Natalie Wolchover

We don’t know why the universe appears to be expanding faster than it should. New ultra-precise distance measurements have only intensified the problem.

Roger Penrose, Reinhard Genzel and Andrea Ghez were awarded the Nobel Prize in Physics for their studies of black holes.

His incompleteness theorems destroyed the search for a mathematical theory of everything. Nearly a century later, we’re still coming to grips with the consequences.

Researchers say there are three possible explanations for the anomalous data. One is mundane. Two would revolutionize physics.

We asked four physicists why gravity stands out among the forces of nature. We got four different answers.

The first official evidence of a key imbalance between neutrinos and antineutrinos provides one of the best clues for why the universe contains something rather than nothing.

Sometimes a mirror that reflects 99.9999% of light isn’t good enough.

In a new paper, physicists argue that hypothetical particles called axions could explain why the universe isn’t empty.

Two independent measurements of the universe’s expansion give incompatible answers. Now a third method, advanced by an astronomy pioneer, appears to bridge the divide.

A study challenged the evidence for the mysterious antigravitational force known as dark energy. Then cosmologists shot back.

When researchers reanalyzed the gold-standard data set of the early universe, they concluded that the cosmos must be “closed,” or curled up like a ball. Most others remain unconvinced.

A new measurement appears to have eliminated an anomaly that had captivated physicists for nearly a decade.