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.”

    I've loved my mother's desk since I was just tall enough to see above the top of it when Mother sat doing letters. Looking at the ink bottle, pens and white paper, I decided that the act of writing must be the most wonderful thing in the world.

    Years later, during her final illness, Mother kept different things for my sister and brother, “But the desk,” she said again, “is for Elizabeth.”

    I never saw her get angry, and never saw her cry. I knew she loved me, and she showed it in action. But as a young girl, I wanted heart-to-heart talks between mother and daughter. They never happened and a gulf opened between us. I was “ too emotional (易动感情的) ”, but she lived “on the surface”.

    As years went by, I had my own family. I loved my mother and thanked her for our happy family. I wrote to her in careful words and asked her to let me know that she did forgive (原谅) me.

    I posted the letter and waited for her answer, but it didn't come. I wondered if the letter had even got to her. I only knew that I had written it, and I could stop trying to make her into someone she was not.

    Now the present of her desk told me that she was pleased that writing was my chosen work, though she had never been able to. I cleaned the desk carefully and found some papers inside … a photo of my father and a one-paper letter, folded (折叠) and refolded many times.

    Give me an answer, my letter asks, in any way you choose. Mother, you always chose the act that speaks louder than words.

    In no particular order, here are some songs on the Music app of my phone:

On a Sunday Afternoon by Lighter Shade of Brown—A student of mine introduced this rap song lo me all the way back in the early 1990s, when 1 was teaching Spanish at a local university. The story in the song takes place not too far from where I live in Los Angeles. It's a good "driving" song, nothing complicated or "deep".

    Say Something by A Great Big World—A more recent song about a couple losing contact with each other. The piano part is very little playing but beautiful.

    American Pie by Don McLean—Another song from my youth in the 80s, very popular with almost every American of my generation. It retells some of the key events of the middle 20th century, a song of happy memories of the past and wanting to return to those better times.

    The Weight by The Band—Another old song, originally made public in 1968, but one I didn't hear until I was in high school more than 10 years later. I don't understand the words to the song completely, but the feeling of the song is very comforting to me.

Under the Bridge by Red Hot Chili Peppers—This Los Angeles group wrote a song that 1 used to listen to when I first moved to LA more than 25 years ago. I didn't know anyone here when I first arrived. When I got bored, I used to drive up and down the major streets that cross the city from east to west, listening to this song about the "city of angel" being as "lonely as I am. (Don t worry! I have plenty of friends now.)

  Dubai Aquarium & underwater Zoo

    Experience
    You will be surprised at the amazing collection consisting of over 140 species including 300 sharks, rays and the largest collection of sand tiger sharks in the world. Walk along the Rainforest, Rocky Shore and Living Ocean environments at the Underwater Zoo and you will find yourself face to face with dangerous piranha, giant catfish, playful otters, a Humboldt penguin colony and more.
    Options
    Basic Pass: With this basic pass, you'll get access to the Dubai Aquarium and underwater Zoo.
    Explorer Pas: If you're looking to get a little closer to the sea creatures, then this pass is for you. Along with the explorer pass you can also get access to the submersible simulator(潜水模拟器)  & big screen theater and a free ride on the glass-bottom boat.
    VIP Line Buster: This pass includes all the benefits of an explorer pass and a tour guide. And you can get to try your hand at fish feeding!
    Timings
    Sunday--Wednesday: 10:00 am--11:00 pm
    Thursday--Saturday: 10:00 am--12:00 am
    Pro Tip
    You can save a lot by buying a combo ticket(套票). This ticket gives you access to Undersea Zoo and Aquarium Tunnel alongside tickets to the observation deck on the 124th floor of the Burj Khalifa. Your government ID card has to be presented at the entrance.

    A killer whale(虎鲸) that can copy words such as “hello” and “bye-bye” is thought to be the first of its kind to copy human speech.

    The female killer whale learned to “speak” some human words by copying a trainer at a park in France. The animal's ability includes speaking the name “Amy” and “one, two, three”.

    Whales and dolphins are among the few animals except humans that can learn to produce a sound just by hearing it. “It is not often seen,” said Dr Josep Call, a co-researcher on the study. “Humans are good at it…Interestingly, the animals that can do best are marine mammals(海洋哺乳动物).” The researchers start to find out whether killer whales could learn new words by copying others. They studied a female named Wikie at Marineland Aquarium in Antibes, France. She was taught to speak human words.

    Dr Jose Abramson, a co-researcher on the study, said basic “conversations” with Wikie may one day be possible. He said,” It has been done before with a famous grey parrot and dolphins using American sign language(手势语).” However, he said they have to be careful about introducing human ideas on animals, as there is more to learn by trying to understand the natural way each kind communicates in its own environment. Wikie made sounds in water, which may be quite different.

    Dr Alex Thornton, senior speaker at the University of Exeter, said they still don't fully understand why some animals learn to copy. Some animals copy sounds to attract possible partners, while others copy sounds to become a member of a group. “Some whales, for example, learn their calls from one another to mark them out as members of their social group,” said Dr Thornton, who doesn't join in the research.

    I used to be crazy about the hunting season. The excitement of waiting for a prey(猎物)and the pride of showing off the kill fascinated me. However, everything changed after that cold morning.

    Early on that day of the late fall, I set off alone for the woods, packing a gun, a bottle of hot coffee and three thick sandwiches. After finding the fresh deer's tracks in the snow, I settled down behind a little bush.

I sat there for about an hour. It was then that I saw him. A deer, a big beautiful deer! There was no cover nearer to him than 30 yards. Surely I couldn't miss! I waited for him to realize I was there. I waited for him to be shocked and run away. But he fooled me completely. He came towards me! He was curious, I suppose, or maybe he was stupid—how else can you explain it? Well, that deer walked right up to where I was sitting. Then he stopped and looked at me!

    What happened next is hard to believe, but it's true. And it all seemed quite natural. Just as when a friendly young deer comes near you, I reached up and scratched his head. And he liked to be scratched. In fact, he practically asked for more. Then, I fed him my sandwich! Yes, I know what a deer eats, but that deer ate my sandwich. Well, he finally went his way, down the hill and up the deer trail. Shoot him? Not me. You wouldn't have either, not after that. I just watched him go.

    When I was about half way back, I heard two shots, followed by a dull slam(撞击)a few seconds later. Those two shots usually mean a kill. I had forgotten there were other hunters that day.

    Those hunters would never know they could have scratched his head.