{"id":358747,"date":"2025-08-20T06:27:20","date_gmt":"2025-08-20T06:27:20","guid":{"rendered":"https:\/\/www.europesays.com\/uk\/358747\/"},"modified":"2025-08-20T06:27:20","modified_gmt":"2025-08-20T06:27:20","slug":"will-our-universe-rip-apart-or-expand-forever-dark-energy-holds-the-answer-technology-news","status":"publish","type":"post","link":"https:\/\/www.europesays.com\/uk\/358747\/","title":{"rendered":"Will our universe rip apart or expand forever? Dark energy holds the answer | Technology News"},"content":{"rendered":"

In 1929, Edwin Hubble made one of the greatest discoveries in astronomy: galaxies were all rushing away from us, their light stretched into longer wavelengths \u2014 redshifted \u2014 by the expansion of the universe itself. The farther a galaxy, the greater its redshift, and hence its apparent recession velocity. This insight laid the foundation for the Big Bang model of cosmology: the idea that the universe began 13.8 billion years ago in a hot, dense state and has been expanding ever since.<\/p>\n

But there was a limit to what Hubble\u2019s data could tell us. His observations revealed that the universe was expanding, but not whether that expansion was slowing down, coasting steadily, or perhaps doing something stranger. For decades, the expectation was that gravity from all the matter in the universe would eventually slow expansion down, maybe even reverse it into a \u201cBig Crunch.\u201d<\/p>\n

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\nWhy the 1990s changed everything<\/b><\/p>\n

For most of the 20th century, astronomers lacked the tools to probe the fine details of cosmic expansion. Measuring distances across billions of light-years required a new kind of yardstick. That breakthrough came in the 1990s with Type Ia supernovae.<\/p>\n

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These supernovae \u2014 the catastrophic explosions of white dwarf stars \u2014 all reach nearly the same intrinsic brightness. Why? Because they explode when the white dwarf accumulates mass from a companion star until it hits a critical threshold, about 1.4 times the mass of the Sun, known as the Chandrasekhar limit. This uniform trigger ensures that Type Ia supernovae release roughly the same amount of energy each time.<\/p>\n

To astronomers, that means they act as \u201cstandard candles\u201d: if you know how bright a light source really is, you can compare it to how faint it appears from Earth to calculate its distance with great accuracy.<\/p>\n

Armed with these cosmic beacons, two international teams \u2014 the Supernova Cosmology Project led by Saul Perlmutter, and the High-Z Supernova Search Team led by Brian Schmidt and Adam Riess \u2014 set out in the 1990s to measure the universe\u2019s expansion history. What they found shocked everyone.<\/p>\n

The discovery of dark energy<\/b><\/p>\n

Instead of slowing down, the expansion of the universe was accelerating. Distant supernovae appeared dimmer than expected \u2014 as if space itself were stretching faster and faster over time. The results, announced in 1998, won the teams the 2011 Nobel Prize in Physics. Adam Riess recalled being so startled that he checked and re-checked every step, convinced it had to be an error.<\/p>\n

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In fact, one of his colleagues later recounted Riess, late at night in the lab, muttering, <\/p>\n

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This can\u2019t be right \u2014 the universe just doesn\u2019t behave this way.<\/p>\n<\/blockquote>\n

But the data held. A mysterious force, dubbed dark energy, seemed to be pushing the universe apart.<\/p>\n

Today, dark energy is thought to account for about 68% of the energy budget<\/a> of the universe. Dark matter makes up another 27%, while ordinary matter \u2014 the stuff of stars, planets, and people \u2014 contributes only about 5%.<\/p>\n

What exactly is expanding?<\/b><\/p>\n

A common misconception is that the universe is expanding into some pre-existing empty space. In fact, it\u2019s space itself that\u2019s stretching. Galaxies are not moving \u201cthrough\u201d space like cars on a road; rather, the road itself is lengthening between them. The distance scale of the cosmos is changing, so that two galaxies not bound by gravity (say, in different clusters) drift farther apart simply because the fabric of space-time is evolving.<\/p>\n

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This explains why redshift increases with distance: the longer light has been traveling, the more the universe has stretched beneath it, elongating its wavelength.<\/p>\n

Beyond Supernovae: Other Clues<\/strong><\/p>\n

Supernovae provided the first evidence, but dark energy\u2019s fingerprints appear elsewhere.<\/p>\n

