Sun rays, or sunlight, travel at the speed of light. In a vacuum, such as outer space, light travels at approximately 299,792 kilometers per second (or about 186,282 miles per second). This speed is often rounded to 300,000 kilometers per second for simplicity in calculations.
When sunlight passes through a medium like Earth's atmosphere, its speed is slightly slower due to interactions with particles in the air. The exact speed of light in the atmosphere depends on factors like air density and composition. On average, light travels through Earth's atmosphere at around 299,702 kilometers per second (or about 186,227 miles per second).
It's important to note that sunlight is a combination of different wavelengths, which make up the electromagnetic spectrum. The visible spectrum, which includes the colors we see, is just a small portion of this spectrum. The speed of light is constant for all wavelengths, including those within the visible spectrum.