Trieste. Ludwig Boltzmann hangs himself while his wife and daughter are swimming in the Adriatic Sea during a vacation. Boltzmann is the first to understand that the arrow of time appears only when there is heat. And that therefore the concept of time is linked to entropy (which measures how many configurations our blurry vision cannot distinguish) and the Second Law of Thermodynamics. Time is a kind of illusion: if I could see the intimate nature of things in detail, time would disappear, and there would be only mutual relations.
