Why is space dark if there are billions of stars? — Part 3: Why is space dark if there are billions of stars? — Part 3: Limits, Trade-offs, and Open Questions
Section 1 of 6
What Limits Exist?
Why don't all the star lights make space bright like day? The vastness of space is one major limit. Even light, which travels incredibly fast, takes a long time to reach us from distant stars. Imagine standing in a huge field at night with just one faraway streetlamp — its light is still there, but it's not enough to light up the whole field. Additionally, cosmic dust and gas can block starlight. Another limit is the expanding universe, which means that stars are constantly moving away, causing their light to stretch and fade.
Predict: What if all the stars were much closer to us, like city lights? Would space look different? Why?