The sun was born in a family of stars. What became of them?
All stars are born in groups but then slowly disperse into space. A new theory seeks to explain how these groups form and fall apart or, in rare cases, persist for hundreds of millions of years
Tipping the scales at less than about a million suns in mass, middleweight black holes may hold clues to how their much larger siblings, and galaxies, first formed
A shadow cosmos, woven silently into our own, may have its own rich inner life
By the latest estimate, the observable universe contains 200 billion galaxies. Astronomers wonder: Why so few?
Dark energy does more than hurry along the expansion of the universe. It also has a stranglehold on the shape and spacing of galaxies
Is the theory at the heart of modern cosmology deeply flawed?
Proof of parallel universes radically different from our own may still lie beyond the domain of science
Our universe may have started not with a big bang but with a big bounce—an implosion that triggered an explosion, all driven by exotic quantum-gravitational effects
Total energy must be conserved. Every student of physics learns this fundamental law. The trouble is, it does not apply to the universe as a whole
Deep down, the particles and forces of the universe are a manifestation of exquisite geometry
An experiment going up outside of Chicago will attempt to measure the intimate connections among information, matter and spacetime. If it works, it could rewrite the rules for 21st-century physics