Rarefactie

Rarefaction refers to a decrease in density of a medium, such as air or water, relative to its normal state. This phenomenon is most commonly associated with sound waves. When a sound wave travels through a medium, it causes compressions, where particles are pushed closer together, and rarefactions, where particles are spread farther apart. These alternating regions of high and low density propagate through the medium, carrying the sound energy.

In simpler terms, a rarefaction is a space where the pressure and density are lower than the surrounding environment. Imagine a Slinky being stretched and compressed. The stretched-out parts represent rarefactions, while the bunched-up parts represent compressions. In the context of air, rarefactions occur when air molecules move away from a particular point, creating a region of lower pressure.

Rarefaction is a fundamental concept in acoustics and wave physics. The distance between successive rarefactions (or compressions) is known as the wavelength of the wave. The frequency of a sound wave, which determines its pitch, is related to how quickly these compressions and rarefactions occur. Understanding rarefaction is crucial for comprehending how sound travels and for various applications in fields like audio engineering and medical ultrasound.