Tag

Gravity

All articles tagged with #gravity

space24 minutes ago•45 min saved

Cosmic Glitch Suggests Gravity Fades at the Universe’s Largest Scales

Researchers from the University of Waterloo and University of British Columbia propose a minimal modification to gravity—a 'cosmic glitch'—where gravity is about 1% weaker on cosmological scales (billions of light-years) than predicted by general relativity, captured by the parameter Ωg. Analyses of Planck 2018 data yield Ωg ≈ -0.0087 ± 0.0046 and a Hubble constant near 68.6 km/s/Mpc; in some data combinations this can lessen the Hubble tension, but the improvement isn't universal across all datasets. The model preserves GR on smaller scales and could be tested by future CMB and large-scale structure surveys (DESI, Euclid). If confirmed, it would hint at physics beyond general relativity at cosmic distances.

via The Brighter Side of News|

#cosmic-glitch-in-gravity #general-relativity #gravity

science4 days ago•15 min saved

Gravity as Information Compression: A Bold New Take on Cosmology

Physicist Melvin Vopson argues that information is as fundamental as mass and energy and that gravity emerges as a data‑compression, entropy‑minimizing process; the theory, which recovers Newton’s law from information dynamics, challenges the need for dark matter and dark energy and points to a computation-like optimization at the heart of the cosmos.

via IAI TV|

#cosmology #dark-matter #entropy

space5 days ago•158 min saved

Milky Way's fastest star rockets around Sagittarius A* at 8% light speed

Astronomers have identified S301, the Milky Way’s fastest star, racing around the galaxy’s supermassive black hole Sagittarius A* at about 15,500 miles per second (over 8% of light). Its tight 8.7-year orbit, roughly 12 AU from the black hole, offers a novel way to probe Sagittarius A*’s spin and test general relativity via frame dragging, using the GRAVITY instrument on ESO’s Very Large Telescope Interferometer. The discovery, reported in Nature, could allow direct measurements of the black hole’s spin within a decade as researchers continue to monitor two full orbits; S301 may have been captured from a binary system.

via Space|

#frame-dragging #gravity #s301

science5 days ago•6 min saved

Star S301's near-miss with Sagittarius A* could unlock the Milky Way's black-hole spin

Astronomers using the GRAVITY instrument on the Very Large Telescope have identified S301, a star on an extremely eccentric orbit that dives to within about 11 AU of the Milky Way's central black hole, Sgr A*. At its closest it speeds around 0.08c, offering a rare opportunity to measure the black hole's spin and to probe its geometry and other properties with future observations.

via Ars Technica|

#astronomy #black-hole-spin #gravity

science7 days ago•2 min saved

NASA's Geoid Visualization Turns Earth into a Lumpy Potato

NASA released a visualization of the geoid—the imaginary sea level defined by gravity and Earth's rotation—showing Earth as a potato‑like shape caused by uneven mass distribution. The geoid is not the planet's physical surface; the display exaggerates height variations 10,000× to illustrate how gravity varies across the globe. Real differences reach about 85 meters above the reference near Iceland and 106 meters below it south of India, with a total range around 191 meters. The visualization combines more than a billion observations from 19 satellites over 15 years (e.g., GRACE and GOCE) and helps researchers study gravity changes for mapping, surveying, and navigation.

via Euronews.com|

#earth #geoid #gravity

science12 days ago•51 min saved

NASA debunks viral gravity-loss claim: Earth’s gravity won’t vanish this week

NASA says a viral claim that Earth will suddenly lose gravity for seven seconds is unfounded. Gravity is determined by Earth’s mass and would only disappear if the planet shed mass, which isn’t happening. The theory, tied to rumors about a secret program and timing with celestial events, originated on social media and was debunked by NASA (via Snopes), with no evidence of any real project or connection to astronomical events.

via Yahoo|

#conspiracy-theory #fact-check #gravity

science13 days ago•2 min saved

NASA debunks the viral gravity blackout claim for Aug. 12, 2026

A viral conspiracy dubbed 'Project Anchor' claims Earth will briefly lose gravity for seven seconds on Aug. 12, 2026, but NASA and fact-checkers say the theory is unfounded: there’s no evidence of a leaked document, no mechanism for gravity to vanish, and eclipses do not affect gravity.

via Bergen Record|

#fact-check #gravity #hoax

science14 days ago•55 min saved

NASA debunks seven-second gravity-loss rumor for Aug. 12, 2026

A viral claim that Earth would briefly lose gravity for seven seconds on Aug. 12, 2026, based on a supposed NASA document called 'Project Anchor,' is false; NASA says gravity will not disappear during a solar eclipse or any other event, and the rumor traces back to a fabricated Instagram post with no credible sources.

