Science briefs: Robots teach robots to learn

Robots teach Robots to learn

Computer scientists at Washington State University have created robots that can teach other robots — in this case, to play the 1980s video-game sensation Pac-Man — and ultimately to outperform their teachers.

The teacher robots advise the student robots on what moves to make, and the students must accept the advice. Soon, the students surpass their teacher, racking up points faster.

Matthew E. Taylor, who along with colleagues described the work in the journal Connection Science, said, "Even a mediocre teacher can increase the speed at which the student learns."

Advice helps the student robots learn faster, but the teacher needs to know when to stop. "If it gives too little advice, the student doesn't learn," Taylor said. "If it gives too much advice, the student can't try new things and improve on its own."

The model has many applications, he said. One day, a housecleaning robot could train its replacement. He and his team are also working on a similar model for robots to train humans, and humans to train robots.

Before Silk Road, the Grain Road

Nomadic shepherds in the high plains of Central Asia used grain imported from China and southwestern Asia more than 5,000 years ago, perhaps to sprinkle over bodies in funeral rituals, a new study said. The discovery came from an investigation of burial sites in Kazakhstan. The scientists, led by Michael Frachetti, an archaeologist at Washington University in St. Louis, included a botanist and local archaeologists.

Because what is now Kazakhstan was at a crossroads in the nomads' path, the findings, published in Proceedings of the Royal Society B, provide clues about the later emergence of the trade route known as the Silk Road. Early on, the nomads moved only by foot, spending winters in warmer valleys and summers in the mountains. Their seasonal moves broadened their interactions and helped disperse the grains, Frachetti said. "These folks were not traveling extremely long distances, but it spread fairly rapidly," he said.

They found evidence that by about 1500 B.C., the nomads were cultivating their own barley, wheat, millet and peas. "We see the evolution," he said, "from the introduction of seeds used for ritual purposes to something that has impact on the local economy."

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