The Kalam Cosmological Argument

William Lane Craig

I picked this up mainly to examine the content relevant to physics and cosmology, so I start with what he calls "empirical confirmation".

Second Premiss: The Universe Began to Exist

p110 Empirical Confirmation

p111 Starts the first empirical confirmation from the expansion of the universe. Einstein-de Sitter with the cosmological constant which gave the expansion from a steady-state model, then Friedmann-Lemaitre model which posited a start from a high density state.

p112 Start of discussion of the Hubble law and Hubble constant

p113 Penzias & Wilson and the CMB discovery.

p114-116 His version of the "first three minutes".

p116 Discusses the deceleration factor from gravity that modifies projected Hubble time from 17.7Gyr to about 15 Gyr. This deceleration parameter is discussed in Carrol & Ostlie, Section 29-1, p1162 where the deceleration parameter q₀ = 0.5 for a flat universe. Current Hubble time from WMAP is 13.7 or 13.8 Gyr.

p116 Quotes "..the universe began from a state of infinite density about one Hubble time ago. Space and time were created in that event and so was all the matter in the universe." from J Richard Gott, James E Gunn, David N Schramm and Beatrice M. Tinsley, Scientific American, March 1976, p65.

p118-121 Interesting discussion of Hoyle and his reluctant abandonment of the steady-state theory based on CMB. Discusses Hoyle's philosophical position.

p121 Brief mention of Tinsley and her indifference to the question of the existence of God.

p122 Quote of Gribbin on the philosophical resistance to the Big Bang.

p123 More discussion of the deceleration factory, which he brought up on pg 116.

p125 Discussion of the average density of matter.

p126 More discussion of density and modeling of lookback time, correlation with deuterium abundance,

p128 Evidence against an oscillating universe

p129 Summary of evidence pointing to and absolute beginning of the universe and against the steady state and oscillating universe models.

p130 Moves to thermodynamic argument for the beginning of the universe. He develops this general outline:

• Clausius first step toward the Second Law of Thermodynamics was the statement that "heat of itself only flows from a point of high temperature toward a point of low temperature"
• Ludwig Boltzmann made the next step of showing that this "tendency toward leveling is founded on the tendency of any system to pass from a less probable to a more probable state."
• The Second Law was then associated with entropy.

p131 Interesting comments about entropy and order, particularly in light of all the discussions I have had about that. "According to Boltzmann, the probability of a state is a function of its order: more ordered states are less probable, and less ordered states more probable. The most probable state is therefore a totally disordered state, that is, a state which is completely undifferentiated. Thus, the second law could be formulated: all systems have the tendency to pass from a more ordered to a less ordered state."

"A third important step in the development of the second law was the realization that disorder is connected with entropy: the greater the disorder, the greater the entropy. This yields a third formulation of the law: all systems have the tendency to pass from a state of lower entropy to a state of higher entropy."

p132 Long quote of Zwart on the progress of the universe toward heat death.

p133 Discussion and quote of P.C.W. Davies on gravity as the origin of all thermodynamic irreversibility and his statement about the heat death of the universe.

p134 Various options about cold death and hot death and bouncing.

p138 Outlines the arguments against the low initial entropy state of the universe being due to a fluctuation. They seem very strong, which may have been what led Carroll in "From Eternity to Here", p224-226 to make strong statements that the low entropy state of our universe was not just a large fluctuation. This is even after on p216 he made the statement that we are on the return from a giant fluctuation.

p139 Important summaries about the universe starting in a low entropy state. Quotes Davies, Physics and I think this is P C W Davies, not Paul Davies -- oops, they are the same person. "Because of the finite age of these models, the entire universe can be regarded as a sort of gigantic branch system, which was created in a low entropy state at t=0 and is in the process of running through its course to equilibrium .. As in the case of branch systems, the initial low entropy condition of the universes not attributed to a fluctuation from an early equilibrium state, because the universe simply did not exist prior to this creation event."

p139 "Thus, the present disequilibrium indicates that the universe has not existed forever, but began to exist at a low state of entropy a finite number of years ago."

p140 "In summary, then, we have argued that (1) thermodynamic considerations point to an origin of the universe a finite number of years ago; (2) these considerations hold true whether we adopt Newtonianor relativistic world models, and (3) traditional objections to this argument are invalid on various counts. Because a universe existing for infinite time could not now be in the present state of disequilibrium, we conclude, therefore, that the universe began to exist."

First Premiss: Everything that Begins to Exist Has a Cause of Its Existence

p141 "Even Hume himself confessed that his academic denial of the principle's demonstrability could not eradicate his belief that it was nonetheless true." Reference the quote:

"But allow me to tell you that I never asserted so absurd a Proposition as that that anything might arise without a cause: I only maintain'd, that our Certainty of the Falsehood of that Proposition proceeded neither from Intuition nor Demonstration; but from another Source." (David Hume to John Stewart, February 1754, in The Letters of David Hume, 2 vols, ed. J. Y. T Greig[Oxford:Clarendon Press, 1932], I:187)