The index of refraction, often represented by the symbol \( n \), is a measure of how much light slows down as it passes through a medium compared to its speed in a vacuum. This is a crucial concept when studying how light behaves in various substances like glass, water, or air.
Key features of the index of refraction include:
- A higher index indicates that light travels slower in the medium than in a vacuum.
- The index of refraction is calculated using the formula \( n = \frac{c}{v} \), where \( c \) is the speed of light in a vacuum, and \( v \) is the speed of light in the medium.
- Common examples include the index of refraction for air, which is approximately 1, and glass, which is typically around 1.5.
By understanding the index of refraction, you can predict how light will change direction, a phenomenon known as refraction, and also calculate the wavelength of light as it travels through different materials.