Computers have beaten human world champions at chess and, earlier this year, the board game Go. So far, though, they have struggled at the card table. So we challenged one AI to a game.

    Why is poker(扑克) so difficult? Chess and Go are “information complete” games where all players can see all the relevant information. In poker, other players' cards are hidden, making it an “information incomplete” game. Players have to guess opponents' hands from their actions—tricky for computers. Poker has become a new benchmark for AI research. Solving poker could lead to many breakthroughs, from cyber security to driverless cars.

    Scientists believe it is only a matter of time before AI once again vanquishes humans, hence our human-machine match comes up in a game of Texas Hold's Em Limit Poker. The AI was developed by Johannes Heinrich, researcher studying machine learning at UCL. It combines two techniques: neural(神经的) networks and reinforcement learning(强化学习).

    Neural networks, to some degree, copy the structure of human brains: their processors are highly interconnected and work at the same time to solve problems. They are good at spotting patterns in huge amounts of data. Reinforcement learning is when a machine, given a task, carries it out, learning from mistakes it makes. In this case, it means playing poker against itself billions of times to get better.

    Mr Heinrich told Sky News: “Today we are presenting a new procedure that has learned in a different way, more similar to how humans learn. In particular, it is able to learn abstract patterns, represented by its neural network, which allow it to deal with new and unseen situations.”

    After two hours of quite defensive play, from the computer at least, we called it a draw.

    While the U.S. is still debating about getting rid of the penny, Sweden is rapidly moving towards abolishing currency altogether. Though this may sound radical(过激的), it is a natural evolution in this digital society.

    Sweden, which was the first European country to introduce banknotes in 1661, has just been working harder to convince its residents that digital payments are a safer alternative to carrying cash.

Over the years, the idea has gained popularity with residents, especially the younger generation that is much more comfortable with technology. Today many banks don't even have ATMs and some have stopped handling cash altogether!

    Tickets to ride public buses in most Swedish cities can only be purchased via cell phones. Numerous businesses are also moving towards accepting only digital payments. Even the homeless that sell street paper to make ends meet have to start accepting this mode of payment!

But despite its growing popularity, some people don't like this radical idea. They include the homeless, elderly people as well as those living in rural areas who are still uncomfortable with mobile phones and computers. But the officials are confident that in the very near future, they will be able to convince everyone to move this safe and more cost-effective payment system.

    Sweden is not the only country trying to abolish paper currency and coins. The movement is rapidly gaining ground in Denmark and Finland as well. In 2014, Israel announced a three-step plan to go cashless and just last week the vendors(小贩)of a popular street in Sydney declared they would stop accepting currency from customers. Whether this phenomenon spreads remains to be seen. But one thing is for sure—With increasingly advanced payment systems being introduced every day, pulling out cash is rapidly becoming “uncool”.

    Rome, Paris and New York are the world's top fashion cities, all of which have produced some of the top trends, from fashionable skirts to the hottest new shoes. But have you ever wondered about the negative ideas that they have enforced?

    In April 2016, the Advertising Standards Authority (ASA) in Britain banned an ad from Gucci that featured models dancing around and having fun, because they were all extremely skinny. Banning ads due to the models' extreme figures isn't new. The ASA banned an ad in 2015 for the same reason. In France, it has been ruled that models are to provide a doctor's note providing that they are at a healthy weight.

    So what is the healthy weight for models? Twenty years ago, the average fashion model weighed 8% less than the average woman. Today, they weigh 23% less.

    People may think that being at an unhealthy weight will help them gain the benefits that the models do. This provides a standard of beauty, and therefore people who want to achieve those things may attempt to obtain them through unhealthy ways. People may think that they are overweight, due to the images of models¹ thin figures. They see something wrong with their bodies, whether they are overweight or not. This is a key factor in a lowered body image, low self-esteem, depression and possibly even eating disorders.

    I'm not blaming the fashion industry by any means. It's not their fault that many people look up to the models and expect to live a life like theirs. I am glad that the ASA is raising its voices when discussing the growing issue of body images in the fashion industry. By banning photos and videos, speaking out against them and pushing for doctor's notes from the models, it's pushing for the ideas that the traditional fashion industry's body image demands should be changed and something more needs to be questioned.

