What is the Difference Between Sound Waves and Light Waves? Sound waves are generated by vibrations of bodies. They are a special case of mechanical waves , which are disturbances in the medium that propagate through space. Whereas light is a special case of electromagnetic waves.
Electromagnetic waves are emitted by rapidly moving charged particles. For example, an electron oscillating with a certain frequency emits waves with the same frequency.
Sound waves are longitudinal waves . An oscillating body, which is a source of waves, exerts pressure on the particles of the medium in which it is located. The medium is compressed and decompressed, thus a series of compressions and rarefactions propagate through it. It follows that sound waves cannot propagate in a vacuum. Since emptiness cannot be compressed and rarefied.
We perceive these environmental disturbances as sound only because we have a special instrument – the ear. It captures insignificant changes in air pressure resulting from the propagation of a longitudinal wave in it. Then it converts them into nerve impulses that the brain analyzes.
Light waves, unlike sound waves, are capable of propagating in a vacuum, since they are not only a wave, but also a particle – a photon. It is clear that a particle can move independently both in vacuum and in many media. And it is obvious that in a vacuum it will fly faster. So it is in fact. The speed of light in space is greater than in air, and even more so in water.
Thus, a charged particle does not just create an electromagnetic wave, but emits a photon. While the body that generates sound waves does not emit anything.
An electromagnetic wave is a transverse wave consisting of an electric and magnetic field. A propagating electromagnetic wave is a variable electric and magnetic fields that mutually generate each other.
The human eye is a fairly complex device that has arisen in an evolutionary way, and can perceive electromagnetic waves in a certain range of their length. Such waves are called visible light.
It should also be noted that the speed of light is much greater than the speed of sound. About 300,000 km/s (light in vacuum) versus 330 m/s (sound in air).