The Anthropic Principle

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The Anthropic Principle

• by
• Robert Nemiroff
• Michigan Tech

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Physics X About This Course

• Officially "Extraordinary Concepts in Physics"
• Being taught for credit at Michigan Tech
• Light on math, heavy on concepts
• Anyone anywhere is welcome
• No textbook required
• Wikipedia, web links, and lectures only
• Find all the lectures with Google at
• "Starship Asterisk" then "Physics X" 
• http//bb.nightskylive.net/asterisk/viewforum.php?
  f39

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Anthropic Principle

• Is it a coincidence that all the physical
  constants like G, e, h, etc. are just that needed
  for life to develop?.
•  
• 1.  Yes, we sure are lucky.
• 2.  No, it has to be this way.
• 3.  Maybe a little bit.

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Anthropic Principle

• The answer is debatable, however a consensus is
  that
• 2.  No. Only those universes with life-enabling
  constants can observe those constants. Other
  universes are unobservable.
• This is the Anthropic Principle.  First coined by
  B. Carter in 1973.
•  

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Anthropic Principle

• Is it a coincidence that you are seeing this
  information on a computer screen?
• 1.  Yes, I could have seen this on paper.
• 2.  No, this is an analog of the Anthropic
  Principle.

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Anthropic Principle

• 2.  No, this is an analog of the Anthropic
  Principle.
• The number of times a paper copy is seen will be
  much less than a computer screen copy.  One can
  estimate how often each is observed.  Say it is
  100 to 1.  Then regardless of the amount of paper
  and the number of computer screens in the world,
  only those showing this slide are relevant. 

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Anthropic Principle

• The Personal Anthropic Principle
• Is it a coincidence that you yourself are
  contemplating the Anthropic Principle?  With all
  of the billions of people, life forms, and
  computer forms, what chance is it that you
  yourself would be contemplating it?

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Anthropic Universe Varieties

• Unique universe Some physical Theory of
  Everything (ToE) can explain everything. If we
  understood the ToE, we would understand how it
  enables life.
• Wheeler's Participatory Anthropic Principle Only
  universes with a capacity for consciousness can
  exist.

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Anthropic Universe Varieties

• Theism God created the universe to be the way it
  is.
• Multiverse All possible universes exist but only
  those universes that develop brains can observe
  their own universe.

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Anthropic Principle

• RJN's view
• Invoking the Anthropic Principle is a scientific
  attempt to include relevant information in
  statistical arguments.  
• It is the physical equivalent of including
  "priors" in Bayseian statistics, or taking a
  better inventory of the number of fair trials, in
  frequentist statistics.
•  
• Therefore,although some consider the AP "not
  science", I consider it an attempt at "good
  science". 

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Boltzmann Brain Paradox

• Boltzmann Brain A random fluctuation that
  develops into a universe-observing, self-aware,
  brain.
•  
• Paradox If entropy and disorder always increase,
  why do we observe such order in the universe?
•  
• Restated paradox Our existence in such an
  ordered universe would seem to be highly
  improbable in a sufficiently vast universe where
  many Boltzmann brains could randomly pop into
  existence and observe a much less ordered
  universe.

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Boltzmann Brain Paradox

• Which is more likely? 
•  
• 1. Our brains developed along side many other
  brains in this large universe.
• 2.  Your single brain developed with false
  memories and only the impression that many other
  brains exist.

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Simulated Reality

• It is not possible to distinguish a sufficiently
  sophisticated computer simulation from reality.
• This is the philosophical Brain in a Vat paradox.
  
• For all we know, we (or just you) may be living
  in such a computer simulation (e.g. The Matrix)

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Simulated Reality

• Boltzmann's computer Multiple computer
  simulations might be easier to run than brains
  are to make. 
•  
• Penrose The human mind is too quantum mechanical
  to be simulated by a conventional (non-QM)
  computer.