Most of us have lost our wallet at some stage in our lives. But few would imagine having it returned after 66 years. Edward Parker dropped his wallet in 1950 into an inaccessible spot behind a bookshelf, while working as an electrician, repairing World War Two bomb damage in the palace. The wallet stayed there until this year when a builder, doing some restoration work, finally found it.

    The wallet is a time capsule. Its leather and webbing has long ago started to disintegrate. But it contains numerous pictures of family, invoices, receipts, old union cards, results of a chest X-ray (sent to him in 1948, the same year as the NHS was founded), a national service card dated 9 December 1944 and a medical insurance card. His business cards—E Parker, Electrical Contractor—seem almost original. Reflecting the typical methods of contact of the time, they have an address but no telephone number.

    A month ago I was speaking to a press officer Lambeth Palace and he mentioned that the wallet had just been handed in. We thought it might be nice to try and work out whose it was and give it back to the family. Edward Parker is a pretty common name, but his medical card contained two places of residence—Poets Road and Springdale Road in north London. From this, Islington Council were able to find details of a marriage between Edward Parker and Constance Butler in 1947.

    That information was enough to work out that he was still alive and in a care home in Essex, so I went to visit him. Now 89, Edward has dementia (痴呆), but he was clearly happy to get the wallet and in particular, the photographs back. He pointed out pictures of his mother and father, his brother, his cousins and his wife Constance, who was with him when I visited. He hadn't seen a picture of his father since he lost the wallet, Constance, 90, said.

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    You may know the English letters A, B and C. But do you know there are people called ABC? You may like eating bananas. But did you know there is such thing as a “banana person”? How strange! Are these people from “another earth”? No. They are just Chinese people like you and me.

    ABC means American-born Chinese. An ABC is a Chinese, but was born in the United States. Sometimes, people call an ABC a “banana person”. A banana is yellow outside and white inside. So, when a person is a banana, he or she is white inside-thinking like a Westerner and yellow outside-looking like a Chinese.

    Do you know why? Usually, ABCs know little about China or the Chinese language. Some of them don't speak Chinese. Also, they are not interested in Chinese politics.

    But if ABCs cannot speak Chinese, can we still call them Chinese people? Yes, of course. They are Chinese. They are overseas (海外的) Chinese. These people may be citizens(公民) of another country like the US, Canada or Singapore. But they have Chinese blood. Their parents, grandparents or even great-grandparents were from China. They all have black eyes and black hair. But they are not Chinese citizens. They are not people of the People's Republic of China. For example, we all know the famous scientist C. N. Yang (杨振宁). He got the Nobel Prize for Physics in 1957. Chinese people love him. But he is an American citizen.

    The boy sat on his chair, with his hand above the keyboard. He thought about what to write.

    He recalled that the competition deadline was merely a week away. But he still had not even started on his piece. He looked at the brochure again." WRITING COMPETITION!" the title read. His mom had encouraged him to enter the writing competition, and now he was taking it on as his personal task for the holidays.

    As the boy reflected on his previous writing efforts, he realized how hopeless his task of winning was. Every story he ever wrote was based on other stories. He had little imagination, and unfortunately, imagination was the key to writing.

    Suddenly, he had a brainwave. This time, he came up with an original and imaginative story.

    The words shot towards him like a storm of leaves. Words were coming easily, flowing through him, faster than he could type. He typed faster than he ever had before. He continued to type, amazed at how easy writing this story was. The boy could not stop writing. He looked at the word count and saw the number" 248" staring right back at him. He was not even halfway yet.

    Then he heard the call of his mother saying time for bed. He continued writing the piece, ignoring her. He had to make up for the time he had lost thinking about a topic to write.

    Finally, he finished. The word count now read"498".

    "Perfect," he thought," just under the word limit." He knew this was the story that would win.

    He went onto Google and searched for the competition. He found the page but there was no "Enter" button.

    Robots come in many shapes and sizes. But most have one thing in common. They are built to help people. Lately engineers have been developing new kinds of humanoid robots. These high-tech machines are designed to lend a hand everywhere from hotels to disaster areas.

    "Robots help people by making their lives easier, safer, and more fun," says engineer Omar Abdelwahed.

    Since November, a robot named pepper has been on the job at the Mandarin Oriental hotel in Las Vegas, Nevada. When guests have questions or need directions, they can ask Pepper. They can also use the robot's touch screen to find the information they need. Pepper is able to talk with guests and entertain them with stories too. It can even tell what kind of mood they are in.

    "Pepper provides our guests with information in an exciting and new way," says hotel manager Donald Bowman.

    For a kid, being in the hospital can be boring and even scary. But a small robot called NAO is helping to make hospital stays easier. It was designed to keep people company.

    A Tennessee doctor named Phil Parker bought a NAO robot three years ago. He programmed it to talk to and play with young patients. He brings it to hospitals to help sick kids. When kids get medical tests, NAO explains what is going on. The robots also reads to kids and plays games with them like rock, paper, scissors.

    "The robot gets many kids to smile for the first time since they've been in the hospital," Parker says.

    Other robots are being developed to help in places where it's hard or risky for people to go. For example, disaster areas can be full of rubble and other dangers. Engineers in Japan are building a robot called E2-DR to go into those areas and search for people who are hurt.

    Thanks to this new hands- free suitcase, carrying around heavy luggage may soon become a thing of the past. Designed by Israeli company NUA Robotics, this "smart" suitcase can follow you everywhere you go.

    The carry­on suitcase, now a prototype(雏形), connects to a smartphone app via bluetooth. It has a built­in camera sensor that can "see" you and follow you around on flat floors. It comes with an anti­theft alarm to prevent someone carrying it away when you're not looking. "It can follow and carry things for people around while communicating with their smartphone, and avoiding bumping into other objects," explained Alex Libman, founder of NUA Robotics. "We're combining sensor network, computer vision, and robotics. So if you download our app(应用), press the 'follow me' button, the luggage recognizes its user and knows to follow and communicate."

    NUA is still testing the products and trying to improve features like speed and customization(客户订制), but they hope to make the suitcase available to customers in a year's time. If it proves successful, they want to use the bluetooth pairing technology to automate(自动化操作)lots of other products, like shopping carts at the supermarket. These products are especially meant to be useful to the physically disabled and elderly. "Any object can be smart and robotic," Libman told Mashable. "We want to bring robots into everyday life."

    The Israeli tech company made it clear that the finished product will look just like a common suitcase. They're planning to partner with a carry­on luggage maker, since the product that makes it "smart" weighs just 2.5 pounds and can be fitted on old­fashion luggage.

    With NUA's smart suitcase, carrying around heavy luggage isn't a burden. But how their invention will handle tough blocks like stairs? It will be interesting to wait.