Stellar Evolution

Sometimes when a star reaches the end of its life it does so with a cataclysmic bang. In quick time it shreds itself, throwing out the raw materials that will seed the next generation of stars and planets. Even companion stars can be caught up in the explosion and scarred by the fallout.

Astronomers have found that this scarring can tell them a great deal about the binary star system as it was before the explosion even occurred. With most stars being a part of multiple star systems, this is of particular interest to scientists trying to understand their evolution.

But not all stars will go supernova as they run out of fuel – only the more massive ones have enough self-gravity to actually explode. A star needs to have roughly eight times more mass than our Sun for what is known as a core-collapse supernova to occur.  And it is gravity that drives the processes that lead to this dramatic ending.

For most of its life, a star exists in a state known as hydrostatic equilibrium, where the inward and outward forces on the star are finely balanced. Gravity draws in surrounding matter towards the star’s core, while radiation pressure from the heat being generated within pushes outwards and prevents the star from imploding.

In fact, these two forces are inextricably linked. If the core were to cool a little, the inward force of gravity would exceed the outward radiation pressure and the star would contract. The contraction would increase the temperature and pressure of the star again, returning it to equilibrium.

The real excitement comes as the star runs out of fuel and can no longer support itself against its own weight. Within a split second the core collapses, sending a shockwave radiating out through the star blowing it apart and causing one of the most energetic events we see anywhere in the Universe.

How much energy are we talking about? Roughly as much as the Sun will generate over something like 10-billion years. All produced in barely a fraction of that time.  If there is a nearby companion star, it can be hit by debris from the explosion. When this happens, the surface heats up and causes the star to swell, a bit like having a burn blister on your skin.

The star blister can be 10 or even 100 times larger than the star itself, but it lasts only for a very short time. Within a few decades, the blister heals, and the star shrinks back to its original form.

The team of Australian and Japanese astronomers, including post-doc researcher Dr Ryosuke Hirai from Monash University and the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav), have carried out hundreds of computer simulations to investigate how companion stars inflate depending on their interactions with nearby supernovae. They then applied their results to SN2006jc, a supernova that was first seen by amateur astronomers and preceded by something that was, well, a little confusing.  TO READ ENTIRE ARTICLE,
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China's Navy

MELBOURNE, Australia — China commissioned 60,000 tons worth of major vessels earlier this month, officially putting into service a new nuclear-powered ballistic missile submarine, a guided-missile cruiser and an amphibious helicopter carrier on the 72nd anniversary of its Navy.

The unprecedented triple commissioning was carried out in a ceremony held at the Yulin naval complex near the city of Sanya on the southern Chinese island of Hainan. Yulin is the main naval base of the South Sea Fleet of the People’s Liberation Army Navy. The fleet’s area of responsibility lies in the waters of the nearby South China Sea.

Chinese President Xi Jinping attended the ceremony, which saw the Type 075 (Yushen-class) amphibious helicopter carrier Hainan, the Type 055 (Renhai-class) guided-missile cruiser Dalian and the Type 094 (Jin-class) nuclear-powered ballistic missile submarine Changzheng-18 join the PLAN.

The Hainan is the lead ship of a new class of amphibious assault ships being built for the PLAN as it continues to boost its naval capabilities. The helicopter carriers, which are estimated to displace between 35,000 to 40,000 tons, have an uninterrupted flight deck with seven deck spots for large transport helicopter operations, and a well dock for launching conventional or air-cushioned landing craft for amphibious landing operations

At least two more Type 075s are under construction at a shipyard in the major eastern city of Shanghai, and their introduction will significantly boost the PLAN’s ability to conduct large amphibious operations — a capability gap for China despite its massive military modernization program.  TO READ MORE, CLICK HERE...

Coffee Rings

An international research team, led by Monash University, has discovered for the first time the mystery behind the formation of ‘coffee rings’ by examining the contact angle of droplets onto a surface, and how they dry. 

The research collaboration involving Monash University and Cambridge University also developed a mathematical model that is capable of predicting when a coffee ring could be observed in hard spherical particle systems.


Professor Gil Garnier, Director of BioPRIA (Bioresource Processing Research Institute of Australia) in the Department of Chemical Engineering at Monash University, led an international team to explore how patterns formed from evaporating droplets – a phenomenon that has mystified physicists for years.

