Tag Archives: dark energy

Geoffrey Rush talks stars

The search for the first stars and the hunt for dark energy both feature in a new planetarium show narrated by Geoffrey Rush. The show premiered in March 2016 at the Melbourne Planetarium and will be seen in planetariums around the world.

“I hope this show conveys some of the wonder of the Universe we live in,” says Professor Elaine Sadler, Director of the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).

The Murchison Widefield Array telescope is discovering when the first stars and galaxies formed.
The Murchison Widefield Array telescope is discovering when the first stars and galaxies formed
Credit: Alex Cherney/Museum Victoria

‘Capturing the Cosmos’ was created by Melbourne Planetarium and CAASTRO, and features the work of two of Australia’s new telescopes, the Murchison Widefield Array and Skymapper.

Continue reading Geoffrey Rush talks stars

Massive galaxy survey confirms accelerating Universe

The Universe is definitely getting bigger, faster—and astronomers using the Anglo-Australian Telescope in NSW have confirmed it.

The WiggleZ survey looked at over 200,000 visible galaxies (middle), but also gave insights into dark matter (the green grid that deforms the gravity field) and dark energy (the purple grid). Credit: NASA/JPL-Caltech
The WiggleZ survey looked at over 200,000 visible galaxies (centre), but also gave insights into dark matter (the green grid that deforms the gravity field) and dark energy (the purple grid). Credit: NASA/JPL-Caltec

The results are now in for WiggleZ, a survey of the night sky, spanning 200,000 galaxies and billions of years of cosmic history.

“This puts a nail in it. Clearly the universe is accelerating, and clearly there is something like dark energy,” says Prof Matthew Colless, director of the Australian Astronomical Observatory and a member of the WiggleZ team.
Continue reading Massive galaxy survey confirms accelerating Universe

Ten times more galaxies

THE 3.9 METRE ANGLO­-AUSTRALIAN TELESCOPE IS COLLECTING OPTICAL GALAXY DATA FOR THE GAMA SURVEY. CREDIT: BARNABY NORRIS.

A new ‘super survey’ is producing the largest database of galaxy measurements, spanning the last five billion years of cosmic history. The International Galaxy and Mass Assembly (GAMA) project is combining data from ground-and space-based observatories to measure the ‘haloes’ of dark matter that surround galaxies.

“The Cold Dark Matter (CDM) model of cosmology makes predictions about how galaxies cluster and, in many cases, collide and merge,” says Andrew Hopkins, a GAMA team member. “Our measurements of the speeds of galaxies will reveal the distribution of dark matter, and enable us to test the CDM model.”

Continue reading Ten times more galaxies

Spinning galaxies reveal missing matter

PHOTO: DARK MATTER DOMINATES GALAXIES AND GROUPS OF GALAXIES, YET ITS IDENTITY REMAINS UNKNOWN. CREDIT: DAVID MALIN, AUSTRALIAN ASTRONOMICAL OBSERVATORY.
PHOTO: DARK MATTER DOMINATES GALAXIES AND GROUPS OF GALAXIES, YET ITS IDENTITY REMAINS UNKNOWN. CREDIT: DAVID MALIN, AUSTRALIAN ASTRONOMICAL OBSERVATORY.

Australian astronomers have long been contributing to our understanding of a strange cosmological phenomenon—the Universe’s missing matter.

In the early 1970s, Ken Freeman of the Australian National University (ANU) determined that spiral galaxies must contain more matter than we can see. He postulated that dark matter—an invisible material first proposed 40 years earlier—must make up at least half the mass of these galaxies. Now, patches of dark matter are thought to be scattered across the Universe, playing a major role in holding galaxies and groups of galaxies together. Continue reading Spinning galaxies reveal missing matter

Galaxies point the way to dark energy

WiggleZ will hunt for dark energy in the faint patterns of 293,000 distant galaxies. Credit: NASA / ESA / HUDF09 Team

A project to produce more than double the number of galaxy distance measurements than all other previous surveys, could lead to an explanation of one of nature’s biggest mysteries—whether dark energy, an invisible force that opposes gravity, has remained constant or changed since the beginning of time.

Continue reading Galaxies point the way to dark energy

L’Oréal Fellow looking for dark energy

Tamara Davis is looking for dark energy. Credit: timothyburgess.net
Tamara Davis is looking for dark energy. Credit: timothyburgess.net

In 1998 astronomers made an astonishing discovery—the expansion of the Universe is accelerating. The discovery required a complete rethink of the standard model used to explain how the Universe works.

“Now we know that stars, planets, galaxies and all that we can see make up just four per cent of the Universe,” says Dr Tamara Davis, a University of Queensland astrophysicist.

“About 23 per cent is dark matter. The balance is thought to be dark energy, which we know very little about.”

Continue reading L’Oréal Fellow looking for dark energy

On the hunt for dark energy

Tamara Davis

University of Queensland / University of Copenhagen

In 1998 astronomers made an astonishing discovery-the expansion of the Universe is not happening at a steady rate, nor is it slowing down toward eventual collapse. Instead, it is accelerating. The discovery required a complete rethink of the standard model used to explain how the Universe works.

Tamara Davis, University of Queensland / University of Copenhagen (Photo credit: timothyburgess.net)

“Now we know that stars, planets, galaxies and all that we can see make up just four per cent of the Universe,” says Tamara Davis, a University of Queensland astrophysicist.

“About 23 per cent is dark matter. The balance is thought to be dark energy, which we know very little about.”

Continue reading On the hunt for dark energy