The average computer user has between 5 and 15 username/password combinations to log in different kinds of accounts. Some demand you use a specific number of symbols and digits, while others require you to change your password every 60 days. The feeling of confusion resulting from memorizing these login information has grown so common that it actually has a name: password fatigue(疲劳).

    Having to remember so many different passwords is annoying, but it can also be dangerous. Because it is virtually impossible to remember a unique password for each of these accounts, many people leave handwritten lists of usernames and passwords on or next to their computers.

    {#blank#}1{#/blank#} While these practices make it easier to remember login information, they also make it easier for thieves to hack into accounts.

    Single Sign-On (SSO) confirmation and password management software can help solve this problem. With SSO, users only need to remember one password to log in to the main system.

    {#blank#}2{#/blank#} SSO software is typically used by large companies, schools, or libraries.

    {#blank#}3{#/blank#} If a user loses or forgets the password required to log in to SSO software, the user will then lose access to all of the applications linked to the SSO account. Users who rely on password management software face the same problems.

    Although most websites or network systems allow users to recover or change lost passwords by providing email addresses or answering a prompt（提示）, this process can waste time and cause further frustration. What is more, recovering a forgotten password is only a temporary solution.

    {#blank#}4{#/blank#}

    Some computer scientists have suggested computers rely on biometrics(生物测定学). {#blank#}5{#/blank#} The use of biometrics raises questions concerning privacy and can also be expensive to practice.

    Software engineers and computer security experts are still searching for the cure to password fatigue. Until they find the perfect solution, however, everyone will simply have to rely on the password system currently in place.

    Reading can be a social activity. Think of the people who belong to book groups. They choose books to read and then meet to discuss them. Now the website BookCrossing.com turns the page on the traditional idea of a book group.

    Members go on the site and register the books they own and would like to share. BookCrossing provides an identification number to stick inside the book. Then the person leaves it in a public place, hoping that the book will have an adventure, traveling far and wide with each new reader who finds it.

    Bruce Pederson, the managing director of BookCrossing, says, “The two things that change your life are the people you meet and books you read. BookCrossing combines both.”

    Members leave books on park benches and buses, in train stations and coffee shops. Whoever finds their book will go to the site and record where they found it.

    People who find a book can also leave a journal entry describing what they thought of it. E-mails are then sent to the BookCrossers to keep them updated about where their books have been found. Bruce Peterson says the idea is for people not to be selfish by keeping a book to gather dust on a shelf at home.

BookCrossing is part of a trend among people who want to get back to the “real” and not the virtual(虚拟). The site now has more than one million members in more than one hundred thirty-five countries.

    It's common knowledge that sleep problems can be caused by things such as stress, anxiety, or even using a smartphone before bedtime. But recently, a team of researchers discovered that genes could also be a cause of sleepless nights.

    The scientists, from Rockefeller University in New York, US, found that delayed sleep phase disorder（DSPD，睡眠相位后移综合症）, a condition that affects one's sleeping patterns, is passed down via a mutated（突变的）gene. DSPD sufferers wake up later and go to bed later than the average person. To come to their conclusion, the team studied a 46-year-old woman who is only usually able to fall asleep at 2 or 3 in the morning. It was discovered that the woman's body produces the hormone that helps her sleep at night up to 7 hours later than regular sleepers. The scientists found this was caused by a mutation in one of the woman's genes, one that helps regulate the “body clock”.

    Some of the woman's family members were also found to share the same mutation—and the same sleeping problems –leading the scientists to believe that sleep troubles are passed down through the generations.

    However, having this mutation doesn't mean you automatically have sleep problems. The team also found two people who had the mutation but reported no problems with their sleep.

    But while this is an interesting discovery, it offers no help to those who can't fall asleep at night—although there are a few things you could try to help you sleep earlier.

    BBC journalist Michael Mosley produced a TV documentary in May in which he talked about his battle with insomnia（失眠）and the techniques he used. “I avoid social media for at least an hour before bed, I do mindfulness exercises, and if I wake up in the middle of the night, I read a book for an hour or so,” he wrote in an article for the Radio Times.

Earth's geologic ages—time periods defined by evidence in rock layers—typically last more than three million years. We're barely 11,500 years into the current age, the Holocene. But a new paper argues that we've already entered a new one—the Anthropocene, or “new man”, age.

    The name isn't brand-new. Nobel Prize winner Paul Crutzen, a co-author of the paper, coined it in 2002 to reflect the changes since the industrial revolution. The paper, however, is part of new push to formalize the Anthropocene age.

