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.”

    On the day the tornado(龙卷风) hit, there was no sign fierce weather was on its way— the sky was blue and the sun had been out. The first warning my husband, Jimmy, 67, and I, 65, got came around 9 p.m., from some text on the TV Jimmy was watching. He ran upstairs to find me in our third-floor bedroom, and we changed the channel from the national television to our local Pensacola, Florida, station.

    Soon the tornado was on top of us. It was the loudest thing I have ever heard. The bones of the house shook, and the power went out. And the wind began to roar(咆哮) through the house, most likely through blown-out windows and the door to our garage. Everything was moving. And the back wall of the house came off and flew into the darkness outside. We had three flights of steps to get to the storeroom down there, the relative safety of the first floor.

    I didn't know how or if we would make it down the steps. It felt as if there were no floor underneath me as the wind lifted me off my feet. As we finally reached the last flight of steps, our front door blew out. Suddenly, a three-foot-long tree branch flew over our heads, missing us by inches.

    By the time I reached the storeroom, the tornado had been over us for about a minute. Jimmy pushed me down to the storeroom floor, but he couldn't get inside himself because of the wind. I held Jimmy's arm as the tornado blew the door open. My knees were full of glass, but I felt no pain. If I had let go, Jimmy would have flown right out the back of the house.

    All of a sudden, Jimmy lifted off his feet. I thought he was gone. And then everything stopped. He landed on his feet. In those first quiet moments, I couldn't believe it was over. Our neighbor says the storm lasted four minutes. In that time, four of the twelve town houses in our unit were completely destroyed. Amazingly, none of us were seriously injured.

    After the operation, Peter suffered severe pain, but insisted that he didn't need any treatment. One evening, he found Susan, his wife, crying in the kitchen of their apartment in a rare outburst of frustration. “If you won't help yourself, no one else can,” she said.

    Peter started a list “How to Help Myself”, and on it he wrote, “Keep communicating with the doctors, even if they are dark thoughts.” On October 20th, a few days before his 33 birthday, Peter wrote in a Facebook post, “It's been hard to get along with having an incurable Grade 4 brain cancer; it's been hard not to get angry and sad about it; and it's been hard to accept that modern medicine isn't able to fix me.” But at the same time, he wrote, “Every day I wake up not-dead is a gift.”

    Peter and Susan had other lists, detailing the things that they hoped to accomplish in life, which included a trip to Wimbledon; climbing Mt. Snowdon in Wales; and a list of musical wishes—from learning the Bach sonatas (奏鸣曲) and partitas (变奏曲) to performing the first violin part in a concert.

    Peter started working on Bach's six sonatas and partitas, the most difficult parts, which George Enescu, a world-famous violinist, once described as the Himalayas (喜马拉雅山) for violinists. Peter practiced every day, even if he could manage only fifteen minutes between medical treatments. As he mastered each piece, he posted his performances on Facebook. He finished on November 12th, then turned to the even more difficult Paganini caprices (随想曲), which he had often listened to in a recording by Itzhak Perlman. “It's something I always wanted to play when I grew up, like wanting to be a great baseball player,” he said.

    Bus Tours in Washington DC

    The Blossoms Tour In Washington DC

    Duration: 3 hours $56.99

    BEST WAY to Experience the Cherry Blossoms! Each year from mid March to mid April, see the beautiful Cherry Blossoms in Washington DC and get great photos because you'll be led to all the best spots by the best guides. The annual spring bloom in DC is a magical time and this tour promises to provide the very best tour opportunity for you!

    The Lights Night Tour in Washington DC

    Duration: 3 hours $56.33

    Highest-rated Night Tour in DC! The ONLY DC Night Tour where the Tour Guides HOP OFF with you at each stop and tell you about each monument and attraction. HOP aboard the The Lights Night Tour! The best time to take a tour of Washington DC is at night.

