All articles tagged with #universe
A BuzzFeed list highlights 11 mind‑blowing space facts—from Eratosthenes’ ancient Earth measurement and the Sun’s energetic core to pulsars that could act as galactic GPS and the Andromeda collision—showing just how vast, strange, and humbling the universe is.
A DESI-based analysis of the 3D map of galaxies finds higher anisotropy in the universe’s large-scale structure than predicted by dark-matter–only simulations. The study computes, for each galaxy, how likely it is to find others at various distances and directions, then averages this to gauge directional differences. The result does not imply a cosmic center, but if confirmed it could challenge the assumption of isotropy and point to new physics—such as a time-varying dark energy, revised dark matter behavior, or modified gravity. Verification with DESI DR2 and Euclid data is key as researchers stress-test the findings.
Scientists estimate there are roughly 200 sextillion (2×10^23) stars in the universe by first counting the roughly 2 trillion galaxies, then multiplying by a typical galaxy’s star count (about 100 billion). Using the Milky Way as a model, they extrapolate to the entire cosmos, noting the Sun is just one of these stars and that many stars are red dwarfs. The article emphasizes how astronomers combine galaxy counts with stellar statistics to reach this staggering total.
The article explains that the Big Bang was not a violent explosion but the starting expansion of the universe, which has been growing for about 13.8 billion years. Evidence from galaxies moving apart and the Cosmic Microwave Background supports this view. Importantly, there was no space or time before the Big Bang, so asking what happened “before” is tricky. The universe’s expansion continues today and is accelerating, a behavior tied to dark energy though its nature remains not well understood.
A sweeping, decade-spanning tour of 20 landmark cosmic discoveries—from early parallax and Neptune’s discovery to the emergence of dark energy and gravitational-wave astronomy—showing how each breakthrough reshaped our understanding of the universe and spurred new questions.
The universe’s expansion allows distant galaxies to recede faster than light while local light-speed limits remain intact, making the observable universe extend about 45 billion light-years even though it’s 13.8 billion years old. Objects’ recession is traced by redshift, with a cosmological event horizon around 17 billion light-years that will never be crossed by light from beyond it; as dark energy accelerates expansion, this horizon grows toward ~60 billion light-years, and in roughly 100 billion years, galaxies beyond the Local Group will vanish from view.
A DESI-based map of the universe hints at anisotropy: galaxies show directional patterns that persist at gigaparsec scales, challenging the long-held cosmological principle that the cosmos is uniform and isotropic. Results are provocative but require replication with larger datasets before altering models of dark energy/matter.
Space itself expanded as photons traveled, so the present observable diameter is about 92–93 billion light-years even though the universe is ~13.8 billion years old. The 13.8 billion years is the lookback time, not a static travel distance; the farthest observable regions are now ~46 billion light-years away. Distances depend on cosmological definitions and parameters, such as the particle horizon, Hubble radius, and event horizon, all described within the Lambda-CDM framework and Planck data. No local light-speed limit is violated.
A Nature study analyzing 47 million galaxies from the DESI survey finds coherent patterns in the cosmic web extending across billions of light-years, suggesting the universe may not be perfectly homogeneous or isotropic on the largest scales. The result challenges a key cosmological assumption and could prompt revisions to models of dark matter, gravity, and structure formation, though independent replication with larger datasets is needed before firm conclusions.
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.
An illustrated poster distills 13.8 billion years of cosmic history—from the end of inflation and the hot Big Bang to the formation of atoms, first stars, and the cosmic web, through to the Milky Way, dark energy, and humanity’s Moon landing—into a single image that communicates the sequence of eras and scales of the Universe.
Big Think launched its first online store in partnership with infographic poster maker Pop Chart, selling the poster “A Visual History of the Universe” (created with astrophysicist Dr. Ethan Siegel) that visualizes the universe from the Big Bang to the present, along with related merch and announced plans for more posters in the future.
Space Daily revisits Carl Sagan’s Cosmic Calendar, compressing 13.8 billion years into one year—Big Bang on January 1, recorded history ends in the final 12–13 seconds, and a human life is about 0.2 seconds. Ongoing JWST observations and cosmological simulations (COLIBRE/FLAMINGO) are refining the timeline, but the 14-second window remains the core takeaway for perspective on humanity’s place in the cosmos.
A large American Physical Society survey of 1,600+ physicists and science enthusiasts reveals broad disagreement on core cosmology topics. While 68% view the Big Bang as a hot, dense state (not necessarily a definite beginning), 20% see it as the absolute beginning with a singularity. On dark matter, only 10% endorse the traditional WIMP view, with about 21% proposing a hybrid of ideas, and on dark energy, 24% see it as a constant while 26% think it evolves over time, per DESI. The results highlight that scientific consensus is tenuous and progress comes from continued testing and debate.
April’s best science images span cosmic to terrestrial: the DESI project delivers the most detailed 3D map of the universe from 47 million galaxies and quasars, accompanied by Earth-bound highlights such as climate-threatened cherry blossoms in Japan, the discovery of a new endangered Liopholis mutawintji skink in Australia, a lab-grown dinosaur-collagen leather bag, insights into limb regeneration, advanced 3D imaging of coral skeletons with deep learning, and NASA’s Artemis II Moon fly-by with Space Launch System boosters.