Why is the universe expanding at an ever-increasing rate? This is one of the most exciting yet unresolved questions in modern ...

Einstein was right: artist's impression of a neutron-star merger. (Courtesy: NASA) Multimessenger observations of neutron stars have been used by astrophysicists in the US to put Einstein’s general ...

So far, the most accurate model describing gravity is still Einstein’s theory of general relativity. It states that gravity as we feel and observe it is a kind of side effect of the fabric of ...

In 1915, Einstein proposed that gravity actually distorts the fabric of space. His calculations perfectly explained certain astronomical observations that Newtonian physics could not account for – ...

Sometimes the biggest puzzle in physics seems like the worst relationship in the universe. Quantum mechanics and general relativity are the two best theories in physics, but they have never been able ...

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. General relativity has withstood perhaps its toughest challenge to date. The theory, which Albert ...

"This work is a step toward understanding how quantum mechanics and gravity work together, a major unsolved problem in physics." The first step toward quantum gravity, the "holy grail of physics," may ...

The story begins with the black hole information paradox. According to relativity, anything that falls into a black hole is ...

Scientists really don't understand time... but they do have some theories about what it might (and might not) be.

When you purchase through links on our site, we may earn an affiliate commission. Here’s how it works. At least 3,700 years ago, Babylonian mathematicians approximated the ratio of a circle's ...