Professor Garnier said this discovery, created by Dr. Michael Hertaeg from BioPRIA, could open up doors in the blood diagnostics arena, especially for the discovery of treatments for anemia and other blood diseases.

A new study has discovered the mystery behind ‘coffee rings’ and how it could advance research in blood diagnostics. Credit: Monash University

Pattern formation is a common occurrence in drying colloidal liquids, such as milk, coffee, paint, aerosols, and blood.

Most common in droplets is a ring distribution where the liquid particles have relocated to the edge, which is referred to as a coffee ring, when drying. This deposit is unfavorable in many manufacturing processes and is of fundamental interest experts in the building, medical, and engineering professions.

They concluded that the contact angles at which a droplet is placed on a wetted surface determines the prevalence of coffee angles. When the droplet is placed at a high contact angle, no coffee rings are present.

“Our research identified the contact angle formed by the suspension of droplets on the surface and its solids content as the two important governing variables to coffee ring formation,” Professor Garnier said.

“Although successful modeling has been achieved previously, we show here for the first time that for each contact angle, there is a critical initial colloid volume fraction over which no ring-like pattern will be formed.

“Essentially, the lower the contact angle, the higher likelihood that ring profiles will be found.”

When a droplet is placed on a surface, it quickly reaches an apparent equilibrium position that can, for small droplets, be defined solely by contact angle and radius.  READ MORE

Wingman Drone

Known as the Airpower Teaming System (ATS), Boeing Australia's new loyal wingman drone for the Royal Australian Air Force (RAAF) has taken to the sky for the first time. It's not clear exactly when the flight took place, but it occurred at the high-security RAAF Base Woomera and its surrounding range complex. The flight was originally supposed to occur around the end of 2020, but it was pushed back due to a number of factors.

The ATS, which is a modular design capable of having its entire nose section swapped out quickly, is seen as a landmark program for Australia and the RAAF. It is the first clean-sheet aircraft Boeing has brought to fruition outside the U.S. and the first military aircraft Australia has independently produced in over half a century. ATS is meant to work in combination with the RAAF's fleet of F/A-18F Super Hornets, EA-18G Growlers, and E-7 Wedgetails, as well as F-35s, acting as loyal wingmen by providing additional offensive and defensive capabilities to these existing combat aircraft. Really, that's an understatement. ATS has the potential to totally revolutionize the RAAF's air combat tactics playbook. You can read all about this promising program and the ATS's stated capabilities in this in-depth War Zone feature.                                    READ MORE

U.S. Has Highest Levels of Illegal Drug Use in the Known World

Drug Use Increasing Worldwide, Survey Finds
Updated on October 27, 2016

In spite of the most stringent drug policies and punitive laws in the world, the United States also has the highest levels of lifetime illegal cocaine and marijuana use, according to a study of more than 54,000 people in 17 countries.

The United States also has the highest rate of lifetime tobacco use but comes in third in alcohol use, behind the Ukraine and Germany. The study, by Louisa Degenhardt of the University of New South Wales (Sydney, Australia) and colleagues, is based on the World Health Organization's Composite International Diagnostic Interview (CIDI).

This trend has also been reported in the National Survey on Drug Use and Health (NSDUH) conducted annually by Substance Abuse and Mental Health Services Administration (SAMHSA). In 2013, that survey indicated that an estimated 24.6 million Americans aged 12 or older—9.4% of the population—had used an illicit drug in the past month.

The number of current illicit drug users (those who have used in the past month) is up from 8.3% in 2002. The increase is mainly due to an increase in the use of marijuana.

While the use of other illegal drugs has leveled off or declined over the past decade, NSDUH figures show that past-month marijuana users increased from 5.8% to 7.5% from 2007 to 2013.

The Office of National Drug Control Policy estimates that $100 billion worth of illegal drugs were sold in the U.S. in 2013.

It is all about the money...

Congress does not want to stop the ILLEGAL DRUG PROBLEM IN AMERICA

States do not want to stop the ILLEGAL DRUG PROBLEM IN AMERICA

Law Enforcement does not want to stop the ILLEGAL DRUG PROBLEM IN AMERICA