Cosmic Microwave Background<\/b> (CMB): The afterglow of the Big Bang, mapped in exquisite detail by satellites like COBE, WMAP, and Planck, shows subtle patterns that encode how the universe\u2019s expansion has evolved.<\/p>\n

Large-Scale Structure:<\/b> How galaxies cluster across vast distances depends on the tug-of-war between matter\u2019s gravity and dark energy\u2019s repulsion.<\/p>\n

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Baryon Acoustic Oscillations<\/b> (BAOs): In the early universe, sound waves rippled through hot plasma, leaving an imprint in the distribution of galaxies. These BAOs act as a \u201cstandard ruler\u201d for cosmic distances, complementing supernovae. By measuring the scale of these patterns today, cosmologists can track how fast the universe has expanded over billions of years.<\/p>\n

Each method strengthens the case: the acceleration is real.<\/p>\n

The future: Probing the dark energy mystery<\/b><\/p>\n

If dark energy is truly a cosmological constant, as Einstein once proposed, it might simply be an intrinsic property of space. But it could also be something more exotic: a new field of physics, or even a sign that our theories of gravity need revision. To answer these questions, astronomers are building powerful instruments:<\/p>\n

DESI (Dark Energy Spectroscopic Instrument):<\/strong> Using 5,000 robotic eyes on the Mayall Telescope in Arizona, DESI is mapping the 3D distribution of 40 million galaxies and quasars. By tracing BAOs with exquisite precision, it reconstructs the expansion history of the last 11 billion years.<\/p>\n

Euclid (ESA):<\/strong> Launched in 2023, Euclid is surveying a third of the sky, mapping billions of galaxies to study weak gravitational lensing and clustering, both sensitive to dark energy\u2019s effects.<\/p>\n

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Dark Energy Survey (DES):<\/strong> From Chile, DES has already measured thousands of supernovae and millions of galaxies, layering multiple techniques to cross-check dark energy\u2019s role.<\/p>\n

Each of these projects aims to determine whether dark energy is constant or evolving \u2014 a distinction that could rewrite physics.<\/p>\n

Why understanding dark energy matters<\/strong><\/p>\n

We live in a universe where the vast majority of energy is in a form we don\u2019t understand, but which governs the fate of everything. Dark energy determines whether the cosmos will expand forever, slow to a crawl, or tear itself apart. The fact that we still call it a mystery shows how far we are from understanding it. As cosmologist Michael Turner put it:<\/p>\n

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If you\u2019re not astounded by dark energy, you haven\u2019t understood it.<\/p>\n<\/blockquote>\n

For now, it remains the greatest riddle in modern science. Yet we are creatures of carbon, on a small planet circling an ordinary star, daring to contemplate the birth and destiny of time itself. And with every new survey, we move one step closer to unveiling the nature of the dark energy that shapes our cosmic home.<\/p>\n

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Shravan Hanasoge is an astrophysicist at the <\/b>Tata<\/b><\/a> Institute of Fundamental Research.<\/b><\/p>\n","protected":false},"excerpt":{"rendered":"In 1929, Edwin Hubble made one of the greatest discoveries in astronomy: galaxies were all rushing away from…\n","protected":false},"author":2,"featured_media":358748,"comment_status":"","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3845],"tags":[7017,126237,126233,6769,126235,14676,126236,74,70,126234,16,15,126231,126232],"class_list":{"0":"post-358747","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-physics","8":"tag-big-bang","9":"tag-cosmic-acceleration","10":"tag-cosmological-constant","11":"tag-dark-energy","12":"tag-dark-energy-survey","13":"tag-desi","14":"tag-euclid-telescope","15":"tag-physics","16":"tag-science","17":"tag-type-ia-supernovae","18":"tag-uk","19":"tag-united-kingdom","20":"tag-universe-expansion","21":"tag-will-the-universe-end"},"share_on_mastodon":{"url":"https:\/\/pubeurope.com\/@uk\/115059677572206916","error":""},"_links":{"self":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/358747","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=358747"}],"version-history":[{"count":0,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/posts\/358747\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media\/358748"}],"wp:attachment":[{"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/media?parent=358747"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/categories?post=358747"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.europesays.com\/uk\/wp-json\/wp\/v2\/tags?post=358747"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}