Here's the explanation:
* Light travels at a finite speed: Light travels incredibly fast (approximately 299,792 kilometers per second), but it's not instantaneous.
* Distance matters: Stars are extremely far away. Even the closest star, Proxima Centauri, is 4.24 light-years away. This means the light we see from it today left the star 4.24 years ago.
* The time it takes for light to reach us: If a star were to suddenly stop shining, we wouldn't know it for many years, depending on its distance. The light that was already emitted would continue traveling towards us, and we would see it for as long as it takes for the last of that light to reach us.
Think of it like this: Imagine you're watching a movie of a distant event. Even if the event stopped happening, you'd still see it unfold on the screen for as long as the film continues to play. The light from stars works the same way.
Therefore, we can still see the light from a star that no longer shines because the light that left the star before it died continues to travel across space towards us.
