The speed of light in air is approximately 299,702 kilometers per second (km/s), or about 99.97% of its speed in a vacuum, which is 299,792 km/s. Although the speed of light is often quoted as being 300,000 km/s for simplicity, it’s important to note that it actually travels slightly slower in air due to the presence of air molecules.
This reduction in speed occurs because light interacts with the atoms and molecules in the air. When light passes through air, it is refracted, meaning its path is bent slightly. This bending doesn’t significantly impact the speed for most practical purposes, but in scientific calculations and precise applications, it’s a factor worth considering.
Furthermore, the speed of light can vary slightly with changes in temperature, pressure, and humidity, as they can affect the density of air. However, for everyday calculations, using the speed of light in a vacuum is typically sufficient, while for more precise scientific work, accounting for the conditions of the medium is necessary.