A planet that suffers 475 ° C beneath a thick acıd atmosphere may be the last place you'd expect alien（外星的） life in our solar system. But one NASA scientist claims that extraterrestrials（天外来客）are most likely hiding on Venus amid conditions that are unbearable for humans. The new theory was put forward by the research scientist Dr Michelle Thaller. She says that possible signs of life have already been seen within the carbon-dioxide filled atmosphere, adding that she was absolutely certain that life exists somewhere.

Venus is often described as Earth's twin due to its similar size and structure. But their conditions couldn't be further apart, as astronomers believe it would be impossible for humans to exist on Venus. Positioned 67 million miles from the Sun, Venus is the hottest planet in our solar system, suffering temperatures that can even melt lead. Its atmosphere also adds to the uninhabitable situation.

Despıte this, scientists have long debated whether Venus clouds may host microbial（微生物的）life forms that can survive. Many scientists think that photosynthesis（光合作用）is possible on the planet's surface as Venus receives enough solar energy to pass through its thick clouds.

However, Professor Dominic Papineau, a biologist at the University College of London, believes Dr Thaller's views are "difficult to realistically assume". He explained, "For life-related chemical reactions to take place, liquid water is necessary. Hence, to find extraterrestrial life, we need to find liquid water, and to find extraterrestrial fossils requires looking for special rocks that were associated with liquid water in the past."

This makes life on Venus today difficult to realistically assume, because its surface is too hot, although Venus might have had liquid water in its past. Even still, both Professor Papineau and Dr Thaller agree that the icy moons of our solar system could also be sites of potential mıcrobıal life. NASA suggests there are 290 "traditional moons" in our solar system—excluding 462 smaller minor planets.

A study of 8 different experiments showed that our brains tend to prefer addition rather than subtraction when it comes to finding solutions—in many cases, it seems we just don't consider the strategy of taking something away at all.

The researchers found that this preference for adding was noticeable in three situations in particular: when people were under higher cognitive (认知的) load, when there was less time to consider the other options, and when volunteers didn't get a specific reminder that subtracting was an option. In one of the experiments, participants were asked to improve a Lego structure so that it was able to take more weight. Half the volunteers were reminded that they could take away bricks as well as add them, and half weren't. In the group that got the reminder, 61 percent solved the problem by taking away a brick—which was a much faster and more efficient way of making the structure stable. In the group that didn't get the reminder, only 41 percent went for the removing bricks approach.

"Additive ideas come to mind quickly and easily, but subtractive ideas require more cognitive effort," says psychologist Benjamin Converse, from the University of Virginia. "Because people are often moving fast and working with the first ideas that come to mind, they end up accepting additive solutions without considering subtraction at all."

The researchers have a few ideas about what might be going on. Our brains might find additive changes easier to process perhaps, or we might be associating adding with ideas of something that's bigger and therefore better in our subconscious. There might also be associations in our minds with the current status being something that needs to be maintained as much as possible—and taking something away is arguably more destructive to the current status than adding something new.

The researchers say their work is important in a much broader sense: for institutions looking to streamline (简化), for example, and even for the human race looking for ways to better manage the planet's resources.

If you love chocolate，maybe you have eaten a bar of Cadbury's Bournville chocolate. But Bournville isn't just the name of an English chocolate bar. It's the name of a village which was built especially for workers at the Cadbury's chocolate factory.

George and Richard Cadbury took over the chocolate business from their father in 1861. A few years later, they moved the factory out of the centre of Birmingham, a city in the middle of England, to an area close to the railways and canals so that they could receive milk deliveries easily and send the finished products to stores across the country. More importantly, here, the air was much cleaner than in the city, and the Cadbury brothers thought it would be a much healthier place for their employees to work.

They named the site Bournville after a local river called “The Bourn” and “Ville”，the French word for town, was used because at the time, people thought French chocolate was the highest quality. The new factory opened in 1879. Close to it, they built a village where the factory workers could live. The Cadbury brothers thought their workers deserved to live and work in good conditions. In the factory, workers were given a fair wage, a pension and access to medical treatment. The village provided everything that workers needed including a shop，a school and a community centre where evening classes were held to train young members of the workforce.

The Cadbury brothers were among the first business owners to make sure that their workers had good standards of living. Soon, other British factory owners were copying their ideas by providing homes and communities for their workers designed with convenience and health in mind.

Today, over 25,000 people live in Bournville village. Over a hundred years since the first house here was built, the aims of its founders have still been carried out.