Tag

Dark Energy

All articles tagged with #dark energy

science1 day ago•18 min saved

Sizing the Cosmos: How the Observable Universe Expands Through Time

By applying the Friedmann equations—relating the expansion rate to the Universe's energy content (radiation, matter, dark energy) and curvature—cosmologists compute the observable Universe's size at any epoch. With current measurements of the Hubble constant and energy fractions, the present horizon is about 46 billion light-years across, and its past growth traces radiation-dominated, then matter-dominated, and now dark-energy–dominated expansion, yielding precise milestones for when the Universe reached fractions of its current size.

via Big Think|

#cosmology #dark-energy #friedmann-equations

space8 days ago•91 min saved

A decade-long sky movie: Rubin Observatory to map a dynamic universe

The Vera C. Rubin Observatory's Legacy Survey of Space and Time (LSST) has begun, capturing thousands of 30-second exposures every night for 10 years to create a digital color movie of the southern sky, with real-time alerts on unusual changes and public data access. The project aims to illuminate dark matter and dark energy, map stellar histories and asteroids, and possibly uncover unexpected phenomena that could revolutionize astronomy, while facing challenges from ultra-bright satellites and other technical hurdles.

via Live Science|

#cosmology #dark-energy #dark-matter

space-and-spaceflight10 days ago•17 min saved

Gravastar Idea: A Dark-Energy ‘Mini-Universe’ Inside a Black Hole Mimic

Physicists propose gravastars—ultra-compact stars with a thin shell of ordinary matter and an interior powered by dark energy—that externally resemble black holes but lack singularities or event horizons. A new model shows how such objects could form from gravitational collapse and, in the process, trigger a Big Bang–like expansion inside a self-contained mini-universe. The scenario hinges on ideal, finely tuned conditions and does not replace black holes as the default outcome of collapse.

via Gizmodo|

#black-holes #dark-energy #general-relativity

space11 days ago•102 min saved

Cosmic movie kicks off: Rubin Observatory's LSST unveils decade-long sky survey

Rubin Observatory launches its ten-year Legacy Survey of Space and Time, using a 3.2 gigapixel camera to scan the southern sky repeatedly (about 800 visits per field) to create an ultra‑high‑definition, time‑resolved map that will probe dark energy and dark matter, track transient events, and reveal millions of solar-system objects; early months already yielded around 11,000 newly discovered asteroids.

via Space|

#astronomy #dark-energy #dark-matter

science11 days ago•14 min saved

Cosmic census kicks off with the world's largest digital camera

The Vera C. Rubin Observatory in Chile has begun a decade-long cosmic survey using the largest digital camera ever built to map billions of stars and galaxies, repeatedly imaging the southern sky to reveal faint objects and help scientists study galaxy formation, dark matter, and dark energy.

via KSL News|

#cosmic-survey #dark-energy #dark-matter

science11 days ago•24 min saved

Cosmic census begins as Rubin Observatory launches decade-long sky survey

The Vera C. Rubin Observatory in Chile has officially begun its 10-year survey to image the southern sky, taking hundreds of images per night to build a deep census of billions of stars and galaxies and to probe dark matter and dark energy, with researchers hoping to shed light on how galaxies form and cluster over cosmic time.

via New York Post|

#astronomy #cosmology #dark-energy

space12 days ago•5 min saved

Star Collapse May Forge a Mini-Universe: Gravastars as Black Hole Alternatives

A new study proposes gravastars—ultra-compact objects formed when collapsing stars create a miniature universe inside, with dark-energy interiors that halt collapse and mimic black holes without horizons or singularities—offering a GR-consistent alternative to black holes. Yet the mechanism requires fine-tuning, questions of stability remain, and it’s unclear how such objects could be distinguished observationally; formation remains a key open problem.

