题型:阅读理解 题类:常考题 难易度:普通
安徽省黄山市2019-2020学年高一下学期英语期末考试试卷
If an emperor penguin wants to survive in the worst of an Antarctic winter, there is no such thing as personal space. The large birds are known to stay very close to each other, feather to feather, in groups of thousands to keep out the cold.
For the first time, German researchers show that these gatherings are carefully organized structures, in which single penguins can cause mass movements within the group that is similar to the movements of cars in a traffic jam.
"If one penguin starts a wave, perhaps walking too close to its neighbor, it travels like a Mexican wave in a football stadium," said physicist Daniel Zitterbart. The Mexican wave happens when all the people watching a sport stand up, move their arms up and down, and sit down again one after the other in a continuous movement looking like a wave on the sea.
Emperor penguins gather in formation when the temperatures drop below -18℃, using each other's bodies to keep warm. They arrived at an arrangement that physicists recognize as a "triangular lattice structure", with a penguin at each point of the triangle. "They gather just by their natural ability," said Zitterbart who filmed and then analyzed the movements of the penguins.
The researchers explain that the movements of a single bird within the huddle (挤作一团的动物) can set off a chain reaction that travels through the rest of the group.
That movement is similar to what happens when a single car in a traffic jam moves forward, setting off a chain reaction of tiny movements by all of the cars behind it. But there's a difference: only the first car in the jam can start off the group movement. On the ice, any penguin among the crowd can cause a wave of small movements.
"This is one case where a traffic jam is very useful," said Zitterbart.
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