The speed of light is so fast (about 300,000 kilometers per second or 186,000 miles per second) that over short distances, like on the Earth, we can essentially perceive light as instantaneous. However, as we observe objects that are extremely far away, like stars and galaxies, the time it takes for the light to travel from the object to us can become significant.
Sun is approximately 150 million kilometers (93 million miles) away from the Earth. This means that when you look up at the sun in the sky, you are seeing the sunlight that left the sun's surface about 8 minutes and 20 seconds ago.
Therefore, in a literal sense, you are seeing the sun in the past when you look up at the sky. This delay in the arrival of light is a reminder of the vast distances in space and the finite speed at which light travels.
