In the elementary equations of the world, the arrow of time appears only where there is heat. The link between time and heat is... fundamental: every… - Carlo Rovelli

Intuitively (and imprecisely) speaking, time "flows", we can never "go back in time", we remember the past but not the future, and so on. Where do all these very peculiar features of the time variable come from? ...[T]hese features... emerge at the thermodynamical level. ...[T]hese are all features that emerge when we give an approximate statistical description of a system with a large number of .

But it isn’t absence that causes sorrow. It is affection and love. Without affection, without love, such absences would cause us no pain. For this reason, even the pain caused by absence is, in the end, something good and even beautiful, because it feeds on that which gives meaning to life.

The landscape is magic, the trip is far from being over.