684 research outputs found

    Why the Quantum Must Yield to Gravity

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    After providing an extensive overview of the conceptual elements -- such as Einstein's `hole argument' -- that underpin Penrose's proposal for gravitationally induced quantum state reduction, the proposal is constructively criticised. Penrose has suggested a mechanism for objective reduction of quantum states with postulated collapse time T = h/E, where E is an ill-definedness in the gravitational self-energy stemming from the profound conflict between the principles of superposition and general covariance. Here it is argued that, even if Penrose's overall conceptual scheme for the breakdown of quantum mechanics is unreservedly accepted, his formula for the collapse time of superpositions reduces to T --> oo (E --> 0) in the strictly Newtonian regime, which is the domain of his proposed experiment to corroborate the effect. A suggestion is made to rectify this situation. In particular, recognising the cogency of Penrose's reasoning in the domain of full `quantum gravity', it is demonstrated that an appropriate experiment which could in principle corroborate his argued `macroscopic' breakdown of superpositions is not the one involving non-rotating mass distributions as he has suggested, but a Leggett-type SQUID or BEC experiment involving superposed mass distributions in relative rotation. The demonstration thereby brings out one of the distinctive characteristics of Penrose's scheme, rendering it empirically distinguishable from other state reduction theories involving gravity. As an aside, a new geometrical measure of gravity-induced deviation from quantum mechanics in the manner of Penrose is proposed, but now for the canonical commutation relations [Q, P] = ih.Comment: 33 pages (TeX, uses mtexsis) plus 3 figures (epsf). To appear in ``Physics Meets Philosophy at the Planck Scale'' (Cambridge University Press). Two footnotes adde

    Is thinking computable?

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    Strong artificial intelligence claims that conscious thought can arise in computers containing the right algorithms even though none of the programs or components of those computers understand which is going on. As proof, it asserts that brains are finite webs of neurons, each with a definite function governed by the laws of physics; this web has a set of equations that can be solved (or simulated) by a sufficiently powerful computer. Strong AI claims the Turing test as a criterion of success. A recent debate in Scientific American concludes that the Turing test is not sufficient, but leaves intact the underlying premise that thought is a computable process. The recent book by Roger Penrose, however, offers a sharp challenge, arguing that the laws of quantum physics may govern mental processes and that these laws may not be computable. In every area of mathematics and physics, Penrose finds evidence of nonalgorithmic human activity and concludes that mental processes are inherently more powerful than computational processes

    Karen Penrose v. Jeffrey Penrose : Reply Brief

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    REPLY BRIEF OF APPELLANT APPEAL FROM THE DECREE OF DIVORCE ENTERED BY THE THIRD JUDICIAL DISTRICT COURT, SALT LAKE COUNTY, STATE OF UTAH, JUDGE SANDRA N. PEULE

    Power Indices in Large Voting Bodies

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    There is no consensus on the properties of voting power indices when there are a large number of voters in a weighted voting body. On the one hand, in some real-world cases that have been studied the power indices have been found to be nearly proportional to the weights (eg the EUCM, US Electoral College). This is true for both the PenroseBanzhaf and the Shapley-Shubik indices. It has been suggested that this is a manifestation of a conjecture by Penrose (known subsequently as the Penrose limit theorem, that has been shown to hold under certain conditions). On the other hand, we have the older literature from cooperative game theory, due to Shapley and his collaborators, showing that, where there are a nite number of voters whose weights remain constant in relative terms, and where the quota remains constant in relative terms, while the total number of voters increases without limit - so called oceanic games - the powers of the voters with nite weight tend to limiting values that are, in general, not proportional to the weights. These results, too, are supported by empirical studies of large voting bodies (eg. the IMF/WB boards, corporate shareholder control). This paper proposes a restatement of the Penrose Limit theorem and shows that, for both the power indices, convergence occurs in general, in the limit as the Laakso-Taagepera index of political fragmentation increases. This new version reconciles the di erent theoretical and empirical results that have been found for large voting bodies

    Karen Penrose v. Jeffrey Penrose : Brief of Appellee

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    Case No. 950774-CA Priority No. 15 BRIEF OF APPELLEE JEFFREY PENROSE Appeal from the Decree of Divorce Entered by the Third Judicial District Court for Salt Lake County, State of Utah Honorable Sandra N. Peuler

    Penrose v. Ross : Brief of Appellee

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    Appeal from the Order Granting Defendant Bryant Ross\u27 Motion for Summary judgment of the THIRD DISTRICT COURT IN AND FOR SALT LAKE COUNTY, STATE OF UTAH, Salt lake Department, the Honorable Judge Leon A. Dever presiding

    The first principle of life : Thomistic dualism and current issues in the mind-body debate

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    https://place.asburyseminary.edu/ecommonsatsdissertations/1992/thumbnail.jp
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