Why Does Light From Distant Stars Show Us the Past?

💡 The Answer

• Light travels at a finite speed of about 300,000 kilometers per second, so the light from a star takes time to reach us.
• For example, the light from the Sun takes about 8 minutes to travel to Earth, meaning we see the Sun as it was 8 minutes ago.
• When observing a galaxy 10 billion light-years away, we see it as it was 10 billion years ago, shortly after the Big Bang.
• This cosmic time machine allows astronomers to study the history and evolution of the universe by looking at light from distant objects.