Thermodynamic Asymmetry in Time
The thermodynamic time asymmetry is one of the most salient and consequential features of the physical universe. Heat flows from hot to cold, never the reverse. The smell of coffee spreads throughout its available volume, never the reverse. Car engines convert fuel energy into work and thermal energy, never the reverse. And so on. The science of thermodynamics is able to capture these generalizations as consequences of its claim that systems spontaneously evolve to future equilibrium states but do not spontaneously evolve away from equilibrium states. This generalization covers an amazing amount of macroscopic physics and is rightly celebrated as one of the great laws of physics.
Despite its familiarity, however, the thermodynamic arrow of time raises many deep questions relevant to both philosophy and the foundations of physics. This entry concentrates on two of them. In contemporary parlance, they are each questions about grounding. (1) What grounds the thermodynamic asymmetry in time? In a world possibly governed at bottom by time-symmetric laws, how do the time-asymmetric laws of thermodynamics arise? (2) Does the thermodynamic time asymmetry ground any other temporal asymmetries? Does it account, for instance, for the fact that we know more about the past than the future? The discussion thus divides between thermodynamics being an explanandum or explanans. What grounds the thermodynamic asymmetry, and given the asymmetry, what does it ground?
- 1. Thermodynamic Time Asymmetry: A Brief Guide
- 2. The Problem of the Direction of Time I
- 3. The Problem of the Direction of Time II
- Academic Tools
- Other Internet Resources
- Related Entries
(ME: Another bad day. However, relieved of need to go downtown to library, as I found that I could not cancel a check since it had already been sent out on Monday. Will be hot and humid here for a while, so I will spend a lot of time in AC'ed bedroom. That means gradually eliminating all my browser tabs so I can start up fresh and faster. Gradually more LJ comments. Possibly setting up WiFi. However, I need to go downtown anyway, not sure when, to do an Instacart order. All for now).