科学美国人60秒 SSS 对蚂蚁来说 天空就是它们的指南针（在线收听）

This is Scientific American's 60-second Science, I'm Christopher Intagliata.

这里是科学美国人——60秒科学系列，我是克里斯托弗·因塔格里塔。

GPS has completely transformed how we g?et around. But other animals have long had their navigation systems built right in—like ants and bees.

全球定位系统（简称GPS）改变了我们的出行方式。但其他动物早已拥有了内置的导航系统，比如蚂蚁和蜜蜂。

"We know their eyes are quite sensitive to polarized light, and the sky has a particular pattern of polarized light, relative to the position of the sun." Barbara Webb, a bioroboticist at the University of Edinburgh.

“我们知道它们的眼睛对偏振光非常敏感，而天空中有一种与太阳位置有关的特殊模式的偏振光。”爱丁堡大学的生物机器人学家芭芭拉·韦伯说到。

You can see polarized light firsthand if you take a pair of polarized sunglasses and rotate them against the sky—the light passing through the lenses changes. Webb says the insects have polarization like that built into facets of their compound eyes.

如果你拿起一副偏振光太阳镜，将其对着天空旋转，你可以亲眼看到偏振光——穿过镜片的光线会发生变化。韦伯表示，这些昆虫复眼的小平面内就有偏振现象。

"You can think of it as the equivalent of having a little polarization directional filter over them or lots of sunglasses pointed in different directions."

“你可以想象在它们眼睛上面有小型偏振方向过滤器，或有许多指向不同方向的太阳镜。”

But Webb was curious whether there's really enough information in the sky to give insects an accurate sense of direction. So her team built a sensor modeled after a desert ant eye and put it under artificial light meant to simulate the sky. They then fed that sensor input into a computational model meant to mimic the brains of desert ants, crickets and other insects with a celestial compass.

但韦伯很好奇，天空中是否真的有足够的信息，能让昆虫拥有准确的方向感。因此，她的团队制作了模仿沙漠蚂蚁眼睛的传感器，并将其置于模拟天空的人工光下。之后，他们将传感器数据输入计算机模型，该模型会模拟沙漠蚂蚁、蟋蟀和其他拥有天文罗盘的昆虫的大脑。

And they found that with the insects' innate sensing and processing equipment, they can likely sense compass direction down to just a couple degrees of error. The results are in the journal PLOS Computational Biology.

他们发现，有了这种昆虫内置的感知和处理设备，他们可能会感知到罗盘方向仅有几度的误差。研究结果发表在《公共科学图书馆·计算机生物学》期刊上。

A system based on that of insects could someday be a cheap, low-energy alternative to GPS. "Insects have very tiny brains. A brain the size of a pinhead that's using hardly any energy. And yet they're still able to navigate better than we can with GPS, which is a huge infrastructure."

基于昆虫这种原理而建立的系统，有一天可能会成为GPS廉价且低能耗的替代品。“昆虫的大脑非常小。这种针头大小的大脑几乎不消耗任何能量。然而，它们的导航能力却能优于GPS这种巨型基础设施。”

Webb is now working on building a robot that can, like the desert ant, use light to get its bearings. Although after sundown, it may have to ask for directions.

韦伯目前正致力于研制像沙漠蚂蚁那样用光来确定方位的机器人。虽然太阳下山后，它可能就要问路了。

Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.

谢谢大家收听科学美国人——60秒科学。我是克里斯托弗·因塔利亚塔。