Researchers created a technique to reduce uncertainty in cosmic birefringence measurements, resolving a key phase ambiguity and improving future studies of fundamental physics.

The night sky deceives us. The universe should be ablaze with starlight, yet it isn’t. Discover how the finite speed of light, cosmic expansion, and invisible radiation from the Big Bang—the Cosmic ...

The oldest stars in the Milky Way are forcing a fresh look at one of cosmology’s biggest arguments. If some of them are about ...

Scientists are reeling from an unexpected blow after news that a much anticipated future observatory—designed to decipher the earliest moments of cosmic history—won’t be able to proceed with its ...

(via Sabine Hossenfelder) In the Big Bang Theory, the cosmic microwave background — microwave-range radiation that floats through the entire universe at a steady 2.7 Kelvin — is evidence that a hot ...

Two new studies have measured the expansion of the universe in our immediate cosmic neighborhood using a novel method that ...

The events surrounding the Big Bang were so cataclysmic that they left an indelible imprint on the fabric of the cosmos. We can detect these scars today by observing the oldest light in the universe.

Ripples in the fabric of space-time called gravitational waves may be the key to solving the Hubble tension — one of the biggest nagging problems in physics.

Observations show the universe appears flat, yet its true size and global shape beyond the observable horizon may remain forever unknown.

It was July 1965 when Arno Penzias and Robert Wilson were struggling to explain strange signal noise being picked up by the Bell Labs Holmdel horn radio antenna. They thought at first those damn ...

The cosmic microwave background, shown at left in this illustration, is a flash of light that occurred when the young universe cooled enough for electrons and protons to form the first atoms. It ...

The clearest pictures yet of the newborn cosmos strengthen the prevailing model of the universe but deepen a mystery about its expansion rate. Measurements of this rate, known as the Hubble constant, ...