1. Speed Change: Light travels at its fastest speed in a vacuum. When it enters a gas, it slows down. The denser the gas, the more the light slows down. This change in speed is crucial for refraction.
2. Change in Direction: Because of the speed change, light bends at the boundary between the vacuum and the gas. The amount of bending depends on the angle at which the light hits the boundary and the difference in speed between the two mediums. This bending is called refraction.
3. Different Gases, Different Refraction: Different gases have different densities, meaning they have varying numbers of molecules per unit volume. This difference in density leads to varying refractive indices. The refractive index is a measure of how much light bends when passing from one medium to another.
4. Light Interacting with Molecules: As light moves through the gas, it interacts with the gas molecules. This interaction involves the absorption and re-emission of photons (light particles). The process of absorption and re-emission causes a slight delay in the light's travel, contributing to its slower speed within the gas.
In summary: Light waves move from empty space into different gases by slowing down and bending due to the difference in speed between the two mediums. This bending, or refraction, is influenced by the density and refractive index of the gas, which are ultimately determined by the properties of the gas molecules.
