Telepathy (心灵感应) is the ability to communicate without the use of the five senses. It's an instinct (本能) which can be woken up in times of emergency or need. When we feel that something is happening or about to happen by instinct, we're using resources within the unconscious mind. When the resources of two persons' unconscious minds link together into the same frequency (频率), we call it telepathy.

    We can either send or receive telepathy. If you know who is calling before you answer the ringing phone，you are probably a good receiver. If you think of a person and he/she calls you，you are most likely to be better at sending.

    You can easily put your ability to the test. Thinking of somebody and wish him or her to contact you. Be patient. The other person may not be a good receiver，but they should contact you much earlier than would normally be expected. Or whenever the phone rings，try ‘feeling' who is contacting you. Don't guess, but try to feel it with your mind. However，if neither of these works for you，that doesn't mean that you have no ability of telepathy. As mentioned earlier, telepathy is most likely to turn up in case of emergency.

    Telepathy dreams often contain telepathic messages. Two people may both dream of the other and find that their dreams have a clear connection. These people are probably linking to each other's unconscious mind.

    Telepathy & relationship. The more people spend time together, the more likely they are to be able to link up to the other's mind, especially when separated. There are two reasons for this. One is that they understand the other's mind through time spent together; the other is that there is usually a strong desire to communicate. A mother will often sense that her child is in danger. This is due to the child's eagerly wanting his or her mother, knowing that this is the person who would always want to be there for them, and the mother's deep desire to protect her child from harm.

    It's a popular belief that a fish's memory lasts for only seven seconds. It may seem sad to think that they don't remember what they've eaten or where they've been, and they don't recognize you or any of their friends — every moment in their life would be like seeing the world for the first time.

    But don't be so quick to feel sorry for them. A new study has found that fish have a much better memory than we used to think. In fact, certain species of fish can even remember events from as long as 12 days ago.

    In the study, researchers from MacEwan University in Canada trained a kind of fish called African cichlids to go to a certain area of their tank to get food. They then waited for 12 days before putting them back in the tank again.

    Researchers used computer software to monitor the fish's movements. They found that after such a long break the fish still went to the same place where they first got food. This suggested that they could remember their past experiences.

    In fact, scientists had been thinking for a long time that African cichlids might have a good memory. An earlier study showed that they behaved aggressively（挑衅地） in front of certain fish, perhaps because they remembered their past “fights”. But until the latest findings, there was no clear evidence.

    Just as a good memory can make our lives easier, it also plays an important part when a fish is trying to survive in the wild.

    “If fish are able to remember that a certain area contains safe food, they will be able to go back to that area without putting their lives at risks,” lead researcher Trevor Hamilton told Live Science.

    For a long time, fish were placed far below chimpanzees, dolphins and mice on the list of smart animals. But this study has given scientists a new understanding of their intelligence.

    If you could be anybody in the world, who would it be? Your neighbour or a super star? A few people have experienced what it might be like to step into the skin of another person, thanks to an unusual virtual reality（虚拟现实）device. Rikke Wahl, an actress, model and artist, was one of the participants in a body swapping experiment at the Be Another lab, a project developed by a group of artists based in Barcelona. She swapped with her partner, an actor, using a machine called The Machine to Be Another and temporarily became a man. "As I looked down, I saw my whole body as a man, dressed in my partner's pants," she said. "That's the picture I remember best."

    The set-up is relatively simple. Both users wear a virtual reality headset with a camera on the top. The video from each camera is sent to the other person, so what you see is the exact view of your partner. If she moves her arm, you see it. If you move your arm, she sees it.

    To get used to seeing another person's body without actually having control of it, participants start by raising their arms and legs very slowly, so that the other can follow along. Eventually, this kind of slow synchronised（同步的）movement becomes comfortable, and participants really start to feel as though they are living in another person's body.

    Using such technology promises to alter people's behaviour afterwards-potentially for the better. Studies have shown that virtual reality can be effective in fighting racism-the bias（偏见）that humans have against those who don't look or sound like them. Researchers at the University of Barcelona gave people a questionnaire called the Implicit Association Test, which measures the strength of people's associations between, for instance, black people and adjectives such as good, bad, athletic or awkward. Then they asked them to control the body of a dark skinned digital character using virtual reality glasses, before taking the test again. This time, the participants' bias scores were lower. The idea is that once you've "put yourself in another's shoes" you're less likely to think ill of them, because your brain has internalised the feeling of being that person.

    The creators of The Machine to Be Another hope to achieve a similar result. "At the end of body swapping, people feel like holding each other in their arms," says Arthur Pointeau, a programmer with the project. "It's a really nice way to have this kind of experience. I would really, really recommend it to everyone."

