Idealization and Idealized Models in Thermostatistical Physics

SES 99-10889 - Chuang Liu (University of Florida)，“热统计物理中的理想化和理想化模型”，该项目的目标是根据对热统计物理中复杂的模型构建实践的研究，发展理想化的哲学理论。整个论证的结构如下。现有的理想化理论及其与近似的关系是不充分的。然后，问题被证明是由于对理想化的目的（因此也是衡量标准）的误解造成的。因此，有人认为，理想化不一定是假设那些本身近似的条件，或者它们的逐渐移除保证了近似的规律和/或模型，而是在自然的接合处雕刻自然——从而获得理论模型——这样，真正的自然规律要么可以应用（如果它们已经被知道），要么可以被发现（如果它们还不被知道）。虽然这种直观的理想化概念给出了科学中广泛的模型构建实践的正确特征，但它违背了一个精确和普遍的公式。要理解这一概念的丰富内涵，就必须详细分析它在不同科学领域的不同表现形式。本项目选择热统计物理学是因为它是跨越微观和宏观鸿沟的最容易理解的科学分支。该项目提供了各种模型的详细研究，以解释相变和临界现象。通过考察PI所称的近似模型和精确模型的理想条件，他将对如何在接缝处雕刻自然的概念进行初步了解。PI希望这个项目能激励他自己和其他人在物理（或科学）的其他领域研究理想化和模型制作的实践（因为它们总是齐头并进）。

SES 99-10889 - Chuang Liu (University of Florida) "Idealization and Idealized Models in Thermostatistical Physics"The goal of this project is develop of a philosophical theory of idealization in light of a study of the intricate practice of model-building in thermostatistical physics. The structure of the overall argument goes as follows. The existing theory of idealization and its relation to approximation is found to be inadequate. The problem is then shown to be caused by a misunderstanding of the purpose (and therefore the measure) of idealization. It is therefore argued that idealization is not necessarily to postulate conditions which are themselves approximate or whose gradual removal guarantees approximate laws and/or models, but to carve nature at its joints -- obtaining theoretical models as a result -- so that genuine laws of nature can be either applied (if they are already known) or discovered (if they are not yet known). While such an intuitive notion of idealization gives the right, albeit inarticulate, characterization of the widespread practice of model-building in science, it defies an exact and universal formulation. To understand the rich content of this notion, one must conduct detailed analysis of its different guises in different fields of science. Thermostatistical physics is chosen for this project because it is the best understood branch of science which cuts across the microscopic and the macroscopic divide. The project provides a detailed study of various models in the explanation of phase transitions and critical phenomena. By examining the kind of ideal conditions going into the making of what the PI calls the approximate and the exact models, he shall develop a glimpse of how the notion of carving nature at its joints is put to work. The PI hopes that this project will motivate himself and others to study the practice of idealization- and model-making (since they always go hand--in-hand) in other areas of physics (or science).