What is the first thing you notice when you walk into a shop? The products displayed(展示) at the entrance? Or the soft background music?

    But have you ever notice the smell? Unless it is bad, the answer is, likely to be no. But while a shop's scent may not be outstanding compared with sights and sounds, it is certainly there. And it is providing to be an increasing powerful tool in encouraging people to purchase.

    A brand store has become famous for its distinctive scent which floats through the fairly dark hall and out to the entrance, via scent machines. A smell may be attractive but it may not just be used for fresheningair. One sports goods company once reposed that when it first introduced scent into its stores, customers' intension to purchase increased by 80 percent.

    When it comes to the best shopping streets in Pairs, scent is justas important to a brand's success as the quality of its window displays and goods on sales. That is mainly because shopping is a very different experience to what it used to be.

    Some years ago, the focus forbrand name shopping was on a few people with sales assistants' disproving attitude and don't-touch-what-you-can't afford displays. Now the rise of electronic commerce(e-commerce) has opened up famous brands to a wider audience. But whilee-shops can use sights and sounds, only bricks-and-mortar stores(实体店) can offer afull experience from the minute customers step through the door to the moment they leave. Another brandstore seeks to be much more than a shop, but rather a destination. And scent is just one way to achieve this.

     Now a famous store uses complex man-made smell to make sure that the soft scent of baby powder floats through the kid department, and coconut(椰子) scent in the swimsuit section. A departmentstore has even opened a new lab, inviting customers on a journey into the store's windows to smell books, pots andd rawers, in search of their perfect scent.

    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.”

    Mountaineers have noted that as they climb, for example, up to the 12,633­foot Humphreys Peak in Arizona, plant life changes greatly. In the Sonoran Desert, one climbs into a pine forest at 7,000 feet and a treeless tundra(冻土带) on the top of the mountain. It may seem that plants at a given altitude are associated in what can be called “communities” －groupings of species. The idea is that over time, plants that require particular climate and soil conditions come to live in the same places, and are frequently to be found together. Scientists study the history of plant life and build up a picture of how groups of plants have responded to climate changes and how ecosystems develop. But are these associations, which are real in the present, permanent?

    A great natural experiment took place on this planet between 25,000 and 10,000 years ago, when small changes in the earth's orbit caused great sheets of ice to spread from poles. These glaciers(冰川) covered much of North America and Europe to depths of up to two miles, and then, as the climate warmed, they retreated. During this retreat, they left behind newly uncovered land for living things to occupy, and as those living things moved in they laid down a record we can read now. As the ice retreated and plants started to grow near a lake, they release pollen(花粉). Some would fall into the lake, sink to the bottom and mix with the sand. By drilling into the lake bottom it is possible to read the record of the plant life around the lake. The fossil record seems clear; there is little or no evidence that entire groups of plants moved north together. Things that lived together in the past don't live together now, and things that live together now didn't live together in the past. Each individual living things moved at its own pace. The fossil record seems to be telling us that we should be thinking about preserving species by giving them room to move about－to respond to environmental changes.

    When my brother and I were young, my mom would take us on Transportation Days.

    It goes like this: You can't take any means of transportation more than once. We would start from home, walking two blocks to the rail station. We'd take the train into the city center, then a bus, switching to the tram, then maybe a taxi. We always considered taking a horse carriage in the historic district, but we didn't like the way the horses were treated, so we never did. At the end of the day, we took the subway to our closest station, where Mom's friend was waiting to give us a ride home—our first car ride of the day.

    The good thing about Transportation Days is not only that Mom taught us how to get around. She was born to be multimodal (多方式的). She understood that depending on cars only was a failure of imagination and, above all, a failure of confidence—the product of a childhood not spent exploring subway tunnels.

    Once you learn the route map and step with certainty over the gap between the train and the platform, nothing is frightening anymore. New cities are just light-rail lines to be explored. And your personal car, if you have one, becomes just one more tool in the toolbox—and often an inadequate one, limiting both your mobility and your wallet.

    On Transportation Days, we might stop for lunch on Chestnut Street or buy a new book or toy, but the transportation was the point. First, it was exciting enough to watch the world speed by from the train window. As I got older, my mom helped me unlock the mysteries that would otherwise have paralyzed my first attempts to do it myself: How do I know where to get off? How do I know how much it costs? How do I know when I need tickets, and where to get them? What track, what line, which direction, where's the stop, and will I get wet when we go under the river?

    I'm writing this right now on an airplane, a means we didn't try on our Transportation Days and, we now know, the dirtiest and most polluting of them all. My flight routed me through Philadelphia. My multimodal mom met me for dinner in the airport. She took a train to meet me.

    Eldon Musk, the entrepreneur and CEO of Tesla and Space X, may have a little more time on his hands, as he's leaving his position on the board of the Open AI, according to a blog post.

    The departure is likely the result of Tesla's moving into the field of Artificial Intelligence (AI), which he said in 2017 would be the “best in the world” and would even be able to “predict your destination.” Musk will continue to “donate and advise the organization,” Open AI said in a blog post on Feb. 20, adding that “As Tesla continues to become more focused on AI, this will avoid a potential future conflict for Eldon.”

    Musk and Y Combiner CEO Sam Altman co-founded the nonprofit enterprise in December 2015, its mission is to develop safe artificial general intelligence and ensure those developments are made public. Open AI researchers published a paper on the site ArXiv.org, detailing the possible secure threats that come with “malicious” AI. In fact, Musk has heard the “evil AI” alarm several times. On Aug. 11, 2017, he warned that artificial intelligence poses a bigger threat to humanity, and he told a gathering of state governors that the government needs to regulate AI before robots start “killing people.”

    Musk's departure from the Open AI board could mean big things for Tesla. As Eton Goodbye, a financial reporter, noted on Futurism, the move “could signal that Tesla is more deeply committed to their own AI projects than we thought.” He added, “Those who have had their ears to any rumors (谣言) that Tesla is ready to deliver vehicles capable of Level 5 autonomy could take this new Open AI development as a sign that the company is inching closer to that unapproachable goal.” No company has reached that level of autonomy, which means that a driverless car could navigate any road under any conditions and that all the human “driver” would need to do is to input a destination.

    Life for almost anyone is increasingly influenced by screens. Not only are screens themselves cheap to make, but they also make things cheaper. Any place that can fit a screen in can cut costs. And any activity that can happen on a screen becomes cheaper. The physical experience of learning, living and dying is becoming smooth glass. All of this has led to a curious new reality: Human contact is becoming a luxury good (奢侈品).

    "What we are seeing now is the luxury of human engagement," Milton Pedraza, the chief of the

    Luxury Institute, said. Expected spending on experiences such as enjoyable travel and dining is outpacing spending on goods, according to his company's research, and he sees it as a direct response to the rapid increase of screens.

    Screens exposure starts young. And children who spent more than two hours a day looking at screen got lower scores on thinking and language tests, according to early results of a landmark study supported by the National Institutes of Health. The study focuses on brain development of more than 11,000 children. Most disturbingly, the study is finding that the brains of children who spend much time on screens are different. For some kids, their cerebral cortex (大脑皮层) would become thinner before expected time. In adults, one study found an association between screen time and depression.

    There is also the reality that in our culture of increasing separation, in which so many of the traditional gathering places and social structures have disappeared, screens are filling a vital gap.

    For normal people, running away from the screen becomes impossible. It's not a luxury, and it's easy to get. It is normal for more people to need the network constantly. In addition, it has become an important part of social interaction.