One of my first memories as a child in the 1950s was a discussion I had with my brother in our tiny bedroom in the family house in Bethlehem, Pennsylvania.

    We had heard in school about a planet called Pluto. It was the farthest, coldest, and darkest thing a child could imagine. We guessed how long it would take to die if we stood on the surface of such a frozen place wearing only the clothes we had on. We tried to figure out how much colder Pluto was than Antarctica, or than the coldest day we had ever experienced in Pennsylvania.

    Pluto, which famously was downgraded from a “major planet” to a “dwarf planet”（矮星） in 2006, captured our imagination because it was a mystery that could complete our picture of what it was like at the most remote corners of our solar system.

    Pluto's underdog discovery story is part of what makes it so attractive. Clyde Tombaugh was a Kansas farm boy who built telescopes out of spare auto parts, old farm equipment and self-ground lenses. As an assistant at Lowell Observatory in Flagstaff, Arizona, Tombaugh's task was to search millions of stars for a moving point of light, a planet that the observatory's founder thought existed beyond the orbit of Neptune. On February 18，1930，Tombaugh found it. Pluto was the first planet discovered by an American, and represented a moment of light in the midst of the Great Depression's dark encroachment (入侵).

    Pluto is much more than something that is not a planet. It's a reminder that there are many worlds out there beyond our own and that the sky isn't the limit at all. We don't know what kinds of fantastic variations on a theme nature is capable of making until we get there to look.

    Sandra Bullock turned 51 last month. But because she looks exactly the same as she did in Miss Congeniality, a movie filmed back in the 20^th century, everyone calls her “ageless.” Bullock is just one of a number of stars in their 40s and 50s who've had birthdays recently but have not gotten older, unlike the rest of us in their age group. Take Halle Berry. One website put a photo of her 20 years ago next to one of the newly 49-year-old Berry and dared us to choose which was which. “This Is What 49 Looks Like,” it said. Seriously, if that's what 49 looks like, I must be 71.

    However, even a generation ago, famous faces evolved. Look at a picture of Grace Kelly at age 52 in the early 1980s. She looks like a beautiful middle-aged woman. Today she'd look old for her age.

    The goal now is to prevent aging while you are still young, using all the magical nonsurgical options medicine has to offer. Eventually these techniques will become less expensive, and ordinary people my daughter's age will have them. Already anti-aging is starting to be considered maintenance, like coloring your hair. My friends and I find ourselves openly debating techniques that we used to make fun of. Does fat-freezing work? How much time do you have to spend in the gym to keep the body of a 35-year-old after 50? It's all so exhausting. But members of the next generation have it tougher. They'll have to ask themselves whether they want to spend their youth trying not to get old. I've already seen “Sexy at 70” headlines. Will everyone be expected to go to their graves(坟墓) looking hot?

    I also have to wonder what else we are slowing along with age. How do you move on if you're working so hard to stay the same? And besides, if you've known the ache of watching a daughter pack up for college, you know you can't stop the clock.

    We ate on the go more than ever before. Here are three health apps that can help you better manage your health when you pursue your dreams.

⑴Doctors On Demand

    Doctors On Demand enables you to visit a doctor without ever leaving your home, helping you use a computer, tablet or smart phone to have a doctor video chat with you. The service will help you locate and connect you to licensed doctors, psychologists, pediatricians (儿科医生) and more. Fees can be paid with HAS&FSA. It costs $40 for 15 minutes with a doctor or $50 for 20 minutes with a psychologist.

⑵Text4baby

    I'm a big fan of Text4baby for a few reasons. The free service for pregnant women and new moms works by sending text messages to your smart phone three times a week with information about how to have a healthy pregnancy and baby. And the messages are timed to the pregnant woman's due date or the baby's date of birth, sending tips that are relevant to where a mother is in her pregnancy or where a baby is in stages of development. Tips range from breastfeeding to car seat safety to reminders about exercise, nutrition and more. The service combines interactive text messages, an app, video and web content in English and Spanish. Sign up by texting BABY to 511-411 or by downloading the app.