    The Best Minibus Tour in Washington DC

    Duration: 3 hours $ 46.92

    See all the key attractions DC has to offer in a 3-hour format. You will learn all about the history and trivia (琐事) that surrounds Washington and visit the major monuments and attractions DC has to offer.

    Please Note: Rates for this tour vary by day of the week. When you choose your specific date on the availability calendar, the rates for that date will be displayed.

Best Mount Vernon & Arlington Cemetery Tour from Washington DC

    Duration: 6 hours $ 78.96

    See Arlington Cemetery, Old Town Alexandria and George Washington's Mount Vernon Estate on this small group bus tour from Washington DC. Your tour guide will accompany you through Mount Vernon, telling you about all of the attractions there and the history of George Washington's home on the Potomac River.

    As winter set in, it's the perfect time to get out of town and escape the seasonal mood disorder. Here are vacation ideas to adopt now.

    Costa Rica

    Costa Rica, located in the Valle del General, is an off-the-radar agriculture town that's not overrun with tourists. The area is known for its coffee, pineapples and sugar cane plantations, as well as its rich forests. What's more, you can enjoy horseback riding, spend afternoons at the spa or tour a nearby wildlife shelter to look out for colorful birds, sloths and other animals.

    Los Cabos, Mexico

    If you love wine, travel to Los Cabos, a beautiful vacation destination at the southern edge of the Baja Peninsula. During your getaway, you can enjoy special wine tastings and dinner cooked by Los Cabos's Michelin-starred chef. There are wildlife-viewing opportunities, too. From December through May, you can spot whales, manta rays and more wildlife.

    Petit St Vincent, the Grenadines

    This private Caribbean island was spared the anger of hurricanes Irma and Maria. What's more, the whole island is only 115 acres and has 22 cottages. Each cottage is located in a quiet place, and you can expect to unplug and recharge phones with no wireless connections, televisions or telephones in the cottages. Even better, you can spend your days admiring fascinating marine (海洋的) life at the Jean-Michel Cousteau Diving Caribbean center.

    The Exumas, Bahamas

    On Fowl Cay's 50-acre private island, you can enjoy a carefree escape. Days can be spent fishing, boating and diving before wandering along white sands. The resort features large one-, two- and three-bedroom houses. Best of all, if you're planning a group getaway or multigenerational trip, you rent the entire island for a one-of-a-kind island escape.

After years of teachers asking for the right answers, students aren't used to someone asking for the wrong ones. Students' failure tends to create mental burden that negatively affects learning. Lifting the burden requires us to face failure bravely and encourage students to accept it as a natural part of getting educated. While educators have to make sure that students have the right content and support to avoid long-term failure, it is just as important to accept mistakes as a normal part of education.

Sadly, our culture is so focused on success or perfection that students generally aren't taught about failure. To fill the gap, I share with students a Samuel Beckett quote "Ever tried. Ever failed. No matter. Try again. Fail again. Fail better". It suggests one becomes better after each failure. I also play a video on game designed by Extra Credits, which shows people can quickly declare their ways as a failure if they don't work out and then learn from. them to move on. Both the quote and the video can help students get a more positive attitude towards failure.

Teachers can help students accept failure better. In her piece "5-Minute Film Festival: Freedom to Fail Forward", Edutopia author Amy Erin Borovoy had a set of videos-and articles on the subject of failure. Borovoy reminds readers that "a true thinker learns as much from failure as from success." Taking these short videos as monthly or weekly reminders can, be a great way to start "how have we failed and what have we learned" discussions with students.

Teachers can actually use a technique called "Effective Failure" to teach about failure at any time. In my writing class, I often have students volunteer to pick out the worst writing of their own. This lets writers deepen their understanding of why a sentence, word choice, or paragraph construction has failed, and it inspires a sincere interest in better writing. This makes failure work well in class.

Also, remember that students are not the only ones who can learn from their mistakes. As those who teach students, we should do that too.