On Lossless Approximations, the Fluctuation- Dissipation Theorem, and Limitations of Measurements

摘要: In this paper, we take a control-theoretic approach to answering some standard questions in statistical mechanics, and use the results derive limitations of classical measurements. A central problem is relation between systems which appear macroscopically dissipative but are microscopically lossless. We show that linear system if, only it can be approximated by lossless over arbitrarily long time intervals. Hence sense dense systems. active nonlinear charged with initial energy. As by-product, obtain mechanisms explaining Onsager relations from time-reversible approximations, fluctuation-dissipation theorem uncertainty state system. The applied measurement devices used quantify limits on so-called observer effect, also called back action, impact device has observed particular, shown deterministic action compensated using elements, whereas stochastic unavoidable depends temperature device.