Sound—it’s almost impossible to imagine a world without it. It’s probably the first thing you experience when you wake up in the morning—when you hear birds chirping or your alarm clock bleeping away. Sound fills our days with excitement and meaning, when people talk to us, when we listen to music, or when we hear interesting programs on the radio and TV. Sound may be the last thing you hear at night as well when you listen to your heartbeat and drift gradually into the soundless world of sleep. Sound is fascinating—let’s take a closer look at how it works!
Butterflies possess some of the most striking color displays found in nature. As they fly from flower to flower gathering nectar, their brightly colored wings seem to shimmer and change colors before your eyes. A butterfly’s rich color can act as camouflage, mate attraction, and warning signal. But what is it that makes the bright colors of butterfly wings appear to dance? How can they possess such intense colors?
It’s often said that no two human fingerprints are exactly alike. For that reason, police often use them as evidence to link suspects to crime scenes.
The same goes for silicon chips: Manufacturing processes cause microscopic variations in chips that are unpredictable, permanent, and effectively impossible to clone.