When milk arrived on the doorstep

    When I was a boy growing up in New Jersey in the 1960s, we had a milkman delivering milk to our doorstep. His name was Mr. Basille. He wore a white cap and drove a white truck. As a 5-year-old boy, I couldn't take my eyes off the coin changer fixed to his belt. He noticed this one day during a delivery and gave me a quarter out of his coin changer.

    Of course, he delivered more than milk. There was cheese, eggs and so on. If we needed to change our order, my mother would pen a note-“Please add a bottle of buttermilk next delivery”-and place it in the box along with the empty bottles. And then, the buttermilk would magically appear.

    All of this was about more than convenience. There existed a close relationship between families and their milkmen. Mr. Basille even had a key to our house, for those times when it was so cold outside that we put the box indoors, so that the milk wouldn't freeze. And I remember Mr. Basille from time to time taking a break at our kitchen table, having a cup of tea and telling stories about his delivery.

    There is sadly no home milk delivery today. Big companies allowed the production of cheaper milk, thus making it difficult for milkmen to compete. Besides, milk is for sale everywhere, and it may just not have been practical to have a delivery service.

    Recently, an old milk box in the countryside I saw brought back my childhood memories. I took it home and planted it on the back porch （门廊）. Every so often my son's friends will ask what it is. So I start telling stories of my boyhood, and of the milkman who brought us friendship along with his milk.

    By now, you've probably been warned that a robot is coming for your job. But rather than repeat the warning, I've decided to throw down a challenge: man against machine.

    Start with the task we're doing right now: communicating in fluent human. We're sharing abstract ideas through words that we choose with an understanding of their slight difference and impact. We don't just speak in human; we speak as humans. A robot who says that science is fun is delivering a line (念一句话). A human who says that science is fun is telling you something important about being alive.

    Here's another inbuilt advantage we take for granted: as humans we are limited by design. We are bound in time: we die. We are bound in space: we can't be in more than one place at a time. That means when I speak to an audience, I am giving them something special. It's a custom-made, one-off, 100% robot-free delivery, from today's one-and-only Australian Chief Scientist.

    True, I now come in digital versions, through Twitter and Facebook and other platforms, but the availability of those tools hasn't stopped people from inviting me to speak in person. Digital Alan seems to increase the appetite for human Alan, just as Spotify (a digital music service) can increase the demand for a musician's live performances.

    Thanks to technology, many goods and services are cheaper, better and more accessible than ever before. We like our mass-produced bread, and our on-tap lectures and our automated FitBit advice. But automation hasn't killed the artisan bakery (面包店). Online courses haven't killed the booming, alongside their machine equivalents.

    Here's a third argument for the win. We humans have learned the habit of civilization. Let me explain this point by a story. A few years go, some researchers set out to study the way the people interact with robots. They sent out a small robot to patrol (巡逻) the local mall. That robot had a terrible time, and the villains of the story were children. They kicked him, bullied him, and smacked (掌击) him in the head.

    The point is not that the children were violent. The point is that the adults were not. They restrained whatever primitive impulse (冲动) they might have felt in childhood to smack something smaller and weaker in the head, because they had absorbed the habit of living together. We call it civilization. If we want artificial intelligence for the people, we'll need every bit of that civilizing instinct.

    Together, these points suggest to me that humanity has a powerful competitive edge. We can coexist with our increasingly capable machines and we can make space for the full breadth of human talents to flourish.

C

Plastic-Eating Worms

    Humans produce more than 300 million tons of plastic every year. Almost half of that winds up in landfills(垃圾填埋场), and up to 12 million tons pollute the oceans. So far there is no effective way to get rid of it, but a new study suggests an answer may lie in the stomachs of some hungry worms.

    Researchers in Spain and England recently found that the worms of the greater wax moth can break down polyethylene, which accounts for 40% of plastics. The team left 100 wax worms on a commercial polyethylene shopping bag for 12 hours, and the worms consumed and broke down about 92 milligrams, or almost 3% of it. To confirm that the worms' chewing alone was not responsible for the polyethylene breakdown, the researchers made some worms into paste(糊状物) and applied it to plastic films. 14 hours later the films had lost 13% of their mass — apparently broken down by enzymes (酶) from the worms' stomachs. Their findings were published in Current Biology in 2017.

    Federica Bertocchini, co-author of the study, says the worms' ability to break down their everyday food — beeswax — also allows them to break down plastic. ＂Wax is a complex mixture, but the basic bond in polyethylene, the carbon-carbon bond, is there as well, ＂she explains, ＂The wax worm evolved a method or system to break this bond. ＂

    Jennifer DeBruyn, a microbiologist at the University of Tennessee, who was not involved in the study, says it is not surprising that such worms can break down polyethylene. But compared with previous studies, she finds the speed of breaking down in this one exciting. The next step, DeBruyn says, will be to identify the cause of the breakdown. Is it an enzyme produced by the worm itself or by its gut microbes(肠道微生物)?

