Summary
The Sun you see is about 8 minutes old. If the Sun vanished instantly, Earth would not notice for about 8 minutes.
Looking at the sky can feel like a kind of time travel. Light is fast, but astronomical distances make delay unavoidable.
The average distance between the Sun and Earth is one astronomical unit. Light needs time to cross it, which comes out to about 8 minutes.
The idea becomes even stronger with stars: some are seen years in the past, and distant galaxies can be seen millions of years earlier. The universe is also an archive.
This delay does not change daily life, but it changes perspective. The sky quietly reminds us that even what we call now may be the past.