Breakthroughs in science and technology are paving the way for modern cities to support bigger populations. Now, we see the most exciting urban innovations to show you exactly how they'll improve your city's infrastructure(基础设施).

Lighting Up The Night

    Anthony Di Mari dreamed up an electric tree to help irrigate public parks and light them at night. These electric trees contain a special infill (填充物) that collects water from rainfall. The water is then distributed through a shallow underground irrigation system with the help from the trees' swaying movement. An electric motor turns energy from the waving of the artificial trees into electricity, which is used to light up the trees' outer LEDs.

Thinking Outside The Box

    As more people flock to urban areas, city planners will need to get increasingly creative about how to satisfy residents' health and transportation needs within decreasing available space. One way to achieve this is by updating infrastructure to support biking and walking by building suspended(悬浮的) roundabouts like hovering in the Netherlands. By lifting bicycle and pedestrian traffic above busy roadways, cities can significantly decrease over-crowded traffic condition.

Waving Hello To Clean Energy

    Cities that don't receive enough sunlight may find an attractive alternative in wave power. Since ocean waves rarely experience disruption(中断), electric engines driven by their clockwork push-and-pull can reliably provide power throughout the year. Further, thanks to advances in wave power technology, engineers have been able to move wave power engines farther offshore, where the waves pack the most punch, making the engines extremely efficient. So in the future, heavily populated coastal cities may use wave to meet their energy needs.

    The brain of an insect isn't very big. But insects are somehow still able to make lots of important decisions. Bees, ants and roaches(蟑螂) build hives(巢穴)with thousands of workers doing specialized work. The jobs are done without a head or even a plan. How do insects manage this?

    To solve the mystery, scientists in Belgium spent months building robotic roaches and then putting them among real roaches. The final goal of the research is to find out how the simple behavior of individuals gives rise to a collective decision. The roach is a good starting point for trying to answer the big question because its social system is simple enough for scientists to study.

    The first step was to build robots that real roaches would accept as their own. Although the robotic roaches don't look much like the real thing, they have similarities with them in three key ways: they naturally head toward dark areas, they are influenced by the behavior of other roaches, and even more importantly, they smell like roaches.

    The next step was getting the robotic and real roaches to work together on common tasks. In experiments, the robots would collectively head towards a dark place, copying the behavior of natural roaches. That got the researchers wondering: if you program the robotic roaches to go woward the lighted place, would the real roaches follow, going against their natural instincts.(本能) ?

    They will – it turned out. Many of the real roaches followed the robots to a lighter shelter. But influence turned out to be a two- way street. On occasion, the real roaches were able to override the programming of the robot roaches and get them to turn into dark hiding places. Being social creatures, both the robotic and natural roaches were paying attention to and following the example set by others.

    In theory, it would be possible to create a robot that could influence collective decision-making in humans. To do this, researchers would have to invent a robot that people would accept. Fortunately, the technology isn't there yet.

    Colorado officials will stick to a plan to kill some mountain lions and bears to support the state's dropping mule deer (长耳鹿) population.

    Wednesday's vote permits organizations to kill up to 25 black bears and 15 mountain lions per year in the central and western parts of the state. The project will run for three years, to be followed by a six-year study of how deer populations respond to fewer predators(捕食者).

    The population of Colorado's mule deer has suffered a puzzling, years-long drop to about 450,000, which state officials said was about 110,000 fewer than there should be. A 2014 state study tied it to seven causes, including predators, whose number has greatly increased in recent years.

    Some experts, however, said the state should focus first on the human-led destruction(破坏) of mule deer habitat(栖息地). “The drop of the mule deer population is obviously not a simple problem with simple causes,” Brian Kurzel, director of the National Wildlife Federation, said. “By far, the greatest problem—the one that I think deserves the most attention in any science-based study—is habitat quantity and quality.”

    Kurzel pointed out that the U.S Bureau of Land Management recently agreed to create 15,000 new oil and gas wells somewhere in western Cororado, which was often called “the mule-deer factory”. There, the number of mule deer has fallen to about 30,000 from more than 100,000 in the early 1980s. Though state officials have known oil and gas development affects the population of mule deer, they didn't go against the plan.

    Other causes like building highways, population growth and human activities are also curbing the mule deer population, according to the study.

    State Parks and Wildlife officials don't necessarily disagree. They started a $4.5 million program as a way to gather research for later decisions.

