‘Bumblebee gravity’ could explain why the universe is expanding so quickly

Physicists have long assumed that the universe is pretty much the same in any direction, and now they’ve found a new way to test that hypothesis: by examining the shadow of a black hole. If that shadow is a wee bit smaller than existing physics theories predict, it could help prove a far-out notion called […]

Unique prediction of ‘modified gravity’ challenges dark matter theory

The best example is represented by the Sunflower galaxy (NGC 5055) with the strongest external fieldamong SPARC galaxies, whose well-measured rotation curve shows a mildly declining behavior at largeradial distance and can be accurately modeled only with an external field effect. Credit: Creative Commons An international group of scientists, including Case Western Reserve University Astronomy […]

Gravity Data Reveal Unexpected Antarctic Ice Variations

As more coastal communities face the looming threat of rising sea levels, it’s more important than ever to accurately predict changes in one of the greatest potential sources of sea level rise—the melting of Antarctica’s massive ice sheet. Recently, scientists analyzed nearly 2 decades’ worth of data from sensitive NASA satellites documenting mass […]

Gravity Waves Leave Ripples Across a Glowing Night Sky

Waves propelled through the air by distant thunderstorms produced glowing bands in the sky during a 2016 “bright night” event, when the atmosphere was illuminated by a green glow visible to the naked eye. The ripples disturbed an atmospheric layer nearly 90 kilometers (56 miles) above El Leoncito Astronomical Complex in Argentina, at […]

Modeling Gravity Waves with Machine Learning

Gravity waves ripple outward from disturbances in the atmosphere, much like the ripples formed from tossing a stone into a still pond. Researchers know that these waves play a critical role in global atmospheric circulation, moving momentum between different layers. But gravity waves are still not well understood. Their small spatial scale and […]

Galileo’s famous gravity experiment holds up, even with atoms

According to legend, Galileo dropped weights off of the Leaning Tower of Pisa, showing that gravity causes objects of different masses to fall with the same acceleration. In recent years, researchers have taken to replicating this test in a way that the Italian scientist probably never envisioned — by dropping atoms. A new study describes […]