Mr. Mysteries' So-True Histories Episode 1 - The Nature of Reality

Hello Eager Learners! I am Mr. Mysteries, formerly of the Learned League, and this is my KARENcast series on the history of our Reality, Reality 69. But to understand our reality, we must first understand some things about all Realities.
  Within the multiverse of all possibilities, it is easiest to picture it as a great tree. Reality Prime is the trunk of the tree and the various other Realities are branches from that core. For ease of reference each Reality Branch is numbered via a complex equation that takes into account numerous minor deviations within each branch and when the branches Great Deviation occurs. Unfortunately this equation is only well understood by some superintelligences and AIs.