Finish%20Part%201%20of%20The%20Elegant%20Universe

1
Lecture 5

• Finish Part 1 of The Elegant Universe
• Review for test 1

2
The Elegant Universe

• Turns out there are 4, rather than 2, fundamental
  forces and that gravity is the weakest,
  particularly at the level of the sub-atomic.
• Determinism seems to hold in terms of large
  objects (us, earthly events, galaxies, and
  stars) there are law-like relationships between
  causes and effects, and events are predictable on
  their basis.
• This is the nature of the universe that Einstein,
  Newton, and generations of physicists believed in
  and sought to understand.

3
The Elegant Universe

• But in the 1930s, physicists such Neils Bohr
  were studying the realm of the very small the
  world of atoms and subatomic particles and
  finding fundamentally different from the
  macroscopic realm in terms of cause/effect
  relationships and, most importantly, in terms of
  determinism.
• It is indeterminacy chance they argued that
  is the norm in the subatomic realm. It is far
  less regular, far less predictable, and far less
  familiar than the determinism that seems to hold
  at the level of large objects.

4
The Elegant Universe

• Quantum theory (or quantum mechanics) the study
  of quanta (plural of quantum) discrete,
  indivisible units of energy emerged and many of
  its predictions were confirmed to an impressive
  degree.
• Einstein hated indeterminacy (stating, famously,
  that God doesnt play dice) and was, more or
  less, left behind as the new forces and phenomena
  at the quantum level became increasingly the
  subject of research.
• Among the implications of experiments in Quantum
  theory you cannot determine both the position
  and the velocity of a quantum at the same time
• Observing events involving quanta changes what
  occurs.

5
The Elegant Universe

• Major themes
• Unification a theory of everything as the holy
  grail of physics
• Reasons to think it is plausible past
  unifications, metaphysical assumptions about the
  universe
• Simplicity! Elegance!
• The laws of physics apply everywhere at all times
• Testability (related to verifiability and
  falsifiability)
• The (at least apparent) impossibility of ever
  observing strings.

6
Review

• Evidence what is it like for theories in physics
  and biology that posit objects or events we
  cannot directly observe?
• What kinds of argument do scientists who posit
  objects or events we cannot directly observe
  offer in support of positing such objects/in
  support of such theories?
• What kinds of philosophical assumptions underlie
  scientific research fallibilism/epistemological,
  universality or contingency, simplicity/elegance
  or jury rigging, metaphysical, aesthetic motivate
  and/or inform scientific research?

7
Review

• Case studies
• Particle physics
• Evolutionary Theory
• Human evolution
• String Theory
• The Copernican Revolution
• The Darwinian Revolution
• Ancient Greeks of Miletus and Democritus
• Vegetation Myths

8
Review

• Forms of reasoning
• Thought experiments
• From data to hypothesis
• Reverse engineering
• Inference to the best explanation
• The Likelihood Principle
• Modus Tollens
• Modus Ponens
• Affirming the consequent
• Denying the antecedent

9
Review

• People and their arguments
• Lederman, Thales, Anaximander, Anaximenes,
  Democritus
• Paley, Darwin, and Gould
• Copernicus, Galileo, and their critics
• Brian Greene, Einstein, Glashow, String Theorists
• Glashows credo