About a century ago, we didn’t even know that galaxies existed.
Mai Lam/The Conversation NY-BD-CC
Pretty much as soon as we understood what galaxies were, we realised they are all moving away from each other. And the ones that are further away are moving faster. In short, the universe is expanding.
Artist s impression of merging neutron stars.
Author University of Warwick/Mark Garlick
Cosmologists who were hoping to be the next Einstein have had to bin their theories.
Image showing where scientists believe dark matter resides in the galaxy cluster Abell 520
– near the hot gas in the middle, coloured green.
Chandra X-ray Observatory Center
Controversial new study challenges contemporary thinking about what the universe is made of.
Part of the new map of dark matter made from gravitational lensing measurements of 26 million galaxies in the Dark Energy Survey.
Chihway Chang/University of Chicago/DES collaboration
We still can't see the dark matter thought to make up about a quarter of the universe, but at least now we have a map of its structure.
Simulated universe: EAGLE collaboration, J Schaye et al 2015.
Is dark energy just an illusion, as is often suggested? To resolve the dilemma, interpreting the basic principles of general relativity in a complex Universe may need a rethink.
There are two broad ways to measure the expansion of the universe. One is based on the cosmic microwave background, shown here, along with our own galaxy viewed in microwave wavelengths.
ESA, HFI & LFI consortia (2010)
The universe is expanding faster than expected, but we don't know what's driving it. Here are a few of the possible explanations, from dark energy to a modification of general relativity.
Artist’s impression of the Square Kilometre Array.
SKA Project Development Office and Swinburne Astronomy Productions/wikimedia
Dark energy is a completely unknown source making up 70% of the universe. Will any of the new projects designed to find out what it is succeed?
CSIRO’s Compact Array telescope under the Milky Way.
Astronomers think they may have found evidence within our galaxy of some of the missing matter thought to make up our universe.
Our tendency to see what we want to see is the biggest threat to cosmology.
Confirmation bias, the psychological effect that makes people unconsciously interpret information to confirm their beliefs, is a big threat to cosmology.
Understanding how galaxies are arranged could be the key to figuring what causes the expansion of the universe.
ESA/Hubble, NASA and S. Smartt (Queen's University Belfast)
A unique map of the galaxies in the sky could shed light on the mysteries of the universe – including dark energy and dark matter.
How do we think about something we can’t see and don’t experience in our everyday lives, but seems to be pushing our universe apart ever faster?
NASA, ESA, G. Illingworth, D. Magee, and P. Oesch (University of California, Santa Cruz), R. Bouwens (Leiden University), and the HUDF09 Team
Einstein's theory of gravity says dark energy must be out there, accelerating the expansion of our universe. But what is it and how can we try to figure out more about it?
Dark Matter: as simulated, the scaffold that underpins the universe.
Dark matter's mysteries are being steadily unravelled by new studies of remote galaxies.
Research of a supernova in our galaxy will increase the precision of which we can measure distances outside of our own galaxy…
If the signs are right, fundamental equations of cosmology may need altering.
A radical discovery by my colleagues and I – reported this week in Physical Review Letters – could help explain why it was possible for life (at least as we know it) to develop on Earth, but not in other…
Even the Hubble telescope, which took this picture of Bright Spiral Galaxy M81, is not capable of taking the wide-angle shots needed for all sky astrophysics, so new equipment must be invented.
Some astronomical questions can only be answered by looking at the whole sky all at once but the technology to do that doesn’t…
Is that a planet, a galaxy or a Rosetta Stone?
A vital part of professional astronomy is collecting data using large telescopes. In many cases, these telescopes are national or international facilities, with time available to all through a competitive…
Artistic view of a close-up of a supermassive black hole. This image shows the material surrounding the black hole, which ultimately will fall in the central region releasing the X-ray radiation detected in this work.
Astrophysicists have discovered black holes that formed up to 12.5 billion years ago – among the oldest examples of the phenomena…
What tasty treats await astronomers in the next few decades?
Predicting the future is a mug’s game. When I reflect back on what we thought we knew at the start of my research career in the mid-1990s, I sound like a wizened octogenarian, recalling a simpler time…
The universe teems with energy and matter we don’t understand.
In questioning the fundamental nature of the universe, cosmology regularly grabs the public’s attention. But in an era in which we are observing deeper and more widely than ever before, our knowledge of…
The existence of mysterious “dark energy” has been confirmed by surveying galaxy distribution in an unprecedented volume…