I tried to describe the 'big picture' of Smolin's book in yesterday's post. Today I'll write about a detail -- a point hidden in the end note, the lengthy note 10 for the chapter 16.
Smolin discusses the different "arrows of time" and the question whether they can all be reduced to one. Is time's directionality one fact, or several? He seems to think it is several distinct facts. There is a cosmological arrow, a thermodynamic arrow, a biological arrow, an experiential arrow, and an electromagnetic arrow. In principle, we could perhaps reduce the biological and experiential flow of time to thermodynamics, though Smolin sounds dubious even about this. "We remember the past and not the future because memory is a form of organization, and organization decreases in the future -- or so it is claimed." Similarly, as to biology, "we age, it is claimed, because disorder accumulates in our cells."
But where he steps in with something more than a skeptical it-is-claimed tone is against any idea of combining thermodynamics with cosmology.
"It's ... possible to imagine a universe that expands to its maximal size and then collapses. As far as we know now, this isn't the universe we live in, but there are solutions to the equations of general relativity that behave this way. This would be a world where the cosmological arrow of time reversed halfway through. Would the thermodynamic arrow of time reverse as well, so that all of a sudden spilt milk cleaned itself up and Humpty-Dumpty reassembled himself? Science fiction writers like to imagine this, but it's wildly implausible."
His note 7 for the same chapter refers us to The Curious Case of Benjamin Button, so I've included a poster from that movie above.