A comprehensive formal system is developed that amalgamates the operational and the realistic approaches to quantum mechanics. In this formalism, for example, a sharp distinction is made between events, operational propositions, and the properties of physical systems.

We briefly review the history of de Broglie's notion of the “double solution” and of the ideas which developed from this. We then go on to an extension of these ideas to the many-body system, and bring out the nonlocality implied in such an extension. Finally, we summarize further developments that have stemmed from de Broglie's suggestions.

Every quantum state can be represented as a probability distribution over the outcomes of an informationally complete measurement. But not all probability distributions correspond to quantum states. Quantum state space may thus be thought of as a restricted subset of all potentially available probabilities. A recent publication (Fuchs and Schack, arXiv:0906.2187v1, 2009) advocates such a representation using symmetric informationally complete (SIC) measurements. Building upon this work we study how this subset—quantum-state space—might be characterized. Our leading characteristic is that the inner (...) products of the probabilities are bounded, a simple condition with nontrivial consequences. To get quantum-state space something more detailed about the extreme points is needed. No definitive characterization is reached, but we see several new interesting features over those in Fuchs and Schack (arXiv:0906.2187v1, 2009), and all in conformity with quantum theory. (shrink)

Should we doubt the exactness of the predictive quantum rules of calculation? Although this question is sometimes raised in connection with the one on how to physically understand quantum mechanics, these two questions should not be mixed up. It is recalled here that even the first one is stil an object of controversy, and it is shown (a) that in one specific case the arguments put forward in support of such doubts are hardly cogent but (b) that, nevertheless, at least (...) in one specific other context, the question is worth attention. This is the problem of repeated imperfect measurements. Relative to it, a theoretical possibility is shown of discriminating between the thesis that the quantum rules are exact and a powerful theory of which it is proved that it cannot be reconciled with the assumption. (shrink)

The eurocentrism of Hegel's philosophy of history is well known. Hegel's reputation has not benefited from many of the claims in the Philosophy of History; such as the one that African history, having no development, has contributed nothing to world history. Because of the general lack of attention that Hegel's philosophy of subjective spirit has received, it is little known that this eurocentrism is based, in part, on the racism of the philosophy of subjective spirit. Only here does Hegel systematically (...) treat the biological category of race. Reading through this section one can find passages about racial distinctions which seem initially to be rather ambivalent, but taken as a whole are decidedly racist. Much of what Hegel says about the �inferiority� of African culture and the �justification� for the slave trade finds its foundation here. This paper is an exhibition of the relevant passages of the �Philosophy of Subjective Spirit� and an attempt to link them to Hegel's other claims about African culture and the slave trade. I will argue that Hegel's philosophy of spirit is tainted by the unusual (for Hegel) causal role which he gives to a biological category, namely race. I will argue further that his philosophy of spirit is not necessarily racist, only contingently so, that is that his racism does not follow from any of his fundamental claims about spirit. Hegel's account of spirit makes his racism possible, not necessary. The source of his racism can be traced to the general ideology of the nineteenth century. Nonetheless, understanding how Hegel could hold racist views is important for understanding features of his political philosophy. It shows both the problems of the Hegelian conception of person hood and exemplifies the conservative bias built into his method of political philosophy generally. (shrink)

Values of some arbitrary parameters appearing in a geometrical model for elementary particles developed by MacGregor are compared with quantities associated with classical properties of blocks of charges±e interacting via Coulomb forces and hard-sphere repulsion only. If it is assumed that masses and radii of individual charged particles are related bymc 2=(2/3)(e 2/r) and thatmc 2=6.87 MeV, then the self-energiesM andM ± of 24-particle neutral blocks and 25-particle charged blocks composed of layers of three octagons and of a square sandwiched (...) by two distorted octagons satisfyM=70.1 MeV,M ±=74.2 MeV. The binding energyB nn of pairs of neutral blocks is given byB nn=4.9 MeV, and the maximum radius of the neutral block is 0.60 F. These four calculated parameter values lie within an average of 1% of the corresponding quantities for nonspinning quarks determined empirically by MacGregor. (shrink)

