A machine can now not only beat you at chess, it can also outperform you in debate. Last week, in a public debate in San Francisco, a software program called Project Debater beat its human opponents, including Noa Ovadia, Israel's former national debating champion.

Brilliant though it is, Project Debater has some weaknesses. It takes sentences from its library of documents and prebuilt arguments and strings them together. This can lead to the kinds of errors no human would make. Such wrinkles will no doubt be ironed out, yet they also point to a fundamental problem. As Kristian Hammond, professor of electrical engineering and computer science at Northwestern University, put it: "There's never a stage at which the system knows what it's talking about."

What Hammond is referring to is the question of meaning, and meaning is central to what distinguishes the least intelligent of humans from the most intelligent of machines. A computer works with symbols. Its program specifies a set of rules to transform one string of symbols into another. But it does not specify what those symbols mean. Indeed, to a computer, meaning is irrelevant. Humans, in thinking, talking, reading and writing, also work with symbols. But for humans, meaning is everything. When we communicate, we communicate meaning. What matters is not just the outside of a string of symbols, but the inside too, not just how they are arranged but what they mean.

Meaning emerges through a process of social interaction, not of computation, interaction that shapes the content of the symbols in our heads. The rules that assign meaning lie not just inside our heads, but also outside, in society, in social memory, social conventions and social relations. It is this that distinguishes humans from machines. And that's why, however astonishing Project Debater may seem, the tradition that began with Socrates and Confucius will not end with artificial intelligence.

    When "Rise of the Planet of the Apes" was first shown to the public last month, a group of excited animal activists gathered on Hollywood Boulevard. But they weren't there to throw red paint on fur-coat-wearing film stars. Instead, one activist, dressed in a full-body monkey suit, had arrived with a sign praising the filmmakers: "Thanks for not using real apes (猿)!"

    The creative team behind "Apes" used motion-capture (动作捕捉) technology to create digitalized animals, spending tens of millions of dollars on technology that I records an actor's performance and later processes it with computer graphics to create a final image (图像). In this case, one of a realistic-looking ape.

    Yet "Apes" is more exception than the rule. In fact, Hollywood has been hot on live animals lately. One nonprofit organization, which monitors the treatment or animals in filmed entertainment, is keeping tabs on more than 2,000 productions this year. Already, a number of films, including "Water for Elephants," "The Hangover Part Ⅱ" and "Zookeeper," have drawn the anger of activists who say the creatures acting in them haven't been treated properly.

    In some cases, it's not so much the treatment of the animals on set in the studio that has activists worried; it's the off-set training and living conditions that are raising concerns. And there are questions about the films made outside the States, which sometimes are not monitored as closely as productions filmed in the Sates.

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    Terrafugia Inc .said Monday that its new flying car has completed its first flight,bringing the company closer to its goal of selling the flying car within the next year.The vehicle-named the Transition – has two seats，four wheels and wings that fold up so it can be driven like a car.The Transition,which flew at 1,400 feet for eight minutes last month, can reach around 70 miles per hour on the road and 115 in the flies using a 23-gallon tank of gas and burns 5 gallons per hour in the air. On the ground, it gets 35 miles per gallon.

    Around 100 people have already put down a $10,000 deposit to get a Transition when they go on sale, and those numbers will likely rise after Terrafugia introduces the Transition to the public later this week at the New York Auto Show. But don't  expect it to show up in too many driveways. It's expected to cost $279,000.And it won't  help if you're stuck in traffic. The car needs a runway.

    Inventors have been trying to make flying cars since the 1930s, according to Robert Mann, an airline industry expert. But Mann thinks Terrafugia has come closer than anyone to making the flying car a reality. The govemment has already permitted the company to use special materials to make it easier for the vehicle to fly. The Transition  is now going through crash tests to make sure it meets federal safety standards.

    Mann said Terrafugia was helped by the Federal Aviation Administration's decision five years ago to create a separate set of standards for light sport aircraft, which are lower than those for pilots of larger planes. Terrafugia says an owner would need to pass a test and complete 20 hours of flying time to be able to fly the Transition,a requirement pilots would find relatively easy to meet.