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cosmology

Lede art for "A Radically Conservative Solution for Cosmology’s Biggest Mystery": This Hubble image shows RS Puppis, a type of variable star known as a Cepheid variable. As variable stars go, Cepheids have comparatively long periods— RS Puppis, for example, varies in brightness by almost a factor of five every 40 or so days. RS Puppis is unusual; this variable star is shrouded by thick, dark clouds of dust enabling a phenomenon known as a light echo to be shown with stunning clarity. These Hubble observations show the ethereal object embedded in its dusty environment, set against a dark sky filled with background galaxies.
Abstractions blog

A Radically Conservative Solution for Cosmology’s Biggest Mystery

Two ways of measuring the universe’s expansion rate yield two conflicting answers. Many point to the possibility of new physics at work, but a new analysis argues that unseen errors could be to blame.

Illustration for first stars
cosmology

Whisper From the First Stars Sets Off Loud Dark Matter Debate

A surprise discovery announced a month ago suggested that the early universe looked very different than previously believed. Initial theories that the discrepancy was due to dark matter have come under fire.

Illustration of a bowl of dark energy on a weighing scale
Abstractions blog

Why the Tiny Weight of Empty Space Is Such a Huge Mystery

The amount of energy infusing empty space seems too small to explain without a multiverse. But physicists have at least one alternative left to explore.

520px illustration of bottle beam
nuclear physics

Neutron Lifetime Puzzle Deepens, but No Dark Matter Seen

Two methods of measuring the neutron’s longevity give different answers, creating uncertainty in cosmological models. But no one has a clue what the problem is.

520px illustration for the bounce model theory
cosmology

How the Universe Got Its Bounce Back

Cosmologists have shown that it’s theoretically possible for a contracting universe to bounce and expand. The new work resuscitates an old idea that directly challenges the Big Bang theory of cosmic origins.

Magellan Baade telescope and CMB illustration
astrophysics

Earliest Black Hole Gives Rare Glimpse of Ancient Universe

It weighs as much as 780 million suns and helped to cast off the cosmic Dark Ages. But now that astronomers have found the earliest known black hole, they wonder: How could this giant have grown so big, so fast?

An artist’s conception of the Vela Supercluster peeking out from behind the Milky Way’s Zone of Avoidance.
astrophysics

Hidden Supercluster Could Solve Milky Way Mystery

Astronomers generally stay away from the “Zone of Avoidance.” When one astronomer didn’t, she found a giant cosmic structure that could help explain why our galaxy moves so fast.

A projection showing how the positions of some 2 million stars measured by the Gaia satellite are expected to evolve in the future.
Abstractions blog

Deathblow Dealt to Dark Matter Disks

New data tracking the movements of millions of Milky Way stars have effectively ruled out the presence of a “dark disk” that could have offered important clues to the mystery of dark matter.

Zoomable Universe - rectangular thumbnail
Multimedia

From the Edge of the Universe to the Inside of a Proton

The Zoomable Universe, a new book by the astrobiologist Caleb Scharf, the illustrator Ron Miller and 5W Infographics, tours the universe’s 62 orders of magnitude.