eli5: How are we accurately able to study far off cosmic objects if our primary source of information is from light (that sometimes has traveled to us for 1000’s of years). Am I missing something?

Question

eli5: How are we accurately able to study far off cosmic objects if our primary source of information is from light (that sometimes has traveled to us for 1000’s of years). Am I missing something?

In: 8

Answer 1

Here’s a good video that explains it: https://youtu.be/pqoN9Z36PrI

The short version is that there are several different ways we can measure interstellar distances, each with different ranges of effectiveness. That’s the idea of the [cosmic distance ladder](https://en.wikipedia.org/wiki/Cosmic_distance_ladder).