Australasian Science Magazine Issue December 2010
How Does a Black Hole Eat Its Breakfast?
A large black hole located at the centre of an active galaxy. An accretion disk forms as matter falls inwards from the galaxy. The matter forms a spiral disc that is compressed and heated so that it begins emitting photons. The accretion disk becomes so hot that its radiation physically pushes matter away from the black hole, and accelerates gas into the jets that emerge from its poles.
By David Floyd
The bending of space–time by mass allows astronomers to peer deep into the universe, and they have begun to use this to probe one of the most enigmatic phenomena in the universe: the explosions of light surrounding black holes known as quasars.
David Floyd is an Australian Astronomical Observatory “Magellan Fellow” and researcher at the University of Melbourne.
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Turning Water into Fuel
A major challenge facing the world is to develop sustainable, non-carbon-based sources of energy. One of the most obvious, renewable and non-carbon-based sources of energy is sunlight.
By Zhiguo Yi and Ray Withers
A simple inorganic semiconductor could deliver an artificial photosynthesis process that will convert sunlight and water directly into hydrogen and oxygen, thus providing the renewable fuel of the future.
Zhiguo Yi is a Postdoctoral fellow and Ray Withers is Professor of Materials Chemistry at the Research School of Chemistry, Australian National University. The assistance of Tim Wetherell in the writing of this article is acknowledged.
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New Tactics in the War on Weeds
The native herb Lomandra stands alone in front of the invasive weed African lovegrass, which was introduced into Australia for pasture improvement but was found to be unpalatable to grazing livestock and native animals.
By Jennifer Firn
Sometimes fertilisers can be more effective than herbicides when it comes to controlling weeds.
Dr Jennifer Firn is OCE Postdoctoral Fellow at CSIRO Ecosystem Sciences.
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Thank God for the New Atheists
Richard Dawkins is one of the New Atheists who are fulfilling the traditional role of prophets. Getty Images
By Reverend Michael Dowd
Religious people of all backgrounds and orientations need to heed what atheists such as Richard Dawkins are saying if they want their traditions to remain relevant to modern society.
Rev. Michael Dowd is the author of Thank God for Evolution: How the Marriage of Science and Religion Will Transform Your Life and Our World (2009, Plume). See http://ThankGodforEvolution.com
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Dangerous Ground
Tim Inglis searching for B. pseudomallei in the Kimberley.
By Tim Inglis
A deadly bacterium lies dormant in tropical soils until it is disturbed by natural disasters, mining operations or even gardening.
Tim Inglis is a medical microbiologist with PathWest Laboratory Medicine WA, QEII Medical Centre, Perth.
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Spitting Image
An archerfish spits a carefully aimed jet of water to knock an unsuspecting insect down to the water.
By Shelby Temple
Archerfish are known for their remarkable hunting technique of spitting water at insects above the water, and their eyes are specially adapted for seeing both above and below the water’s surface.
Archerfish have earned their name for spitting jets of water at insects to knock them down to the water’s surface where they can be eaten. However, what is most incredible is not that they can spit, but that they can spit accurately despite the distortion that occurs due to refraction as light travels from air to water. Recent research is giving us new clues as to how they achieve their astonishing accuracy.
Heat Stress in a Warming World
Global warming is, unsurprisingly, making heat waves hotter.
By Steven Sherwood, Tord Kjellstrom and Donna Green
Heat stress could be the most dangerous consequence of global warming this century.
Imagine you are working in a Vietnamese shoe factory without air conditioning. During the hot season, as temperatures soar towards 40°C inside the stifling building, your production targets remain fixed. To maintain your output you are allowed to take a little longer on your breaks to cool down. Still, the sweltering heat means that you just can’t work as efficiently, so in order to complete your work you start an hour earlier and finish later.
The National Science Curriculum: Not Yet!
By Professor John Rice
The draft science curriculum scores a “fail, more work needed” from the Deans of Science.
The Australian Curriculum Assessment and Reporting Authority (ACARA) has been developing a national K–12 curriculum for more than
18 months. It is currently discussing a draft of a K–10 science curriculum with state and territory education authorities.
