We produce 500 billion of plastic bags in a year worldwide and they are thrown away polluting oceans, killing wildlife and getting dumped in landfills where they take up to 1,000 years to decompose. Researchers have been unsuccessfully looking for a solution.

    The 16-year-old Canadian high school student, Daniel Burd, from Waterloo Collegiate Institute, has discovered a way to make plastic bags degrade(降解) in as few as 3 months, a finding that won him first prize at the Canada Wide Science Fair, a ＄10,000 prize, a ＄20,000 scholarship, and a chance to revolutionize a major environmental issue.

    Burd's strategy was simple: Since plastic does eventually degrade, it must be eaten by microorganisms(微生物)．If those microorganisms could be identified, we could put them to work eating the plastic much faster than under normal conditions.

    With this goal in mind, he grounded plastic bags into a powder and concocted(调制) a solution of household chemicals, yeast(酵母) and tap water to encourage microbes growth．Then he added the plastic powder and let the microbes work their magic for 3 months．Finally, he tested the resulting bacterial culture on plastic bags, exposing one plastic sample to dead bacteria as a control．Sure enough, the plastic exposed(暴露) to the live bacteria was 17% lighter than the control after six weeks.

    The inputs are cheap, maintaining the required temperature takes little energy because microbes produce heat as they work, and the only outputs are water and tiny levels of carbon dioxide.

    “Almost every week I have to do chores and when I open the closet door, I have piles of plastic bags falling on top of me．One day, I got tired of it and I wanted to know what other people are doing with these plastic bags．The answer: not much．So I decided to do something myself.” Said Daniel Burd.

    Have you ever considered why you begin yawning too when you see someone yawn? Or how hard it is to be among people laughing and not laugh yourself? Well, apparently it's because we have mirror neurons (神经元）in our brains.

    Put simply, the existence of mirror neurons suggests that every time we see someone else do something, our brains imitate it whether or not we actually perform the same action. This explains a great deal about how, we learn to smile, talk, walk, dance or play sports. But the idea goes further: mirror neurons not only appear to explain physical actions, they also tell us that there is a biological basis for the way we understand other people.

    Mirror neurons can undoubtedly be found all over our brains, but especially in the areas which relate to our ability to use languages, and to understand how other people feel. Researchers have found that mirror neurons relate strongly to language. A group of researchers discovered that if they gave people sentences to listen to ( for example: “The hand took hold of the ball” ) , the same mirror neurons were triggered as when the action was actually performed (in this example, actually taking hold of a ball).

    Any problems with mirror neurons may well result in problems with behavior. Much research suggests that people with social and behavioral problems have mirror neurons which are not fully functioning. However, it is not yet known exactly how these discoveries might help find treatments for social disorders.

    Research into mirror neurons seems to provide us with even more information regarding how humans behave and interact. Indeed, it may turn out to be the equivalent (相等物）for neuroscience of what Einstein's theory of relativity was for physics. And the next time you feel the urge to cough in the cinema when someone else does — well, perhaps you'll understand why.

    Google's new camera, called Clips, is a small, smart device. It comes with a case that has a clip (夹子), but it's not designed to be worn on your clothing. Most interestingly, it uses artificial intelligence to take photography out of your hands so it can capture moments on its own.

    This roughly 2-inch by 2-inch camera, with a three-hour battery life and Gorilla Glass for toughness, is intended for candid moments, like when a child does something cute that may happen too quickly for you to pull out your smartphone.

    Onboard the Clips device, it uses machine learning algorithms ( 计 算 程 序 ) to help capture scenes. Those algorithms include face recognition. "Once it learns that there's a face you see frequently, it'll try to get nice photos of those faces," said Juston Payne, the device's product manager. And they also want it to recognize facial expressions, which involved "training it to know what happiness looks like". The Google team also trained it to recognize what not to shoot—like when a child's hand is over the lens, or if it is tossed in a dark purse.

    The only way to see the images is by connecting the camera with your phone, as it has no screen for viewing or editing.

    Were people concerned it could seem strange? Yes, Payne admitted. But they said they addressed that by making it obvious what it is. A green light on the front signals that it is on. Besides, unlike a camera meant to monitor your home, it is not connected to the Internet.

    "This product is only possible because of the way that silicon has advanced," Payne said, noting that it was only in the past year or so that they could squeeze the technology down into a device this size. Going forward, we're likely to get more assistance from the artificial intelligence packed into our apps and gadgets.

    Not long ago, a good friend of mine asked me to help him in a halfway house in Nashville. I agreed and made my way there one evening.

    When I got there, I sat with my friend and talked about how he ended up there. As we talked, another man came up, lighting up his cigarette as he sat down. He had dark, leather skin, and looked like he had endured the sun, the rain, and the wind for long, long time. I couldn't tell how old he was, but I was sure that he was younger than he looked.

    Through a bit of conversation, I found out that he had been on the streets for many, many years.

    Without my asking, he started describing life as a homeless man. How he got food; how he stayed warm; how he got money. And he told me something that caught my attention.

    He said, "You want to know how I keep my stuff safe at night?"

    "Sure," I replied.

    "I put it up in the trees."

    "Why is it safe in the trees?" I asked.

"The homeless are always looking for treasure on the ground— coins, something someone's dropped, half-smoked cigarettes. I know if I put my stuff in the trees, they'll never find it because they never look up. Never. "

    Profound words from an unexpected place. And his message is for all of us.

We all have our particular search. We're looking for treasure on this earth. But what we are REALLY looking for is right there above us. There's really nothing we need on the ground.

    In fact, it's surrounding us.

    It seems we're always being told to get more sleep. Studies suggest spending less time on sleep can lead to obesity(肥胖) and even cancer. You might even find yourself with a head full of false memories. But rarely does science explore the dark side of sleeping too much. That's because few of us in today's busy world have the luck of exploring that option.

    In an August 2018 study, published in the Journal of the American Heart Association, researchers researched the sleep patterns of those "fortunate" few and found they may not be so lucky after all. In fact, they found people who get more than eight hours of sleep have greater health risk compared to those who sleep together less than seven hours. What's more, sleep-aholics-those who manage to get 10 hours a night-stand a 30 percent higher chance of dying compared to the seven-hour crowd.

    The wide-ranging global study involved(涉及) more than three million people who self-reported on their sleep habits and came to an eye-opening conclusion: If you tend to sleep a lot, you may want to buy an alarm clock. As with all things in life, sleep is best taken in moderation(适度).

    You may be thinking: What if I only sleep in on Saturday and Sunday, am I still at risk? The answer is yes, according to a 2019 study published in Current Biology.  Researchers discovered that even if a person sleeps more than seven hours on the weekends but still sleeps less than that on weeknights, they are at risk of gaining weight and developing sensitivity to insulin, which controls the level of sugar in blood.

    For the study, 36 participants were divided into three groups that each had a different sleep schedule: nine hours every night, five hours every night, and five hours from Monday to Friday and sleeping much on weekends. People who get too much sleep tend to feel tired and lack energy. Also, both sleep-deprived(睡眠不足的) groups consume more food and gain weight.