In 1905, as part of his Special Theory of Relativity, Albert Einstein published the point that a large amount of energy could be released from a small amount of matter. This was expressed by equation E = me 2(energy = mass times the speed of light squared). But bombs were not what Einstein had in mind when he published this equation.

    In 1929, he publicly declared that if a war broke out he would “refused to do war service, direct or indirect…” His position would change in 1933, as the result of Adolf Hitler's coming into power in Germany.

    Einstein's greatest role in the invention of the atomic bomb was signing a letter to President Franklin Roosevelt urging that the bomb be built because some physicists feared that Germany might be working on an atomic bomb. Among those concerned were physicists Leo Szilard and Eugene Wigner. But Szilard and Wigner had no influence with those in power. So in July 1939 they explained the problem to someone who did: Albert Einstein. After talking with Einstein, in August 1939 Szilard wrote a letter to President Roosevelt with Einstein's signature on it, which was delivered to Roosevelt in October 1939.

    Germany has invaded Poland the previous month; the time was ripe for action. That October research of a-bomb began but proceeded slowly because the invention of the atomic bomb seemed distant and unlikely. In April 1940 an Einstein letter, ghost-written by Szilard, pressed the researchers on the need for “greater speed”.

    As the realization of nuclear weapons grew near, Einstein looked beyond the current war to future problems that such weapons could bring. He wrote to his friend about his fear about the future use of the a-bomb.

    The atomic bombings of Japan occurred three months after Germany gave in.

In November 1954, five months before his death, Einstein summarized his feelings about his role in the creation of the atomic bomb: “I made one great mistake in my life… when I signed a letter to President Roosevelt recommending that atom bombs be made; but there was some justification—- the danger that the Germans would make them”.

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    People who like travelling have their reasons. They believe that travelling can help them expand their field of view, especially in the geographical and historical sense. They also think that touring will give them more chances to enjoy different kinds of food and experience new things that would never be brought by other activities. But those who dislike travelling also have some reasons.

    Travelling, in my opinion, does more good than harm. Most importantly, it broadens our mind. We can get in touch with other civilizations (文明), cultures, customs and ideas.

    Through history, most people travelled because of necessity (必要性)-not for pleasure. People travelled just in order to remain alive. They searched for food to eat or places to live in. They sometimes ran away from enemies. This is not to say that no one ever travelled just for the fun of it. In ancient times, for example, rich Romans travelled all the way to Greece to take part in the Olympic Games, and festivals. Of course, some people decided to travel just out of curiosity. They wanted to find out what it looked like beyond the horizon (地平线). Also business travel has been going on for centuries. Traders could not only make money but also learn to speak several languages and be introduced to different cultures.

    So, travelling does enrich our mind and draw new ideas to us. There is no doubt that we can get much from it.

    If you ever visit an English village, make sure to look out for morris dancing. Undoubtedly one of the strangest traditions of English culture, morris dancing is a form of folk dancing that dates back to the 15th century. If you ever get the opportunity, you really have to see it.

    Men and women wearing old-fashioned, shabby clothing dance in the streets of towns and villages across the country during the holiday periods. Women wear long, frilly (有褶皱边的) skirts and men wear short trousers with bells attached to them. They dance to traditional folk music which is often played on traditional musical instruments.

    Some groups carry heavy black sticks which they beat against each other while they dance. Other groups wave handkerchiefs in the air while they perform. The dances are usually performed near a pub so that when it's over, the dancers and audience can sing some traditional folk songs over a pint of beer. The celebrations will often continue long into the night, by which point most people are too drunk to think about performing again.

    Morris dancing is a great English tradition but it's facing a big crisis. As the years go by, fewer and fewer young people are joining morris dancing groups. The dancers are getting older and older and eventually. If you've ever had the fortune to see morris dancing, you may understand why teenagers aren't rushing to sign up. Putting it to the point, it's not exactly the coolest thing for an 18-year-old to be doing. Why dress up in bells and funny costumes when you could be going clubbing? Or playing sport? Or doing anything else?

However, it would be a great shame to lose such a fun and lively part of England's history and culture. It's important to look after some traditions and customs especially when it's something as harmless and happy as morris dancing. So here's a toast to the next generation of would-be morris dancers! Let's hope they don't leave it too late.

    Chinese researchers say they have come up with a simple way to find out a person's biological age —how much the body has aged physically – through a urine (尿) test.

