[科学美国人60秒] SSS 2015-10-13
时间：2019-01-20 作者：英语课 分类：2015年Scientific American(十)月
If you are lost, you need a map and a compass. The map pinpoints 1 where you are and the compass orients you in the right direction. Migratory 2 birds, on the other hand, can traverse entire hemispheres and end up just a couple of miles from where they bred last year, using their senses alone. Their compass is the sun, the stars and the earth's magnetic fields, but their map is a little more mysterious. One theory goes that they use all factual cues, how a place smells. Another is that they rely on the sense of magnetism 3. Researchers in Russia investigated the map issue in a past study by capturing ? on the Boltic sea as they flew northeast towards their breeding grounds near St Petersburg. And they moved the birds six hundred miles east near Moscow, and the birds, they just reoriented themselves to the northwest, correctly determing their new position. Now the same scientists have repeated that experiment. Only this time they didn't move the birds at all. They just put them in cages that simulate the magnetic field of Moscow while still allowing the birds to experience the sun, the stars and the smell of the Boltic. Once again the birds reoriented themselves to the northwest, suggesting that the magnetic field alone, regardless of smells and other cues is enough to author the birds' mental map. The study is in the journal Current Biology. And if you are envious 4 of that sixth sense, keep in mind that since the earth's magnetic field fluctuates, the researchers say magnetic root finding is best for crude navigation, meaning for door-to-door directions, you are still better off with your GPS.
- The bombs hit the pinpoints at which they were aimed. 炸弹精确地击中了目标。
- There's really no point in arguing about pinpoints. 为芝麻绿豆般的小事争论实在毫无意义。
- Many migratory birds visit this lake annually.许多候鸟每年到这个湖上作短期逗留。
- This does not negate the idea of migratory aptitude.这并没有否定迁移能力这一概念。
- We know about magnetism by the way magnets act.我们通过磁铁的作用知道磁性是怎么一回事。
- His success showed his magnetism of courage and devotion.他的成功表现了他的胆量和热诚的魅力。