No one can deny that buttons are an important device. Whenever we see a button, we are eager to press it because we know something will happen. This is true in most cases, for example on a doorbell and on the “on/off” button on the TV. But some buttons are actually fake, like the “close” button on a lift.

    Many people are in the habit of pressing the “close” button because they don't have the patience to wait for the lift doors to shut. But lifts' “close” buttons are a complete scam (骗局), at least in the US － the doors will not close any faster no matter how hard you press.

    It started in the 1990s when the Americans with Disabilities Act was passed in the US, making sure that all lifts stayed open long enough so that people with disabilities could enter. Only US firefighters and repairmen can use the buttons to speed up the door-closing process if they have a code or special keys.

    But to normal lift riders, the buttons aren't completely useless. According to psychologists, fake buttons can actually make you feel better by offering you a sense of control.

     “Perceived (能够感知的) control is very important. It reduces stress and increases well-being,” Ellen J. Langer, a psychology professor, said, “ having a lack of control is associated with depression.”

    Experts have revealed that a lot of buttons that don't do anything exist in our lives for this same purpose. For example, many offices in the US have fake thermostats (温度调节器) because people tend to feel better when they think they can control the temperature in their workspace.

    But psychologists found it interesting that even when people are aware of these little “white lies”, they still continue to push fake buttons because as long as the doors eventually close, it is considered to be worth the effort.

     “That habit is here to stay,” John Kounios, a psychology professor, said. “Even though I have real doubts about the traffic light buttons, I always press them. After all, I've got nothing else to do while waiting. So why not press the button in the hope that this one will work?”

    A team of engineers at Harvard University has been inspired by Nature to create the first robotic fly. The mechanical fly has become a platform for a series of new high-tech integrated systems. Designed to do what a fly does naturally, the tiny machine is the size of a fat housefly. Its mini wings allow it to stay in the air and perform controlled flight tasks.

    “It's extremely important for us to think about this as a whole system and not just the sum of a bunch of individual components (元件),” said Robert Wood, the Harvard engineering professor who has been working on the robotic fly project for over a decade. A few years ago, his team got the go-ahead to start piecing together the components. “The added difficulty with a project like this is that actually none of those components are off the shelf and so we have to develop them all on our own,” he said.

    They engineered a series of systems to start and drive the robotic fly. “The seemingly simple system which just moves the wings has a number of interdependencies on the individual components, each of which individually has to perform well, but then has to be matched well to everything it's connected to,” said Wood. The flight device was built into a set of power, computation, sensing and control systems. Wood says the success of the project proves that the flying robot with these tiny components can be built and manufactured.

    While this first robotic flyer is linked to a small, off-board power source, the goal is eventually to equip it with a built-in power source, so that it might someday perform data-gathering work at rescue sites, in farmers' fields or on the battlefield. “Basically it should be able to take off, land and fly around,” he said.

    Wood says the design offers a new way to study flight mechanics and control at insect-scale. Yet, the power, sensing and computation technologies on board could have much broader applications. “You can start thinking about using them to answer open scientific questions, you know, to study biology in ways that would be difficult with the animals, but using these robots instead,” he said. “So there are a lot of technologies and open interesting scientific questions that are really what drives us on a day to day basis.”

    Kunta wondered why the white people had done this to him. Born a free man, he was now in chains. Heavy iron chains around his feet and hands were fixed to a metal bar that ran round the hall about ten centimeters off the ground. He was just able to lie down on the ground, but could not stand up.

    Kunta had been seized in the forest and then hit on the head with a hard object. When he woke up, his hands and feet had already been tied together. What shocked him most was that the men who carried him were black. He reasoned with them, and tried to persuade them to set him free. But they would not listen to him. When they came to the river, a white man was waiting in the boat for them. There was an argument about money, so it seemed, in a language that Kunta did not understand. Finally, Kunta was thrown into the bottom of the boat and covered with an old smelly cloth. The men took him in their boat to the castle on the coast where he was now held prisoner.

    Another thing which shocked Kunta was that women were held in the castle too. He could hear their crying, also children's voices. What was to become of them all, he wondered. For all his life, he had known that people suddenly disappeared from their villages. He had known that it was not safe to travel alone in the forest near the coast. But why did white people want to catch Africans and put them in chains? Would they be killed or even eaten? The situation seemed hopeless and he knew his life was in danger.

    Worse was to come. A few days later about 140 black people were taken and put on a tall sailing ship waiting off the coast. Once on the boat, they were taken below and their chains were fixed to two bars that ran the length of the ship. Their feet were fixed to one bar and their hands to another bar. Thus they lay on hard wooden boards, unable to stand up or move around.

