Add Yahoo as a preferred source to see more of our stories on Google. A blue nebula looks like an eye in this NASA image The expansion of the universe could be a mirage, a potentially controversial ...

Dark energy remains among the greatest puzzles in our understanding of the cosmos. In the standard model of cosmology called the Lambda-CDM, it is accounted for by adding a cosmological constant term ...

Ryan Keeley does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their ...

Everything in the universe has gravity – and feels it too. Yet this most common of all fundamental forces is also the one that presents the biggest challenges to physicists. Albert Einstein’s theory ...