Hot and Heavy Matters in the Foundations of Statistical MechanicsCallender, Craig
doi: 10.1007/s10701-010-9518-zpmid: N/A
Are the generalizations of classical equilibrium thermodynamics true of self-gravitating systems? This question has not been addressed from a foundational perspective, but here I tackle it through a study of the “paradoxes” commonly said to afflict such systems. My goals are twofold: (a) to show that the “paradoxes” raise many questions rarely discussed in the philosophical foundations literature, and (b) to counter the idea that these “paradoxes” spell the end for gravitational equilibrium thermodynamics.
The Quasiclassical Realms of This Quantum UniverseHartle, James
doi: 10.1007/s10701-010-9460-0pmid: N/A
The most striking observable feature of our indeterministic quantum universe is the wide range of time, place, and scale on which the deterministic laws of classical physics hold to an excellent approximation. This essay describes how this domain of classical predictability of every day experience emerges from a quantum theory of the universe’s state and dynamics.
Reduction and Emergence in Bose-Einstein CondensatesHealey, Richard
doi: 10.1007/s10701-010-9481-8pmid: N/A
A closer look at some proposed Gedanken-experiments on BECs promises to shed light on several aspects of reduction and emergence in physics. These include the relations between classical descriptions and different quantum treatments of macroscopic systems, and the emergence of new properties and even new objects as a result of spontaneous symmetry breaking.
Emergence, Singularities, and Symmetry BreakingBatterman, Robert
doi: 10.1007/s10701-010-9493-4pmid: N/A
This paper looks at emergence in physical theories and argues that an appropriate way to understand socalled “emergent protectorates” is via the explanatory apparatus of the renormalization group. It is argued that mathematical singularities play a crucial role in our understanding of at least some well-defined emergent features of the world.
How Classical Particles Emerge From the Quantum WorldDieks, Dennis; Lubberdink, Andrea
doi: 10.1007/s10701-010-9515-2pmid: N/A
The symmetrization postulates of quantum mechanics (symmetry for bosons, antisymmetry for fermions) are usually taken to entail that quantum particles of the same kind (e.g., electrons) are all in exactly the same state and therefore indistinguishable in the strongest possible sense. These symmetrization postulates possess a general validity that survives the classical limit, and the conclusion seems therefore unavoidable that even classical particles of the same kind must all be in the same state—in clear conflict with what we know about classical particles. In this article we analyze the origin of this paradox. We shall argue that in the classical limit classical particles emerge, as new entities that do not correspond to the “particle indices” defined in quantum mechanics. Put differently, we show that the quantum mechanical symmetrization postulates do not pertain to particles, as we know them from classical physics, but rather to indices that have a merely formal significance. This conclusion raises the question of whether many discussions in the literature about the status of identical quantum particles have not been misguided.