Trust Wikipedia

I refer to Wikipedia all the time, I think it’s great!

And soon you’ll have a new reason to trust the information you find on Wikipedia: An optional feature called “WikiTrust” will color code every word of the encyclopedia based on the reliability of its author and the length of time it has persisted on the page.

Despite its popularity, Wikipedia has long suffered criticism from those who say it’s not reliable. Because anyone with an internet connection can contribute, the site is subject to vandalism, bias and misinformation.

Now, researchers have created a system to help users know when to trust Wikipedia. Called WikiTrust, the program assigns a color code to newly edited text using an algorithm that calculates author reputation from the lifespan of their past contributions. It’s based on a simple concept: The longer information persists on the page, the more accurate it’s likely to be.

Text from questionable sources starts out with a bright orange background, while text from trusted authors gets a lighter shade. As more people view and edit the new text, it gradually gains more “trust” and turns from orange to white. Read more here.

Power the world with solar

Well done to the Australian scientists who have developed the world’s most efficient solar cell. They concocted a multi-cell combination that converts 43% of sunlight into electricity, besting the previous record of 42.7%! Read more here.

But surely solar cells would never be able to provide enough electricity to power the whole world. Especially by the year 2030, by which time our electricity demands will have increased. Surely we would have to cover most of the planet with solar cells to achieve this feat. Surely ….

Maybe not. Check out how many solar cells would actually be required to power the entire human population in the year 2030 (click to enlarge).

Amazing isn’t it!

The evolution of sad

It’s no fun being sad. Some people who have depression are sad all the time.

Now scientists believe that depression may be an evolutionary advantage developed early in human history. So what could possibly be good about depression?

Depressed people often think intensely about their problems. These thoughts are persistent and depressed people have difficulty thinking about anything else. Numerous studies have also shown that this thinking style is often highly analytical. They dwell on a complex problem, breaking it down into smaller components, which are considered one at a time.

This analytical style of thought, of course, can be very productive. Each component is not as difficult, so the problem becomes easier to handle. Indeed, when you are faced with a difficult problem, such as a math problem, feeling depressed is often a useful response that may help you analyze and solve it. For instance, in some of our research, we have found evidence that people who get more depressed while they are working on complex problems in an intelligence test tend to score higher on the test. Read more here.

Ozone threat is no laughing matter

Laughing gas—known to scientists as nitrous oxide (N₂O)—is now the biggest threat to Earth’s ozone layer.

The ozone layer, part of Earth’s upper atmosphere, protects plants and animals from harmful ultraviolet radiation from the sun.

In 1987 countries around the world united to ban chlorofluorocarbons, or CFCs—gases that were commonly used in refrigerators and air conditioners. These gases made their way into the atmosphere and thinned the ozone layer by about 5 percent worldwide.

CFC emissions drastically dropped following the ban, and the ozone layer has been on track to largely recover by mid-century.

Now, nitrous oxide, commonly known as laughing gas, is now the dominant ozone-depleting substance emitted by humans – and is likely to remain so throughout the century.

Scientists suggest use of the compound (which is produced by the breakdown of nitrogen in fertilisers and sewage treatment plants) should be reduced to avoid thinning the protective ozone layer that blankets the Earth. Read more here, here or here.

Molecules made visible

Pentacene is a molecule consisting of 5 rings of carbon atoms.

Interestingly, pentacene is also the first molecule to be seen at a high level of detail due to a new microscopic technique. See:

Read more here or here.

The crazy animals you see at zoos

Visitors to the Bristol Zoo can read all about the species Homo sapiens in this plaque hung by the window of the zoo’s cafe (click to enlarge).

It says, in part:

The human is one of the most widespread species, and is present on all the continents.

After a gestation period of nine months, humans usually live in their parents’ nest for around 16 years. While the parents are out foraging for food, juveniles are looked after in large groups by other adults. …

… Humans usually pair for life, retiring from most social activity and moving into brick or concrete nests once a partner is found. Pairs produce an average of 2 young.

Read more here or here.

Videos of things blowing up

If your interested in chemistry you’ll know all about the periodic table. The periodic table is a list of known atoms, or chemical elements. In the table the elements are placed in the order of their atomic numbers starting with the lowest number. The atomic number of an element is the same as the number of protons in the atom.

Online periodic tables have become more and more interesting in the last few years. For example this one enables you to click on any element to see hundreds of pictures, stories and facts about it.

And when you click on an element in this periodic table it shows you a video about the element. The main reason this is good, is that heaps of the videos demonstrate the element being involved in a chemical reation, and that often involves an explosion. Like this Hydrogen video:

If Chemistry’s not your thing you can always go here to see a bunch of similar Physics videos.

Obstacles makes evacuations faster

Apparently, if you need to evacuate people quickly through a narrow opening it’s a good idea to put something in their way.

Some scientists timed a crowd of people as they exited as fast as possible through a door, and then repeated the experiment with a 20-centimetre-wide pillar placed 65 centimetres in front of the exit to the left-hand side.

The obstacle improved the exit rate by an extra seven people per minute, from 168 people to 175 people. The pillar creates a relatively uncrowded area where it’s needed most – just in front of the exit.

Usually, the exit becomes clogged by people competing for the small space, and the crowd is slowed. The pillar blocks pedestrians arriving at the exit so effectively that the number of people attempting to occupy the space just in front of the exit is reduced. With reduced crowding there are fewer conflicts and the outflow rate increases. Read more here.

What’s the story morning glory

The Morning Glory cloud is a rare meteorological phenomenon observed in Northern Australia’s Gulf of Carpentaria. A Morning Glory cloud is a roll cloud that can be up to 1000 kilometers long, 1 to 2 kilometers high, and can move at speeds up to 60 kilometers per hour.

Read more here or here.

Artificial life is nearly a reality

Scientists are only months away from creating artificial life!

The first artificial lifeform is likely to be a simple man-made bacterium that proves that the technology can work. But it will be followed by more complex bacteria that turn coal into cleaner natural gas, or algae that can soak up carbon dioxide and convert it into fuels. They could also be used to create new vaccines and antibiotics. Read more here.

WOW !!!