Scientific puzzles don’t come much bigger than these. How old is the Universe? How big is it? And what is its ultimate fate?
A single number, Hubble’s constant, is the key that can unlock all of those questions, but it’s a number that has proved notoriously hard to accurately measure. Hubble’s constant is the rate at which the Universe is expanding. The first team to accurately make that measurement was co-led by Jeremy Mould, now a professor at Swinburne University of Technology and professorial fellow at the University of Melbourne. Continue reading Measuring the Universe from start to finish→
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.”
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→
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.
Imagine printing your own room lighting, lasers, or solar cells from inks you buy at the local newsagent. Jacek Jasieniak and colleagues at CSIRO, the University of Melbourne and the University of Padua in Italy, have developed liquid inks based on quantum dots that can be used to print such devices and in the first demonstration of their technology have produced tiny lasers. Quantum dots are made of semiconductor material grown as nanometre-sized crystals, around a millionth of a millimetre in diameter. The laser colour they produce can be selectively tuned by varying their size.
High tech cling wraps that ‘sieve out’ carbon dioxide from waste gases can help save the world, says Melbourne University chemical engineer, Colin Scholes who developed the technology. The membranes can be fitted to existing chimneys where they capture CO2 for removal and storage. Not only are the new membranes efficient, they are also relatively cheap to produce. They are already being tested on brown coal power stations in Victoria’s La Trobe Valley, Colin says. “We are hoping these membranes will cut emissions from power stations by up to 90 per cent.”
Far outback in Western Australia, at the Murchison Radio Astronomy Observatory located on Boolardy Station, 315 km north-east of Geraldton, 32 tiles each carrying 16 dipole antennas have begun to collect scientific data on the Sun. At the same time they are providing engineering information to be used to extend the facility to a much bigger array of 512 tiles – the Murchison Widefield Array (MWA).
Macquarie University laser physicists are part of a consortium developing a micro-processing platform that will revolutionise photonic chip fabrication. This technology has implications for a diverse range of applications such as fibre-to-thehome (FTTH), smart sensor arrays for aircraft, biosensing and astronomy.
Western Australia’s International Centre for Radio Astronomy Research (ICRAR) is only three months old but is rapidly expanding—much like the early Universe. ICRAR’s scientists have ambitious projects ahead contributing to global science and engineering through the SKA.