ARNOLD Schwarzenegger is back, once again taking on his iconic killer robot role, the T-800, in August's new movie Terminator Genisys. While the T-800 model—even if it can be evil—has a fond place in moviegoers' hearts, the reality of autonomous machines is no joke, according to scientists.

    Autonomous weapons use artificial intelligence (AI) to choose targets without human help. They were described as “the third revolution in warfare, after gunpowder and nuclear arms” in an open letter signed by over 1,000 important technology figures in July. The list included British scientist Stephen Hawking and Apple co-founder Steve Wozniak. They asked governments around the world to ban autonomous weapons, warning that killer robots could start ethnic cleansings and an arms race.

     “They will look like tanks. They will look like battleships. They will look like jet fighters,” UK robotics professor Noel Sharkey told CNET, a leading technology website.

    But unlike these machines, which require a human hand in their action, so-called “killer robots” would have some decision-making abilities and the ability to act on their own.

     “If any major military power pushes ahead with AI weapon development, a global arms race is almost inevitable,” said the letter released at the 2015 International Joint Conference on Artificial Intelligence in Buenos Aires, Argentina.

    The idea of an automated killing machine was made famous by Schwarzenegger's first Terminator movie in 1984. While no red-eyed robots have been sent after human beings, the idea of AI being used as a weapon has gotten much more likely in the years ever since. The US military is already developing autonomous flying vehicles that can carry out all the steps of a strike mission without a human controlling them, according to a May report in Nature magazine.

    Scientists have even painted a destructive picture of autonomous weapons falling into the hands of terrorists or warlords hoping to carry out ethnic cleansings.

     “The development of full artificial intelligence could lead to the end of the human race,” Hawking said to the BBC in 2016.

Authorities are gradually waking up to the risk of robot wars. Last May, for the first time, the United Nations brought governments together to begin talks on autonomous weapons systems.

    Still, a ban on autonomous weapons is “easier said than done”, commented The Guardian. The dual (双重的) uses of the AI technology—for harm and for good—is difficult to manage. This is because the exact same technology can be used in a wide range of ways, the paper said.

    David Lindenmayer of the Australian National University College of Science in Canberra says that older trees play important roles in maintaining landscapes and ecosystems.

    David studies conservation, landscape, ecology and biodiversity at the Australian National University College of Science in Canberra. “Lots of people recognize that as humans get older they tend to have less and less children while trees do it the other way around. What really happens is that the older some of these really big old trees get, the more seeds they produce and the more germinant（萌芽的）they're likely to be. So it's actually the polar opposite of what we see with humans and most other animals, so really quite extraordinary. “On January 26th he spoke to Scientific American Editor in Chief Mariette DiChristina when they were both at the World Economic Forum in Davos.

    In actually it's quite a worrying situation, because in plenty of forests and woodland and other ecosystems around the world, populations of large old trees are declining very quickly. And this matters because a lot of biodiversity, a lot of carbon, a lot of key ecosystem processes are associated with those really big, old trees.

    We can make sure we grow more forests, that we protect the big trees we have now, and that we don't do things that really put a lot of pressure on those trees. We should not be cutting down really big old trees anymore.

    When the natural climate changes due to global warming, it can surely affect seals. The majority of them live in the Antarctic region so as the ice is melting, their natural habitat（栖息地）can be seriously affected. These changes don't take place overnight. They can be the result of many years of additional temperatures in the area. The seals then have to find ways to adapt.

    Seals depend on the cool air currents to bring plenty of food for them. When the temperatures get higher, there is less and less food and the seal population starts to get depleted. Mothers aren't healthy enough to feed their babies. Many of them end up abandoned as the mothers have to leave to find their own source of food.

    The fact that their desire to produce young can be changed by the warmer temperatures is frightening too. It is also believed that the warmer temperatures can allow different diseases and viruses to attack the seals. This is a huge concern as they can rapidly wipe out huge numbers of seals out there.

    However, these changes in climate and temperature aren't all bad for other species of seals. Scientists have found that those living in warmer climates are producing more young due to the changes. Research also shows that the females are moving further to find food and water. When they are out of the reach of the governing males, they are more willing to accept the moves of other males in the group.

    This is good news too because it means that there will be more selection in the gene pool（基因库）for future generations. It can help the seals as a species adapt to changes in their natural environment more easily.

    The climate change problem for seals is directly linked to humans. When we take action to change what we let out into the environment, we will make positive changes for the seals. However, it is going to take a very long time to reverse（彻底改变）the effects of what has already been done.

