The medium of a wave is any substance that carries the wave, or through which the wave travels. Ocean waves are carried by water, sound waves are carried by air, and the seismic waves of an earthquake are carried by rock and soil.
A wave is a disturbance travelling through matter or space, transferring energy from one place to another. Mechanical waves, such a sound waves and water waves, carry energy through a medium, but the molecules of medium itself are generally not permanently displaced. Electromagnetic radiation, which includes light and radio waves, sometimes behaves as waves and sometimes as particles called photons. Electromagnetic waves can travel without a medium.Learn More
Spherical aberration in mirrors is usually corrected by using a mirror which is not a sphere. A parabolic mirror is often used instead of a spherical mirror. In lenses, the simplest method for minimizing spherical aberration is to use an aperture in front of the lens. Symmetric doublets, such as the orthoscopic doublet, are also efficient in greatly reducing the spherical aberration in lenses.Full Answer >
An echo can be heard in a cave when a sound reflects off surrounding walls and then is heard again. It is also possible to hear an echo in an empty room, in a mountain valley, under a bridge or by calling down into a well.Full Answer >
An audio oscillator works by altering resistance over an electric circuit and turning electricity into a pure sound, explains a resource on the Ohio University website. William Hewlett patented and designed a better audio oscillator when he was a graduate student at Stanford University in 1938. The model 200A oscillator was Hewlett Packard's first product sold to businesses and consumers.Full Answer >
The Rayleigh criterion defines the minimum resolvable detail in an imaging process. Two images are resolvable when one’s diffraction center pattern is directly over the other image’s first diffraction pattern.Full Answer >