Light & Sound FAQ's! What is sound? Simple, it’s the vibrating of any surface. When can we hear sound? We can hear it when it has frequencies of between 15,000 and 20,000 herts. What is a sound wave? A sound wave is the vibration of sound moving through the air. Can a substance not have sound traveleing through it? Sound travels through all substances, even solid substances. What's a phonograph and what does it have to do with sound? It's a very early recorder of sound and of course it has to do with sound if it records it. Can bats hear? Yes, they can very well but they can’t see very well. The way they hear is by sending off high-pitched sounds called ultrasounds. Do all musical instruments vibrate the air out of them? Yes, they all do, no matter what kind they are. What uses sunlight as its source of energy? Photosynthesis How does light behave? It can behave like a wave sometimes and then like a particle at other times. How is light emitted? It is emitted by electrons circling around the nucleus of an atom. Are atoms unique? Yes. Each has a different level of energy. What color light do our eyes respond best to? They respond best to light that is green.