See more of our trusted coverage when you search. Prefer Newsweek on Google to see more of our trusted coverage when you search. Researchers have detected an extremely energetic cosmic ray from an ...

In 1991, the University of Utah Fly's Eye experiment detected the highest-energy cosmic ray ever observed. Later dubbed the Oh-My-God particle, the cosmic ray's energy shocked astrophysicists. Nothing ...

(via Dr. Becky) There's a strange, unexplained feature of the Cosmic Microwave Background which seems to be aligned with the Solar System, and we don't why. Is it real or just a coincidence? And if it ...

As it studies cosmic microwaves, the Simons Observatory in Chile aims to help prove or disprove cosmic inflation, a notion that the universe expanded rapidly in the moment after the Big Bang. Two of ...

So much happened in the earliest moments of the universe. Elementary particles appeared, the first nuclei of hydrogen and helium, and fluctuations of energy and matter set into motion the formation of ...

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 studying a mysterious effect called cosmic birefringence—a subtle twist in the polarization of the universe’s oldest light—have developed a new way to reduce uncertainty in how it’s ...

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 ...

Isocurvature perturbations denote primordial fluctuations in which the relative number densities of different cosmic components (such as photons, baryons, dark matter and neutrinos) vary while the ...