Weird Science: How did Aussie get its snakes?

Ever wonder where Australia's snakes - like this red-bellied black snake - slithered in from? Photo / 123RF

Ever wonder where Australia's deadly snakes slithered in from?

Scientists now have the answer, with a new study helping to explain how they descended from creatures that came from Asia over the past 30 million years.

Australian National University's Dr Paul Oliver said about 85 per cent of more than 1000 snake and lizard species in Australia descended from creatures that floated across waters from Asia to Australia.

The research helped explain how Australia has become home to about 11 per cent of the world's 6300 reptile species - the highest proportion of any country around the world.

"Around 30 million years ago it appears that the world changed, and subsequently there was an influx of lizard and snakes into Australia," Oliver said.

"We think this is linked to how Australia's rapid movement north, by continental movement standards, has changed ocean currents and global climates."

The researchers conducted the study using animal tree-of-life data combined with empirical evidence and simulations.

The origins for reptiles contrast with other famous Australian animal groups including marsupials and birds, which include many more species descended from ancestors that lived on Gondwana, a super continent that included Australia, Antarctica, South America, Africa and Madagascar.

Oliver said the study found that the immigration of reptiles into Australia was clustered in time.

"The influx of lizards and snakes into Australia corresponds with a time when fossil evidence suggests animal and plant communities underwent major changes across the world," he said.

"The movement of Australia may have been a key driver of these global changes."

Downloading data - to your clothes

A new type of smart fabric could pave the way for jackets that store invisible passcodes and open the door to your apartment or office.

US computer scientists have created fabrics and fashion accessories that can store data - from security codes to identification tags - without needing any on-board electronics or sensors.

The University of Washington team used previously unexplored magnetic properties of off-the-shelf conductive thread.

The data could be read using an instrument embedded in existing smartphones to enable navigation apps.

"This is a completely electronic-free design, which means you can iron the smart fabric or put it in the washer and drier," study author Associate Professor Shyam Gollakota said.

Using magnetic properties of conductive thread, University of Washington researchers are able to store data in fabric. In this example, the code to unlock a door is stored in a fabric patch and read by an array of magnetometers. Photo / Dennis Wise, University of Washington

"You can think of the fabric as a hard disk - you're actually doing this data storage on the clothes you're wearing."

Most people today combine conductive thread - embroidery thread that can carry an electrical current - with other types of electronics to create outfits, stuffed animals or accessories that light up or communicate.

But the researchers realised that this off-the-shelf conductive thread also has magnetic properties that can be manipulated to store either digital data or visual information like letters or numbers.

This data could be read by a magnetometer, an inexpensive instrument that measures the direction and strength of magnetic fields and is embedded in most smartphones.

"We are using something that already exists on a smartphone and uses almost no power, so the cost of reading this type of data is negligible," Gollakota said.

In one example, they stored the passcode to an electronic door lock on a patch of conductive fabric sewn to a shirt cuff.

They unlocked the door by waving the cuff in front of an array of magnetometers.

The researchers also created fashion accessories like a tie, belt, necklace and wristband and decoded the data by swiping a smartphone across them.

The team created prototype fashion accessories - a tie, belt, necklace and wristband - out of the magnetized fabric. Photo / Dennis Wise/University of Washington

They used conventional sewing machines to embroider fabric with off-the-shelf conductive thread, whose magnetic poles start out in a random order.

By rubbing a magnet against the fabric, the researchers were able to physically align the poles in either a positive or negative direction, which can correspond to the 1s and 0s in digital data.

Like hotel card keys, the strength of the magnetic signal weakens by about 30 per cent over the course of a week, though the fabric can be remagnetised and reprogrammed multiple times.

In other stress tests, the fabric patch retained its data even after machine washing, drying and ironing at temperatures of up to 160C.

This was in contrast to many smart garments today that still require on-board electronics or sensors to work.

That could be problematic if you get caught in the rain or forget to detach those electronics before throwing them in the washing machine - a potential barrier to widespread adoption of other wearable tech designs.

The team also demonstrated that the magnetised fabric could be used to interact with a smartphone while it is in yourpocket.

They developed a glove with conductive fabric sewn into its fingertips, which was used to gesture at the smartphone.

Each gesture yields a different magnetic signal that can invoke specific actions like pausing or playing music.

"With this system, we can easily interact with smart devices without having to constantly take it out of our pockets," lead author Justin Chan said.

In the team's tests, the phone was able to recognise six gestures - left flick, right flick, upward swipe, downward swipe, click and back click - with 90 per cent accuracy.

Future work was focused on developing custom textiles that generate stronger magnetic fields and are capable of storing a higher density of data.