人教版（2019）选择性必修四高中英语 Unit 1 Science Fiction Section I

A team of engineers at Harvard University created the first robotic fly. 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.

"The added difficulty with a project like this is that actually none of its components is off the shelf and so we have to develop them all on our own," said Robert Wood, a Harvard engineering professor.

They engineered a series of systems to start and drive the robotic fly. "The seemingly simple system which just moves the wings has lots of interdependence(互相依赖) of 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.

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."

An online supermarket company—Ocado in the UK, has recently displayed a robotic hand that can pick fruits and vegetables!

When an embryo is in the womb(子宫), the very first sense it develops is touch. The sense of touch is also the one that lasts the longest—as we get older and our vision and hearing begin to weaken, touch still remains. Humans use their touch to protect themselves, to create emotional relationships with other people and to experience pleasure. Can you imagine life without it?

The sense of touch comes from a network of nerve endings(神经末梢) and special touch receptors on the surface of the skin. While there are different kinds of touch receptors, they help us judge pressure, texture and vibrations. They are located in our fingertips, palms, soles of our feet, face, lips and tongue.

When we touch something, the mechanoreceptors feel the touch and through a network of nerves send signals to the brain. This informs the brain about the location of the touch, the amount of force used, and the speed at which it was used.

Several different techniques have been tried in the past few years to create such a robotic hand—using three fingers. But this latest design by SoMa copies the human hand. It is made up of flexible materials which grasp the thing based on its size and shape. Then air pressure is used to control the movement of the robotic fingers to pick objects safely and without causing damage.

The next step would be for the robot to judge how ripe the fruits and vegetables are, and apply pressure accordingly. Members of the research team are currently working on adding computerised vision to the robots, so that they can see what they are grasping.

Does all this mean robots can replace people? According to Ocado, they help improve productivity by removing some of the repetitive tasks done by humans.

In the story of The Crow and the Pitcher from Aesops Fables, a thirsty crow(乌鸦) drops stones into a narrow jar to raise the low level of water inside so he can take a drink.

Now scientists have evidence to back up that story. Crows actually do understand how to make water displacement(移位) work to their advantage, experiments show. The results suggest that the birds are, at least in some aspects, as smart as first-graders.

Researchers, led by Sarah Jelbert at the University of Auckland in New Zealand, presented six crows with tubes filled with water. Inside the tubes, a worm or piece of meat on a piece of wood was floating, just out of reach of the crows. In front of the tubes, the researchers arranged several rubber erasers that would sink, and some plastic objects that would float. The crows found out that they could drop the erasers into the tubes in order to raise the water level and get their snack.

However, the birds handled awkwardly in experiments in which they could choose to drop objects in either a wide tube or a narrow one to get a snack, the researchers said. Dropping objects into the narrow tube would lift the water level by a greater amount and put the treat within reach after just two drops; while it took around seven drops to raise the snack to the same level in the wide tube. The crows obviously didn't realise this, and most of them went for the wide tube first.

Previous studies showed that chimps and human children can solve similar tasks. In a 2011 study, chimps and kids found out that they could put water into a tube to reach a peanut that was floating in a small amount of water at the bottom.