    Astronauts in the space stations for long missions often work very long days. Tasks are scheduled(安排) so tightly that break times are often used to finish the day's work. It's especially hard for long missions on the International Space Station (ISS). ISS crew members usually live in space for at least a quarter of a year. They work five days on and two days off to mimic the normal way they do things on Earth as much as possible. Weekends give the crew valuable time to rest and do a few hours of housework. They can communicate with family and friends by email, Internet phone and through private video meetings.

    While astronauts cannot go to a baseball game or a movie in space, there are many familiar activities that they can still enjoy. Before a mission, the family and friends of each ISS crew member put together a collection of family photos, messages, videos and reading materials for the astronauts to look at when they will be floating 370 kilometers above the Earth. During their mission, the crew also receives care packages with CDs, books, magazines, photos and letters. Today, the Internet can be used on the ISS, giving astronauts the chance to do some “web surfing” in their personal time. Besides relaxing with these more common entertainments, astronauts can simply enjoy the experience of living in space.

    Many astronauts say that one of the most relaxing things to do in space is to look out of the window and stare at the universe and the Earth's vast land mass and oceans.

    "Bill, you never miss!" Joe said admiringly. "Unless I'm in a real game," Bill complained. "Then I miss all the time." Joe knew that Bill was right. Bill performed much better when he was having fun with Joe in the school yard than he did when he was playing for the school team in front of a large crowd. "Maybe you just need to practice more," Joe suggested. "But I practice all the time with you!" Bill objected. He shook his head. "I just can't play well when people are watching me." "You play well when I'm watching," Joe pointed out. "That's because I've known you since we were five years old," Bill said with a smile. "I'm just not comfortable playing when other people are around." Joe nodded and understood, but he also had an idea.

    The next day Joe and Bill met in the school yard again to practice. After a few minutes, Joe excused himself. "Practice without me," Joe said to his friend. "I'll be back in a minute. "

    Joe hurried through the school building, gathering together whomever he could find-two students, a math teacher, two secretaries, and a janitor(看门人). When Joe explained why he needed them, everyone was happy to help. Joe reminded the group to stay quiet as they all went toward the school's basketball court. As Joe had hoped, Bill was still practicing basketball. He made five baskets in a row without noticing the silent people standing behind him.

    "Hey, Bill!" Joe called out finally. Bill turned. A look of surprise came over his face. "I just wanted to show you that you could play well with people watching you," Joe said. "Now you'll have nothing to worry about for the next game!"

While watching videos on Douyin one day, I came across a very unique profile（轮廓）: an 88-year-old farmer livestreaming trendy products in a rural setting. I clicked his page and saw that he was livestreaming because he needed to cover his wife's medical expenses. Curious, I decided to contact him and learn more about his story.

Now a retired farmer, Wu relies on government subsidies（补贴）. One rainy day, he returned to his rundown one-floor cottage in the suburb of Henan province and found his wife lying on the ground in great pain. She had broken her leg and lost the ability to walk.

A great burden befell this already poverty-stricken family. The medical expenses for Wu's wife are about 800 yuan per month. Her daughter, a mother of three and a housewife, has no means of supporting Wu financially. As a heavy user on Douyin, Wu's daughter thought that perhaps they too could try livestreaming as a way to help their family. With a 9.9 yuan phone holder, they began livestreaming on Douyin, and Wu became one of the oldest livestreamers on the platform.

Every day, Wu livestreams for a total of six hours, separated into morning and afternoon sessions. With a broad smile and soothing（宽慰的）voice, he explains the products on his table, which range from water bottles, makeup removers and vegetables to traditional Chinese clothing that Wu himself wears in front of the camera. Thousands of viewers are drawn in by his moving story and amiable（和蔼的）personality. They refer to him dearly as "my uncle Wu" or "Laoxiang".

During my interview with him, Wu would laugh warmly. His strong Henan dialect was sometimes hard to understand, but his tone was full of comfort and optimism. "I enjoy livestreaming. One day, one of the viewers came to visit me. I was so happy." Wu spoke about the friendships he made after becoming a livestreamer, and his voice was so contagious（感染力的）that it put a smile on my face.

He also does not avoid showing affection for his wife: "I will buy her good food when I have the money." I am moved by his ability to see the optimistic side of life despite being struck by hardships and his resilience（坚韧）sailing through the low tides of life.