\u2019re reading an excerpt \u2013 sign up to get the whole newsletter in your inbox<\/a>.<\/p>\n

Something is very wrong with our understanding of the universe.<\/p>\n

In 2011, Australian astrophysicist Professor Brian Schmidt co-won the Nobel Prize in physics for discovering that the universe is expanding at an accelerating rate.<\/p>\n

\"AA way to settle astronomy\u2019s deepest mystery may have been found in the violent, bright jet of a neutron star collision.Carl Knox\/OzGrav\/Swinburne University of Technology<\/p>\n

It was a finding that held weight for every other observation we make about the vast expanse of the cosmos \u2013 a wilderness of galaxies, supernovae and colossal gas clouds that has always captured the imagination of Earthlings.<\/p>\n

But two camps of scientists are brawling (or at least politely publishing opposing papers) over something crucial: the rate of that expansion, known as the Hubble constant.<\/p>\n

There are two evidence-backed estimates, but they don\u2019t agree. This disarray is called the Hubble tension. Some have started calling it the Hubble crisis<\/a>.<\/p>\n

\u201cIt\u2019s incredibly important. It tells us the true age of the universe,\u201d says CSIRO astronomer Dr Kelly Gourdji of the Hubble constant. \u201cIt tells us the true distance to objects \u2013 galaxies and what have you \u2013 in the universe. And it also tells us their true size.<\/p>\n

\u201cSo having an incorrect or imprecise value of the Hubble constant is kind of like having all of our metre sticks on Earth off by a centimetre.\u201d<\/p>\n

Now Gourdji and her colleagues have used a super-rare cataclysmic collision and a colossal jet of light to help settle the debate. And they may have found a way to unpick the biggest crisis in astronomy.<\/p>\n

Two opposing sides<\/p>\n

There are two different ways scientists have tried to clock the rate of the universe\u2019s expansion.<\/p>\n

One method analyses cosmic background radiation, the leftover \u201cecho\u201d from the Big Bang which still murmurs across the entire universe.<\/p>\n

\"TheThe cosmic microwave background (CMB) as mapped by the WMAP satellite, can be used to estimate the expansion rate of the universe.NASA\/WMAP Science Team<\/p>\n

This is called the \u201cdistant universe\u201d method because it uses the earliest, most ancient light we can detect.<\/p>\n

The other is the \u201cnearby universe\u201d method. It looks at phenomena including Cepheid variable stars (which \u201cpulse\u201d with brightness at a known rate) and supernovae explosions.<\/p>\n

As these bright objects move away from Earth, the wavelength of the light they emit is stretched out \u2013 like an ambulance\u2019s siren becoming longer and deeper as it moves away from you \u2013 and becomes more red.<\/p>\n

This is called redshift, and measuring it helps astronomers determine how fast objects are moving away from each other as the universe expands.<\/p>\n

\"AsAs the universe expands, it stretches the wavelengths of light along with it, a process called redshift. The further away an object is, the more the light from it has stretched by the time it reaches Earth.NASA\/JPL-Caltech\/\/R. Hurt (Caltech-IPAC)<\/p>\n

The expansion rate is measured in kilometres per second per megaparsec (km\/s\/Mpc). A megaparsec is a cosmological unit of distance equal to about 3.26 million light years.<\/p>\n

The distant universe method using the Big Bang\u2019s echo has yielded an estimate of about 67-68km\/s\/Mpc.<\/p>\n

The nearby universe method using stars and supernovae puts the rate at 72-74 km\/s\/Mpc.<\/p>\n

\u201cWhen we try and stitch the history of the universe together based on these two sets of observations, they don\u2019t match up. It doesn\u2019t make sense,\u201d said Professor Adam Deller of the Swinburne University of Technology.<\/p>\n

Perhaps one team has a mistake lurking in their calculations. Or, more intriguingly, there may be some undiscovered maxim of physics or dark energy at work that we need to find and factor in.<\/p>\n

But a paper just published by Deller and Gourdji \u2013 both part of the ARC Centre of Excellence for Gravitational Wave Discovery, or OzGrav \u2013 in The Astrophysical Journal<\/a> offers new hope the tension can be rectified.<\/p>\n

