Cosmology
Researchers calculate all the photons ever emitted by the observable universe and find an astronomical number.
Theoretical physicists come up with a new way to analyze the firework of signals coming from particle collision experiments.
Physicists come up with alternate explanation of gravity that may implicate dark energy, which comprises 70 percent of our universe.
Physicists speculate that decaying neutrons may be producing particles unknown to science that make up the elusive dark matter.
Enjoy a rainbow of pictures this month, featuring Hubble's 28th anniversary image and the richest image of the Milky Way Galaxy yet.
Signal hints at possible interactions between ordinary hydrogen and dark matter in the early universe, but some scientists remain skeptical.
About 100 years ago Henrietta Swan Leavitt helped prove the existence of other galaxies. She is still inspiring astronomers today (infographic).
The gigantic celestial body has exploded multiple times, confounding scientists.
The signal, from two merging black holes 3 billion light-years away, is the most distant observation yet.
Theoretical physicists contemplate the seemingly impossible situation of a point in space-time where gravity goes to infinity.
New simulations suggests life could exist in universes very different from our own.
A team of scientists develop a model that describes the accelerating expansion of the universe without the need for mysterious dark energy.