Flu Recombination Risk High
A future pandemic with more severe effects than last year’s could gain resistance through co-infection with a seasonal variety.
By Stephen Luntz
The discovery of high rates of co-infection between two versions of the flu virus has raised the danger of a drug-resistant flu pandemic.
“Last year our influenza season began with the circulation of the regular seasonal A/H1N1 strain, which is Tamiflu-resistant,” says Dr Matthew Peacey of New Zealand’s Institute of Environmental Science and Research. “This seasonal A/H1N1 strain was rapidly overtaken by the worldwide pandemic A/H1N1 strain. In New Zealand there was a short 4–5-week period when both strains were circulating within the community, and in some cases both strains were able to infect a single patient.”
Vitamin Deficiency Doubles Schizophrenia Risk
By Stephen Luntz
Important evidence has firmed up the suspected link between vitamin D deficiency and schizophrenia.
Babies in Denmark routinely have blood samples taken at birth, and analysis of these published in the Archives of General Psychiatry shows that those who were deficient in vitamin D have twice the rate of schizophrenia as adults.
The finding is far from a surprise. Evidence for connections between vitamin D deficiency in the latter months of pregnancy and increased risk of schizophrenia has been growing for many years (AS, July 2005, pp.35–38).
Polygyny History Found in Non-Coding DNA
By Stephen Luntz
If you want to know about certain aspects of human history you need to avoid looking at the genes, argues Dr Murray Cox, a computational biologist at Massey University’s Institute of Biosciences. Instead it is important to look at non-coding DNA that is located well away from the genes, as data from genes can pollute the sample.
Cox was part of a team seeking evidence for polygyny – the practice of men having multiple wives. He compared patterns in X chromosomes, which spend the majority of their history in women, with those of the non-sex chromosomes, which spend equal time in men and women. The Y chromosome is too small to offer as many data points as Cox was seeking.
Moa Males Hatched Eggs
Moa egg shells were remarkably thin for their size, providing indications that males incubated eggs. Photo: S. Brookbanks
By Stephen Luntz
Detective work on egg shells from moa have provided insights into the behaviour of these extinct species, including evidence that males kept eggs warm prior to hatching.
Along with colleagues at Griffith University, Dr Craig Miller of the University of Auckland’s School of Biological Sciences collected DNA from the outside of remnant moa egg shells. Miller was able to match the DNA with samples from bones to identify which species the eggs came from, including some of the largest of the ten known moa species.
Vale Frank Fenner, Vanquisher of Smallpox
By Stephen Luntz
One of Australia’s greatest scientists, Professor Frank Fenner, passed away on 22 November 2010 after a short illness. He was 95.
Fenner studied science and medicine at the University of Adelaide before joining the Army Medical Corp. He was awarded an OBE for his work combating malaria in New Guinea.
Fenner first came to prominence when he, along with Macfarlane Burnet and Ian Clunies Ross, injected themselves with the myxoma virus to prove it was harmless to humans. The subsequent release of the virus controlled rabbit plagues for decades until resistance became widespread.
Fossilised Stromatolites Push Back Date for the Great Oxidation Event
These fossilised stromatolites may have been producing oxygen 270 million years earlier than previously accepted. Photo: David Flannery
By Stephen Luntz
The fossilised stromatolites of the Pilbara region are among the oldest evidence for life we know. Now it appears some are even older than first thought, possibly pushing back the date at which oxygen-forming species appeared by 270 million years.
Between 2.45 and 2.32 billion years ago the Earth experienced the Great Oxidation Event, in which the atmosphere first gained a high oxygen content. While this is accepted, there is much debate about what happened earlier.
Evidence for Family Cancer Syndromes
By Stephen Luntz
A study of women diagnosed with cancer before the age of 35 has found that their close relatives have double the risk of cancer for the general population.
The findings held true even after women with the BRCA1 and BRCA2 breast cancer gene mutations were removed as these mutations are already associated with family histories of ovarian and prostate cancer, respectively.
“The results suggest there could possibly be undiscovered genes causing breast cancer in these young women, and perhaps other cancers in their families,” says Prof John Hopper, Director of Research from the Centre for Molecular, Environmental, Genetic and Analytic Epidemiology at the University of Melbourne.
