Scientists studying a mysterious effect called cosmic birefringence—a subtle twist in the polarization of the universe’s ...

The earliest light in the universe has been traveling across space since just after the Big Bang. Known as the cosmic microwave background, it is imperceptible to the human eye. But if scientists can ...

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 ...

The night sky deceives us. The universe should be ablaze with starlight, yet it isn’t. Discover how the finite speed of light ...

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.

(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 ...

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, ...

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