It seems the more time we have, the longer we put off living the life we see in our heads, because we feel like we've got some time to kill.

I know where you think I'm going with this, and I also know you've heard it all before: seize the day, make the most of it, live life to its fullest, and so on. But that's the problem. You've heard it all before. These ideas have their impact and have become a cliché. Luckily, that's not my thing.

The real answers wake something up inside you. They make you think. That's what I want to give you today, the story of Bobby Darin, which wakes you up to the truth.

If you haven't heard of the man, I know you've heard his songs. Among his many hits are Mack the Knife, Beyond the Sea, Dream Lover, and Splish Splash.

    If seven years, Darin had several top ten hit songs, was nominated(提名) for four Grammy Awards (winning two), nominated for four Golden Globes (winning one), and even nominated for an Oscar.

    So what was his secret?

All his life, Darin had a heart condition that developed from a childhood illness. The doctors at the time said he would be lucky to live to 16. In other words, his time was limited. And this was secret. He knew the truth. He knew that we all have such a hard time accepting: Life is short. You can't just say it; you can't just hear it. You have to know it, believe it, and feel it. Because Darin knew his time was limited, he packed as much life as he could into the time he had. But he had an unfair advantage. He knew, without a doubt, his time was limited.

    There was no fooling himself, no putting it off. It was now or never.

    Most academics would view a post at an elite university like Oxford or Harvard as the crowning achievement of a career—bringing both honour and access to better wine cellars. But scholars desire such places for reasons beyond glory. They believe perching on one of the topmost branches of the academic tree will also improve the quality of their work, by bringing them together with other geniuses with whom they can collaborate and who may help spark new ideas. This sounds reasonable. Unfortunately，as Albert Laszlo Barabasi of Northeastern University，in Boston (and also, it must be said, of Harvard), shows in a study published in Scientific Reports, it is not true.

    Dr Barabasi and his team examined the careers of physicists who began publishing between 1950 and 1980 and continued to do so for at least 20 years. They ranked the impact of the institutions these people attended by counting the number of citations each institution's papers received within five years of publication. By tracking the association of individual physicists and counting their citations in a similar way, Dr Barabasi was able to work out whether moving from a low to a high-ranking university improved a physicist's impact. In total, he and his team analysed 2,725 careers.

    They found that, though an average physicist moved once or twice during his career, moving from a low-rank university to an elite one did not increase his scientific impact. Going in the opposite direction, however, did have a small negative influence. The consequence is that elite university do not，at least as far as physicists are concerned，add value to output. That surprising conclusion is one which the authorities in countries such as Britain, who are seeking to concentrate expensive subjects such as physics in fewer, more elite institutions—partly to save money, but also to create what are seen as centers of excellence—might wish to consider.

    No one is sure how the ancient Egyptians built the pyramids near Cairo. But a new study suggests they used a little rock 'n' roll. Long-ago builders could have attached wooden poles to the stones and rolled them across the sand, the scientists say.

    "Technically, I think what they're proposing is possible," physicist Daniel Bonn said.

    People have long puzzled over how the Egyptians moved such huge rocks. And there's no obvious answer. On average, each of the two million big stones weighed about as much as a large pickup truck. The Egyptians somehow moved the stone blocks to the pyramid site from about one kilometer away.

    The most popular view is that Egyptian workers slid the blocks along smooth paths. Many scientists suspect workers first would have put the blocks on sleds(滑板). Then they would have dragged them along paths. To make the work easier, workers may have lubricated the paths either with wet clay or with the fat from cattle. Bonn has now tested this idea by building small sleds and dragging heavy objects over sand.

    Evidence from the sand supports this idea. Researchers found small amounts of fat, as well as a large amount of stone and the remains of paths.

    However, physicist Joseph West thinks there might have been a simpler way, who led the new study. West said, "I was inspired while watching a television program showing how sleds might have helped with pyramid construction. I thought, 'Why don't they just try rolling the things?' "A square could be turned into a rough sort of wheel by attaching wooden poles to its sides, he realized. That, he notes, should make a block of stone "a lot easier to roll than a square".

    So he tried it.

    He and his students tied some poles to each of four sides of a 30-kilogram stone block. That action turned the block into somewhat a wheel. Then they placed the block on the ground.

    They wrapped one end of a rope around the block and pulled. The researchers found they could easily roll the block along different kinds of paths. They calculated that rolling the block required about as much force as moving it along a slippery(滑的)path.

    West hasn't tested his idea on larger blocks, but he thinks rolling has clear advantages over sliding. At least, workers wouldn't have needed to carry cattle fat or water to smooth the paths.

    The weather outside might be freezing at home, but that doesn't mean you have to spend the winter shivering. Instead, grab your bathing suit and sunscreen and head to these sunny spots that offer the best warm-weather getaways for every interest.