The neutron star collision and a giant jet<\/p>\n

It all came down to the smashing together of two neutron stars \u2013 the densest objects that exist, apart from black holes \u2013 in a galaxy 140 million light years away.<\/p>\n

\u201cIt was so massive, this collision, that the ripples in spacetime fabric travelled all the way to us on Earth,\u201d Gourdji says of the event called GW170817.<\/p>\n

\"AnAn illustration of two neutron stars colliding and ejecting a jet of high-speed particles \u2013 bursts that represent some of the most powerful events in the universe.Sonoma State Univ.\/A. Simonnet; NASA<\/p>\n

But that\u2019s not all. From the explosion launched a violent jet of radiation rocketing at close to the speed of light. The jet itself only lasted two seconds, but its resulting glow was detectable by Earth\u2019s telescopes for about a year.<\/p>\n

For the first time, astrophysicists could analyse both gravitational waves and light from this rarely observed event.<\/p>\n

That allowed them to estimate the Hubble constant in a new way.<\/p>\n

\u201cThis particular merger we were very lucky with,\u201d Gourdji says. \u201cIt\u2019s not only the first binary neutron star collision that was detected via gravitational waves, but it stands to this day as the first and only one where its afterglow \u2013 the light that was emitted after this collision \u2013 was detected.<\/p>\n

\u201cThat allows us to pinpoint precisely which galaxy the merger occurred in. And that\u2019s one of the crucial ingredients required to directly make a measurement of the Hubble constant.\u201d<\/p>\n

Deller, meanwhile, pinpointed in unprecedented resolution the direction of the jet of light.<\/p>\n

By combining data from three telescopes \u2013 including the famous Hubble telescope itself \u2013 they used the fiery event to calculate a new Hubble constant estimate: between 61-70km\/s\/Mpc.<\/p>\n

\"OurOur understanding of the universe \u2013 and everything in it \u2013 depends on knowing how quickly it\u2019s expanding.NASA, ESA, CSA, STScI, Webb ERO Production Team via The New York Times<\/p>\n

That finding is exciting because it used a measurement similar in method to the \u201cnearby universe\u201d Hubble constant estimate, but achieved results closer to the \u201cdistant universe\u201d method.<\/p>\n

After decades of debate, we may have found ourselves a tie-breaker.<\/p>\n

\u201cThe precision they\u2019ve managed to get out of a single option is quite impressive,\u201d says Schmidt, our Nobel Prize winner, who wasn\u2019t involved in the study.<\/p>\n

The new estimate is, however, four times less precise than other Hubble constant measures. Another neutron star collision is needed to sharpen up the estimate, but they are rarely detected.<\/p>\n

Related Article\"A<\/a><\/p>\n

Deller says they\u2019ve been scanning the skies for another collision since GW170817 was observed in 2017, but \u201cthe universe has not played ball\u201d.<\/p>\n

Schmidt predicts we may spot between two and 10 collisions in coming years. The suspense!<\/p>\n

Says Deller: \u201cIf we want to understand the origin and evolution of the universe \u2013 which is the biggest-picture question you can really ask, I think \u2013 then we need to resolve this.\u201d<\/p>\n

The Examine newsletter explains and analyses science with a rigorous focus on the evidence. Sign up to get it each week<\/a>.<\/p>\n

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\"AngusAngus Dalton<\/a> is the science reporter for The Sydney Morning Herald.Connect via X<\/a> or email<\/a>.From our partners<\/p>\n","protected":false},"excerpt":{"rendered":"Save You have reached your maximum number of saved items. Remove items from your saved list to add…\n","protected":false},"author":2,"featured_media":770931,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24],"tags":[49,48,314,66],"class_list":["post-770930","post","type-post","status-publish","format-standard","has-post-thumbnail","category-physics","tag-ca","tag-canada","tag-physics","tag-science"],"_links":{"self":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/770930","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/comments?post=770930"}],"version-history":[{"count":0,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/posts\/770930\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media\/770931"}],"wp:attachment":[{"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/media?parent=770930"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/categories?post=770930"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.newsbeep.com\/ca\/wp-json\/wp\/v2\/tags?post=770930"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}