Category: Science

MeerKAT to get an optical companion

It can happen in the blink of an eye: millions of light years away a star collapses in on itself. From Earth, that cataclysmic event is only a sudden brightening of a point in the night sky, and on the ground, astronomers scramble to investigate it.

A new telescope, to be installed at South Africa’s Sutherland astronomy site in the next year, will catch these faint flickerings, among others, and help us understand more about what is happening in the universe.

But what makes it different from other optical telescopes observing these transient astronomical phenomena in Sutherland is that the MeerLicht (“more light” in Dutch) telescope will be linked directly to South Africa’s MeerKAT radio telescope, more than 200km away.

“This is a novel way of doing things – creating a real-time link with optical and radio telescopes,” says Patrick Woudt, head of astronomy at the University of Cape Town and South Africa’s principal investigator on the MeerLicht project.

 

For more, you can read the rest of the story here.

New app for small-scale fishing industry

A free app – co-developed by academics, government, civil society and fishing communities – will be the lynchpin in the government’s efforts to launch and roll out a small-scale fishing industry in South Africa.

Traditional and artisanal fishing communities, according to an Equality Court ruling in 2007, have been consistently marginalised during both apartheid and in the democratic South Africa. With a new small-scale fisheries policy, almost nine years in the making, the government is attempting to redress the situation.

The foundation of this policy is data and the co-management of South Africa’s resources.

The app, known as Abalobi (abalobi bentlanzi is isiXhosa for someone who fishes), will be the information management system for the small-scale fisheries industry, says Craig Smith, the director of small-scale fisheries management in the department of agriculture, forestry and fisheries.

In South Africa, living marine resources are allocated via fishing permits, but only three groups were previously recognised groups: commercial, recreational and subsistence.

To continue reading, you can find the story here.

10 things to know about SA’s 2016 science budget vote

To save you having to watch Parliament TV when no one is toyi-toying, or reading the minister’s 17-page speech, here are my top 10 things to take away from this year’s science and technology budget vote.

State of the Cosmos: gravitational waves

This was perhaps the worst-kept secret in all of science: the detection of gravitational waves.

It has been seeping out of sources like leaky taps. But on 11 February, it was finally announced that scientists had detected gravitational waves.

Gravitational waves are distortions in space and time that – rather than the force of “gravity” – explain the dances of planets, stars and galaxies.

In 1916, in his theory of General Relativity Albert Einstein predicted the existence of these gravitational waves, linking space and time. Now, a century later, scientists from the California Institute of Technology, the Massachusetts Institute of Technology and the LIGO scientific collaboration called the media together to tell them what they have been anticipating for weeks.

LIGO, which stands for Laser Interferometer Gravitational-wave Observatory, is a system of two detectors, one in Louisiana and the other in Washington.

LIGO
LIGO

Each detector involves two 4km tunnels that meet at right-angles (like an L). A laser beam is split to run down the two tunnels, and is then reflected back and forth down the tunnel. There is a detector at the juncture of the two arms.

If there are no gravitational waves, the laser beams cancel each other out at the detector (because the laser beams have both travelled the same distance). But if there is a ripple in space time, the distance travelled by the beams differs slightly, and this is picked up at the detector.

Think of two people at opposite sides of the equator who start walking towards the North Pole: they will meet eventually, not because there is a force pulling them together, but because the planet is curved. The same idea applies into the rest of the universe, explaining the motion of planets and stars.

Although the dedicated gravitational-wave-hunting facility has been around since 2002, by 2010 it hadn’t detected the merest ripple. It got a five-year overhaul, and opened for business again in September 2015. Within six months, this $620-million facility has brought something to the table.

To be fair, though, gravity is a very weak force (comparatively) and gravitational waves are very difficult to detect (which is an example of stating the obvious because despite billions of dollars in experiments around the world, this is the first time they have been detected).

The scientists on Thursday announced that they had detected the “ringing” of two black holes colliding about 1.3-billion light years away.

Unlike other claims that were later disproved, this group came prepared with a peer-reviewed paper, published in Physical Review Letters.

“Up to now, we’ve been deaf to gravitational waves, but now we can hear them,” David Reitze, LIGO executive director at Caltech, said. “We’ll hear things we expected to hear … But also things we never expected.”

The plight of South Africa’s great white sharks

South Africa’s great white shark may be under threat, and while that may be music to the ears of anyone terrified by the movie Jaws, this actually may have dire consequences for the balance of the local ecosystem.

More than 90% of South Africa’s great white sharks share the same genetic sequence, threatening their genetic diversity and the future of the unique type of great white found in South Africa’s waters, according to research out of Stellenbosch University.

