Dark energy

One of the most contested issues in astrophysics is our understanding of the Universe’s expansion. Adam Riess discusses why there is disagreement and what might resolve it.

Recent observations suggest that dark energy is changing over time. Theorists wonder if dark matter is, too.

Astronomers are preparing for a new era of big-data astronomy, and results are already starting to arrive.

In an unprecedented step, researchers crafted a detailed model compatible with the universe’s accelerated expansion.

Physicists spotted a “terribly exciting” new black hole, doubled down on weakening dark energy, and debated the meaning of quantum mechanics.

Tony Tyson’s cameras revealed the universe’s dark contents. Now, with the Rubin Observatory’s 3.2-billion-pixel camera, he’s ready to study dark matter and dark energy in unprecedented detail.

Last year, an enormous map of the cosmos hinted that the engine driving cosmic expansion might be sputtering. Now physicists are back with an even bigger map, and a stronger conclusion.

Physicists discovered strange supersolids, constructed new kinds of superconductors, and continued to make the case that the cosmos is far weirder than anyone suspected.

The largest-ever 3D map of the cosmos hints that the dark energy that’s fueling the universe’s expansion may be weakening. One community of theoretical physicists expected as much.