ब्रह्माण्डविद्या

thumb|upright=1.35| Except for the few stars in the foreground (which are bright and easily recognizable because only they have diffraction spikes), every speck of light in the composite photo is an individual [[galaxy, some of them as old as 13.2 billion years; the observable universe is estimated to contain more than 2 trillion galaxies. From the Hubble eXtreme Deep Field.]]

AI overview

Cosmology is the study of the universe's structure and history, including the billions of galaxies it contains and their ages stretching back billions of years. It matters because understanding the universe's scale, composition, and origins helps us comprehend our place in the cosmos and the fundamental nature of reality itself.

AI-generated from the Wikipedia summary — may contain errors.