For many people who live in cities, parks are an important landscape. They provide a place for people to relax and play sports, as well as a shelter from the often severe environment of a city. What people often overlook is that parks also provide considerable environmental benefits.

    One benefit of parks is that plants absorb carbon dioxide and give off oxygen. According to one study, an acre of trees can absorb the same amount of carbon dioxide that a typical car emits in 11,000 miles of driving. Parks also make cities cooler. Scientists have long noted what is called the Urban Heat Island Effect: building materials such as metal and concrete (混凝土) absorb much more of the sun's heat and release it much more quickly than trees and grass. Because city landscapes contain so much of these building materials, cities are usually warmer than surrounding rural areas. Parks and other green spaces help to lessen the Urban Heat Island Effect.

    Unfortunately, many cities cannot easily create more parks. However, cities could benefit from many of the positive effects of parks by encouraging citizens to create another type of green space: rooftop gardens. While most people would not think of starting a garden on their roof, human beings have been planting gardens on rooftops for thousands of years. Some rooftop gardens are simple container gardens that anyone can create with the investment (投资) of a few hundred dollars and a few hours of work.

    Rooftop gardens provide many of the same benefits as other urban parks and garden spaces, but without taking up the much-needed land. In the summer, rooftop gardens prevent buildings from absorbing heat from the sun, which can significantly reduce cooling bills. In the winter, gardens help control the heat that materials like brick and concrete release so quickly, leading to savings on heating bills. Rooftop vegetables and herb gardens can also provide fresh food for city settlers, making their diets healthier. Rooftop gardens are not only something everyone can enjoy but also a smart environmental investment.

    "I really wrote it for me. It was what I found funny and what I liked". Those are the words of J K Rowling, author of the enormously popular "Harry Potter" books. The quote refers to the first in a series of novels featuring a young character who has carved out a permanent place for his creator in the world of children's literature.

    Joanne Kathleen Rowling was born in England in 1965, and wrote her first story at the age of six. She was in her mid-20s when the idea for the Harry Potter novels came to her, during a long train ride. By the end of that journey, she says, the character of Harry and the school for wizards which he attends were more or less fully formed in her mind.

    It would be several years, however, before the novel was completed. By that time, Rowling had been through a failed marriage. Living on welfare as a single parent, she wrote about Harry Potter while sitting in an Edinburgh café with her daughter asleep beside her. She could not have dreamed of the fame and success which Harry would bring her in the years to come.

    Harry Potter is not your average superhero. He is 12 years old, skinny, wears glasses, and tends to worry a lot. Yet, he has captured the imagination of children and adults the world over, and has introduced millions to the joys of reading.

    Harry's appeal stems from his role as a very ordinary boy who finds himself in extraordinary situations. Orphaned as a baby, Harry spends the next 10 years being mistreated by the awful relatives with whom he lives. On his 11th birthday, he learns that he possesses magical powers and is admitted for training at the Hogwarts School of Witchcraft and Wizardry.

    The adventures of Harry and his friends at the school are superbly narrated by J. K. Rowling. She manages to lead her millions of readers deep into the world of the supernatural, while at the same time dealing with the fears and emotions of the ordinary human world. Many feel that this is the real magic of Harry Potter.

So far this winter, a theater in the Alps has staged more than 60 unique concerts. Winter temperatures in the remote mountain village can drop high below zero. Performers wear down jackets and play ice instruments. In fact, almost everything from drums and guitars to horns and harps at the music festival is carved from ice even the stage the musicians play on. The audience sits on ice chairs and benches and claps their hands to listen, both to praise the performers and to keep themselves warm when the air flows through.

The musical instruments used were almost entirely made by an American ice artist, Tim Linhart. Since he created his first musical instrument out of ice more than a decade ago, he has already carved various ice instruments, including violins, violas, timber drum sets, xylophone, double bass, mandolin and cello. He also created his own large wind instrument, which uses the vibration of an ice tube to produce sound when the air flows through.

Linhart makes the different parts of the ice instrument and then uses a liquid mixed with snow to glue them together, with a metal support placed where the strings need to be. A violin can usually be made in two or three weeks, while larger instruments can take more time and efforts, sometimes taking months to make.

An ice instrument has a clearer sound than a wooden instrument. However, ice instruments are more easily broken or damaged than ordinary instruments. The temperature in the ice theater changes depending on the number of people in the audience. This also changes the temperature of the ice instruments, which in turn affects the 1 sound they produce. Musicians need to tune their instruments frequently during performances.

Although playing an ice instrument is not easy, Linhart believes that ice and snow are good materials for making instruments. The only downside is melting when the temperature is above freezing.

"Assume you are wrong." The advice came from Brian Nosek, a psychology professor, who was offering a strategy for pursuing better science.

To understand the context for Nosek's advice, we need to take a step back to the nature of science itself. You see despite what many of us learned in elementary school, there is no single scientific method. Just as scientific theories become elaborated and change, so do scientific methods.

