Do all colors of light travel at the same speed in a vacuum?

All colors of light, including red, blue, green, and any other colors in the visible spectrum, travel at the same speed in a vacuum. This speed is known as the speed of light, which is approximately 299,792 kilometers per second (or about 186,282 miles per second).

The key principle here is that in a vacuum, there are no particles or medium to hinder the travel of light waves, allowing all wavelengths to propagate at this constant speed. While different colors of light can have different wavelengths and frequencies, those variations do not affect their speed when in a vacuum.

In contrast, if light travels through mediums like air, water, or glass, the speed can change, resulting in refraction and other optical phenomena, but in a vacuum, the speed remains consistent across all colors. This fundamental aspect of light is crucial for understanding many concepts in physics and chemistry, including the behavior of light in various environments and applications in technologies such as fiber optics and lasers.