In the late 1950s, a Russian geneticist called Dmitry K. Belyaev attempted to create a tame (驯化的) fox population. Through the work of a breeding programme at the Institute of Cytology and Genetics at Novosibirsk, in Russia, he sought to find the evolutionary pathway of tame animals. His test subjects were silver-black foxes, a melanistic (带黑色的) version of the red fox that had been bred in farms for the color of their fur.

    He selected the animals based on how they responded when their cage was opened. About 10% of the foxes displayed a weak “wild-response”, meaning they were docile around humans. Those that hid in the corner or made aggressive voices were left in the farm. Of those friendly foxes, 100 females and 30 males were chosen as the first generations of parents.

    When the young foxes were born, the researchers hand-fed them. They also attempted to touch or pet the foxes when they were two to two-and-a-half months old, for strictly measured periods at a time. If the young foxes continued to show aggressive response, even after significant human contact, they were thrown away from the population—meaning they were made into fur coats. In each selection, less than 10% of tame individuals were used as parents of the next generation.

    By the fourth generation, the scientists started to see dramatic changes. The young foxes were beginning to behave more like dogs. They wagged their tails and “eagerly” sought contact with humans. By 2005-2006, almost all the foxes were playful, friendly and behaving like domestic dogs. The foxes could “read” human hints and respond correctly to gestures or glances.

    A telescope, called Gaia, is being designed by astronomers in Europe, and it couldn't be more different from Pan-STARRS, which is another telescope being designed. While Pan-STARRS will be looking for asteroids (小行星) and comets headed for Earth, Gaia will be looking at our entire galaxy (银河系).

    Gaia is designed to draw a map of the Milky Way, our home galaxy. Just as a map of your town gives you a picture of where things are located, Gaia's map of the galaxy will tell astronomers where the stars are. Over five years, Gaia will observe (观察) about a billion stars and other objects in our galaxy. Each object will be observed about 70 times.

    Gaia will be sent into space connected to a rocket. It contains two telescopes, each focused at a different angle (角度). These two telescopes act like Gaia's “eyes”. The reason why humans can see things in 3D is that we have two eyes focused on the same object, at slightly different angles. By using two telescopes like eyes, Gaia can produce the first 3D map of the positions of the stars it views.

    Gaia, which is to be sent into space, will be a powerful telescope. If you were to use it on Earth, for example, you could stand 600 miles away from your best friends and still get a clear picture of their hair.

    Gaia is one of more than a dozen telescopes being designed by scientists right now. The next generation of telescopes will reveal new parts of our universe that will seem surprising. The universe, with all its planets, stars and other strange objects, is a puzzle with pieces that we can see by using powerful telescopes.

    With online courses, anyone can gain knowledge in any field of interest for free. You can educate yourself and get a certificate after finishing the course.

Coursera

    It offers high-quality courses from top universities for free to everyone to improve your resume, advance your career, expand your knowledge, and gain your confidence. This online learning website provides courses from Princeton University, Stanford University, University of California, and University of Pennsylvania. Learn more at https://coursera.com

Udemy

    Its goal is to promote education by enabling anyone to learn online. It seeks to hugely change education by inviting millions of experts worldwide to teach and share what they know. Whether you want to learn business, arts, health, music or technology, there is a course for you. Learn more at https://udemy.com

iTunes U

    If you are a student who uses Apple devices, you will be happy to know that you have access to iTunes U, which gives you access to different educational courses from all leading universities for free! Learn more at https://iTunesU.com

Skillfeed

    If you hope to learn a new skill, or improve your Photoshop skills, it offers unlimited access to high-quality video courses from a worldwide community of instructors. You have a month's free trial, after which you will pay a monthly fee to gain unlimited access to all courses. Learn more at https://skillfeed.com

UC Berkeley

    It offers courses in Japanese, legal studies and public health. Since they are recordings of actual lectures, they are short of lecture notes and extra materials. However, each course has audio recordings of lectures through iTunes U or video recordings of lectures through YouTube. Learn more at https://ucberkeley.com

    Are you sometimes a little tired and sleepy in the early afternoon? Many people feel this way after lunch. They may think that eating lunch is the cause of the sleepiness. Or, in summer, they may think it is the heat. However, the real reason lies inside their bodies. At that time – about eight hours after you wake up – your body temperature goes down. This is what makes you slow down and feel sleepy. Scientists have tested sleep habits in experiments where there was no night or day. The people in these experiments almost always followed a similar sleeping pattern. They slept for one long period and then for one short period about eight hours later.

