How does the light that astronomers see from distant stars and galaxies tell htem that the same atoms with the same properties exist throughout the universe?

Answer 1

We determine the types of elements contained in the star or within the corona by analyzing the spectrum of the light we receive. Each element will radiate at a set of specific discreet frequencies, and the frequencies they radiate tell us what the element is, and how deeply ionized it is. The spectral analysis is exact; we can even determine the proportions of the elements that we see by the relative brilliance of their light.

But there IS one thing that the spectrum cannot tell us; is this a normal matter star, or an anti-matter star?

Answer 2

Astronomers study the spectrum of light from distant stars and galaxies, which shows specific patterns of absorption and emission lines unique to different elements. By identifying these signatures, astronomers can determine the composition of celestial objects and confirm that the same atoms with the same properties exist throughout the universe. This consistency in the chemical makeup of celestial objects supports the idea that the fundamental properties of atoms are universal.