Dujiangyan is the oldest man-made water system in the world, and a wonder in the development of Chinese science. Built over 2,200 years ago in what is now Sichuan Province in Southwest China, this amazing engineering achievement is still used today to irrigate over 6,000 square kilometres of farmland, take away floodwater and provide water for 50 cities in the province.

    In ancient times, the region in which Dujiangyan now stands suffered from regular floods caused by overflow from the Minjiang River. To help the victims of the flooding, Li Bing, the region governor, together with his son, decided to find a solution. They studied the problem and discovered that the river most often overflowed when winter snow at the top of the nearby Mount Yulei began to melt as the weather warmed.

    The simplest fix was to build a dam, but this would have ruined the Minjiang River. So instead Li designed a series of channels built at different levels along Mount Yulei that would take away the floodwater while leaving the river flowing naturally. Better still, the extra water could be directed to the dry Chengdu Plain, making it suitable for farming.

    Cutting the channels through the hard rock of Mount Yulei was a remarkable accomplishment as it was done long before the invention gunpowder and explosives. Li Bing found another solution. He used a combination of fire and water to heat and cool the rocks until they cracked and could be removed. After eight years of work, the 20-metre-wide canals had been carved through the mountain.

    Once the system was finished, no more floods occurred and the people were able to live peacefully and affluently. Today, Dujiangyan is admired by scientists from around the world because of one feature. Unlike modern dams where the water is blocked with a huge wall, Dujiangyan still lets water flow through the Minjiang River naturally, enabling ecosystems and fish populations to exist in harmony.

    Standing in the shower waiting for the water to het up could be a thing of the past, along with all the wasted water. Three and a half years ago, Lindy Honeychurch, a thirty-year-old Australian full-time mum living on a farm outside Launceston, didn't consider herself a very good water saver. Neither did her partner who often complained about it with good reasons. Their farm had to rely on tank water and solar power, which meant water had to be trucked in if he tank water ran out in summer.

    “I looked at where I could save because I could lead an easier life without the complaint,” she said. Modeling her idea on a car thermostat(恒温器), Lindy used her kids' magnetic(磁的)drawing board to design a device that diverts the cold water back down the hot water pipe. “The first aim when I started designing was to keep it really small and simple without having to use power. I wanted to keep it as something that everyone could use,” said Lindy.

    She got a patent for her design and took it to some engineers to have it tested out. At first, even though the engineers were amazed that she wasn't an engineer, she said she sometimes found it hard to be taken seriously. “My age was a real factor because in the plumbing(管路系统)and manufacturing industries you're dealing with people who've got a lot of experiences,” she said. But the engineers soon saw the potential of her design, which she estimated would save average families between 14,000 to 22,000 liters per year.” when you transfer that to the dollar savings on tank water that you have to buy, it can be a saving of $600 per year,” said Lindy.

    Armed with positive feedback from engineers and people using rainwater tanks, her design proved a great success. Soon she found a manufacturer early this year, and completed a state government commercial ready course to help her research, her markets and distribution channels. With an Australian Standard for her device just approved, she's about to start manufacturing and wishes to see her products on the shelves within the next few months. Once that happens, Lindy plans to return to being a full-time mum.

Dear Dad,

    Today I was at the shopping mall and I spent a lot of time reading the Father's Day cards. They all had a special message that in some way or another reflected how I feel about you. Yet as I selected and read, it occurred to me that not a single card said what I really want to say to you.

    You'll soon be 84 years old, Dad, and you and I will have had 55 Father's Days together. I haven't always been with you on Father's Day but I've always been with you in my heart.

    You know, Dad, there was a time when we were separated by the generation gap. You stood on one side of the Great Divide and I on the other.

    The Father-Daughter Duel shifted into high gear ( 档位) when you taught me to drive the old Dodge and I decided I would drive the Chevy whether you liked it or not. The police officer who sent me home, after you reported the Chevy stolen, didn't have much tolerance for a stubborn 16 year old, while you were so tolerant about it, Dad, and I think that was probably what made it the worst night of my life.

    Our relationship greatly improved when I married a man you liked, and things really turned around when we began making babies right and left. Somewhere along the line, the generation gap disappeared. I suppose I saw us and our relationship as aging together, rather like a fine wine.

    But the strangest thing happened last week. I was at a stop sign and I watched as you turned the corner in your car. It didn't immediately occur to me that it was you because the man driving looked so elderly and fragile behind the wheel of that huge car. It was rather like a slap in the face delivered from out of nowhere. Perhaps I saw your age for the first time that day.

    I guess what I'm trying to say, Dad, is what every son and daughter wants to say to their Dad today. Honoring a father on Father's Day is about respect and sharing and acceptance and tolerance and giving and taking. It's about loving someone more than words can say, and it's wishing that never had to end.

    I love you, Dad.

Love,

Jenny

    A good modern newspaper is an extraordinary piece of reading. It is remarkable first for what it contains: the range of news from local crime to international politics, from sports to business to fashion to science, and the range of comment and special features as well, from editorial page to feature articles and interviews to criticism of books, art, theatre, and music.

    A newspaper is even more remarkable for the way one reads it: never completely, never straight through, but always by jumping from here to there, in and out, glancing at one piece, reading another article all the way through, reading just a few paragraphs of the next. A good modern newspaper offers a variety to attract many different readers, but far more than any one reader is interested in. What brings this variety together in one place is its topicality(时事性), its immediate relation to what is happening in your world and your locality now. But immediacy and the speed of production that goes with it mean also that much of what appears in a newspaper has no more than transient value.

    For all these reasons, no two people really read the same paper: what each person does is to put together, out of the pages of that day's paper, his own selection and sequence, his own newspaper. For all these reasons, reading newspapers efficiently, which means getting what you want from them without missing things you need but without wasting time, demands skill and self-awareness as you modify and apply the techniques of reading.

Robots have long been drawing inspiration from animals, with the creation of robot dogs or snake-shaped robots. And yet, the field of robotics is far less enthusiastic about the other kind of living things—plants. Barbara Mazzolai, an Italian roboticist owes this to a misconception about plant behavior: that they cannot move or think. "It's not true at all, " she says. To challenge this view, Dr Mazzolai and her team recently launched a machine called "FiloBot", a robot based on a climbing species. 

To survive, a climbing plant must switch between several different behaviors. In forest environments, it must first grow out of the soil and travel along the ground in search of a support to hold onto, such as a nearby tree. Once a support is located, though, the plant fixes itself around the object and then growing towards the light. To choose the best angle to grow upwards, a climbing plant uses its shoots(芽) to receive information about light and gravity. 

FiloBot has sensors on its main shoot. It can 3D-print its body with plastic and grow at a controllable rate. These functions, researchers found, enabled FiloBot to cross gaps, and find things to attach to. The lack of heavy on-board computing device means that it is light and requires minimal care, while its slow pace means that it doesn't disturb things around it, making it possible to move through a complex, unseen environment, or monitoring disaster sites. 

For now, FiloBot is still being tested. Its tendrils(卷须) have not left the laboratory. Still, it has already been employed in deconstructing plant behaviour. For example, it was long assumed that climbing plants find their supports by growing towards shade, though the exact mechanism was unclear. FiloBot could imitate this behaviour by detecting far-red light, which is typical of shaded areas, providing clues to how plants do it. 

Dr Mazzolai hopes that such projects will inspire other roboticists to take their cues from plants and develop completely new technologies.