On Monday, the Centers for Disease Control and Prevention predicted that 42% of Americans could be overweight by 2030. Our expanding bodies not only lead to a medical problem, but also endanger personal safety in some situations—in an airplane crash, for example, according to a recent article in The New York Times.

The New York Times' Christine Negroni reports that engineers and scientists are questioning whether airplane seats are designed to protect overweight travelers. Government standards(标准) for airplane seat strength—first set more than 60 years ago—require that the seats be made for a passenger weighing 170 pounds. Today, the average American man weighs nearly 194 pounds and the average woman 165 pounds. Negroni reports:

     “If a heavier person completely fills a seat, the seat is not likely to behave as designed during a crash,” Robert Salzar, the leading scientist at the Center for Applied Biomechanics at the University of Virginia. “The energy that is built into the aircraft seat is likely to be overpowered and the passengers will not be protected properly”.

     “Nor would the injury be limited to that passenger only,” Dr. Salzar said. “If a seat or a seat belt fails,”he said, “those people who are seated nearby could not be safe from the uncontrolled movements of the passenger.”

    Most complaints(投诉) about airplane seats focus on their lack of comfort and high ticket price, and whether overweight passengers should be made to buy two seats. But The New York Times' article brings up another reason to feel anxious about flying. Investigators(调查者) got in touch with the airplane seat and seat belt makers, but they refused to talk about the problem. Experts agreed that crash testing should be done. Both airplane seats and seat belts should be tested, they said.

    Fortunately, however, according to Nora Marshall, a senior adviser at the National Transportation Safety Board, the board's investigators have never seen an accident involving a commercial plane in which the weight of a passenger was a problem.

    Crown shyness(树冠羞避) is a mysterious natural phenomenon in which the crowns of some tree species do not touch each other, but get separated by a gap clearly visible from ground level. The effect usually occurs between trees of the same species, but has also been observed between trees of different species.

    There are many theories going around, most of which make sense, but no one has been able to prove without the shadow of a doubt why some trees avoid touching each other.

    In his 1955 book Growth Habits of the Eucalypts, Australian forester M.R. Jacobs writes that the growing tips of the trees are sensitive to abrasion(擦伤), which results in crown shyness phenomenon. This theory was also supported by Dr. Miguel Franco. Some experiments have shown that if trees displaying crown shyness are artificially prevented from swinging in the wind and touching each other, they gradually fill up the gaps between them.

    But while the above theory is arguably the most widespread, it's certainly not the only one. Some scientists have suggested that crown shyness is a mechanism to stop the spreading of leaf-eating insects. These pests have been known to work together and create structures that extend up to 10 cm off of tree branches in order to reach other plants, so the gaps are the trees' natural defense method.

    One Malaysian scholar studied many trees, but found no traces of abrasions, despite their clear crown shyness. Instead, he suggests that the growing tips of the trees were sensitive to light levels and stopped growing when they got too close to other trees. Plants are able to sense how close they are to other plants and in order to get more light, they give off some chemical element to stop other trees from growing too close.

    Whatever the reason, one thing is for sure: plants are more intelligent than people used to think.

    The morning had been a disaster. My tooth was aching, and I'd been in an argument with a friend. Her words still hurt: “The trouble with you is that you won't put yourself in my place. Can't you see things from my point of view?” I shook my head stubbornly-and felt the ache in my tooth. I'd thought I could hold out till my dentist came back from holiday, but the pain was really unbearable. I started calling the dentists in the phone book, but no one could see me immediately. Finally, at about lunchtime, I got lucky.

    “If you come by right now,” the receptionist said, “the dentist will fit you in.”

    I took my purse and keys and rushed to my car. But suddenly I began to doubt about the dentist. What kind of dentist would be so eager to treat someone at such short notice? Why wasn't he as busy as the others?

    In the dentist's office, I sat down and looked around. I saw nothing but the bare walls and I became even more worried. The assistant noticed my nervousness and placed her warm hand over my ice-cold one.

    When I told her my fears, she laughed and said, “Don't worry. The dentist is very good.”

    “How long do I have to wait for him?” I asked impatiently.

    “Come on, he is coming. Just lie down and relax. And enjoy the artwork,” the assistant said.

    “The artwork?” I was puzzled.

    The chair went back. Suddenly I smiled. There was a beautiful picture, right where I could enjoy it: on the ceiling. How considerate the dentist was! At that moment, I began to understand what my friend meant by her words.

    What a relief!

    I'm a reporter. Last month I was in Stockholm, Sweden. Now I'm in Frankfurt, Germany. Next month, who knows?

    You certainly won't believe that I can call you from my laptop, which is what I'm often doing these days using something called Skype.

    Skype lets me call any phone number anywhere in the world for about 2 cents a minute, a little more to some places, such as the Middle East and Asia. My computer does the dialing, and the processing of incoming and outgoing voices. All you need is a broadband connection (宽带接头). With the basic version of Skype, all anyone needs to make or receive a call is to install the program on his or her computer (and that includes personal digital assistants). All calls from PC to PC are free.

    You don't even need a pair of headphones, though headphones can be a good idea if you wish to be discreet. I use my laptop's built-in microphone.

    The paid service for calling regular telephones is called SkypeOut. The quality is completely clear, provided that there's not too much traffic on the Internet. If there's an echo, hang up and try again, and it usually gets better. There is one warning: on some computers, especially those running older versions of Windows, it doesn't always work, or can sound like a confusing conversation. You can't hear a thing.

    Skype was invented chiefly by a Swede named Niklas Zennstrom along with a group of programmers in Estonia.

Ammaar Reshi, 28, has been fascinated by technology since he was a child. One day, when he was experimenting with an AI-powered chatbot, he began to consider how artificial intelligence could be used to create a basic children's book to give to his friends. Without ever picking up a pen and paper, he created a 12-page picture book. 

Just 72 hours later, Reshi self-published his book on Amazon's digital bookstore. The next day he got the paperback（平装书）, which was made available for free through another Amazon service called KPD. 

Reshi said he paid nothing to have the book created and published, although he has already paid for a $30-per-month Midway subscription. Impressed by the speed and results of his project, Reshi shared the experience in a Twitter thread that attracted more than 2,000 comments and 5,800 retweets（转发）. 

Reshi stated that he received great feedback（反馈）from users, who lauded his creative work at first. But the next day, the replies were negative. "There was this incredibly passionate reaction," Reshi said. "At 4 am, I was woken up by my phone ex ploding every two minutes with a new tweet saying things like ‘We hate you'. "

Reshi was taken aback by the outpouring of emotion in response to what was supposed to be a present for some friends' children. He didn't realize he had landed in the heart of a much broader argument. 

Some artists have expressed concern that AI art generators are stealing their work in response to Reshi's book. And some artists claim that their work has been used without their permission to train Al picture generators. 

"I wouldn't even call myself an author," Reshi said. "The AI is essentially the ghostwriter（代笔者）, and the other AI is the illustrator. " But he thought the process was creative.