    Their findings will help researchers conduct numbers of ageing studies and even predict a person's risk of age-related diseases, according to a paper published in the journal Frontiers in Ageing Neuroscience.

    Another paper by researchers at the Beijing Hospital and the West China Hospital in Chengdu, Sichuan province, said on Tuesday that people aged at different rates due to changes in their genetic make-up and their environment.

    Chronological age – which is based on one's birth date —was not an exact measure of biological age so a more exact method was needed, the team said.

    Ageing is driven by the lifelong gradual accumulation(积累) of a broad variety of molecular (分子) faults in the body's cells. The team said they had identified a matter 8-oxoGsn that indicated increases in oxidative (氧化性) damage in urine as people's bodies aged.

    Cai Jianping, a co-author at the Beijing Hospital, said: “As we age, we suffer increasing oxidative damage and so the levels of oxidative matters increase in our body.” The team tested the levels of 8-oxoGsn in urine samples from 1,228 Chinese people aged two to 90 and concluded the marker helped accurately determine the stage of biological ageing in adults.

    They had previously found that 8-oxoGsn levels also increased with age in the urine of animals such as mice.

    The team has also developed a rapid analysis technique called ultra-high-performance liquid chromatography(层析法), which can process up to 10 urine samples an hour, according to the study.

    In the online world, it's very difficult to talk to Chinese people without using emojis. However, did you know that people in different age groups have totally different preferences for choosing their emojis? The result is based on a report released by Tencent's WeChat, China's most popular messaging app, on its official weibo account on Wednesday.

    Specifically, for users who were born in the 2000s, their favorite WeChat emoji would probably be the widely used "facepalm", rumored to be based on the famous Hong Kong movie star Stephen Chow. They also may be a night owl without much sleep, while iced beverages and desserts are their cup of tea.

    For China's post-90s WeChat users, they are likely to get out of bed later in the morning compared with other groups, and the emoji "face with tears of joy" may rule their online social life. Also, their reading materials have shifted from entertainment and gossip three years ago to the current relationship and lifestyle pieces.

    For those born in the 1980s, their tastes have remained the same, as they are still fond of reading news on national affairs. And "smiling widely" is their emoji of the year.

    WeChat users born in the 1970s are called the optimistic group, who like to use the emoji "laughing quietly" and go through their moments frequently every day. Their bed time usually takes place around 11:30 pm.

    Users over 55 are the early-bird group with rich entertainment activities in WeChat platforms, such as looking through moments, reading and shopping. They like to cheer up other age groups, so their favorite emoji is "giving a thumbs-up".

    The report also indicates that WeChat boasts more than 1.08 billion active users with 45 billion messages being sent and 410 million calls getting through the app each day in 2018. In addition to covering users' socializing, WeChat has gradually come into our daily lives. Compared to the year before, people used WeChat 4.7 times more to purchase public transport tickets, and 2.9 times more to pay for medical expenses. Also, the app was used 1.5 times more over the previous year to pay for meals, with Beijing, Guangzhou and Shenzhen ranked as the top three cities in dining purchases through WeChat.

    A recent study followed nearly 1,500 old people for 10 years. It found that those who had a large network of friends lived longer than those with fewer friends by more than 20%.This study isn't the only one that shows friendships can be good for our health.

    Lots of research has shown social support and good health are connected. One recent study focuses on people with ovarian cancer. It says those with lots of social support had much lower levels of a protein connected to more dangerous cancers. This made their treatments (治疗) work better. In another study, women with breast cancer in a support group lived twice as long as those not in a support group. They also had much less pain.

    Sheldon Cohen, a professor at Carnegie Mellon University in Pittsburgh, says strong social support helps people deal with stress. "There may be more benefits as well," Cohen says. "Friends encourage you to look after yourself better. And people with more friends have higher self­confidence, so they feel they have more control over their lives."

    Other studies show people with fewer friends are likely to die sooner after having a heart attack, compared with people having a strong social network. Having lots of friends may even lower your chance of catching a cold. "People with social support have fewer immune (免疫的) problems and lower levels of stress," says Tasha Howe, who works at Humboldt State University. "We are social animals, and we were born to be in groups," Howe says. "We have always needed others to survive better. It's in our genes." People with a big social group are likely to be more at peace, which leads to better health, Howe says.