For years, cosmologists have argued over a simple question with an awkward answer: How fast is the universe expanding right ...

We have known for several decades that the universe is expanding. Scientists use multiple techniques to measure the present-day expansion rate of the universe, known as the Hubble constant. These ...

A proposed five-satellite Cosmic Positioning System could measure cosmic distances directly and help address discrepancies in the Hubble constant through solar system–scale triangulation.

Astrophysicists propose a new “stochastic siren” method using the gravitational-wave background from black hole mergers to ...

This article is the latest in the Health Affairs Forefront series, Accountable Care for Population Health, featuring analysis and discussion of how to understand, design, support, and measure ...