The Dark Energy Spectroscopic Instrument (DESI) collaboration published a new analysis of dark energy on 19 March 2025. DESI created the largest three-dimensional map of the universe ever made, using data from nearly 15 million galaxies and quasars collected in the first three years of observations. This map covers 11 billion years of cosmic history. Dark energy has long been considered a constant (called the “cosmological constant” in the standard Lambda CDM model), that is, a force that does n

What is dark energy? Physicist Tessa Baker at the University of Portsmouth, UK, is at the forefront of the search for elusive dark matter, using some of cosmology’s most powerful tools, including the Laser Interferometer Gravitational-Wave Observatory (LIGO). By studying ripples in space-time sent out by the most extreme events in the cosmos, such as black hole mergers, experimentalists like Baker are beginning to test radical ideas: that dark energy might stem from hidden dimensions, elusive fi