We consider the superposition of macroscopically distinguishable states for a measuring process whose time evolution is described by the Schrödinger equation. We ask whether it is possible to observe interference effects due to the above mentioned superposition and how to observe them, taking into consideration an experiment performed by other authors. We find a necessary condition in order to be able to observe these effects. We also point out some very serious difficulties in observing them and analyse the connection between (...) some of these difficulties and the Wigner-Araki-Yanase theory. We try to explain why the whole problem seems to us to be far from having a solution and we suggest some paths we think worthy of further investigation. (shrink)

It is shown that both covariant harmonic oscillator formalism and quantum field theory are based on common physical principles which include Poincaré covariance, Heisenberg's space-momentum uncertainty relation, and Dirac's “C-number” time-energy uncertainty relation. It is shown in particular that the oscillator wave functions are derivable from the physical principles which are used in the derivation of the Klein-Nishina formula.

In the face of new forms of popular radicalism in the 1790s, British Whigs turned increasingly hostile to the French Revolution and doctrines of radical social improvement. Yet, rather than turn to Burke's Reflections on the Revolution in France to frame their anti-radical arguments, Whiggism took up the claims of Thomas Malthus' Essay on the Principle of Population. By eschewing the voluntarist idiom of Burke's Reflections in favour of a Newtonian rhetoric which resonated with the discursive traditions of radicalism itself, (...) Malthus provided a powerful anti-radical weapon which became a central pillar of the emerging ‘science’ of political economy. Debates in political economy thus moved to the forefront of the contest between Whigs and popular radicals. (shrink)

Two categories of life are currently recognized—chemosynthetic and photosynthetic—indicating their principal free energy resource as either chemicals or electromagnetic radiation. Building on recent developments in thermodynamics, we posit a third category of life—thermosynthetic life (TL)—which relies on environmental heat rather than traditional free energy sources. Since thermal energy is more abundant than chemicals or light in many settings, thermosynthesis offers compelling evolutionary possibilities for new life forms. Based on variants of standard cellular machinery, a physical model is proposed for the (...) conversion of thermal energy into biochemical work. Conditions favorable to thermosynthetic life and prospects for its discovery are assessed. Terrestrially, deep-subsurface unicellular anaerobic superthermophiles are deduced to be likely TL candidates. (shrink)

The nucleon spin problem raises experimental and theoretical questions regarding the contribution of the orbital angular momentum of the quarks to the total spin of the nucleon. In this article we examine the commutation relationships of various operators that contribute to the total angular momentum of the nucleon. We find that the sum of the orbital plus gluon field angular momenta should satisfy the angular momentum commutators, at least up to the one-loop level. This, requirement on the sum of these (...) operators imposes a non-trivial restriction on the form of the color electric and magnetic fields. This is similar to the magnetic monopole/electric charge system where it is only the sum of the orbital plus field angular momentum that satisfies the correct commutation relationships. (shrink)

It is the genius of the Fourth Evangelist to have created a gospel in which Jesus as the representative of the world above visits and really lives in this world without depriving it of its verisimilitude and without depriving life here of its seriousness.

Previous research suggests that children can infer causal relations from patterns of events. However, what appear to be cases of causal inference may simply reduce to children recognizing relevant associations among events, and responding based on those associations. To examine this claim, in Experiments 1 and 2, children were introduced to a “blicket detector,” a machine that lit up and played music when certain objects were placed upon it. Children observed patterns of contingency between objects and the machine's activation that (...) required them to use indirect evidence to make causal inferences. Critically, associative models either made no predictions, or made incorrect predictions about these inferences. In general, children were able to make these inferences, but some developmental differences between 3- and 4-year-olds were found. We suggest that children's causal inferences are not based on recognizing associations, but rather that children develop a mechanism for Bayesian structure learning. Experiment 3 explicitly tests a prediction of this account. Children were asked to make an inference about ambiguous data based on the base rate of certain events occurring. Four-year-olds, but not 3-year-olds were able to make this inference. (shrink)