Mindless Sensationalism: A Quantum Framework for Consciousness

The ideas of Sensible Quantum Mechanics are expressed in lay terms for philosophers of consciousness and others. A framework is proposed and explained for the `psycho-physical-parallelism' between conscious experiences and the mathematical structures of quantum physics (e.g., a set of quantum operators obeying some algebra, and a quantum state giving the expectation value of each operator). In particular, it is proposed that each set of possible conscious experiences has a measure given by the expectation value of a corresponding operator (a positive-operator-valued measure). Then one has a generalization of the Weak Anthropic Principle named the Conditional Aesthemic Principle: given that we are conscious beings, our conscious experiences are likely to be typical experiences in the set of all conscious experiences with its measure.Comment: 36 pages, no figures, LaTeX, invited contribution to be published in Consciousness: New Philosophical Essays, edited by Quentin Smith and Alexandar Jokic (Oxford: Oxford University Press, 2002). (This is mainly a philosophical account of the ideas of Sensible Quantum Mechanics in quant-ph/9506010 and elsewhere.

Born's Rule Is Insufficient in a Large Universe

Probabilities in quantum theory are traditionally given by Born's rule as the expectation values of projection operators. Here it is shown that Born's rule is insufficient in universes so large that they contain identical multiple copies of observers, because one does not have definite projection operators to apply. Possible replacements for Born's rule include using the expectation value of various operators that are not projection operators, or using various options for the average density matrix of a region with an observation. The question of what replacement to use is part of the measure problem in cosmology.Comment: LaTeX, 7 page

The Lifetime of the Universe

Current observations of the fraction of dark energy and a lower limit on its tension, coupled with an assumption of the non-convexity of the dark energy potential, are used to derive a lower limit of 26 billion years for the future age of the universe. Conversely, our ordered observations, coupled with an assumption that observers are smaller than the universe, are used to argue for an upper limit of about e^10^50 years if the universe eventually undergoes power-law expansion, and an upper limit of only about 10^60 years left for our universe if it continues to expand exponentially at the current rate.Comment: 9 pages, submitted to the Journal of the Korean Physical Society for a special issue giving the proceedings of the 9th Italian-Korean Symposium on Relativistic Astrophysics, Seoul, South Korea, and Mt. Kumgang, North Korea, 2005 July 19-24; 1999 Starobinsky reference added October

Possible Anthropic Support for a Decaying Universe: A Cosmic Doomsday Argument

I have suggested that one possible solution of the Boltzmann brain problem is that the universe is decaying at an astronomical rate, making it likely to decay within 20 billion years. A problem with this suggestion is that it seems to require unnatural fine tuning in the decay mechanism that would not be explained anthropically. Here it is pointed out that if a spacetime version of volume averaging were used in the cosmological measure problem, this would give anthropic support for an impending cosmic doomsday.Comment: 18 pages, LaTe

Normalized Observational Probabilities from Unnormalizable Quantum States or Phase-Space Distributions

Often it is assumed that a quantum state or a phase-space distribution must be normalizable. Here it is shown that even if it is not normalizable, one may be able to extract normalized observational probabilities from it.Comment: 15 pages, LaTe

Black Hole Information

Hawking's 1974 calculation of thermal emission from a classical black hole led to his 1976 proposal that information may be lost from our universe as a pure quantum state collapses gravitationally into a black hole, which then evaporates completely into a mixed state of thermal radiation. Another possibility is that the information is not lost, but is stored in a remnant of the evaporating black hole. A third idea is that the information comes out in nonthermal correlations within the Hawking radiation, which would be expected to occur at too slow a rate, or be too spread out, to be revealed by any nonperturbative calculation.Comment: 48 pages, 292 references, LaTeX. Spaces were removed before reference abbreviations, so that citation numbers would be LaTeXed correctly by the current software, as the previous version of the paper had been by the old LaTeX software in use when that version was submitted. After Eq. (7), a new reference [290] was added, to Foong and Kanno's paper, which appeared after this review was published in the Proceedings of the 5th Canadian Conference on General Relativity and Relativistic Astrophysic

Observational Selection Effects in Quantum Cosmology

Scientific theories need to be testable by observations, say using Bayes' theorem. A complete theory needs at least the three parts of dynamical laws for specified physical variables, the correct solution of the dynamical laws (boundary conditions), and the connection with observations or experience or conscious perceptions (laws of psycho-physical parallelism). Principles are proposed for Bayesian meta-theories. One framework that obeys these principles is Sensible Quantum Mechanics (SQM), which is discussed. In principle, it allows one to test between single-history and many-worlds theories, and to discuss threats to certain theories from fake universes and Boltzmann brains. The threat of fake universes may be dismissed if one doubts the substrate-independence of consciousness, which seems very implausible in the SQM framework. Boltzmann brains seem more problematic, though there are many conceivable solutions. SQM also suggests the possibility that past steps along our evolutionary ancestry may be so rare that they have occurred nowhere else within the part of the universe that we can observe.Comment: 18 pages, LaTeX, for Proceedings from the 13th International Congress of Logic, Methodology and Philosophy of Science, Tsinghua University, Beijing, China, August 9-15, 200

Gravitational Capture and Scattering of Straight Test Strings with Large Impact Parameters

The capture or scattering of an initially straight infinite test cosmic string by a Kerr-Newman black hole, or by any other small source of an electrovac gravitational field, is analyzed analytically when the string moves with initial velocity v and large impact parameter b >> M so that the string stays very nearly straight (except during the final capture process, if that occurs, or except far behind the gravitating object, if b is not much greater than the energy of the object in the frame of the string). The critical impact parameter for capture at low velocities is shown to be [(pi/2)(M^2-Q^2)/v]^{1/2}. For all larger b, the displacement of the string from the plane of the gravitating object after the scattering approaches the final value [b^2 - (pi/2)(M^2-Q^2)/v]^{1/2} - 2 pi M v/(1-v^2)^{1/2}, for any v, so long as b >> M.Comment: 27 pages, no figures, Late

Information Loss in Black Holes and/or Conscious Beings?

In 1976 Stephen Hawking proposed that information may be lost from our universe as a pure quantum state collapses gravitationally into a black hole, which then evaporates completely into a mixed state of thermal radiation. Although this proposal is controversial, it is tempting to consider analogous processes that might occur in certain theories of consciousness. For example, one might postulate that independent degrees of freedom be ascribed to the mental world to help explain the feeling of a correlation between one's desires and one's choice of actions. If so, one might ask whether information in the physical world can be lost to such postulated degrees of freedom in the mental world. Or, one might hypothesize that the mental world can affect the physical world by modifying the quantum action for the physical world in a coordinate-invariant way (analogous to the alpha parameters in wormhole theory).Comment: 10 pages. LaTe

Inconsistency of Canonically Quantized N=1 Supergravity?

D'Eath's proof (hep-th/9304084) that there can be at most two allowed quantum states of N=1 supergravity with zero or a finite number of fermions can be extended to show that there are no such states.Comment: 4 pages, Alberta Thy-28-93, LaTe