Light and sound are both forms of energy that propagate as waves, but they travel at vastly different speeds. The speed of light in a vacuum is approximately 299,792 kilometers per second (km/s), while the speed of sound in air is about 343 meters per second (m/s) at room temperature.
The primary reason for this stark difference in speed is that light and sound waves travel through different mediums. Light can travel through vacuum, such as space, where there is no matter or air. On the other hand, sound waves require a medium, such as air, water, or solids, to propagate. The particles in the medium vibrate and transfer energy, causing the sound waves to propagate.
Additionally, the speeds of light and sound are determined by the physical properties of their respective mediums. Light waves are electromagnetic in nature and are composed of photons. They interact with electric and magnetic fields, which propagate in a vacuum at a constant speed determined by the fundamental properties of space and time.
Sound waves, on the other hand, propagate through the compression and rarefaction of particles in a medium. The speed of sound depends on the density, compressibility, and temperature of the medium. In general, sound travels faster through denser materials, such as solids, and slower through less dense materials, such as gases like air.
Therefore, light and sound waves differ in terms of their medium of propagation and the physical properties of those mediums, resulting in the significant speed disparity between them.