Ultrasound. Bats Have It!
摘要
Bats, dogs, and many other animals can hear it, humans cannot: ultrasound. The science of sound started with Pythagoras in the sixth-century BCE. Lazzaro Spallanzani (1729–1799) was the first to study bats. He found out that they use sound to navigate and hunt instead of vision. Again, as in the long history of medicine, it was wartime that drove the science forward.