2 . In recent studies we have been investigating mirror writing by typical 4- to 6-year-old children. The term is used because the characters — numbers and capital letters — are reversed (反向), yet are correct when looked at in a mirror.

Mirror writing entered the scientific literature in 1878. The explanations for the phenomenon were not only insufficient but also often wrong. One of them is — writing with the left hand. Throughout the 20th century, scientific journals have published mirror writing mostly produced by left-handed children. Even today, left-handedness is often the favorite explanation of teachers when children produce mirror writing.

The explanation we find for the phenomenon of mirror writing of characters works on two successive levels, the first cerebral and the second behavioral. The cerebral level shows that the brain removes orientation (left or right) when storing images, a process called symmetrisation or mirror generalization. This mirror-generalization process leads children aged 5 to know, from memory, the shape of the characters, but not their left/right orientation. Given the features of the process — horizontal mirror in the visual modality (视觉模式) — it is important to note that the initial learning of the form of the characters by the children is mainly visual, and that the children only produce horizontal mirror writing.

At the behavioral level, when children write the characters from memory, they must give them an orientation. In countries whose primary languages are written in Latin characters — written from left to right — children most often point them toward the right. This leads them to reverse mainly the left-oriented characters: J, Z, 1, 2, 3, 7, and 9. However, when spatial constraints cause them to write from right to left, the children instead reverse the right-oriented letters.

Since this explanation has nothing to do with the handedness of the children, it can be predicted that right-handed children will reverse characters almost often as left-handed children, and that – left-handed or right-handed – children will primarily reverse left-oriented characters in Western culture. This is because they strictly orient the characters in the direction of writing.

3 . Lena Mars and her parents had taken a trip to Costa Rica. While enjoying one of the country’s many beautiful beaches, the girl’s parents gave her a snack. But it turned out that she wasn’t the only one who was hungry: A wild iguana (鬣蜥) appeared unexpectedly as the girl at e her cake by the water. The iguana ran up to the girl and bit her on the back of her left middle finger, causing her to drop the cake. The animal then ran off with the snack, but it did leave something else behind.

The Mars immediately took the girl to a local clinic, where a doctor disinfected the wound with alcohol and gave her some antibiotics (抗生素). The wound appeared to have cleared up in about two weeks. It was five months later, when Lena’s parents noticed a coin-sized bump (肿块) on her hand in the same spot causing mild pain, that they thought they should take her to another doctor.

The doctor removed the 2-centimeter mass and took a closer look at the growth in the lab and discovered that the child had a rare infection that more commonly causes a tuberculosis-like illness in fish. It’s ubiquitous in fresh and salt water but rarely infects humans. Typically, when humans are infected, it’s after a wound has been exposed to the bacteria in water.

Most antibiotics alone don’t work on these kinds of infections, so the doctor gave the girl a different medical treatment often used for skin infections. She responded well to the treatment.

“Generally, iguanas will go about their day. But like any wildlife, if they start associating people with food, they’re going to risk coming closer.” said Anna Meyer, operations manager at a zoo in Florida. “The lesson here is that no one should feed wildlife, because they will most likely give you a bite.”

4 . Most people, if you quizzed them, probably wouldn’t know how much of all global trade is done by sea. It’s one of several reasons that the pollution and carbon emissions from shipping gain much less attention than those from road transport and other industries. It’s over the horizon, out of sight and out of mind.

Today, the international shipping industry is the main mode of transport for around 90 per cent of world trade. It’s powered almost entirely by fossil fuels. Studies show that alternative technologies and zero-emission fuels — including electrofuels such as hydrogen, ammonia and methanol — have the potential to significantly reduce the industry’s carbon footprint and thus require urgent implementation (实施). There’s just one catch: they don’t exist yet.

Even if the technology were available, the infrastructure (基础设施) for that technology or fuel is going to take time to develop. And an even bigger challenge is going to be whether that methanol or ammonia fuel is green, which touches on other industries such as renewable electricity. Do we even have enough renewable electricity in the world to be able to generate these fuels? It’s a complex supply chain that requires cooperation across the industry. It’s not something that one company can solve by itself.

According to Piotr Konopka, senior manager for energy and decarbonisation (碳减排) programs at DP World, there are some simple behavioral changes that can help cut down on fuel used in the meantime, from the regular maintenance and reduced idling of port equipment to the implementation of weather routing that helps ships avoid rougher, more fuel-intensive stretches of water. “Of course, efficiency is unlikely to ever reduce emissions by more than five or ten per cent, but it’s definitely a low-hanging fruit,” he says.

“This is the last moment for the IMO to act decisively to eliminate shipping emissions” says Delaine McCullough, shipping emissions policy manager at environmental NGO Ocean Conservancy. “We need countries to demand that the IMO set strong emission-reduction goals and take action at home if the IMO fails to do the right thing.”

5 . A common claim states that a sheet of paper cannot be folded in half more than seven times. But is this true?

In 2002, Britney Gallivan, then a junior in high school in Pomona, California, folded a single piece of paper in half 12 times. She currently holds the Guinness World Record for the most times to fold a sheet of paper in half.

The prompt that led Gallivan to accomplish this was an extra-credit challenge in math class to fold anything in half 12 times. Her teacher asked the students to fold something thicker: a piece of paper.

Gallivan said “it was very frustrating, as I had many unsuccessful attempts at trying to fold different papers in half. I began to question if folding paper in half more than eight times could be impossible.” However, Gallivan recalled. “I knew I needed to understand what was limiting the folding progression.”

The equations (方程式) that Gallivan came up with calculated how many times a sheet of paper could be folded. She found that in order to fold many times, a long thin sheet is needed — the more a sheet is folded, the thicker the resulting stack becomes, and once the stack becomes thicker than it is long, there is nothing left to fold. She ultimately set her record with a sheet of tissue paper she found online that was 4,000 feet (1,219 meters) — more than three-quarters of a mile, or over a kilometer long, Guinness World Records noted.

“Working on the problem took a tremendous amount of time and effort,” Gallivan said. “As frustrating as it was at times, I learned an immense amount from the experience, which has been valuable to me throughout my life in more capacities than one would expect.”

Since Gallivan set her record, others have made claims of folding a sheet of paper more than 12 times. Still, “I anticipate that my current record will be surpassed,” Gallivan said.

9 . Sometimes, determining which projects you should devote your time and energy to first takes energy you don’t have to spare (which is why we have tips for how to do it). But even when you know what tasks need to be done, you still need to figure out how to prioritize them. Try the 3-3-3 method.

This technique comes from Oliver Burkeman, author of Four Thousand Weeks: Time Management for Mortals($13.99). He advocates planning each workday around a 3-3-3 model, first devoting three hours to deep work on your most important project. Next, complete three other urgent tasks that don’t require three hours of focus. Finally, do three “maintenance” tasks, like cleaning, answering emails, or scheduling other work.

What distinguishes this method from other approaches are those first three hours of deep work. Jumping into them first means you’ll be fresh, focused, and more likely to be able to jump into a task without getting distracted. Keep those three hours free of emails, texts, chats, or other menial duties, to the best of your ability. (Check out our full guide to engaging in deep work here.)

Deep work produces major productivity, so you’ll get a lot accomplished if you commit to it, but you can’t stay in that mindset (思维模式) forever. You’ll top out after about three hours, so it’s best to have those three other, smaller tasks lined up and ready to go so you can stay productive even while slowing down into less demanding responsibilities.