    In most parts of the world, many students help their schools make less pollution. They join “environment clubs”. In an environment club, people work together to make our environment clean.

    Here are some things students often do.

    No-garbage lunches. How much do you throw away after lunch? Environment clubs ask students to bring their lunches in bags that can be used again. Every week they will choose the classes that make the least garbage and report them to the whole school.

    No-car day. On a no-car day, nobody comes to school in a car. Not the students and not the teachers! Cars give pollution to our air, so remember: walk, jump, bike and run. Use your legs! It's lots of fun.

    Turn off the water! Did you know that some toilets can waste twenty to forty cubic (立方) meters of water an hour? In a year, it would fill a small river! In environment clubs, students mend those broken toilets. We love our environment. Let's work together to make it clean.

    Dolphins, African gray parrots and some other animals understand the idea of “zero,” but researchers were surprised to find that honeybees also comprehend this abstract concept, considering the insects' tiny brains, according to a new study. Honeybees have fewer than one million neurons (神经元), compared with the 86 billion neurons in humans—and yet, they grasp a concept that humans, by some measures, don't start to understand before preschool.

    The researchers set up two cards, each of which had a set of symbols on them, like triangles or circles. Then, they trained a group of the bees to fly to the card with the lower number of symbols. The bees quickly learned what the humans wanted them to do to get their delicious, sweet rewards. The trained bees were then shown a card that was empty and one that had symbols on it. There is no need for the bees to be trained to fly more often to the empty card—thus showing that they understood that “zero” was a number less than the others.

    Although they flew more often to an empty card than to one that had one symbol on it, it became easier for them to distinguish when the symbols on the card increased in number. For example, they more often flew to the zero when the other card had four symbols than when it had one.

    Perhaps these findings will explain the brain mechanism (机制) behind what allows us to understand the concept of “nothing,” Adrian Dyer, a researcher said. This understanding, in turn, could help in the development of artificial intelligence (AI) that also understands this concept. “If bees can understand 'zero' with a brain of less than a million neurons, it suggests there are simple, efficient ways to teach AI new tricks,” Dyer said in the statement.

    A good disguise keeps you hidden, right? Well, sometimes the best disguise is actually the most dazzling because research reveals that flashy metallic iridescence(金属彩虹色) can visually puzzle predators, which allows colorful prey to survive another day. Those surprising results appear in the journal Scientific Reports.

    Shining iridescent color, which changes depending on the angle from which it's viewed, is favored by everything from birds to beetles and blossoms to butterflies.

    "And in our research group we are of course interested in why this vivid metallic color is so widespread in nature." Karin Kjernsmo of the University of Bristol adds that in some cases the showy splashes of light are a sexual strategy. " Here I would like to point out that in some species, particularly those that display strong sexual dimorphism(雌雄两性), such as birds of paradise or some butterflies or fishes, the occurrence of iridescence is most likely driven by sexual selection. For example, in many of these cases it is the males that have these vivid iridescent colors and they use them in mate choice or they use them as a signal to attract mates."  But iridescence also shows up in situations where reproduction is not an issue. " So what we are studying now is whether natural selection imposed by predation(捕食行为) could explain the occurrence of iridescence in prey animals."

    The idea that eye­catching colors could be used as a cover­up isn't a new one." The father of camouflage theory, Abbott Thayer, really believed that iridescence should be categorized as a camouflage strategy. And he wrote in his famous lifework Concealing­Coloration in the Animal Kingdom, already in 1909, that 'brilliantly changeable or metallic colors are among the strongest factors in an animal's concealment'. And this sounds like a completely unreasonable thing to say, because how can colors that are both brilliant and changeable contribute to animal's concealment？"

    "In a similar way, we were asking whether iridescence, due to its changeability, could work as a form of camouflage by preventing shape recognition." Kjernsmo and her colleagues trained bumblebees to associate a particular shape—a circle or an oval—with a sugar reward. And they found that the bees, when given a choice, would preferentially visit the shape they knew to be sweet. But when the shapes were iridescent, the bees had trouble telling them apart. "It seemed that the strikingly iridescent surfaces on our targets visually broke up the otherwise recognizable shape of the targets, which made them hard to distinguish." As for making use of this method for hiding in plain sight, "Any practical applications is of course directly linked to any industry that has an interest in camouflage, that is how to conceal objects or make them more difficult to recognize." The researchers are currently conducting experiments with birds, which often prey on iridescent insects to see if it helps to have a bird's­eye view.