Topic

Cosmology

A deep field crowded with thousands of galaxies of many shapes and colours against black space, some stretched into arcs, with a few bright foreground stars showing six-pointed spikes.

CosmosExplainer

How old is the universe? 13.8 billion years, and three ways we know

The number comes from running the expansion of space backwards. We did that calculation ourselves, then checked it against the oldest stars, a clock that no expansion measurement can touch.

CosmosLens EditorsNovember 10, 20265 min read

Long-exposure photograph of observatory domes on a mountaintop beneath concentric star trails.

CosmosAnalysis

Is dark energy running out of steam?

The largest three-dimensional map of the universe hints that the force driving cosmic acceleration may be weakening. A 2026 reanalysis has made that evidence weaker, and more interesting.

CosmosLens EditorsNovember 8, 20264 min read