So if I open that famous Schrodinger cat box the cat is alive or dead. My observation determines the cat's fate.
Aren't I creating two universes, one for the alive cat and one for the dead? If so I have 'created' an entire
universe. That's my reading of this stuff.
No, it is not the simple act of looking that separates the universes. it is the decay of the particle that kills the cat or not that determines the split of the universe. Your looking only lets you know which universe you are in.
The quantum event produces the split (in those interpretations that have a split), not the observation.