Snippets

Snippets

Snippets

SIZE DOES NOT MATTER

Galaxies spin like clockwork

Astronomers have discovered that all galaxies rotate once every billion years, no matter how big they are. The earth spinning around on its axis once gives us the length of a day, and a complete orbit of the earth around the sun gives us a year. Professor Gerhardt Meurer from the UWA node of the International Centre for Radio Astronomy Research said that by using simple maths, you can show all galaxies of the same size have the same average interior density. "Discovering such regularity in galaxies helps us to better understand the mechanics that make them tick," he said. Gerhardt also found evidence of older stars existing out to the edge of galaxies. "Based on existing models, we expected to find a thin population of young stars at the very edge of the galactic discs we studied," he said. "But instead of finding just gas and newly formed stars at the edges of their discs, we also found a significant population of older stars along with the thin smattering of young stars and interstellar gas."

EXPERIMENTAL FINDINGS

New phase of matter

Researchers have produced a 'human scale' demonstration of a new phase of matter called quadrupole topological insulators (QTIs) that was recently predicted using theoretical physics. These are the first experimental findings to validate this theory. The findings are published in Nature. The team's work with QTIs was born out of the decade-old understanding of the properties of a class of materials called topological insulators (TIs). "TIs are electrical insulators on the inside and conductors along their boundaries, and may hold great potential for helping build low-power, robust computers and devices, all defined at the atomic scale," said Gaurav Bahl, a senior investigator.

DOCUMENTARY

The Year of Pluto

After a nine year journey across the deepest stretches of the galaxy, a specially designed rocket glided past the distant planet of Pluto on July 14, 2015. The documentary, The Year of Pluto outlines the decades of preparation that have transpired to bring NASA to this milestone.

What do Pluto and its moons look like, and what revelations await through a collection of data around their orbit? The hugely ambitious mission to find those answers began in January 2006 as NASA mounted the New Horizons project. The Year of Pluto takes tireless efforts of thousands of intensely inventive scientists, researchers, scholars and manufacturers that made the journey possible. To watch the documentary, visit www.bit.ly/1FOYItW.

WITH A BANG

A high-flying wild petunia

When it's time for the hairy flower wild petunia to pass its genes to the next generation, it does it with a bang. To reproduce, the plants fling tiny seeds from a small torpedo-shaped fruit more than 20 feet through the air. That's not an easy task. The seeds are discs about a tenth of an inch in diameter - smaller than the circles that fall out of a hole punch - and 1/50th of an inch thick. "It's like throwing confetti," said Dwight Whitaker, a professor of physics at Pomona College, USA. But somehow these seeds slice smoothly through the air. In an article published recently in the Journal of the Royal Society Interface, Dwight and a trio of undergraduate physics majors worked out what happens in that moment of explosion that launches the seeds so far. The seeds sit within a small fruit that is a bit over one inch long. A spine along each half of the fruit is made of three layers, which shrink at different rates as they dry. That creates a strain that bends them outward. The two halves remain held together by glue. Drip some water onto it, the glue dissolves and the fruit violently splits in half. With ultrahigh speed video - up to 20,000 frames a second - Dwight and his students slowed down the action, watching as hooks in the fruit accelerated the seeds to speeds of more than 30 mph. When they did the calculations, they were stunned to find that some of the seeds were spinning at a rate of more than 1,600 revolutions a second.

ROBUST & EFFICIENT

A low power humidity sensor

Scientists from Indian Institute of Technology, Kharagpur and GLA University, Mathura have developed a novel, low power humidity sensor using molybdenum disulphide nanoflakes and platinum nanocrystals. The researchers developed few-layered molybdenum disulphide (MoS2) decorated with platinum nanoparticles (PtNPs) to function as a low power, highly sensitive humidity sensor. MoS2 was mixed with a solvent and then exfoliated to form the nanoflakes. Next, chloroplatinic acid hexahydrate were reduced to PtNPs using a novel reduction technique. To check their performance, the composites were drop coated onto gold interdigitated electrodes to form a humidity sensor. The sensor was then exposed to various levels of relative humidity. The results show a mixing ratio of 0.25:1 of PtNPs to MoS2 had the best response.

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