We've all experienced that feeling that comes when your phone makes a sound to tell you that its battery level is low. It often comes at the worst times – when you're out on a trip and don't have a charger, or when you're expecting an important phone call.

    Indeed, this feeling is so common that South Korean electronics manufacturer LG has given it a name: low battery anxiety.

    According to a survey of 2,000 US adults conducted by the company last year, 90 percent of respondents said that they panic if their battery level reaches 20 percent or lower.

    And last month, UK telecommunications service provider 02 found that around 15.5 million Britons live in “constant fear” of their mobile phones running out of power, according to a survey by the company.

    “The problem is not about being unable to make calls, but is rooted in the fact that smartphones are now where we store digital memories,” noted the Daily Mail.

    However, battery worries don't just affect smartphone lovers. Many owners of electric vehicles also suffer from so-called “range anxiety”. This refers to the concern that the vehicle may not make it to its destination before the power runs out.

    Meanwhile, it isn't just low power that people worry about. A study carried out by South Korea's Sungkyunkwan University and China's City University of Hong Kong found that many of us also worry about not having constant access to our phone.

    This condition is known as nomophobia, short for “no mobile phone phobia（恐惧症）”. Symptoms include feeling uncomfortable when access to one's phone isn't possible, being unable to turn off your phone, and constantly topping up the battery to make sure it never dies.

    So, why do so many people treat their smartphone with such importance? The underlying reason may be that they keep us connected to the people around us, and if we're unable to use our phone, we feel like we're cut off from our social life.

    With products with bigger batteries being released all the time though - such as Xiaomi's Mi Max smartphone range or Tesla's Model S cars – battery anxiety may hopefully soon be a thing of the past.

    Many experts say that Billy Wilder changed the history of American movies. He is often called the best movie maker Hollywood has ever had. He was known for making movies that offered sharp social comment. Wilder was one of the first directors to do this.

    Billy Wilder was born in 1906 in the former Austro-Hungarian Empire. Billy Wilder started law school in Vienna, Austria. However, he began reporting for a Vienna newspaper after graduation. By the 1920s, he was writing movies in Germany. However, the Nazis had risen to power in the nation. Wider was Jewish, and he recognized that he had no future in Nazi Germany. In 1933, he went to Paris. There he directed a movie for the first time. It was called “The Bad Seed”. Then he received word that producers in the United States had accepted one of his scripts. Billy Wilder left Europe for America.

    In America he formed a writing team with Charles Brackett. The two writers created many films together. Wilder and Brackett wrote several successful movies. One was the nineteen thirty-nine movie, “Ninotchka”, starring Greta Garbo. Ernst Lubitsch directed the film. Wilder always praised this man as a friend and teacher whose humor and expert direction greatly influenced his works.

    In 1954, Billy Wilder became an independent producer. The nest year, Wilder's first movie as an independent filmmaker was a huge success. It was “The Seven Year Itch”. In 1959, Wilder made a funny movie that was very popular. I.A.L. Diamond joined Wilder in writing “Some Like It Hot”.

    By the 1980s, Wilder no longer was considered the most unusual, creative movie-maker in Hollywood. In recent years, however, Billy Wilder received many more awards and honors. Critics praised his gifts to movie making. In 1987, the Academy of Motion Picture Arts and Sciences gave him the Irving G. Thalberg Memorial Award. It is the highest award a producer can receive.

    Science fiction writers create imaginary worlds. The way things work in your imaginary worlds will be based on actual science. So it's important for you to be familiar with the scientific principles and inventions that are related to your creation. For example, if you're writing about human living on a planet with zero gravity, then you need to know the effects of zero gravity on the human body.

    Then you have to figure out the exact rules of your imaginary worlds. And you have to follow them. If humans are able to breathe underwater in Chapter 1, your character can't drown in a swimming pool in Chapter 3. The issue here is maintaining your readers' trust. That means the readers are willing to pretend along with you. If you start out with an ordinary detective novel and then throw in someone breathing underwater in the 6th chapter, you will pull the readers out of their imagination. The same thing happens if you change the rules halfway.

    Part of your preparation work for the novel is to map out its worlds in great detail. You should decide the following issues: the history of the world, the geography, what possibilities it offers, how everything works in this new reality, and how all of these factors affect the way your characters think, feel, and react to things. You don't have to tell your readers all the rules in the first chapter. But you have to let readers know enough to understand what's going on. This also allows you to work out logical problems and contradictions before you start writing.

    When you are writing, remember to make it feel real. You are inviting readers to visit a new world. They will want to be able to see, hear, feel, smell, and even taste what it's like. Whether your novel is about a world without disease or an undiscovered planet, help your readers feel like they're actually there.

