1 . A huge crowd has gathered to watch China’s new scientific research ship enter the water for the first time. This ship, equipped with on-board labs and the latest scientific kit, will eventually explore the world’s oceans. But it is also going to help China plunge beneath the waves: it will serve as a launch-pad for submarines that can dive to the deepest parts of the ocean. “Humans know much less about the deep oceans than we know about the surface of the Moon and Mars. That’s why I want to develop the facility for ocean scientists to reach the deep seas,” says Prof. Cui Weicheng.

He is the dean of deep sea science at Shanghai Ocean University but he has also set up a private company called Rainbow Fish, which built the new research ship and is busy developing submersibles. One of its unmanned subs reached a depth of 4,000m (13,000ft) in its most recent trial. But Rainbow Fish’s ultimate goal is manned exploration and it plans to take humans to the very bottom of the ocean the Mariana Trench, in the Pacific, at a depth of nearly 11,000m (36,000ft). He shows me around a life-size model of the submarine and explains that there is room inside for a crew of three, who will be protected by a thick metal sphere.”At the moment, we are in the design stage, so we are testing several extremely high-strength materials for it.” It will have to bear immense pressures from the crushing weight of water above. If there are any weaknesses, the submarine will implode. The deepest ocean is a place few people have ever experienced first-hand. The first dive to the Mariana Trench was carried out in 1960 by US Navy Lieutenant Don Walsh and Swiss engineer Jacques Picard. Their vessel, the Bathyscaphe Trieste, creaked and groaned as it made the descent, taking nearly five hours.

The only other manned expedition was carried out by Hollywood director James Cameron, who took a solo plunge in a bright green submarine in 2012. Rainbow Fish wants its sub to be next. The team insists its venture isn’t about politics and that it is looking to collaborate with American, Russian and European scientists. It is, though, a commercial operation. The company plans to charge people to use its research ship and submarines, and is targeting three groups, says managing director Dr. Wu Xin. “The first is definitely the scientists who are interested in studying deep-sea science and technology. The second group is offshore companies and oil companies. The last one is tourists and adventurers [who] want to go down themselves to have a look at what’s going on there,” he says. This kind of entrepreneurial approach may be a new model for science in China. Deep-sea research is a difficult, high-risk activity — and much of the ocean remains unexplored. But Cui, who hopes to be the first Chinese person to reach the Mariana Trench, believes that China could be the nation to truly open up this final frontier.

Human memory is notoriously (众所周知地) unreliable. Even people with the sharpest facial recognition skills can only remember so much.

It’s tough to quantify how good a person is     1     remembering. No one really knows how many different faces someone can recall, for example, but various estimates tend to hover in the thousands – based on the number of acquaintances a person     2     have.

Machines aren’t limited this way. Give the right computer a massive database of faces, and it can process what it sees – then recognize a face it     3     (tell) to find – with remarkable speed and precision. This skill is     4     supports the enormous promise of facial-recognition software in the 21^st century. It is also what makes contemporary surveillance (监控) systems so scary.

The thing is, machines still have limitations when it comes to facial recognition. And scientists are only just beginning to understand what those constraints are.     5     (figure) out how computers are struggling, researchers at the University of Washington created a massive database of faces – they call it MegaFace – and     6     (test) a variety of facial-recognition algorithms(算法) as they scales up in complexity. The idea was to test the machines on a database that included up to 1 million different images of nearly 7,000 different people – and not just a large database     7     (feature) a relatively small number of different faces, more consistent with what’s been used in other research.

As the databases grew, machine accuracy dipped across the board. Algorithms     8     were right 95% of the time when they were dealing with a 13,000-image database, for example, were accurate about 70% of the time when     9     (face) with 1 million images. That’s still pretty good, says one of the researchers, Ira Kemelmacher-Shlizerman. “Much better than we expected,” she said,

Machines also had difficulty adjusting for people who look a lot alike –either doppelgangers (长相极相似的人), whom the machine would have trouble       10     (identify) as two separate people, or the same person who appeared in different photos at different ages or in different lighting, whom the machine would incorrectly view as separate people.

4 . Neuro-technology has long been a favourite of science-fiction writers. In “Neuromancer”, a wildly inventive book by William Gibson written in 1984, people can use neural(神经的) implants to get into the sensory experiences of others. Iain M. Banks came up with the idea of a neural lace, a mesh (网格) that grows into the brain, in his “Culture” series of novels. “The Terminal Man” by Michael Crichton, published in 1972, imagines the effects of a brain implant on someone who is convinced that machines are taking over from humans.

Where the sci-fi led, philosophers are now starting to follow. In Howard Chizeck’s lab at the University of Washington, researchers are working on an implanted device to administer deep-brain stimulation (DBS) in order to treat a common movement disorder called essential tremor. Traditionally, DBS stimulation is always on, wasting energy and robbing the patient of a sense of control. The lab’s ethicist (伦理学家), Tim Brown, a doctoral student of philosophy, says that some DBS patients suffer a sense of isolation and complain of feeling like a robot.

To change that, the team at the University of Washington is using neuronal activity associated with intentional movements to turn the device on. But the researchers also want to enable patients to use a conscious thought process to override these settings. That is more useful than it might sound: stimulation currents for essential tremor can cause side-effects like distorted (失真的) speech, so someone about to give a presentation, say, might wish to shake rather than make his words unclear. Giving humans more options of this sort will be essential if some of the more advanced visions for brain-computer interfaces are to be realized. Hannah Maslen from the University of Oxford is another ethicist who works on a BCI project. One of her jobs is to think through the distinctions between inner speech and public speech: people need a dependable mechanism for separating what they want to say from what they think.

That is only one of many ethical questions that the sci-fi versions of brain-computer interfaces bring up. What protection will BCIs offer against neural hacking? Who owns neural data, including information that is gathered for research purposes now but may be understandable in detail at some point in the future? Where does accountability lie if a user does something wrong? And if brain implants are performed not for treatment but to improve people’s abilities, will that make the world an even more unequal place?