    As we age, our ability to think and remember starts to deteriorate. But not everyone. Some of us have brains that age more slowly. Enter the super-ager!

    Super-agers are people over the age of 80 who have the brain structures and abilities of much younger people. Eighty-seven-year-old Bill Gurolnick is a super-ager. “What do I feel like? If I was to give a number, I probably feel like I'm about my early 70s…”

    Scientists know that parts of the brain decrease in size with age. But in super-agers that process is much slower. Emily Rogalski is a neuroscientist at Northwestern University's Feinberg School of Medicine, in Chicago, Illinois. In a recent study, she showed that super-agers have young brains. The area of the brain responsible for attention and memory—the cortex—was shown to be thicker in super-agers. “When we look at the cortex of their brain, we see that, on average, that it looks more like a 50-year-old brain that it looks like an average 80-year-old bran…”

    Not only do super-ages have thicker cortexes, they have more spindle neurons. These large brain cells appear to be involved with social-emotional communication. But their exact purpose is still a mystery. Scientists writing for Smithsonian magazine say they are “brain cells for socializing.”

    Several factors affect how our brains age. Scientists say super-agers have several things in common, including an active lifestyle. Many travel and play sports. They are often big readers. And they usually have healthy relationships and spend time with friends. Super-agers also seem to have certain common personality traits. Rogalski says they are, for the most part, known for their optimism, resilience and perseverance. Growing old, she adds, does not have to be depressing and sad. “Perhaps, if we expected a bit better from ourselves, then we would understand that not all aging is stressful!”

    Can we all be super-agers? The science behind super-aging is a relatively new, but growing field. Scientists involved in the research offer this advice as we age: Stay active. Learn new things. Challenge yourself. Surround yourself with healthy relationships.

    Making friends is a skill like many other skills. It improves with practice. If you want to meet people and make friends，you must be willing to take some actions. You must first go where there are people. You won't make friends staying home alone. Join a club or a group. Talking with those who like the same things as you do is much easier. Or join someone in some activities. Many people are nervous when talking to new people. After all meeting strangers means facing the unknown. And it's human nature to feel a bit uncomfortable about the unknown. Most of our fears about dealing with new people come from doubts about ourselves. We imagine other people are judging us or finding us too tall or too short，too this or too that. But don't forget that they must be feeling the same way. Try to accept yourself as you are and try to put the other person at ease. You'll both feel more comfortable.

    Try to act self­confidently even if you don't feel that way. When you enter a room full of strangers，such as a new classroom，walk tall and straight，look directly at other people and smile.

    If you see someone you'd like to speak to，say something. Don't wait for the other person to start a conversation.

    Just meeting someone new does not mean that you will make friends with that  person—friendship is based on mutual liking and“give and take”. It takes time and effort to develop.

    Art Gallery of New South Wales

    Art Gallery Road

    Phone 61 29225-1744

    Cost: Free, except for special exhibits

    Hours: Daily 9 a.m. to 5 p.m.

    Every Sunday afternoon at 2:30, families can enjoy special performances on various topics, including art appreciation, dance and storytelling. During school holidays, the museum schedules storytelling and performances, often in mime or Aboriginal dance, for children aged 6-12. Children can also participate in occasional hands-on art workshops.

    The Australian Museum

    6 College Street

    Phone 61 29320-6000

    Cost: Free

    Hours: Daily 9 a.m. to 5 p.m.

    For children under 5, Kids Island is decorated with a model hot-air balloon and features a slippery side and a shipwrecked boat with interesting cubbies to explore. The museum's dinosaur exhibition appeals to children aged 5-12. A Science and Discover Room, with microscopes, specimens and reference books, allows children to conduct their own “research”.

    Taronga Park Zoo

    Bradley's Head Road

    Phone 61 29969-2777

    Hours: Daily 9 a.m. to 5 p.m.

    Admission charged

    Taronga lets children visit up close with some of Australia's most spectacular creatures- native koalas, of course, but also kangaroos, dingoes, Tasmanian devils and wombats.

    Centennial Park

    Oxford Street, Paddington

    Phone 61 29331-5056

    Cost: Free

    Hours: Daily, but hours change seasonally

    Rent children's bikes and rollerblades to help youngsters bum off excess energy in the park's beautiful setting. A nearby Equestrian Center offers horseback rides, and guided nature walks are available during school holidays.