Thermodynamic Depth of Causal States: When Paddling around in Occam's Pool Shallowness Is a Virtue
| dc.creator | Crutchfield, James P. | |
| dc.creator | Shalizi, Cosma Rohilla | |
| dc.date | 1998-08-13 | |
| dc.date.accessioned | 2026-07-07T03:11:18Z | |
| dc.date.available | 2026-07-07T03:11:18Z | |
| dc.description | Thermodynamic depth is an appealing but flawed structural complexity measure. It depends on a set of macroscopic states for a system, but neither its original introduction by Lloyd and Pagels nor any follow-up work has considered how to select these states. Depth, therefore, is at root arbitrary. Computational mechanics, an alternative approach to structural complexity, provides a definition for a system's minimal, necessary causal states and a procedure for finding them. We show that the rate of increase in thermodynamic depth, or {\it dive}, is the system's reverse-time Shannon entropy rate, and so depth only measures degrees of macroscopic randomness, not structure. To fix this we redefine the depth in terms of the causal state representation---$ε$-machines---and show that this representation gives the minimum dive consistent with accurate prediction. Thus, $ε$-machines are optimally shallow. | |
| dc.description | 11 pages, 9 figures, RevTeX | |
| dc.identifier | https://arxiv.org/abs/cond-mat/9808147 | |
| dc.identifier | http://arxiv.org/abs/cond-mat/9808147 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/28522 | |
| dc.subject | Statistical Mechanics | |
| dc.subject | Adaptation and Self-Organizing Systems | |
| dc.subject | Chaotic Dynamics | |
| dc.title | Thermodynamic Depth of Causal States: When Paddling around in Occam's Pool Shallowness Is a Virtue | |
| dc.type | text |