Rust Never Sleeps
Robert Park (right) inspects wheat plots in Ethiopia.
By Stephen Luntz
The battle against crop diseases is gaining increased attention, and Robert Park plays a leading role in keeping the world fed.
Prof Robert Park helps to ensure that our shelves stock affordable bread and pasta, standing guard against the diseases and pests that once made food supplies unreliable.
Park is a leader in the fight against wheat rust, a fungus that has historically been the most significant suppressor of wheat production. In 1973 an epidemic of stem rust reduced wheat yields by $200–300 million across south-eastern Australia. “Today something of the same size would cost more than $1 billion dollars,” says Park.
Australia’s Acoustic Environmental Accounts
Birds, bats, frogs and a few insects will dominate the data collected by the network but it is still a cheap and effective start to monitoring biodiversity at a continental scale
By Professor Hugh Possingham
A network of acoustic monitoring boxes spread across Australia’s bioregions could provide a cheap continent-wide biodiversity surveillance system providing feedback on how biodiversity is changing over time.
Interest in developing environmental accounts for Australia is enormous. The reason is simple – people have realised that if we can’t find credible and transparent metrics to quantitatively predict the consequences of policy and management on environmental issues like biodiversity, then those issues will always take a back seat to economic measures in policy development. This means that our growth in GDP, and other metrics like interest rates, will dominate our leaders’ attention rather than our declines in biodiversity.
An Irrigation Channel Too Far
The confluence of the Murray and Darling rivers at Wentworth, NSW.
By Ian Lowe
How much will reduced water allocations in the Murray–Darling Basin really hurt regional communities?
The media has been full of confected outrage about the Murray–Darling Basin Plan even though we have known for at least 15 years that the Basin was in deep trouble as a direct result of over-allocation of water for irrigation. The 1996 State of the Environment report noted that the approved extraction was 80% of the median annual flow. Clearly, then, water allocations have to be reduced.
The Truth About Skeptics
Our minds shouldn’t be so open that our brains fall out.
By Peter Bowditch
A skeptic is not a cynic, an atheist or a poor speller. So what, then, is a skeptic?
The word “skeptic” has been hijacked by people who should more correctly be described as “denialists”. The following definition of denialism appears in several places on the Internet:
How Much Do Stars Weigh?
A planet/moon transit that may be imaged by NASA’s Kepler spacecraft.
By David Reneke
Dave Reneke brings news from the space and astronomy communities around the world.
How do astronomers weigh a star that’s trillions of kilometres away and way too big to fit on a bathroom scale? In most cases they can’t, although they can “guesstimate” using computer models of stellar structure.
New work by Dr David Kipping of University College, London says that in special cases we can weigh a star directly. If the star has a planet, and that planet has a moon, and both of them cross in front of their star, then we can measure their sizes and orbits to learn about the star. This is cutting-edge astronomy.
Nobel Committee Brushes Ethics Aside
By Michael Cook
What did the Swedes have in mind when they awarded the 2010 Nobel Prize in Medicine to the inventor of the test-tube baby?
The Nobel Prize for Medicine is given for a “discovery” that has “conferred the greatest benefit on mankind”. IVF, though, is more a clinical application than a theoretical advance. So when the 2010 prize was given to British biologist Robert G. Edwards, the father of French IVF, Jacques Testart, expressed his disdain for the Nobel committee’s choice in the journal Quotidien du Médecin: “That deserves a Nobel? I thought that the prize was meant for discoveries, not for inventions.”
A Plan So Cunning... Or Courageous
By Simon Grose
The government’s backflip on a carbon price was politically opportunistic, but public support could suffer if global emissions keep rising.
Labor Senator and eminence grise John Faulkner has observed that his party has come to be seen as “cunning rather than courageous”. Prime Minister Julia Gillard’s policy reversal on a carbon price could be seen to be either – or even both – depending on your view on dealing with climate change.
It was also boldly duplicitous, a fact that failed to anger the general polity, indicating that soon after an election win is probably the best time for you to change your tune.
