We have known for a long time that flowers of different plants open and close at different time of day. Yet no one really understands why flowers open and close like this at special times. It is not as simple as we might think, as new experiments(实验) have shown. In one experiment, flowers were kept in darkness. We might expect that the flowers, without any information about the time of the day, did not open as they usually do. In fact, they continued to open at their usual time. This shows that they have some mysterious (神秘的) way of knowing the time.

    Their sense of time does not depend on information from the outside world; it is, so to speak, inside them, a kind of “inner clock”. This discovery may not seem to be very important. However, it was later found that not just plants but also animals including man have this “inner clock”which controls(控制) working of their bodies and their activities.

    Human beings, then, are also controlled by this mysterious power. Whether we wish it or not, it affects such things in our life as our need for sleep, our need for food. And our ability to concentrate(集中).

    Is your TV connected to the Internet? What about your chair, or your fridge? Probably they are not. But in the future, most things in your home may be connected, thanks to the so-called "Internet of things".

    The Internet of things may be coming sooner than you think. Earlier this year, Samsung CEO spent a lot of time talking about the Internet things. He said that three years from now, every Samsung product will be part of the Internet of things, no matter whether it's a remote control or a washing machine.

    So, how do household objects that are part of the Internet of things work? Well, think of a common chair. When connected to the Internet, the chair warms up when it knows the user has just walked into the room and is feeling cold.

    An Internet-connected camera could help people feel safer in their homes. It can know people's faces and has an infrared sensor（红外传感器）, so even if it's dark it can see when someone passes by and send you a message on your smart-phone to let you know who's there. If the person is someone you don't know, it can tell you that, too.

    But according to MIT Technology Review, whether companies are connecting dog food bowls or safety systems to the Internet, there may be some problems. For example, many early connected-home objects don't have much built-in security, which means they could be hacked（攻击）. Moreover, it could be difficult to get these new machines to work together especially when they are made by different companies. To fight this, many companies have joined the Open Interconnect Consortium, which had 45 members by late 2015.

    So, picture this: you enter your home. The temperature changes to make you feel comfortable. Your favorite music starts playing for you. Do you think that this would be a good thing? It may happen sooner than you think.

    Today there are robots working in factories. Some can help to build cars, and they do easy jobs over and over again. Few people will do such jobs in the future because they are boring, but robots will never get bored.

    Scientists are now trying to make robots look like people. Some robots in Japan can walk and dance. However, some scientists believe that it will be difficult to make them really think like people. For example, scientist James White thinks that robots will never be able to wake up and know where they are. But many scientists don't think so. They think that robots will even be able to talk in 25 to 50 years.

    Some scientists believe that there will be more robots in the future. These new robots will look very different. Some will look like people, and others might look like animals. In India, for example, scientists made robots that look like snakes. When buildings fall down with people inside, these snake robots can help look for people under the buildings. This was not possible 20 years ago, but computers and rockets also seemed impossible 100 years ago. We never know what will happen in the future!

    Many objects in the universe are invisible, but they send radio waves. The radio telescope* thus appeared, and it is considered one of the greatest inventions in the twentieth century. Reber built the world's first radio telescope in 1937. Ryle and Hewish developed radio telescope systems for the location of weak radio sources, and they shared the Nobel Prize for Physics in 1974.

    A radio telescope is usually made up of:

    One or more antennas to collect the radio waves. Most antennas are made in the shape of a dish to collect and reflect, the radio waves to the sub—reflector, in the same way as a curved mirror focuses visible light to one point.

    A receiver and amplifier to receive the radio waves from the sub—reflector, and make these weak radio waves strong enough to be recorded and turned into electronic signals. To make an amplifier sensitive enough, it is usually cooled to, very low temperatures (e. g. as low as —270℃）.

    A recorder to keep a record of the electronic signals. Most radio telescopes today keep the signals to the computer's memory disk for astronomers to analyze later.

    Radio wavelengths are much longer than those of visible light, and the radio waves from deep space are always weak. To catch Radio wavelengths are much longer than those of visible light, and the radio waves from deep space are always weak. To catch these waves, radio telescopes usually have huge antennas. The sizes of most antennas in use today are around 50 to 300 metres in diameter. The antenna of FAST in Guizhou, China, the latest and largest radio telescope in the world, is 500 metres in diameter, as large as the size of 30 football fields.

    To avoid interferences, and keep the telescopes sensitive, radio telescopes are built in places where there are no human radio waves or electronic signals. For example, FAST is 5 kilometres away from the closest village and 25 kilometres away from the nearest town.

    Radio telescopes create pictures of the sky, not in visible light, but in radio waves. This is extremely useful, because there are objects that can't be seen, objects that we wouldn't even know without radio telescopes.