For decades, astronomers were certain that half of the ordinary matter in the universe — protons and neutrons, the building blocks of everything we see — had simply gone unaccounted for. The cosmic ...

Repulsive gravity at the quantum scale would have flattened out inhomogeneities in the early universe First light The cosmic microwave background, as imaged by the European Space Agency’s Planck ...

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 ...