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Hubble constant

Distorted galaxies
Abstractions blog

A New Cosmic Tension: The Universe Might Be Too Thin

September 8, 2020

Cosmologists have concluded that the universe doesn’t appear to clump as much as it should. Could both of cosmology’s big puzzles share a single fix?

Magnetic fields in the universe.
cosmology

The Hidden Magnetic Universe Begins to Come Into View

July 2, 2020

Astronomers are discovering that magnetic fields permeate much of the cosmos. If these fields date back to the Big Bang, they could solve a major cosmological mystery.

An image of space with lines emanating from a central point, as if the viewer is traveling at warp speed.
Abstractions blog

What Might Be Speeding Up the Universe’s Expansion?

April 27, 2020

Physicists have proposed extra cosmic ingredients that could explain the faster-than-expected expansion of space.

Antares photograph.
Abstractions blog

New Wrinkle Added to Cosmology’s Hubble Crisis

February 26, 2020

A problem confronts cosmology: Two independent measurements of the universe’s expansion give incompatible answers. Now a third method, advanced by an astronomy pioneer, appears to bridge the divide.

An illustration of the cosmologists Wendy Freedman and Adam Riess debating the expansion rate of the universe at a recent meeting at the Kavli Institute for Theoretical Physics in Santa Barbara, California.
cosmology

Cosmologists Debate How Fast the Universe Is Expanding

August 8, 2019

New measurements could upend the standard theory of the cosmos that has reigned since the discovery of dark energy 21 years ago.

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

May 1, 2018

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: man using rulers stacked on a compass as a telescope
insights puzzle

Solution: ‘Triangulation and Motion Sickness’

January 30, 2018

A method for estimating distances in sailing and astrophysics helps explain why riding on buses and boats can make us nauseous.

Illustration: man using rulers stacked on a compass as a telescope
insights puzzle

How Triangulation Leads to Knowledge

January 4, 2018

What does measuring distances in sailing and astrophysics have to with motion sickness?

Artist’s rendering of merging neutron stars.
cosmology

Colliding Neutron Stars Could Settle the Biggest Debate in Cosmology

October 25, 2017

Newly discovered “standard sirens” provide an independent, clean way to measure how fast the universe is expanding.