All articles tagged with #planck satellite
An accessible guide to the cosmic microwave background: the fossil light from 380,000 years after the Big Bang that made the universe transparent, now observed as a 2.7 K microwave map by COBE, WMAP, and Planck; its tiny fluctuations seed galaxies, constrain curvature and matter content, and even highlight the current tension in the measured Hubble constant, reminding us that the cosmos still has mysteries to unveil.
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.