    In many parts of the world, people take naps in the middle of the day. This is especially true in warmer climates where the heat makes work difficult in the early afternoon. Researchers are now saying that naps are good for everyone in any climate. A daily nap gives one a more rested body and mind and therefore is good for health in general. In countries where naps are traditional, people often suffer less from problem such as heart disease.

    Many working people, unfortunately, have no time to take naps. Though doctors may advise taking naps, employers do not allow it! If you do have the chance, however, here are a few tips about making the most of your nap. Remember that the best time to take a nap is about eight hours after you get up. A short sleep too late in the day may only make you feel more tired and sleepy afterward. This can also happen if you sleep for too long. If you do not have enough time, try a short nap – even ten minutes of sleep can be helpful.

    I first began experiencing anxiety and depression at the age of 14, after being bullied (欺凌) at school for years. While at first anxiety and depression would come and go, it eventually became a constant part of my life.

    I was so eager to find the solution to overcoming my anxiety and depression that I tried everything from when I was in college to graduate school: mood-changing medication, special teas, yoga, anything I read about in books, and advice given by doctors. Despite this, I still felt I hadn't even come close to managing the problem.

    But one afternoon, my eyes fell upon an article in a magazine I was reading that talked about how dogs were able to help people with anxiety and depression. The very next day, I decided to get a dog—a corgi. When I brought my little corgi, Buddy, home. I didn't realize how much he would change my life. It didn't happen right away, however.

    Once the “puppy excitement” went away, my anxiety and depression came back as usual. One morning, I woke up with those familiar feeling again. I didn't want to get out of bed. I turned to pull the covers back over my head and give up. That's when I saw Buddy.

    Buddy started jumping all over me, licking my face, letting me know that it was time to go outside. It was as if he were saying, “There's no time to be sad; the world is amazing!” And for the first time in my life, my life was changing. I really was a new person. This was my new beginning.

    It's been more than a year since that day, and I've never spent another morning unable to get out of bed. I've not cried myself to sleep or spent my days stuck with fear and regret. Sure, I still have days when I feel sad or anxious. But with Buddy, my best friend, by my side, I've finally learned how to manage these feelings and emotions.

    While most people have the idea that volcano eruptions are one of the most destructive disasters in nature, seeing a volcano erupt is a wonderful experience, and you can really feel the heat by climbing to the summit of Pacaya for a close-up view.

    There are guided tours every day up this highly active volcano from Antigua, giving travelers a chance to see Mother Nature at her most powerful. Pacaya is an easy drive from Antigua, a beautiful city with many colorful houses along its old streets that are turned into art-works during its Holy Week festival. No matter when you come to Antigua, you won't miss the Pacaya-tour companies.

    But climbing Pacaya is no easy job: it is 2,560 meters high, and reaching the summit takes two to three hours of seemingly one-step-forward and two-step-back movements. As you climb you hear the dull sounds of eruptions high above. Steaming, hot remains from recent eruptions begin to line the path as you near the active summit: the Mckenney Cone (火山锥). Just as though you were going to walk over to the edge of the cone, the road turns to the left and up to the relative safety of the old, inactive summit.

    Many tours are timed so that you arrive at the cone of the volcano in plenty of time for sunset and the full contrast between the erupting red lava(岩浆) and the darkening sky. On a good day the view from the summit is extremely exciting. The active mouth boils, sending red lava over its sides, and once in a while shoots hot steams up to 100 meters into the air. There is a strong bad smell in the air even if you take care to be upwind of the cone. As evening turns deeper into the night, the burning lava quietly falls down the side of the volcano. For you, too, it is time to get down.