The most compelling evidence of a Universe before the Big Bang | by Ethan Siegel | Start with a bang! | October 2025
Press enter or click to view full size image When the entire sky is observed at a variety of wavelengths, certain sources corresponding to distant objects beyond our galaxy are revealed. This first Planck all-sky map includes not only the cosmic microwave background, but also extragalactic contributions and foreground contributions from matter within the Milky…