But methodological reform hasn't come without some fretting and friction. Nasty things have been said by and about methodological reformers. Few people like having the value of their life's work called into question. On the other side, few people are good at voicing criticisms in kind and constructive ways. So, part of the challenge is figuring out how to bake critical self-reflection into the culture of science itself, so it unfolds as a welcome and integrated part of the process, and not an embarrassing sideshow.

What Nosek recommended was a strategy for changing the way we offer and respond to critique. Assuming you are right might be a motivating force, sustaining the enormous effort that conducting scientific work requires. But it also makes it easy to interpret criticisms as personal attacks. Beginning, instead, from the assumption you are wrong, a criticism is easier to interpret as a constructive suggestion for how to be less wrong—a goal that your critic presumably shares.

One worry about this approach is that it could be demoralizing for scientists. Striving to be less wrong might be a less effective motivation than the promise of being right. Another concern is that a strategy that works well within science could backfire when it comes to communicating science with the public. Without an appreciation for how science works, it's easy to take uncertainty or disagreements as marks against science, when in fact they reflect some of the very features of science that make it our best approach to reaching reliable conclusions about the world. Science is reliable because it responds to evidence: as the quantity and quality of our evidence improves, our theories can and should change, too.

Despite these worries, I like Nosek's suggestion because it builds in cognitive humility along with a sense that we can do better. It also builds in a sense of community—we're all in the same boat when it comes to falling short of getting things right.

Unfortunately, this still leaves us with an untested hypothesis （假说）: that assuming one is wrong can change community norms for the better, and ultimately support better science and even, perhaps, better decisions in life. I don't know if that's true. In fact, I should probably assume that it's wrong. But with the benefit of the scientific community and our best methodological tools, I hope we can get it less wrong, together.

I've just arrived from New York City at the airport in Rome and already I'm lost, wandering left and right and searching for the right exit. I'm supposed to meet my wife Elvira, who lives in Italy now, and then drive to Guardia Sanframondi, the little town where we own a house, to meet our newborn granddaughter Lucia, now all of 11 weeks old.

But I takes a wrong turn, and then another, all in vain. I'm lost for 15 minutes, then 30, and finally about 45, unable to get my passport properly scanned and pick up my luggage. This is more than mildly inconvenient. After all, I've just flown more than 4,000 miles, a flight into my future.

But suddenly I see Elvira, who is holding baby Lucia in her arms. I'm found.

I stay in Italy for three weeks. It's impossible for me to get enough of Lucia, and so I follow a strict agenda(日程). Hold Lucia in my arms. Kiss Lucia all over her face. Wheel Lucia in her carriage in the most public places available. Make faces at her and even sillier gestures and sounds.

Today, at 70, I'm a permanent resident of Italy, with Lucia living a five-minute walk away. We visit her at her house and she visits us at ours almost every day. In most American families, adult children with grandchildren live in different towns and states far away. Italian families, on the other hand, are more likely to live near each other. Sometimes three generations here even stay together in the same home. I've happily turned my life upside-down to be a grandpa Italian-style. Lucia is just what I need right about now. If I'm lucky, I'll be just what she needs, too.

When it comes to architectural accomplishments, humans like to think they stand at the top. That is to underestimate the astonishing achievement s of social insects; for example, white ants raise skyscraping nests. The true master builders of the insect world, however, are the hundreds of species of stingless bees.

In a new study, Ms. Di Pietro and her colleagues observed over 400 colonies of the stingless bee species in a large bee house in Brazil in 2022 and 2023. Around 95% of the colonies exhibited honeycombs（a structure made by bees） built up in horizontal layers（水平分层）, like tiered wedding cakes, while the rest adopted a spiral（螺旋的） structure.

Since the stingless bee shows a strong preference for a horizontal-layer honeycomb structure, it's surprising that spiral honeycombs occur. The team confirmed that there was no difference in the average cell-building rate between the two styles, and therefore no efficiency advantage.

In order to rule out a genetic explanation for the different styles, the researchers transplanted workers from colonies that built in one tradition to colonies that built in the other, having first emptied the host structures of their native adults. The imported workers soon switched to the local style, which was then continued by the colony's young insects as they eventually matured into workers.

Dr. Tom Wenseleers guessed that the bees may switch styles as a way of coping with the build-up of small construction errors made by their fore-runners. Such a process, in which multiple organisms indirectly affect each other's behavior through the traces they leave in their environment, is known as stigmergy（共识主动性）. The researchers later introduced a sign of spirals to the otherwise perfect horizontal-layer honeycombs, and found that it did indeed cause the bees to switch to building spirals.

These results suggest that stingless bees can pass on different building traditions across generations and individuals needn't be instructed by their peers. "The findings are the clearest demonstration of cultural differences naturally appearing in insects. Insect culture would once have been thought impossible," says behavioral biologist Andrew Whiten, who wasn't involved in the research. "Less than a century ago, culture was thought to be uniquely human."