⑶RISE

    RISE, an app available on iPhone(coming to Android in 2016), pairs you up with (与……绑定) a registered dietitian to improve your diet and reach health goals. You share photos of your meals and your exercise for the day with your coach, who then looks for areas where you can improve and gives advice, helps you set goals and is there to pat you on the back virtually(虚拟地) when you hit a milestone. What's also great is that you can text as much as you want with your dietitian and there is no need to go into an office. Fees for this service range from $9 per month to $50 a month. There is a free 7-day trial so you can try it out for a week to see if it's fit for you.

    Chinese students' extremely neat handwritten compositions have aroused a heated debate among Internet users since photos of the compositions and a teacher's picky remarks were published on Daily Mail Online.

    “Can you believe this essay is handwritten? ” Daily Mail Online asked.

    The website reported on the compositions that looked like they had been machine printed and on the teacher's remarks at Hengshui High School in North China's Hebei Province, one of China's top 100 high schools. The teacher wrote, “not one stroke (笔画) more, not one stroke less” about some compositions that weren't neatly written.

    The story immediately aroused a heated debate among British Internet users and got 652 comments after it was published on Wednesday. Some British readers were amazed by the neat handwriting and attributed (归于)China's growing development to this strict teaching method. A reader named Jim said, “This is another example of why China is rising to the top”, and his comment gained 72 supports. But some readers thought the too-picky method doesn't make sense in helping students learn better English and suppresses（压制） students' creativity.

    Chinese Internet users also expressed different opinions after English newspapers, a user of China's Twitter like Sina Weibo, posted the story along with its comments on Weibo on Thursday. Since then, the post has received 1, 479 comments. Sina Weibo user wenjinzetui said, “Beautiful handwriting proves an ability”, echoing an old Chinese saying that the style is the man. However, another Weibo user, honorificabilitus, said, “It's meaningless to pursue that neat English handwriting, since learning language is for communicating, let alone English students don't write that neatly. ”

    There are also many Weibo users showing worry about this too-strict teaching method, as weibo user li-owl-stop said, “We should reflect the Chinese-style education, and it's hard to imagine what would happen if all the schools in China adopted the teaching method at Hengshui High School. ”

    The human beings seem to be facing a crisis （危机）． After Our best Go players were defeated one by one by the artificial intelligence (AI) AlphaGo, we lost our pride of being at the top of the intelligence chain. And in October，when Saudi Arabia gave citizenship to a robot named Sophia, another privilege of being human was take away．It looks like everything that separates humans and AI is at risk fight now．

    But we keep hoping that instead of “everything ”, there's still something left in us that makes us irreplaceable.

    To Hao Jingfang, winner of the 2016 Hugo Award for Best Novelette, that “something” is our consciousness. “AlphaGo is intelligent in a certain way, but not intelligent enough to ask the important questions – Do I like playing Co? Do I want to play Go today? Why do I have to play Go when you tell me to?” she once said．In other words, computer programs don't have a choice to say “no”． They probably don't even know what a “choice” is – all they ever do is calculate．

    And to He Huaihong，a philosophy (哲学) professor at Peking University，imagination and creativity are also what make us special. A machine couldn't have come up with the theory of gravity just because it was hit by a falling apple，he said．It's human imagination that connects what seem to be completely random and irrelevant concepts，something that a machine—which works by fixed rules only—can't do，at least for now．

    This is why BBC reporter Viktor Mayer-Schonberger suggested that instead of focusing on how computers have overshadowed us on calculating abilities than humans，we should probably “consider our quality at a different end of the spectrum (光谱)：creativity，originality (原创性)，even plain illogical craziness，instead of hard-nosed (顽固的) logic”，he wrote．

    So maybe in the future，as artificial intelligence becomes even more intelligent，humans and A1 will learn to use each other's talents for good．If AI can handle the boring tasks like calculating and driving for us，we'll have more time to create，think，and be busy with “being human”．