    The best city beaches: San Juan, Puerto Rico

    Being able to relax on a warm sandy beach in the middle of the winter is obviously a dream getaway, but not everyone wants their sand and surf to be hidden in a remote comer of an island. Instead, head to the sizzling（炎热的）city nightlife of San Juan, where the streets of chic Condado back right into the palm trees and lapping waves of the Atlantic beaches. Top chefs, stylish hotels, bars ， clubs, and shops are all just steps away from the tropical beaches. And since Puerto Rico is a United States Commonwealth, it's one of the easiest islands in the Caribbean to visit since you won't need a passport, have to change money, or even worry about your cell phone working. Puerto Rico is also one of the best tropical vacations you can take without leaving the United States.

    The best swimming holes: Riviera Maya, Mexico

    What's better than diving into the salty sea? Submerging in the crystal clear and salt-free waters of the naturally occurring limestone cenotes of the Riviera Maya and Yucatan Peninsula. Spend a sunny day exploring these natural cave pools filled cool filtered water that springs from the ground below and the lush palm forests that surround them. Then head back to the perfectly located Fairmont Mayakoba for comfortable rooms and modem Mexican cuisine.

    The best girlfriend getaways: New Orleans

    New Orleans vibrant nightlife and live-music scenes make the “Big Easy” a great girl's trip winter getaway (check out the Girl's Trip movie if you don't believe us). And even if your crew isn't one to seek out the boozy Bourbon Street crawl, there's plenty of amazing food to be discovered in the French Quarter, plenty of shopping and strolling in the Garden District, and warm weather cruises along the bayou, too. Check out these other great weekend getaways for girls trips.

    The best aquatic movie star-spotting: Clearwater, Florida

    If you want to meet a real movie star while also soaking up the sun, head to the Gulf shores of Clearwater, Florida. Here you can meet the stars of Dolphin Tale and Dolphin Tale 2, Winter and Hope, who are in residence full-time at the Clearwater Marine Aquarium. The amazing dolphins will probably make you want to hit the waves yourself, which won't be a problem since the beautiful white sand beaches here boast 361 days of sunshine per year. Next, don't miss these destinations that are even better in the winter.

    Nowadays six Amazon Scout delivery robots rolled out in a pilot program in Snohomish County, Wash. The robots carry meals, groceries and packages to homes and offices in this region just north of Seattle. They have appeared on the sidewalks of London, Beijing and other cities and communities worldwide. These machines must overcome pedestrian legs, naughty dogs and broken pavement, which raises some questions.

    These services are gaining attraction as a growing number of city residents expect immediate or scheduled delivery for just about everything. Between 2017 and 2018 online retail sales in the U.S. increased by 16 percent. On the final step of all these deliveries, called the last mile, humans on bicycles, motorized scooters (电动车) or large delivery trucks typically deliver packages. All the vehicles compete for space on busy urban streets. "Deliveries are trending upwards in all crowded city centers, and if city and state leaders don't start thinking about creative solutions like robot deliveries, we can expect even worse traffic jams," says Paul Mackie, director of a transportation policy research center in Arlington.

    A study by this center found 73 percent of delivery vehicles in Arlington were parked outside of authorized areas, often blocking bike lanes and crosswalks. By moving the last step of deliveries from the road to the sidewalk, cities could reduce traffic jams and solve the parking problem entirely, Mackie says.

    Companies such as Amazon are not developing this delivery technology simply to clear up urban traffic. Self-driving vehicles and sidewalk robots could cut down last-mile delivery costs in cities by as much as 40 percent, according to a 2018 report by a consultancy firm. A delivery robot can cost thousands of dollars to manufacture, and most currently require human management and conservation. But in the long run companies that use autonomous delivery vehicles in the next several years could end up saving billions of dollars, the report stated.

I was living in Sao Paulo, Brazil. It is a1 city, with more people living in it than in my whole country. We rented a flat in a guarded community, but there was a favela (棚户区) quite 2 .

For several months I didn't have a car, so three times a week, I took buses to go to the city centre. During these 3 , I would ride with the people who took the same bus from the favela to go to work. When I got on the bus, all the seats were already 4 . But when people saw that my bag was heavy, they offered to hold it on their legs to make me feel lighter5 . At first, I was 6 . Then I realized that these people had absolutely no 7 to steal from me: they only wanted to 8 .

Once, on my way back, I had to 9 for a long time at a bus stop. I was alone, except for a woman who was 10 very poor. She carried a small paper bag of popcorn and nothing else.

While we were waiting she walked over and 11 me some popcorn. I 12 her, but didn't want to help myself to it. She then repeatedly insisted that I take from what was clearly her only food.

That was the first time I had thought about how people who have almost nothing are sometimes able to 13 the little they have more "14 "than those who own a lot. I wonder if it's true that the more you have, the bigger the difficulty to share anything with others. I was so moved by that woman's simple generosity that day. I clearly 15 more than she did, but she naturally and joyfully shared what little she had with me.