Rovelli explains this through entropy, a measure of disorder first introduced in thermodynamics by Ludwig Boltzmann. As the universe moves from order to chaos, we perceive an arrow of time.

of Vienna (1986-1998), Associated Scientist with the Ludwig Boltzmann Institute of Osteology, Vienna (since 1993), Visiting Scientist at Heriot Watt Univ. Edinburgh (1993-1994), Visiting Professor at ...