Waves in air, such as sound waves, do not have infinite speed. In fact, sound waves travel at a finite speed through air and other materials. The speed of sound in air is approximately 343 meters per second (at room temperature).
On the other hand, beams of light, which are electromagnetic waves, also have a finite speed. The speed of light in a vacuum is approximately 299,792,458 meters per second. In other transparent materials, such as air, water, or glass, light travels at slightly slower speeds due to interactions with atoms and molecules in those materials.
The reason light and sound waves have different speeds is related to the nature of the medium through which they propagate. Sound waves travel through a medium, such as air or water, by causing particles in the medium to vibrate and transmit the energy from one particle to the next. The speed of sound depends on the properties of the medium, such as its density and elasticity.
On the other hand, light waves are not vibrations of particles but rather fluctuations in electric and magnetic fields. They can travel through a vacuum, which is empty space devoid of any particles. The speed of light in a vacuum is determined by fundamental properties of the vacuum, specifically the electric permittivity and magnetic permeability of free space.
In summary, both sound waves and light waves have finite speeds, but their speeds depend on the properties of the medium through which they propagate. Sound waves require a material medium to travel, while light waves can travel through a vacuum. The speed of light in a vacuum is faster than the speed of sound in air, which is why we often perceive light as nearly instantaneous compared to sound.