via Universe Today|

#black-holes #but-we-only-need-five-ensure-only-five-so-remove-extra #cosmology

science15 days ago•14 min saved

Roman Space Telescope widens its view to map the sky 1,000× faster

With the same 2.4-meter mirror as Hubble, Roman will not go deeper but cover far more sky per exposure with a 300-megapixel infrared camera, surveying more than 50× as much sky in five years as Hubble did in 30 and up to 1,000× faster overall. This breadth enables large-scale studies of dark energy, exoplanet microlensing, and time-domain astronomy, while a sophisticated data system turns massive image catalogs into usable science—complementing, not replacing, Hubble and Webb.

via Space Daily|

#astronomical-data #dark-energy #exoplanet-microlensing

science19 days ago•96 min saved

Cosmic acceleration holds firm as new study affirms dark energy's role

A new study published in Monthly Notices of the Royal Astronomical Society confirms that the universe's expansion continues to accelerate due to dark energy; claims in 2025 that dark energy was weakening are attributed to calibration errors in Type Ia supernova brightness and host-galaxy mass corrections, and when corrected, the measurements still support ongoing cosmic acceleration.

via Space|

#astronomy #cosmology #dark-energy

science19 days ago•11 min saved

Hidden Dimension May Unify Dark Energy and Dark Matter

New observations hint that dark energy may not be constant and could interact with dark matter. Building on DESI results that dark energy evolves over time, theorists are testing models where the energy density of dark energy and the mass of dark matter change in tandem, potentially via a dark, micron-scale dimension suggested by string theory. In this picture, gravitons could leak into the dark dimension, producing dark gravitons that drive the coupling between the two dark components and possibly helping to resolve the Hubble tension. While intriguing and partially compatible with data, these ideas remain theoretical and require further observational tests.

via Quanta Magazine|

#cosmology #dark-dimension #dark-energy

science23 days ago•9 min saved

Dying Stars May Spawn Tiny Universes to Form Gravastars Instead of Black Holes

A new dynamic solution to Einstein’s equations suggests that collapsing massive stars could birth a miniature expanding universe inside, creating a gravastar that counteracts collapse and avoids a singularity or event horizon, potentially explaining a theoretical alternative to black holes. The mechanism hinges on an outward-expanding mini-universe powered by dark energy, balancing gravity to produce a stable gravastar, though it remains a theoretical model and not observational evidence.

via SciTechDaily|

#black-holes #dark-energy #general-relativity

science26 days ago•2 min saved

Tiny Universes May Spawn Inside Collapsing Stars, Study Suggests

Researchers propose that extremely collapsed stars could halt at a gravastar stage, with outward dark-energy pressure creating a stable, tiny universe inside rather than forming a traditional black hole; the idea preserves black holes as possible outcomes but adds an exotic alternative, published in Physical Review D.

via Futurism|

#astrophysics #black-holes #dark-energy

science26 days ago•8 min saved

NASA's Roman Space Telescope Aims to Map the Sky at Unprecedented Pace

NASA's Nancy Grace Roman Space Telescope is on track for an Aug. 30 launch, promising sky surveys hundreds of times faster than Hubble to map hundreds of millions of stars and billions of galaxies, advance our understanding of dark matter and dark energy, and uncover thousands of exoplanets; first data could arrive within months after launch.

via NBC News|

#astronomy #dark-energy #dark-matter

science27 days ago•6 min saved

Dying Stars Could Birth Tiny Universes to Form Gravastars

A new theoretical study proposes that when a massive star collapses, it might birth a miniature universe inside the collapsing matter, driven by dark energy, expanding to counter gravity and halt collapse, thereby forming a stable gravastar instead of a black hole.

via ScienceDaily|

#dark-energy #general-relativity #gravastar

space-and-spaceflight1 month ago•17 min saved

Cosmic Acceleration Stands Firm Amid End-of-Universe Debates

A new MNRAS analysis reinforces that the universe’s expansion is still accelerating, countering a recent paper that argued measurement biases could mimic deceleration; after recalibrating for stellar ages, host-galaxy mass, and environmental factors, the results remain consistent with ongoing cosmic acceleration, underscoring the Big Freeze fate while highlighting ongoing scientific scrutiny of dark energy.

via Gizmodo|

#cosmic-acceleration #cosmology #dark-energy