Causal entropic principle / entropic principle

[dmtr]

Can somebody comment on the following paper: http://arxiv.org/abs/hep-th/0702115"

Abstract: We compute the expected value of the cosmological constant in our uni-
verse from the Causal Entropic Principle. Since observers must obey the laws of thermo-
dynamics and causality, the principle asserts that physical parameters are most likely to
be found in the range of values for which the total entropy production within a causally
connected region is maximized. Despite the absence of more explicit anthropic crite-
ria, the resulting probability distribution turns out to be in excellent agreement with
observation. In particular, we find that dust heated by stars dominates the entropy pro-
duction, demonstrating the remarkable power of this thermodynamic selection criterion.
The alternative approach—weighting by the number of “observers per baryon”—is less
well-defined, requires problematic assumptions about the nature of observers, and yet
prefers values larger than present experimental bounds.

Here are some (disrespectful?) comments in the blogosphere: http://resonaances.blogspot.com/2007/08/entropic-principle.html"

As I was able to understand the paper, this 'entropic principle' was applied to the initial condition/physical parameters/cosmological constant selection, which is a rather grand scale. Can the same principle be applied to a smaller scale of elementary quantum event outcomes (would more 'entropic' outcome be more probable)?

 

[rlreetz]

The Causal Entropic Principle isn't a complex concept. It is the simple application of the 2nd Law's demand for increased universal entropy as a result of every change in any system. It says that every action in every system must be that action that causes the largest reduction in the quality of information or energy (the greatest dissipation). It says that a universe has only one possible end state – heat death – and that processes that maximize the rate towards this end state will be evolutionarily favored (selected), simply because entropy-maximizing processes and structures demand a higher throughput of energy and thus end up dominating their respective locality. Such entropy-maximizing schemes are thus more likely to determine the structure and behavior of the event cone stretching off into the future. An obvious extension of this principle is that complexity, or more precisely, the family of complexity that can find, record, and process abstractions that represent the salient aspects (physics) of the (an) universe, will help that complexity better predict the shape and behavior it must assume to maximize its competitive influence upon the future of entropy maximization. The "Causal Entropic Principle" thus represents a logically self-consistent (scientific) replacement for the awkwardly self-centered and causally impossible "anthropomorphic principle" (which lacks a physical or causal explanation and leans heavily on painfully erroneous macroscopic stretching of the quantum electro dynamics). Stretching circular logic to its most obvious and illogical end, the anthropomorphic principle borrows awkwardly and erroneously and ironically form the Heisenberg / Uncertainty Principle by asserting the necessity of "observers" as a precursor to the emergence of complexity. The Causal Entropic Principle explains the production of localized complexity without the need for prior-knowledge, and does so within the bounds of, as a result of, the 2nd Law of Thermodynamics, by showing that localized complexity can both come into existence as a result of the constant increase in universal entropy, and more specifically, that localized complexity has an evolutionary advantage, and will thus out-compete, less complex structures. In a Causal Entropic Principle universe, intelligence is the expected evolutionary result of competition to reach heat death faster. Falling down is enhanced by a particular class of complexity that can come into existence as a natural result of things falling down. Should one form of such complexity "understand" the universe better than another form, it will have an advantage and will be more likely to influence the shape of complexity in the future. The better a system gets at abstracting the dynamics of its environment the more likely it will be able to eat other systems than be eaten by them. Where the anthropomorphic principle requires an a-priori "observer", the causal entropic principle simply requires the 2nd Law's demand for increased entropy, for things falling down.