via Yahoo|

#fact-check #gravity #misinformation

space20 days ago•11 min saved

Orbit by Speed, Not Altitude: Why 28,000 km/h Keeps You Falling Around Earth

Reaching orbit isn’t about climbing higher; it’s about building sufficient horizontal velocity so the ground curves away beneath the spacecraft as it keeps falling around Earth. Typically around 28,000 km/h for low Earth orbit, most of which is sideways, is achieved after an initial vertical climb to clear the atmosphere and a pitch-over as air thins. The launch involves staging to shed dead weight, plus exploiting Earth's eastward rotation for a small speed boost. Precise direction and velocity matter to ensure the spacecraft remains in a stable orbit rather than re-entering, with engines used for later adjustments rather than simply holding it up. In short, orbit equals the right speed in the right direction, not just the right height.

via Space Daily|

#gravity #orbit #orbital-mechanics

science25 days ago•4 min saved

NASA’s gravity map paints Earth as a potato-shaped geoid, not a real sphere

NASA's high-precision geoid map reveals subtle gravity highs and lows across Earth; the potato-like visualization is a magnified representation and does not show the planet's actual shape. The geoid model improves GPS accuracy, sea-level monitoring, and understanding Earth's interior, built from GOCE and GRACE data over 15 years, with notable gravity highs near Iceland and lows south of India.

via geekspin|

#earth #geoid #grace

science26 days ago•6 min saved

Half-Turn Physics: Why Buttered Toast Lands Butter-Side Down

The buttered toast phenomenon isn’t superstition but physics: a slice slid off a table begins to rotate and, at typical kitchen heights, has just enough time to complete about half a turn before hitting the floor, landing butter-side down. If you raise the table height to around ten feet, the toast can execute a full rotation and land butter-up. The outcome is tied to the fall time and the observer’s height, with the butter’s weight deemed negligible; historical notes include the 1991 Q.E.D. experiment and Robert Matthews’ Ig Nobel Prize-winning explanation, which links the effect to human-scale limits and physics rather than chance.

via Boing Boing|

#buttered-toast #gravity #ig-nobel-prize

science28 days ago•19 min saved

NASA’s gravity-based geoid visual reveals Earth's irregular surface

NASA released a gravity-based geoid visualization showing how the ocean surface would look under gravity alone (tidal and wind effects removed). Exaggerating gravity differences 10,000× highlights irregularities caused by dense interior regions, with the geoid peaking near Iceland (about 279 feet above the global average) and dipping south of India (about 348 feet below). Derived from over a billion measurements from the GOCE and GRACE satellites across ~15 years, the highly detailed geoid is not Earth’s physical shape but a tool to improve navigation, topographic surveys, and our understanding of the planet’s interior.

via Diario AS|

#cartography #earth #geoid

science1 month ago•8 min saved

Gravity Emerges from Entropy: A Thermodynamic View of the Cosmos

Physicist Ginestra Bianconi proposes Gravity from Entropy (GfE), a quantum gravity framework in which gravity arises from an information-theoretic tension between two spacetime metrics. They find total entropy increases with cosmic expansion while entropy per unit volume falls, allowing local structure to form even as the universe trends toward disorder. GfE reduces to General Relativity at low energies but includes a dynamical dark-energy term that could yield observable effects, offering a potential bridge between gravity, thermodynamics, and quantum theory.

via SciTechDaily|

#cosmology #entropy #gravity

science1 month ago•4 min saved

Entropic Gravity: A Thermodynamic Bridge to Cosmic Complexity and Life

Researchers led by Ginestra Bianconi propose Gravity from Entropy (GfE), a quantum-gravity framework in which gravity emerges from informational entropy between two spacetime metrics; while the Universe’s total entropy grows, the entropy per unit volume decreases with expansion, potentially allowing local structure and life to emerge without violating the second law; GfE reproduces General Relativity at low energies but predicts a dynamical dark energy component at higher curvature, offering testable cosmological implications; the idea points to a thermodynamic or informational basis for gravity and spacetime, though it remains preliminary.

via ScienceDaily|

#cosmology #darkenergy #entropy

science1 month ago•13 min saved

Gravity as the Mind’s Anchor: How Spaceflight Might Recalibrate Consciousness

A Perspective in Frontiers in Psychology argues Earth’s constant gravity acts as a foundational scaffold for brain models of reality; in weightlessness, astronauts’ brains may recalibrate, loosening self-boundaries in a way that echoes psychedelic states. The article cites spaceflight-linked brain changes (ventricular shifts, altered vestibular networks, reduced default-mode activity) and frames the comparison as a computational parallel, not a mechanistic equivalence, emphasizing the idea is a synthesis, not an experiment, and calling for future tests to confirm or challenge the claim.

via Space Daily|

#consciousness #gravity #neuroscience