Download Welcome to Physics 112N

Philosophical Issues in Quantum
Physics and Metaphysical
Implications
9
14
19
28
30
Q/M
Physics
Q/M
Philosophical
Issues
Implications
Discussion
Quiz
Relativity
Thermodynamics
Implications
Discussion
4
6
11
13
18
20
25
Astronomy/
Cosmology
Religious
Cosmologies
Implications
Discussion
Quiz
Evolution
The Science
Creationism
Intelligent
Design
Implications
Discussion
Summary
Discussion
Quiz
Essay Due
Readings
• Barbour, I.G, Religion and Science
(1997)
• Whitaker, A, Einstein, Bohr and the
Quantum Dilemma (1996)
• Online Readings
Papers for Discussion
• Is there a moon when nobody look? Reality and the
Quantum Theory by David Mermin
• Is scientific realism compatible with quantum physics
by Arthur Fine
• Critical Realism in Science and Religion (Reading
from Belief in God in an Age of Science by John
Polkinghorne)
• Quantum Complementarity and Christological
Dialectic by Christopher Kaiser
Recap: The Strange Quantum World
• Wave Particle Duality
• How to describe systems?
• Wave Function describes the state of a
system in a probabilistic sense
• Systems exist a superposition of states
• Observation collapses to a particular state
Recap : Two Views
• Complementarity (Critical Realism?)
– Must consider interaction between subject
and object in an experiment
– Conceptual limitation of understanding
• Realism
– Theories are description of nature in itself
– Hidden Variables to explain away apparent
indeterminacy?
Points to Ponder
• Does Complementarity imply
instrumentalism?
• Complementarity a good paradigm for
science and religion?
• Indeterminacy
– temporary ignorance?
– measurement or conceptual issue?
– inherent to nature?
• Parts and Wholes – A new paradigm for
understanding the world?
Determinism
• State (of an object or event) is
determined by prior states
• Laplace’s Clockwork Universe
• Classical Physics
• Cause and Effect
• First Cause Argument?
• Chaos?
Indeterminacy
• Temporary human ignorance
• Inherent experimental or conceptual
limitations
• Indeterminacy in nature
Realism
• Observations in science related to a real
existing world independent of
observations
• Scientific theories are attempts to gain
information about reality
• Classical Physics
Positivism
• Observed Phenomena are all that
require scientific analysis
• Discussion of underlying mechanisms
or ‘real entities’ meaningless
• Self Defeating, Quine and Kuhn’s
Objections
Instrumentalism
• Scientific Theories tools to calculate
experimental Results
• Non Observable theoretical constructs
useful but disposable
• Shift away discourse from the realism
debate
Reductionism
• Complex system is nothing but the sum
of its parts
• Again a clockwork universe
• Greedy Reductionism (Dennet)
• Emergent Phenomena
• Holism
Holism
• The tendency in nature to form wholes
that are greater than the sum of the
parts
• Complex Systems
• Copenhagen Interpretation
Bohr’s Copenhagen
Interpretation
• Complementarity
• Indeterminacy
• Critical Realism
• Holism
Complementarity
• Wave Particle Duality
• Complimentary’ properties and uncertainty
• Mutual Exclusiveness
– One quantity being measured precludes
measurement of the other
• Joint Completion
– The two quantities jointly provide a complete
description of the motion
Complementarity
• e.g. x & p OR sx & sy (or sz)
• Must discuss the value of observable in
terms of the experimental setup
Disturbance Interpretation
The Heisenberg Cut
• Boundary between observer and
observed
• Ambiguity; does it mean the end of
disturbance interpretation
• Observer and observed handled as a
whole
Wholeness
• Observed object and measuring
apparatus are inextricably linked
• Rebirth of Aristotle?
• Eastern Mysticism?
Problems with Copenhagen
• An absolute wave function representing
the world is rejected by Bohr
– System (quantum), Observing devices
(classical)
• Heisenberg Cut
Complementarity in other Fields
• Mechanical and Vitalistic points of view
of Biology
• Free Will and Determinism in
Psychology
Wave Function Collapse
• Projection postulate
• What causes the wave function to
collapse at the time of observation?
• Epistemic Interpretation
• Wigner and Consciousness
The Realist View
• The theory as it stands is incomplete
• Hidden Variables?
• EPR paradox as an example
• Bohr’s response
Metaphysical Implications
• Is it all in the Mind?
•
• Free will and Determinism
• God’s action in the world
• Eastern Mysticism
Biological Life
• Exact predictions for large ensembles
• But micro events can have macro
consequences
• Firing of neurons
• Genetic Mutations
Human Freedom
• Quantum Indeterminacy = Possibility of
human freedom?
• Dualistic view needed?
God’s Action in the World
• Does God control how events unfold
using indeterminacy?
• Collapse of the wave function
Eastern Mysticism
• Complementarity and Yin/Yang
• Holistic Picture and Pantheism
• A Process point of view
Next Time……….
• Summary and wrap up
• 15 min presentations
• Quiz in class