    Sherlock: The Abominable Bride.

    Release date: January 1, 2016

    Price: $8

    Plot: Sherlock Holmes and Dr. Watson travel back to the Victorian era to solve the case of “The Abominable Bride”

    The Revenant

    Release date: January 8, 2016

    Price: $6

    Plot: In the 1820s,a frontiersman，Hugh Glass，sets out on a path of vengeance against those who left him for dead after a bear mauling.

    The Fifth Wave:

    Release date: January 15,2016

    Price: $6.5

    Plot：Four waves of increasingly deadly attacks have left most of Earth decimated. Against a backdrop of fear and distrust, Cassie is on the run, desperately trying to save her younger brother. As she prepares for the fifth wave, Cassie teams up with a young man who may become her final hope-if she can only trust him.

    Kung Fu Panda 3

    Release date: January 29, 2016

    Price:Adult$7.5   Child（aged six &up）$3.5

    Plot：Po reunites with his biological father and travels with him to a secret sanctuary of pandas where, to his surprise, he does not fit in. There he meets Mei Mei, an overly eager panda, who had been promised to Po through an arranged marriage when they were children. To make matters worse, an evil ancient spirit called Kai begins terrorizing China and stealing the powers of defeated kung fu masters. Now, in the face of incredible odds, Po must learn to train a village of clumsy, fun-loving pandas to become a band of Kung Fu Pandas.

    Researchers found that walking around with a forced smile and fake happiness simply leads to people feeling unhappier. So, putting a brave face on your sadness could be harmful. The research also found that women suffered more than men when pretending to be happy.

    Dr. Brent Scott, who led the study, said employers should take note because forcing workers to smile when dealing with the public can result in bad outcomes. He said, “Smiling for the sake of smiling can lead to emotional tiredness, and that's bad for the organization.” He also said the research showed customer-service workers who had “fake smiles” throughout the day didn't want to work, so their productivity dropped.

    The study is one of the first of its kind to examine emotional expressions over a period of time and compare the different effects on men and women. Dr. Scott's team examined the effects of “surface acting”, or fake smiling, compared to “deep acting”, or making people smile by thinking of pleasant memories.

    Dr. Scott said, “Women were harmed more by surface acting, meaning their moods worsened even more than men's. However, they were helped more by deep acting, which means their moods improved more by thinking of pleasant memories.”

    According to Dr. Scott women tend to suffer more when pretending to be happy because they are expected to be more emotionally expressive than men. Therefore, forcing a smile while feeling down is more likely to go against their normal behavior and cause more harmful feelings.

    Although deep acting can improve moods a little in the short term, Dr. Scott says it's not a long-term solution to feeling unhappy. There have been some suggestions that if you do this over a long period you start to feel unreal. You're trying to develop positive emotions, but at the end of the day you may not feel like yourself any more.

    Around this time a few years ago, it was common to see videos of friends on social media having a bucket of icy water thrown on them. Known as the "ice bucket challenge", it was created as a way to raise money for the medical condition ALS. But now, there's a new challenge and this time, no water is involved.

    What is it? Well, think of a fruit that you'd never normally sink your teeth into. Perhaps you've got it: a lemon. While we enjoy using lemons to add flavor to dishes, very few of us would actually eat one as we'd eat an apple or an orange.

    But the horrible taste is the precise reason why the "lemon face challenge" is taking off. Participants bite into a lemon, taking a selfie as they do it before posting the photo online. The fun is all about expression people make as all that citric acid(柠檬酸)hits their taste buds(味蕾). Every expression seems to say, "This is worse than freezing water."

    The serious side to this trend is the good cause it's all in aid of. The challenge aims to raise awareness of a rare brain cancer that affects young children. It was started by Aubregh Nicholas, an 11-year-old US kid. She was diagnosed with this rare brain cancer herself in September 2017, but has since raised almost $50000 to cover her medical expenses thanks to the challenge.

    If a challenge is going to raise publicity and contributions from people, it has to be something interesting and original. That way the ice bucket challenge took off in 2014 and it explains why so many people are now sharing their lemon faces. There are a lot of stories about the downside of social media these days. The charity challenges, however, show how online culture can unite the world and bring help to the people who most need it.