Most read science stories of 2019

This year’s most popular science stories took readers from melting Antarctic ice sounding the alarm on microbes and climate change, to a pest-proof fence to protect native wildlife in far western NSW, and early signs of life in ancient rocks in the Pilbara, WA.

Sea ice

Antarctic sea ice with a brown layer of ice algae. These microbes thrive in sea ice and are the beginning of many food webs, which branch out to feed larger lifeforms. The melting sea ice has a downstream effect on ice algae, which means a diminished food web and greater risk of starving ocean life. Picture: Rick Cavicchioli

Maths whiz solves 48-year-old multiplication problem

David Harvey solves maths problem

A/Prof David Harvey demonstrates the traditional method of multiplication which is impractical when multiplying huge numbers. Picture: Natalie Choi

A UNSW Sydney mathematician cracked a decades-old maths problem that allows quick multiplication of huge numbers.

Associate Professor David Harvey, of UNSW’s School of Mathematics and Statistics, said the new method was a lot faster than the familiar “long multiplication” method people might remember learning in school.

“More technically, we have proved a 1971 conjecture of Schönhage and Strassen about the complexity of integer multiplication,” A/Prof Harvey said.

“They predicted that there should exist an algorithm that multiplies n-digit numbers using essentially n * log(n) basic operations.

“Our paper gives the first known example of an algorithm that achieves this.”

Earliest signs of life: scientists find microbial remains in ancient rocks

dresser_formation.jpg

Ridges in the ancient Dresser Formation in the Pilbara Craton of Western Australia that preserve ancient stromatolites and hot spring deposits. Picture: Kathleen Campbell

Western Australia’s renowned 3.5-billion-year-old stromatolites contain microbial remains of some of the earliest life on Earth, UNSW scientists found.

Scientists discovered the well-preserved organic remnants in some of the fossilised microbial structures from the ancient Dresser Formation in the Pilbara.

The stromatolites were believed to be of biogenic origin – primarily composed of plant and animal remains – when they were discovered in the 1980s, but this research was the first to reveal the definitive presence of preserved organic matter.

Lead researcher Dr Raphael Baumgartner, research associate at the Australian Centre for Astrobiology in Professor Martin Van Kranendonk’s team at UNSW, said the finding was an exciting leap forward in the world of geology and offered clues for how life on Earth originated.

Prof Van Kranendonk said the revelation was the closest the team had come to a “smoking gun” to prove the existence of such ancient life.

“This represents a major advance in our knowledge of these rocks, in the science of early life investigations generally, and – more specifically – in the search for life on Mars. We now have a new target and new methodology to search for ancient life traces,” Prof Van Kranendonk said.

200 times faster than before: the quickest quantum operation yet

MIchelle Simmons and team

Prof Michelle Simmons with her team’s latest breakthrough in quantum computing. Pictured, left to right: Prof Simmons, Dr Sam Gorman, Dr Yu He, Ludwik Kranz, Dr Joris Keizer and Daniel Keith.

A group of physicists at UNSW Sydney built a super-fast version of the central building block of a quantum computer – the realisation of a 20-year vision.

The team of scientists, led by 2018 Australian of the Year Professor Michelle Simmons, achieved the first two-qubit gate between atom qubits in silicon – a major milestone on the team’s quest to build an atom-scale quantum computer. The pioneering research was published in world-renowned journal Nature.

A two-qubit gate is the central building block of any quantum computer – and the UNSW team’s version of it is the fastest that’s ever been demonstrated in silicon, completing an operation in 0.8 nanoseconds, which is ~200 times faster than other existing silicon spin-based two-qubit gates.

Prof Simmons, Director of the Centre of Excellence for Quantum Computation and Communication Technology (CQC²T) and founder of Silicon Quantum Computing Pty Ltd, said the past decade of research challenged and inspired her team to shift the boundaries of what was previously thought possible.

“We’ve really shown that it is possible to control the world at the atomic scale and, that the benefits of the approach are transformational, including the remarkable speed at which our system operates,” she said.

Excluding microbes from climate change will have dire consequences

Climate change is a threat to microbes which live on sea ice. Sea ice cover levels are believed to have changed dramatically about 32,000 to 40,000 years ago. Picture: Shutterstock

A group of leading microbiologists warned that excluding microbes – the biosphere’s support system – from the problem of climate change will have a devastating impact.

More than 30 microbiologists from nine countries called for the world to heed the “unseen majority” in Earth’s biodiversity and ecosystem when discussing climate change.

Professor Rick Cavicchioli, microbiologist at the School of Biotechnology and Biomolecular Sciences at UNSW Sydney, led the global campaign to raise awareness about how microbes can influence climate change and how climate change will affect microbes.

“Micro-organisms, which include bacteria and viruses, are the lifeforms that you don’t see on the conservation websites,” says Prof Cavicchioli.

“They support the existence of all higher lifeforms and are critically important in regulating climate change. However, micro-organisms are rarely the focus of climate change studies and are not considered in policy development.”

Huge feral-free haven ready for return of native mammals

The Wild Deserts team have created a sanctuary for native Australian animals in the Sturt National Park that is completely free of feral animals

Workers finish one of the fenced safe haven areas for native wildlife in Sturt National Park. Picture: UNSW

UNSW scientists have built a 40-square-kilometre sanctuary for native Australian animals in far western NSW that has no feral animals such as rabbits, foxes or cats.

The zone, in Sturt National Park, is part of a major project to reintroduce locally extinct mammals such as the bilby to desert habitat.

After completing 40km of special feral-proof fencing in October 2018, the Wild Deserts team, a partnership between UNSW, Ecological Horizons and the NSW government, removed every rabbit, cat and fox from two fenced exclosures, each 4km x 5km.

UNSW scientist and Wild Deserts project co-ordinator Dr Reece Pedler, who lives in the park, said it had been a been a huge effort to eradicate the pest animals from such a large area.

“This 40-square-kilometre area now represents one of the largest rabbit-free areas in the country – this is an amazing achievement given these deserts supported millions of rabbits in the past, which decimated vegetation, causing soil erosion and the loss of our native fauna,” Dr Pedler said.

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