“A photograph that one has taken of oneself, typically with asmart phone or webcam and uploaded to a social media website” is the definitionof “selfie” in the Oxford English Dictionary. In fact, it wasn't even in thedictionary until August of last year. It earned its place there because peopleare now so obsessed with (对……痴迷) selfies ─ wetake them when we try on a new hat, play with our pets or when we meet a friendwhom we haven't seen in a while.

But is there any scientific explanation for this obsession?Well, you should probably ask James Kilner, a neuroscientist(神经系统科学家) atUniversity College London.

Through our lifetime we become experts at recognizing andinterpreting other people's faces and facial expressions. In contrast,according to Kilner, we have a very poor understanding of our own faces sincewe have little experience of looking at them ─ we just feel them most of thetime.

This has been proved in previous studies, according to the BBC.

Kilner found that most people chose the more attractive picture.This suggests that we tend to think of ourselves as better-looking than weactually are. To further test how we actually perceive our own faces,Kilner carried out another study. He showed people different versions of theirown portrait ─ the original, one that had been edited to look less attractiveand one that was made more attractive ─ and asked them to pick the versionwhich they thought looked most like them. They chose the more attractiveversion.

But what does it say about selfies? Well, isn't that obvious?Selfies give us the power to create a photograph ─ by taking it from variousangles, with different poses, using filters (滤色镜) and so on ─that better matches our expectations with our actual faces.

“You suddenly have control in a way that you don't have innon-virtual(非虚拟的)interactions," Kilner told the Canada-based CTV News. Selfies allow you“to keep taking pictures until you manage to take one you're happy with”, heexplained.

    Does Fame Drive You Crazy?

    Although being famous might sound like a dream come true, todays star, feeling like zoo animals, face pressures that few of us can imagine. They are at the center of much of the worlds attention. Paparazzi (狗仔队) camp outside their homes, cameras ready. Tabloids (小报) publish thrilling stories about their personal lives. Just imagine not being able to do anything without being photographed or interrupted for a signature.

    According to psychologist Christina Villareal, celebrities（famous people名人) worry constantly about their public appearance. Eventually, they start to lose track of who they really are, seeing themselves the way their fans imagine them, not as the people they were before everyone knew their names. “Over time,” Villareal says, “they feel separated and alone.”

    The phenomenon of tracking celebrities has been around for ages. In the 4th century B.C., painters followed Alexander the Great into battle, hoping to picture his victories for his admirers. When Charles Dickens visited America in the 19th century, his sold-out readings attracted thousands of fans, leading him to complain about his lack of privacy(隐私). Tabloids(小报) of the 1920s and 1930s ran articles about film-stars in much the same way that modern tabloids and websites do.

    Being a public figure today, however, is a lot more difficult than it used to be. Superstars cannot move about without worrying about photographers with modern cameras. When they say something silly or do something ridiculous, there is always the Internet to spread the news in minutes and keep their “story” alive forever.

    If fame is so troublesome, why arent all celebrities running away from it? The answer is there are still ways to deal with it. Some stars stay calm by surrounding themselves with trusted friends and family or by escaping to remote places away from big cities. They focus not on how famous they are but on what they love to do or whatever made them famous in the first place.

    Sometimes a few celebrities can get a little justice. Still, even stars who enjoy full justice often complain about how hard their lives are. They are tired of being famous already.

    Young people almost never get a good press(评论) these days. “Their outlook is centered on trashy books and films,” expressed one citizen in a letter I recently came across in the Daily Mail. It seems that people have been complaining about the young since ancient times. However, the young are probably no worse than they've ever been. And I think they're better. Teenagers today are brighter, more energetic, more outgoing, and more interesting than any generation before.

    The truth is, we hear plenty of bad news about youth, but we never hear about the majority. Surely they all want to be footballers or attractive models? Not a bit of it. When research company Britain-Thinks examined teenagers attitudes earlier this year, they found that the most popular goal (shared by some 70 percent) was to “have a job you love”, followed by having a university degree, owning your own home and being in a happy, long-term relationship. It tallies with another study by the Institute for Economic and Social Research, which found that what made teenagers happiest wasn't a new smart-phone or pair of shoes, but “the simple things in life” such as close friends, going swimming and spending time with their parents.

    Indeed, the more you look at the young, the more impressive they seem. They are, of course, more technologically knowledgeable and skillful than any generation before them. But the interesting thing is that they're not merely consumers; they're creators. Think of all those young people developing their own websites or machines.

    Seventeen-year-old Nick D'Aloisio is an example. He invented a news-summary app (应用程序)called Summly and sold it to Yahoo this year for a reported £18 million. The company offered him a job in California, but he turned it down. “I'll be staying in London,” he explained. “I want to finish my A levels and I couldn't really live on my own out there.”

    Of course they aren't perfect, and every generation has its fair share of bad apples. But I think our future is in safe hands.

    I can proudly say that last year I broke the record for the oldest person in the world to ride a roller-coaster. I'm 105, but I feel younger. Even the doctor agrees I'm in good condition. I'm a bit deaf and my legs feel weak, but they are the only issue.

    I rode the Twistosaurus at Flamingo Land, which spins you round quite fast. I didn't choose to go on that. I'd have preferred a really fast one that went upside down. But I was told I couldn't ride something like that, because my blood pressure could drop and I might have some danger.

    I wasn't nervous — I don't get frightened of anything. I was securely fastened, so I knew I wouldn't fall out. The roller-coaster ride went on for three or four minutes, and it couldn't be a better experience. And I raised a lot of money for the Derbyshire, Leicestershire & Rutland Air Ambulance fund, which was fantastic.

    People were saying I'd got a place in the Guinness World Records. Later, someone came to present me with the certificate. I had it on the wall in my living room, with another one that got a year earlier.

    My record-breaking ways really began a couple of years ago, with the ice-bucket challenge. It turned out that I was probably the oldest person in the world to do it, and the video was very popular. After that, I stared to think about what else I could do to raise money for different charities.

    I'm not sure if anyone admires all the fun I'm having. They just say I'm daft and that's about it. But I've had many good days and many exciting times. I've had a really good life. I don't think I've wasted any of it.

    Walk through the Amazon rainforest today and you will find it steamy, warm, damp and thick. But if you had been there around 15,000 years ago, during the last ice age, would it have been the same? For more than 30 years, scientists have been arguing about how rainforests might have reacted to the cold, dry climate of the ice ages, but till now, no one has reached a satisfying answer.

    Rainforests like the Amazon are important for mopping up CO2 from the atmosphere and helping to solve global warming. Currently the trees in the Amazon take in around 500 million tons of CO2 each year: equal to the total amount of CO2 given off in the UK each year. But how will the Amazon react to the future climate change? If it gets drier, will it survive and continue to draw down CO2? Scientists hope that they will be able to learn in advance how the rainforest will manage in the future by understanding how rainforests reacted to climate change in the past.

    Unfortunately, collecting information is incredibly difficult. To study the past climate, scientists need to look at fossilized pollen (花粉) kept in lake mud. Going back to the last ice age means drilling down into lake sediments (沉淀物), which requires specialized equipment and heavy machinery . There are very few roads and paths, or places to land helicopters and aeroplanes. Rivers tend to be the easiest way to enter the forest, but this still leaves vast areas between the rivers completely unsampled (未取样). So far, only a handful of cores have been drilled that go back to the last ice age and none of them provide enough information to prove how the Amazon forest reacts to climate change.