    Being physically active three times a week reduces the odds of being depressed by about 16%, according to new UCL research carried out as part of the Public Health Research Centre.

    The study, published in JAMA Psychiatry, found a two-way relationship between depression and physical activity. People who increased their weekly activity were reported to have fewer depressive symptoms but those with more depressive symptoms were less active, particularly at younger ages.

    Researchers followed 11,135 people born in 1958 up until the age of 50, recording depressive symptoms and levels of physical activity at regular intervals in adulthood. They found that each additional activity period per week reduced odds of depression by 6%. In England 19% of men and 26% of women are currently classed as "inactive", and this study suggests that activity could significantly improve their mental as well as physical health.

    "Assuming the association is causal, physical activity has a protective effect against depression. If an adult between his twenties and forties who isn't physically active became active 3 times per week, he would reduce his risks of depression by about 16%," said Dr Snehal of the UCL Institute of Child Health, lead author of the study.

    Professor Mark，Director of the Public Health Research Centre, said: "Many people are already aware of the benefits of physical activity on their general health, but now we are seeing more evidence that suggests it also has a positive effect on a person's mental well-being. The latest research highlights just how important it is to ensure that people are working and living in environments that allow them to be both physically active and mentally healthy."

The True Story of a Young Man

When Reginald Lindsay received a scholarship to Morehouse College in Atlanta, Georgia in 1967, what he wanted most was not a job with a good salary, but a chance to be a member of Congress as a southern representative. After earning his degree at Harvard Law School in 1970, he returned to the South to practice law among the poor. "I want to help them understand what their rights are and to help them achieve them," he said. Then he ran for political office at the local and state level until he was ready to try for Congress.

Reg grew up in a low-income Negro section of Birmingham, Alabama. Brought up by his grandparents after his parents were divorced while he was very young, Reg had been living through a period of far-reaching progress in race relations. In the summer of 1968 Reg himself became a good example of this progress when he became the first Negro student appointed to a special new program. The program introduced bright young students to the workings of the Georgia State government and encouraged them to seek employment there after finishing their education. "I've been lucky," he said. "I seem to have been in the right place at the right time."

But luck was only part of Reg's story, for he made the most of opportunities that came his way. He learned to read in kindergarten and began visiting the public library regularly to borrow books. His grandparents encouraged him, though neither of them had much education, and they bought him a set of encyclopedias. "I loved those books," he remembered. "I used to come downstairs before breakfast and read short articles. I enjoyed reading about famous men, and then I would pretend to be one of them. I guess it was partly a childish game and partly an escape. It wasn't too much fun to be a Negro when I was a kid." While studying for his bachelor's degree at Morehouse College, Reg worked on several political campaigns helping candidates get elected to government offices. At the same time he maintained a "B" average while majoring in political science.

With just two more years to complete at Harvard Law School, which also gave him a scholarship, Reg made a good start on his professional career. He said, "The good life for me is the kind of life where I can find satisfaction in public service." Then in 1975 he was the Massachusetts state commissioner of public utilities and from 1993 to 2009 he was judge of the United States District Court for the District of Massachusetts.

    Four books that will inspire you to travel the world

    There's truly nothing like travel when it comes to gaining perspectives and exposing yourself to other cultures. To get you in the adventuring mood, we asked Amazon Senior Editor Chris Schlep to help you come up with a list of books that transport readers to another time and place. Below, see his list of four books that will inspire you to travel the world.

    ITALY: Beautiful Ruins by Jess Walter

    This book by the popular author Jess Walter is a love story that begins on the Italian Coast in the early 60s and eventually concludes in contemporary Hollywood's screen. As the settings shift from Italy to Edinburgh and Los Angeles, you will find yourself longing to go as well. Buy it on Amazon. Price: $28.90

    SEATTLE: Where'd You Go, Bernadette by Maria Semple

    Maria Semple's first novel is not exactly a love story in Seattle, but if you read it, you just might want to come here to see if people are really as self­involved as the characters in her book. What really shines through is the strange storytelling and the laughs. Buy it on Amazon. Price: $26.60

    ENGLAND: Wolf Hall by Hilary Mantel

    You can't travel to Thomas Cromwell's England without a time machine, but reading Mantel's prize­winning novel is the next best thing. It will make you long to see the ancient buildings and green grass of the English countryside, most of which are still there. Buy it on Amazon. Price: $25.10

    NANTUCKET: Here's to Us by Elin Hilderbrand

    Elin Hilderbrand has built a writing career out of writing about her hometown island of Nantucket. Her latest book is Here's to Us, which, perhaps not surprisingly, is a great beach book. Buy it on Amazon. Price: $30.80