Time Line for Evolution of the Universe

The Universe

Cosmology – study of the universe, including its properties, structure, and evolution  
Universe thought to be Earth-centered for most of human history
Immanuel Kant proposed fuzzy patches in the sky were distant galaxies in 1700s  

Edwin Hubble, 1919 – set out with telescope to solve mystery of Kant’s fuzzy patches
Studied Cepheid variables – pulsating variably bright stars
Absolute magnitude – true brightness
Can only be known by knowing rate at which these stars pulsate

Large telescopes can look back in time
Big Bang theory – model that most accurately describes birth and current state of the universe.  
Cataclysmic explosion 13.7 billion years ago