Doomsday: Inside Job

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

We knew the world would not be the same ... "Now I have become Death, the destroyer of worlds"...I suppose we all thought that, one way or another.

J. Robert Oppenheimer, director of the Manhattan Project

History
In 1933, Leó Szilárd proposed that free neutrons could be used to start a chain atomic reaction. In 1938, Otto Hahn and Fritz Strassmann found barium in a uranium solution bombarded with neutrons. The next year, World War II started, during which the United States undertakes the Manhattan Project. It produced the first working nuclear weapons (atomic bombs), one of which dropped on Hiroshima, Japan and another on Nagasaki (pictured above). These attacks caused Japan to surrender, ending the War.

GST on Gold Selling

As questionable it may be, gold selling is a way to make money. Like any other Australian business, a Australian gold seller may get taxed on their proceeds, and if they have not been declaring such income on their BAS (business activity statement), they may well be running up a tax debt...

Josh, as well as his friends Guy and Sandy, have dipped their toes into the grey market, and are now wondering if they will have to pay GST (Goods and Services Tax). Unfortunately, they find the A New Tax System (Goods and Services Tax) Act 1999 (GST Act) too daunting to find out themselves. Will you be able to help them?

This problem has been taken out of Understanding Taxation Law 2011 (see bibliography for full citation), and the GST Act as of 1 November 2010 has been referred to.

How to attract the tax collector
In the GST Act:

• s 7-1 says that "GST is payable on taxable supplies and taxable importations".
• s 9-5 says that a taxable supply is made if a supply is made for consideration in the course or furtherance of an enterprise carried on, if it is connected with Australia and the supplier is registered or required to be registered.

In defense of merchanting

Merchanting is the activity of buying items at a low price and selling them higher later. If done properly, the merchanter can make substantial amounts of profit. Given factors such as the non-production of items in the process and an apparent increase in price volatility, this kind of business is often stigmatised.

However, merchanting may serve a useful role in the economy. Such activity can actually help to keep prices more stable and, as a bonus, the merchanter will be rewarded for it.

Elastic supply and demand
Price elasticity is how much the quantity of an item in the market changes with a given change in price. The more elastic the price, the more quantity will change with a given price change. There are two types of elasticity:

Lemon Dungeoneers

In 1970, economist George Akerlof released a journal article about the used car market. In it, he drew the distinction between cherries (good cars) and lemons (faulty cars), and predicted how those selling cherries would be driven out of the market (and conversely how the proportion of lemons would increase).

There is often comment by World of Warcraft players how they would, at times, join a sub-par pickup group (PuG) and resultingly endure an excruciating dungeon run. The 'market' for dungeoneering 'labour' may well degenerate similarly, for the fellow dungeoneers likely do not know how skilled each other is.

The thing about asymmetric information
In the lemon market as described by Akerlof, it is asymmetric information that drives cherries out of the market. In such a market, the buyer does not know much about the quality of the seller's product so as to form a price. In the used car market example, the used car has many parts hidden away from view, so the buyer cannot completely know whether the car is free from defects. As a result, they make a best guess that the car is of 'average' quality and so will be willing to pay an 'average' price.

Doomsday: High Impact

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

Impacts with space debris are truly spectacular events, as the size of the object belies the devastation they can wreak. Not only does an impact event obliterate the the area around it, rock can also be thrown high into the air and particularly large ones can change the very evolution of life.

History
After the birth of the solar system 4.6 billion years ago, its planets saw many planet-sized collisions. Mercury was hit by an object that formed the 1550km Caloris basin. Venus suffered a glancing blow that was enough to make it spin the other way. Mars saw an impact that created a crater the size of half the planet's surface.

Doomsday: Pandemic

Earth is humanity’s cradle, but by no means can it completely harbour us from harm. Many risks threaten individual lives, but there are some catastrophic enough to wipe out entire species. Is it possible for the prolific human species to face extinction?

It is not good to be sick. At this day and age, the practice of medicine ensures that people stand a good chance of survivng all common illnesses. However, some diseases do pop up which no medical literature covers and against which no treatments exist. The burden then falls to the rest of society to contain its spread as a pandemic as scientists work frantically to develop a cure...

History
The Bible describes ten 'plagues' that befell the citizens of Ancient Egypt. Subjecting the Israelites to slavery, the Jewish God was accounted to have exacted His vengeance. The tenth plague, which finally convinced the Pharaoh to release the Israelites, was one which killed all firstborn sons in the kingdom. It is known that it was common practice to feed the firstborn son a double helping of grain, and with the ruin of their crops from the previous hailstorm and locust plagues, they needed to draw from supplies stored underground.

WoW Mathematics: Heavy Breathing

When Valiona breathes fire, she breathes lots of it. Not only does it reach the very edges of the room she is in, it also has a 180° angular spread.

Given that most fires tend to be bad, it is usually prudent to run out of it. There are, of course, a multitude of possible directions to run, which leave the player roasting for different amounts of time. Which path is the quickest?

Summary:

• The quickest path out of Devouring Flames is a straight line perpendicular (at right angles) to the boundary of the cone.
• If Valiona is facing the player, the quickest path out is through Valiona.
• Given a Cartesian coordinate system, the starting position (x₁,y₁) and the equation of the boundary ax + by + c = 0 ,the distance d to run is: