I've been writing a lot recently about whether the reason for the increase of entropy over time (i.e. the second law of thermodynamics) is the time irreversibility of the weak nuclear force. I would like to get some people's thoughts on this topic (perhaps links to important papers on this subject.) My thoughts are below and also found at this link: http://eddiesblogonenergyandphysics.blogspot.com/2011/07/what-is-source-of-directionality-of.html" [Broken] I think that the time irreversibility of the weak nuclear force (the only known force with CP violation, and hence no Time reflection symmetry) is the main (if not only) reason for the thermodynamic arrow of time to only move in the direction of increasing entropy, i.e. one's knowledge of the exact microstate of a system can only decrease in time unless you spend work to measure the microstate of the system...and then your knowledge of the microstate decreases (regardless of how well you measure the properties of the system.) The loss of knowledge requires a source of randomization, which can not come from gravity, E&M or the strong nuclear force if they have Time reflection symmetry. This a major point in which I disagree with the work from Prigogine, who suggested that the reason for the irreversibility of large systems was that correlations between particles go away when the particles are far away from each other. How would one prove Prigogine's assumption? (upon which his books on non-equilibrium thermodynamics were based) I instead suggest that the only way for the entropy of the system to increase is if the Hamiltonian of the system is time irreversible, and hence that one of the forces of nature must be time irreversible. Here's the evidence I see that the weak nuclear force is the cause of the irreversibility in every day thermodynamic systems. 1) Entropy generation requires collisions between particles 2) There is virtual no entropy generation when a current flows through a superconductors (no resistance) or when a superfluid flows (no viscosity), i.e. virtually no entropy production in B-E condensates 3) Entropy generation appears in fermion-fermion (e.g. electron-electron collisions) and fermion-boson (electron-phonon collisions) 4) There are known T symmetry violations for the weak nuclear force 5) Recent evidence from neutron stars suggests that there are still protons in the core of neutron star and that they are in a superconducting/superfluid state and are unable to convert to neutrons because they are in boson state and unable to interact via the weak nuclear force. This is the main evidence I see for the weak nuclear force being the main (if not sole) cause for the thermodynamic 'arrow of time.' Let me know what you think.