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”.

    “The failure to play is now a serious issue and it calls for action for change,” says Sir Ken Robinson, a leading expert in education, creativity and human development. This is the driving force behind Outdoor Classroom Day—a global teacher-led campaign, supported by Dirt is Good, a company producing daily chemical products.

    Outdoor Classroom Day, taking place on 17th May and 1st November this year, will see schools around the world swap the inside for the outside and take learning into the playground and beyond to make playtime a key part of the school day. This might involve using natural objects like stones to do sums, or going on an insect hunt to encourage curiosity. By now, Outdoor Classroom Day has grown from a grassroots movement to a global campaign that is expected to benefit five million children and over 40,000 schools from all around the world in 2018.

    This is helping to change the trend that sees many schools selling up or building on their playgrounds and cutting back on playtime to make more room for academic studies, while at home children's lives are increasingly filled with organized activities intended to help them learn. Today globally 61% of parents surveyed in the Dirt is Good Qualitative Study said that children don't know how to play without using technology.

    Outdoor Classroom Day is making playing time happen, with 22% of participating schools having increased their playtime since joining the campaign. 93% of teachers surveyed saw improvements in children's creativity after playing outside, and 97% believe that time outdoors is necessary for children to reach their full potential.

    Scientific studies show that real play—the active, physical, self-directed play—is essential for children to develop key life skills that are not taught elsewhere. Few would question the value of developing creativity, leadership, resourcefulness, and curiosity.

    What do we think of when we someone mentions Scandinavia(斯堪的纳维亚半岛), the group of Northern European countries? Many things come to mind. We might think of the breath-taking natural beauty of Norway's fjords(海湾). If we enjoyed the fairy tales of Han Christian Anderson as children, perhaps we will think of  Denmark's capital, Copenhagen, and its statue of Anderson's Little Mermaid（美人鱼）.

    Perhaps we shiver at the thought of Scandinavia, as the countries there can be very cold. Or maybe we imagine this part of the world, so high up in the Northern Hemisphere, as dark and a little gloomy.

    What doesn't come to mind is people who like to party. However, according to a survey released by travel site Hostel-world this month, Scandinavia has some of the most sociable cities on the planet.

    For the study, 12,188 people from cities around the world were asked about their attitudes to socializing. Overall, Gothenburg in Sweden came out on top, but Copenhagen and Stockholm also placed highly, among with more predictably lively cities like New York and Madrid.

    A city made up of many little islands, Gothenburg is, according to The Daily Telegraph, "charming in an old-fashioned way". The city's authorities have preserved Gothenburg's attractive wooden houses from the 19^th century. Many of these have been made over into restaurant and coffee bars. Music fans are as well satisfied too — Gothenburg has dozens of record stores and live music venues(场所).

    As you'd expect, Scandinavia cities are also welcoming to visitors. People here don't care about your cultural background or anything else that some other places might take exception to. In these friendly Scandinavia cities, everyone's invited to the party.

    Three boys were enjoying themselves in their hometown of Bovina, Mississippi .However, their lives were turned upside down when they discovered the jawbone of a Mastodon (齿乳象).

    Brothers Shawn and Caid Sellers and cousin Michael Mahalitc found the prehistoric bone in a piece of earth that was recently plowed (犁、耕)."I thought it was a log," Caid said. "I tried to pick it up and it was really heavy and I saw teeth on it." The bone weighed about 50 pounds. They eventually got the bone to their home and fitted it in their tub (浴盆), but it took their collective strength, might and a golf cart, to carry the large Mastodon bone.

    "They didn't expect to find that," Michael's mom said. "Now that they have, I believe that they will be more aware of their surroundings and what they're digging up when they are digging and playing."

    "We've gotten a lot of petrified (石化的) wood and Civil War relics from the area and that's what I thought it was," the brothers' mother said. "This is our first set of teeth we've found. So we thought it was their imagination. We were quite surprised to see that it was not their imagination."

    They were exploring near the brothers' home. Lo and behold (真想不到), they saw what they thought resembled a fossil. It was the curator of paleontology (古生物负责人) of the Mississippi Museum of Natural Science, George Phillips, who first identified the bone as a "very mature individual."

    The Mastodon was a mammal who lived during the prehistoric times. They had long tusks and trunks, like elephants. They were clearly different from their modern-day counterparts, as well as woolly mammoths (猛犸).

    Johnny Jennings is 86 years old, but he first visited the Georgia Baptist Children's Home when he was 18, and the visit changed his life forever.

    A child ran up to Jennings, begging to be adopted, and it was at that moment that Jennings realized his life's mission. From that day forward, Jennings did everything he could to help, and that turned out to be quite a lot. Since he wasn't ready to adopt a child of his own, he decided to contribute financially. Since he wasn't wealthy, he did so by collecting paper and aluminum (铝) products and cashing them in for money. That may not sound like it would amount to much, but Jennings has donated more than US$400,000 over the past 30 years. That's a lot of paper products.

    Over those 30 years Jennings has become a cornerstone of the children's home.

But how does he get all that paper? Now that people know about his efforts, the paper pretty much comes to him. People drop it off at his house after collecting it through churches, organizations or in their own lives. Jennings also collected pennies, and as they say: A penny saved is a penny earned. Well, he's saved 24 miles' worth of pennies. It's the truth. "84,480 is a mile of pennies," Jennings said. "We finished 24 miles. We had most people from church collecting pennies." Each and every mile was a donation to the church.

    One of Jennings' favorite events is the church's annual meeting, which is when he presents his check each year. During this time, the kids who live in the children's home are also in attendance and he loves the opportunity to spend time with them. Jennings has served on the board for 45-year terms. "I've been a trustee for 20 years," Jennings said. "I'm just part of the family." And what a special family it is, thanks in large part to Johnny Jennings.

Your 2018 Reading List, Provided by Bill Gates

    Most of us can't live like billionaire Microsoft co-founder Bill Gates, but we can read like him. Gates recommended four books in 2018—though some were published earlier.

    Leonardo da Vinci, by Walter Isaacson (2017)

    The bestselling biographer of Steve Jobs and Albert Einstein researched deeply into da Vinci's contributions beyond art, highlighting the breadth of his scientific, technological, and creative output. “Leonardo nearly understood almost all of what was known on the planet at the time. That's mostly because of his curiosity about every area of natural science and the human experience,” said Gates.

    The Best We Could Do: An Illustrated Memoir, by Thi Bui (2017)

    Gates calls this graphic novel “really impressive”. Bui is the daughter of Vietnamese refugees who came to America after the fall of Saigon, and becoming a parent inspired her to look into her own parents' miserable history. “I was struck by how the experiences Bui illustrates manage to be both universal and specific to their circumstances,” said Gates.

    Lincoln in the Bardo, by George Saunders (2018)

    Saunders, a long-time short story writer, won high praise for this novel. The book imagines the ghosts that haunt (萦绕) the basement of Willie Lincoln, Abraham Lincoln's son, who died at 11 in real life. “Willie's death after the Civil War made the president have a new understanding of the grief he's creating in other families by sending their sons off to die in battle,” said Gates.

Origin Story: A Big History of Everything, by David Christian (2018)

    This new book is by the creator of Big History, a free, online social studies course. It traces history in wide, sweeping movements, starting with the Big Bang, and it provides, in effect, a short course in modern science. This is a brief history of the universe. “David gets a little stuck on the current economic and political problems in the West, and I wish he talked more about the role innovation will play in preventing the worst effects of climate change,” said Gates.