Physics

Testing the multiverse hypothesis requires measuring whether our universe is statistically typical among the infinite variety of universes. But infinity does a number on statistics.

For five years physicists have been tantalized by possible evidence of dark matter in the Milky Way’s center. But new results from small satellite galaxies have complicated the story.

A potent theory has emerged explaining a mysterious statistical law that arises throughout physics and mathematics.

Cosmic dust in the high latitudes of the Milky Way could account for the entire swirl pattern that had been presented as proof of a leading Big Bang theory, according to a new data analysis from the Planck satellite.

The astrophysicist Joshua Frieman seeks to pinpoint the mysterious substance driving the accelerating expansion of the universe.

Newly discovered particles are forcing physicists to extend their simple picture of subatomic interactions or replace it with a more nuanced understanding.

Physicists have begun to explore the idea that mass and length may not be fundamental properties of nature. The hypothesis could help to avoid the conclusion that our world is just a weird bubble in an endlessly foaming multiverse.

Katherine Freese, a physicist who will soon lead the Nordic Institute for Theoretical Physics, reflects on the hunt for dark matter and how dark matter heating may have produced the first stars.

The cosmologist David Spergel explains why a widely publicized gravitational-wave discovery could be wrong, and how the “overreaching” study could affect the public’s perception of science.