    The sea journey lasted over sixty days and nights. They had rough weather and Kunta's back bled from rolling over on the hard wooden boards. Many of the men fell sick with fever. They sighed and cried out for more water, but food and water were only given out once a day. Once in a while sailors came down, Kunta thought, to carry sick men upstairs for treatment. When the ship finally arrived in a port, the wooden cover was opened wide and Kunta could see in daylight for the first time across the part of the ship where he had been chained. About a third of the people who had been chained up below at the beginning of the journey were missing.

    Experience the newly opened Grand Canyon West Skywalk in Colorado.Departing from Grand Canyon's South Rim by Airplane to Grand Canyon's West Rim,you will land and take a ground tour to the Skywalk! Walk on air for 70 feet over the edge of Grand Canyon West.

    This Skywalk has been open since March 28,2007.Daily visitor-ship to the Skywalk has been over 4000 people. Please be patient to enjoy your moment on the Skywalk.

    After you have experienced the one and only Grand Canyon Skywalk Glass Bridge from where you can enjoy the scenery better,you will return to the Grand Canyon West airport and take your Airplane for a flight back to the South Rim of the Canyon.This is a tour never to be forgotten as you will have walked on air over the Grand Canyon.

Tour Itinerary

    It is widely accepted that nightmares (噩梦) are a reaction to negative experiences that happen during waking hours. However, some scientists believe that nightmares do have some real benefits. One 2017 study, for example, found that frequent nightmare sufferers rated themselves as more empathetic (有同理心的). They also displayed more of a tendency to unconsciously mirror other people through things like yawning People who have constant nightmares also tend to think further outside the box on psychoanalysis tasks. Some other researchers have found support for the idea that nightmares might be linked to creativity.

    People seeking cure for nightmares were not necessarily more fearful or anxious, but rather had a general sensitivity to all emotional experience. Sensitivity is the driving force behind intense dreams. Heightened sensitivity to threats or fear during the day results in nightmares, whereas heightened passion or excitement may result in positive dreams. And both these forms of dreams may feed back into waking life, perhaps increasing suffering after nightmares, or promoting social bonds and empathy after positive dreams.

    The effects go further still. This sensitivity overflows into awareness and thoughts －people who have a lot of nightmares experience a dreamlike quality to their waking thoughts. And this kind of thinking seems to give them a creative edge. For instance, studies show that such people tend to have greater creative talent and artistic express and people who often have nightmares also tend to have more positive dreams than the average person.

    The evidence points towards the idea that, rather than disturbing normal activity, people who are unfortunate in having a lot of nightmares also have a dreaming life that is at least as creative, positive and vivid as it can be distressing and terrifying. What's more, this imaginative richness is unlikely to be limited to sleep, but also is filled with waking thoughts and daydreams. Even after people wake up and shake off the nightmare, in other words, a mark of it stays behind, possessing them throughout the day.

    The World's Best Hearing Aid Value Under $200, the Doctor's Choice for Advanced Hearing Aid Technology

    How can a hearing aid cost less than $200?

    When you buy a hearing aid, be sure to choose a pair that every bit of it is as good as one that sells for $2500 or more.

    Although great progress has been made in Advanced Hearing Aid Technology, those cost reductions or falls in prices have not passed on to you­Until Now.

    The MDHearingAid PRO has been carefully tested by leading ENT (Ear, Nose and Throat) physicians and audiologists (听力学家) who have totally agreed that the sound quality and output in many cases is better than more expensive hearing aids.

    Since Medicare and most private insurance do not cover hearing aids, ENT surgeon Dr. Cherukuri designed a game­changing solution without sacrificing the quality of components that you can actually afford.

    "I recommend them to my patients with hearing loss."

—Amy S.Audiologist Indiana

    "I have had this aid two days and all I can say is WOW!"

—Terrsa H.,Grove, NJ

    "It is so much better than the $3000 hearing aid I had been using for years."

—Robert C. South Bend

    The fact is, you don't need to pay high prices for a medical-grade FDA registered hearing aid, MDHearingAid PRO is a high performance hearing aid that works right out of the box with no time-consuming "adjustment" appointments. You can conveniently access a hearing specialist online or by phone­even after the sale. No other company provides such extensive support. Over 75000 satisfied customers agree. Now that you know, why pay more?

    Try it at home within our 45-Day Risk-Free Trail (免费试用).

    If you are not completely satisfied, simply return it within that time period and we will give back your money for a 100% of your purchase price.

    800-475-7618

    Use Code: DB91

    For a year supply of Free Batteries and Free Shipping

    GetMDHearingAid.com