1 . Future means a time that is not yet here. It can be a short time from now or a long time from now. Scientists think that many wonderful things may come true in our future life.     1    

Are you wondering whether there’ll be televisions in the future?     2     Television screens (屏幕) probably will be large and flat, hanging on the wall or going across the four walls of a room. People on the screen will look as real as if they were right in the room with you.

    3     What people may eat in the future will be man-made in factories from such surprising things as coal, limestone, air, and water. Worry about the taste? You may be wrong. The man-made food will be delicious and healthy because all the things that you need to live a long and healthy life will be put into it.

What about driving cars in the future? Well, a very small child probably will be able to drive a car. Computer systems will hold each car on the right road to get wherever the “driver” wants to go.     4     Computer controls will make all speeding cars miss each other or stop in time. Driving cars will be as safe as being at home.

    5     Cities may have large domes (穹顶) over them to keep out snow, rain, or storms. When you plan a picnic in a park, you won’t have to worry about the weather. It will rain only when the “weather man” thinks it is necessary. In all other days you will be able to enjoy pleasant weather.The future should be a wonderful time to live. But the time you are living in now is also “a wonderful future” to the people who lived 100 years ago.

2 . What if we had the power to control time, instead of moving from the past to the present to the future? What if we could jump and travel through time in a machine? What if we could go wherever and whenever we pleased?

This ability would allow us to witness historic wonders, change decisions and see people from the past. We could right wrongs and stop wars from starting.

The mysterious puzzle of time has kept people debating its nature for hundreds of years. Science fiction writers have turned it into imaginative stories. Some scientists have even attempted to explain it using math. This math tries to make the dream of time travel come true.

The scientist Albert Einstein said that time and space are one thing. He called it “spacetime”. Einstein said that there are three dimensions (维度) in space: height, width and depth. A scientist named Hermann Minkowski added time as a fourth dimension.

Einstein introduced two ideas that have led to theories about the possibility of time travel. The first is relativity (相对论). The idea of relativity is that the force of gravity causes space to bend, which causes time to twist. The second idea focuses on special relativity. The idea is that a traveler moving super-fast through flat spacetime will enter the future. Einstein considered time “relative” because it is measured based on where we are on Earth or in space.

Stephen Hawking is a famous scientist. He believes that a time machine will never be built. If it were possible, he thinks we would already know. If a time machine could be built, how come no one from the future has invaded us?

The first science fiction story with this theme is The Clock That Went Backward by Edward P. Mitchell, which was published in 1881. Since then, thousands of books, films and television shows have explored the idea of time travel, in which some tools such as phones, watches, photographs and old books take travelers backward and forward.

Will time travel ever happen? Who knows? Most important is to keep our eyes open and have a sense of wonder.