Great white sharks are “important for the balance in the ecosystem”, says Dr Sara Andreotti, who undertook the research as part of her PhD. “They get rid of sick individuals from other species and they maintain a balance in the population numbers.”

 

For more, find the full article — first published on Htxt Africa — here.

Plant dupes dung beetles

It looks like a pellet of buck dung, it smells like one too, but the centimetre-long seed is not dung, and is one of the few proven instances of sensory deception for seed dispersal.

“The smell is incredible,” says Jeremy Midgley, a professor in biological sciences at the University of Cape Town. “From the smell, we should have known there was something going on.”

The relatively large seeds of long-grass-like Ceratocaryum argenteum have such a pungent odour that they fool dung beetles into thinking that they are pellets of dung. The findings of the research were published in journal Nature Plants earlier this month.

Below is a multimedia clip made by Nature:

 

“As the seeds are hard and offer no reward to the dung beetles, this is a remarkable example of deception in plant seed dispersal,” the authors write in the paper.

Midgley was initially convinced that a rodent species was removing the seeds and eating or burying them. During a field trip to the De Hoop Nature Reserve in the southern Cape, Midgley, UCT small mammal expert Dr Gary Bronner and masters student Joseph White set up motion-sensitive cameras to see what was happening to the seeds.

“We used motion-sensing trail cameras to observe small mammal interactions with the nuts under field conditions, and it seemed that they were either disinterested or even repelled by the seeds,” White says. While a field mouse species ate the insides of the seeds if they happened to be cracked, they did not hoard them.

Instead they saw that dung beetles removed the hard-shelled seeds and buried them, thinking that they were dung. The advantages for the plant are that its seeds do not get incinerated in the fire-prone area and that they get dispersed, but the dung beetle “can’t eat them or lay its eggs inside them”, Midgley says.

The team included University of KwaZulu-Natal professor Steve Johnson, who undertook a chemical analysis of the seeds. He found that the volatiles [the chemicals which create the aroma] were three hundred times higher in the C. argenteum seeds than in seeds of other plants in the family (Restionaceae). “The volatile composition of emissions from C. argenteum seeds is similar to that of the dung of large mammalian herbivores, particularly eland and bontebok,” the authors write in their paper.

But because the seeds are only around for two to three weeks of the year, the dung beetles have not adapted to recognise the different between dung and the C. argenteum seeds, Midgley says. “There isn’t enough time for beetles to get smarter about what is dung and what isn’t.”

Researchers plug carbon sink gaps

The stormy waters south of the Cape suck carbon dioxide out of the atmosphere and are key to understanding what will happen to our climate as the Earth heats up.

The storms are part of the reason the Southern Ocean is one of the most under-researched in the world, although it absorbs almost half of the world’s man-made carbon emissions.

Last week, more than 50 researchers returned from a scientific voyage of the waters encircling Antarctica, the first leg of a two-year experiment – the third Southern Ocean Seasonal Cycle Experiment – that aims to fill in many of the blank spaces about how this ocean mitigates the effects of climate change.

A report from the United Nation’s Intergovernmental Panel on Climate Change, released last year, says the world is already experiencing climate change. “African ecosystems are already being impacted by climate change, and the future impacts are expected to be substantial,” it said.

Mediating global climate
Pedro Monteiro, chief oceanographer of the Council for Scientific and Industrial Research and head of the CSIR’s Southern Ocean Carbon-Climate Observatory programme, says: “Globally, there is a renewed interest in understanding what is going on in the Southern Ocean from a climate perspective and how it mediates global climate.

“Although anthropogenic carbon dioxide emissions – those created by humans – are well studied and account for about 10 gigatonnes per year, the natural carbon cycle between the ocean and the atmosphere is substantially larger at 100 gigatonnes per year and is less understood,” he says.

But, because of the stormy and cold weather in the Southern Ocean, researchers struggle to obtain scientific measurements during winter, something that this experiment plans to change.

 

For more, find the article — originally published in Mail & Guardian — here.

Stem cell research outstrips legislation

It starts in a dish: a collection of cells that can be made to grow into corneas, hearts or livers, or used to treat currently incurable diseases. This is the future that stem cell therapies could offer us, but the path to that future is strewn with ethical and legal pitfalls that South Africa needs strong laws and regulations to govern.

“The law has struggled to keep pace with science and medicine,” said Professor Michael Pepper, the director of the Institute for Cellular and Molecular Medicine at the University of Pretoria. “Things move too quickly and the law lags behind.”

Although there are only a few proven stem cell therapy treatments, namely blood stem cell transplants such as bone marrow transplants and skin stem cell grafts, future developments in the field could alter the trajectory of healthcare.

 

For more, find the article — originally published in Mail & Guardian — here.