THE COSMIC SCALE
�x �SUBATOMIC~10⁻¹⁵ m � Quarks, protons, neutrons
�a:ATOMIC~10⁻¹⁰ m � Atoms, molecules
�x��BIOLOGICAL~10⁻⁶ m � Cells, organisms
�xR�PLANETARY~10⁷ m � Moons, planets, dwarf planets
�ܬSTELLAR~10⁹ m � Stars, star systems, nebulae
�xRRGALACTIC~10²⁰ m � Galaxies (Milky Way: 10²¹ m)
�x"�SUPERCLUSTER~10²³ m � Laniakea: 520M light-years
��~OBSERVABLE UNIVERSE~8.8�10²⁶ m � 93 billion light-years
UNIVERSE HISTORY
t = 0Big Bang � all energy in a single point
10⁻³⁵ sCosmic Inflation � universe expands faster than light
3 minBig Bang Nucleosynthesis � H, He, Li nuclei form
380,000 yrRecombination � CMB released; universe becomes transparent
200M yrFirst Stars (Population III) ignite � end of the Cosmic Dark Ages
1B yrFirst galaxies form; quasars at peak activity
4.6B yrMilky Way disk forms; Population II stars present
9.2B yrSolar System forms from molecular cloud collapse
9.6B yrEarth forms; Moon-forming giant impact ~30M yr later
10.1B yrFirst life on Earth � simple prokaryotes
13.5B yrHomo sapiens evolve; first astronomy begins
13.8B yr⬤ NOW � You are here, reading this
+4.5B yrAndromeda-Milky Way collision begins
+5B yrSun becomes red giant; Earth's surface sterilized
+10¹⁴ yrLast stars exhaust fuel; universe goes dark
+10¹⁰⁰ yrProton decay � all ordinary matter gone