    Recent human impacts have been so great that they'll result in an obvious boundary (界限 ) in Earth's rock layer, the author's say. “We are so skilled at using energy and exploiting the environment that we are now a defining force in the geological process on the surface of the Earth,” said co-author Jan Zala, a geologist with the University of Leicester in the UK. Even so, it could take years or even decades for the International Union of Geological Science to formalize the new age.

If the concept of the Anthropocene age is to be formalized, scientists will first have to identify and define a boundary line ,or marker, that's set in stone. “The key thing is thinking about how—thousands of years in the future—geologist might come back and actually recognize in the deposit in the UK.” It's not as straightforward as you might think. The market has to be very precise, and it has to be recognized in many different parts of the world,” said Haywood, who wasn't involved in the new study.

One candidate for the market is the distinctive radioactive signature left by atom bomb tests, which began in 1945. “The fallout (沉降 ) is basically across the world,” Haywood said. In a similar way, scientists used traces of the element iridium (铱) left by shooting star strikes to help define the boundary between the Cretaceous and Tertiary periods—the time of the great dinosaur extinctions.

    The push for a formal declaration of the Anthropocene age is about more than just scientific curiosity. The move the scientists write in the last issue of the journal Environmental Science & Technology, “might be used as encouragement to slow carbon emissions and biodiversity(生物多样性)loss” or “ as evidence on protection measures” Just as Haywood said, by underlining how much we're changing the environment, the formalization would be "a very powerful statement”.

Happy birthday

    The China National Opera (CNO) will give a concert to celebrate its 50th birthday.

Different generations of CNO vocalists, like Li Guangxi, Yao Hong and Ma Mei, will present the concert which will feature both songs from famous Chinese operas like “The White-haired Girl” and “The Hundredth Bride”, as well as, arias of such Western opera classics as “Madame Butterfly”, “La Traviata” and “Rigoletto”.

Time/ date: 7:30 p.m., September 7th, 8^th

Location: Tianqiao Theatre

Tel: 6551-4787, 8315-6170

Tickets: 60-500 yuan (U.S. $7.2- 60.2)

Folk music

    A concert will be held to feature some recently composed traditional Chinese music works. The concert, given by the Folk Orchestra of the China Opera and Ballet Theatre, will include such pieces as “Memory of Childhood”, “Memorial Ceremony for God” and “Wine Song”.

Time/date: 7:30pm, September 13th

Location: Concert hall at the National Library of China

Tel: 6848 –5462, 6841-9220

Tickets: 30-200 yuan (U.S. $3.6-24.1)

Moon music

    A concert of traditional Chinese music will be given on the eve of the Moon Festival which falls on September 21^st this year. The concert will feature a number of famous pieces centered on the theme of the moon, such as “Moonlight”, “Spring night on a Moonlit River” and “Lofty Mountain and Flowing River.”

A number of established traditional Chinese music performers like Zhou Yaokun and Fan Weiqing, will play solos as well as collaborate with the folk music orchestra.

Time / date: 7:30 pm, September 21^st

Location: Grand Theatre of the Cultural Palace of Nationalities

Tel: 6606-8888, 6606-9999

Ticket: 40-240 yuan (U.S. $4.8-27)

    People have grown taller over the last century, with South Korean women shooting up by more than 20cm on average, and Iranian men gaining 16.5cm. A global study looked at the average height of 18-year-olds in 200 countries 1914 and 2014. The results show that while Swedes were the tallest people in the world in 1914, Dutch men have risen from l2th place to claim top spot with an average height of 182.5cm. Larvian women, meanwhile, rose from 28th place in 1914 to become the tallest in the world a century later, with an average height of 169.8cm. James Bentham, a co-author of the research says the global trend is likely but once you average over whole populations, genetics plays a less key role," he added.

    But while height has increased around the world, the trend in many countries of north and sub-Saharan Africa causes concern, says Elio Riboli of Imperial College. While height increased in Uganda and Niger during the early 20th century, the trend has reversed in recent years, with height decreasing among 18-year-olds.

    "One reason for these decreases in height is the economic situation in the 1980s," said Professor Alexander. The nutritional and health problems that followed the policy of structural adjustment, he says, led to many children and teenagers failing to reach their full potential in terms of height.

    Bentham believes the global trend of increasing height has important implications. "How tall we are now is strongly influenced by the environment we grew up in," he said. "If we give children the best possible start in life now, they will be healthier and more productive for decades to come."