    Bertocchini agrees and hopes her team's findings might one day help employ the enzyme to break down plastics in landfills. But she expects using the chemical in some kind of industrial process — not simply ＂millions of worms thrown on top of the plastic.＂

    The US teenager Thomas Cheatham had planned to study Latin during his time at Hebron High School in Texas. But when he learned that the school district was going to offer a Mandarin class, he quickly changed his mind.

    “I thought Mandarin would be more beneficial than Latin,” said Cheatham, who is now in his second year of studying the language. He speaks Mandarin to order food at Chinese restaurants and can read social media posts from his Chinese-speaking friends.

    While it's a difficult language to master, the high school junior, who plans to study computer engineering, thinks it will be important for his career. “Chinese is a good language to know, especially with China becoming a growing power,” he said.

    Many experts agree that proficiency in a language spoken by a billion people worldwide will give American students an edge in the global economy. “People are looking at China as our next economic competitor, and interest in Mandarin is growing,” said Marty Abbott, executive director of the American Council on the Teaching of Foreign Languages. “We're seeing it in all parts of the country. ”

    Abbott estimates that as many as 100, 000 students are now studying Mandarin throughout the US, in public and private schools. She said the US government has designated (指定) Mandarin as a “critical needs” language and provides professional development programs for teachers. “Our government wants to increase our language competency for national security and economic competitiveness,” Abbott said.

    At the same time, the Chinese government is spreading knowledge of the Chinese language and culture through Confucius Institutes established in many US states. For example, the Confucius Institute at the University of Texas in Dallas has been the home of a Confucius Institute for 10 years. It sponsors Confucius Classrooms at 21 local public and private schools, where tens of thousands of students are learning Mandarin.

    Have you ever wondered what wild animals do when no one is watching? Scientists have been able to record the "private" moments of wildlife with leading-edge technology. Low-cost, dependable and small modern cameras are of big help.

    Cameras placed in hard-to-reach places have taken videos of everything from small desert cats to later snow loving felines (猫科) in the northern Rocky Mountains. These cameras are important tools to learn new information on wildlife.

    Some videos help scientists see the effects of climate change. For example, the desert animal javelin and the tree-loving coatimundi have been caught on cameras north of their normal home. This could mean global warming is enlarging their living area northward.

    Researchers use cameras along with global positioning systems, or GPS. They attach GPS devices (设备) to mule deer and antelope in and around Yellowstone National Park. Then they can record their movements, or migrations (迁移) . These cameras can be left in very rural (荒野的) areas for days, weeks or even month. They can provide information on how many animals are moving over a given period of time.

    Rural video can show details about animal behavior, such as the calls made by migrating. Also some cameras record animal life and show everything from bison in Saskatchewan, Canada, to the underwater weed forest off California's Channel Islands.

    However, rural cameras have their problems too. Animals such as wolverines and bears sometimes attack them. Scientists do not know if the attacks are the result of anger or interest. Also, the devices have become popular tools to help hunters look for animals. Some people argue that it is unfair to use the cameras that way. Even with such problems, rural cameras are clearly an important scientific tool in researching wild animals.

    One day when I was 12, my mother gave me an order: I was to walk to the public library, and borrow at least one book for the summer. This was one more weapon for her to defeat my strange problem—inability to read.

    In the library, I found my way into the "Children's Room." I sat down on the floor and pulled a few books off the shelf at random. The cover of a book caught my eye. It presented a picture of a beagle. I had recently had a beagle, the first and only animal companion I ever had as a child. He was my secret sharer, but one morning, he was gone, given away to someone who had the space and the money to care for him. I never forgot my beagle.

    There on the book's cover was a beagle which looked identical (相同的)to my dog. Iran my fingers over the picture of the dog on the cover. My eyes ran across the title, Amos, the Beagle with a Plan. Unknowingly, I had read the title. Without opening the book, I borrowed it from the library for the summer.

    Under the shade of a bush, I started to read about Amos. I read very, very slowly with difficulty. Though pages were turned slowly, I got the main idea of the story about a dog who, like mine, had been separated from his family and who finally found his way back home. That dog was my dog, and I was the little boy in the book. At the end of the story, my mind continued the final scene of reunion, on and on, until my own lost dog and I were, in my mind, running together.

    My mother's call returned me to the real world. I suddenly realized something: I had read a book, and I had loved reading that book. Everyone knew I could not read. But I had read it. Books could be incredibly wonderful and I was going to read them.

    I never told my mother about my "miraculous" (奇迹般的) experience that summer, but she saw a slow but remarkable improvement in my classroom performance during the next year. And years later, she was proud that her son had read thousands of books, was awarded a PhD in literature, and authored his own books, articles, poetry and fiction. The power of the words has held.