1 . When it came to imaging the future, Arthur C. Clarke stubbornly refused to take credit for any predictions. The Internet, 3-D printers, email: he may have described them all long before they existed. As a science fiction writer, he came up with the idea of a “personal transceiver” that is small enough to be carried about, able to contact with anyone in the world and perform global positioning, making getting lost a thing of the past. Elsewhere, he predicted everything from online banking to reusable spacecraft. His best remembered fictional work of all is 2001: A Space Odyssey. It also happened to forecast the iPad, computer software that is able to read lips, and space stations.

Interestingly, his vision of the future has barely aged. For example, life in Sri Lanka inspired his 1979 novel, featuring a “space elevator”, a planet-to-space transportation system that would do away with the need for rocket travel. Those human settlements on Mars or Venus are decidedly behind schedule(we humans were expected to have set foot on both by 1980), and we’re still looking for the key that should have fully unlocked the languages of whales and dolphins by 1970.

It’s a way of thinking that was likely fuelled by his inability to be anything other than utterly absorbed in all that interested him. At the very start of his career, he shared a flat on London’s Gray’s Inn Road with fellow science fiction writers who nicknamed him “Ego” because of his talent for turning out (关掉) distraction. Once he’d become a big enough name to be interviewed, he’d send journalists home loaded with research papers.

He once said, “Trying to predict the future is a discouraging and risky occupation.” If a prediction sounds at all reasonable, technological progress is sure to leave it seeming “ridiculously conservative”. But if, by a miracle, a person were to be able to describe the future exactly as it will unfold, “His predictions will sound so absurd and far-fetched that everybody would laugh him to scorn (轻蔑).”

2 . Who has no regrets about things done in the past? Wouldn’t it be nice if, somehow, we could go back to change a couple of bad decisions? This sounds like science fiction.

The laws of physics prohibit traveling back in time for many reasons. If we did travel back in time and changed the course of events, we would be altering the course of history. An example often cited is the grandfather’s paradox (悖论): If your grandfather died when he was still a high school student, he wouldn’t have met your grandmother and your father and you wouldn’t exist.

Putting humans or consciousness traveling back in time aside for the moment, is there anything in science even similar? Surprisingly, yes. At the level of quantum particles (量子粒子), there is something called Wheeler’s delayed-choice experiments that show that actions in the present can influence the past. The experiments use something called the wave-particle duality (波粒二象性) of light and of matter. The fact that the physical nature of quantum objects is undetermined until it is measured. In other words, this means that a particle of light or of matter can behave either as a wave (spreading out in space) or as a particle (staying together) depending on the measuring devices. Long and ongoing discussions about the nature of quantum physics are still trying to work out what this actually means. Do our minds determine the nature of physical reality?

Should we offer food for thought for the future or the past? Unfortunately, these experiments say very little about how we could interfere with the past in events relevant to the human scale. Better to think carefully about decisions than to try to fix them backwards.

5 . “May 17, 2157

Dear diary,

Today, Tommy found a real book!...”

“What’s it about?” Margie asked.

“School.” replied Tommy, turning the yellow pages.

“Why would anyone write about school? I hope they can take my geography teacher away.”

“It’s not our school. This is the old sort that they had centuries ago.”

“Anyway, they had a teacher.” Margie said, reading the book over his shoulder.

“Sure, they had a teacher, but it wasn’t a regular teacher. It was a man.”

“A man? How could a man be a teacher?”

“Well, he just told the boys and girls things and gave them assignments and asked them questions.”

“A man isn’t smart enough.”

“Sure, he is. My father knows as much as my teacher.”

Margie wasn’t prepared to argue about that. She said, “I wouldn’t want a strange man in my house to teach me.”

Tommy laughed. “The teachers didn’t live in the house. They had a special building and all the kids went there.”

“And all the kids learned the same thing?”

“Sure, if they were the same age.”

“But my mother says a teacher has to be adjusted to fit the mind of each boy and girl it teaches and that each kid has to be taught differently.”

“If you don’t like it, you don’t have to read the book.”

“I didn’t say I didn’t like it,” Margie said quickly.

They weren’t even half-finished when Margie’s mother called, “Margie! School!”

“Not yet, Mamma.”

“Now!” said Mrs. Jones.

Margie said to Tommy, “Can I read the book some more with you after school?”

“Maybe,” Tommy said.

Margie went into the schoolroom, right next to her bedroom, and the mechanical teacher was on waiting for her.

The screen was lit up, and it said, “Please insert yesterday’s assignments in the proper slot.”

Margie was still thinking about the old schools they had when her grandfather’s grandfather was a little boy. All the kids from the whole neighborhood came, laughing and shouting in the schoolyard, sitting together in the schoolroom, going home together at the end of the day. They learned the same things, so they could help one another on the assignments and discussed them.

And the teachers were people…

7 . When people talk about the future, we like to think that we will be able to drive out of our garages and take to the ________ in our own personal flying car. The advantages are obvious. Some people ________ this technology will allow complete three-dimensional freedom of movement. We could fly at 489 kilometres per hour, ________ traffic lights, busy roads and speeding tickets. However, some people point to the disadvantages of flying cars. They claim that there are certain to be problems with traffic ________. Another big problem is mechanical ________. What will happen if they break down? ________, if they become popular, there is likely to be another big problem: air traffic congestion. So it looks like flying cars face more than a few problems if they are to get off the ground!

Most of us have printed out an electronic document on paper, but think about the ________ of printing out a three-dimensional object in plastic. 3D printers build an object using layers line-by-line like a(n) ________ printer until the object is complete. Vehicle companies like BMW and Volkswagen already use 3D printers to make life-size models of car parts. At the moment the process is slow and quality is ________, but before long it might be possible to see a product on a website and then ________ it to your printer at home. In the future we could make our own furniture, jewellery, cups, plates, shoes and toys from designs on our computers, and reduce the amount of ________ we have to do.

Imagine having your own Ironman suit. There are several companies trying to build a practical robot ‘exoskeleton’. This is a suit of robot arms and legs which follows your ________. It will allow the wearer to lift heavy objects, walk long distances and even punch through walls! There are ________ military advantages for this technology and might help people to walk again after disease or injury. However, besides cost and battery life, another problem is that a badly ________ robot suit could injure the wearer because you wouldn’t want your robot leg or arm bending the ________ way.