But axions were pushed aside as the WIMPs hypothesis gained more steam. Back-of-the-envelope calculations showed that the ...

How is matter different from mass? These and other questions about the deepest levels of physics, answered inside.

Some of the faintest, coldest stars in the universe may be powered not by fusion—but by the annihilation of dark matter deep ...

420 BC: The Greek philosopher Democritus was not the first person to suggest matter is made of tiny particles. But he got the credit when scientists finally accepted the idea 2,000 years after his ...

String theory implies that the particles that comprise all the matter that you see in the universe—and all the forces that allow matter to interact—are made of tiny vibrating strands of energy.

Celestial objects known as dark dwarfs may be hiding at the center of our galaxy and could offer key clues to uncover the ...

Dark matter remains one of science's deepest mysteries. It makes up about 25% of our universe, yet scientists only observe ...

Two studies fill in gaps about the cosmos’s ordinary matter. One maps it all, even the “missing matter.” The other details one of its hiding spots.

The spectrum of visible light consists of a range of wavelengths that seems very small — 400 to 700 nanometers and a color range of violet through red.

Particles of light emitted from collisions of deuterons with gold ions provide direct evidence that energetic jets get 'stuck' — a key signature of quark-gluon plasma ...

Don't rule out primordial black holes as dark matter suspects just yet! Particle-sized black holes may resist evaporation, surviving long enough to account for the universe's most mysterious stuff.