> [!Seven brief lessons on physics, Carlo Rovelli] > - We don't live in an inert box. Space curves and bends, like the waves of the sea. > - It is energy, heat, what bends space. The sun bends space around itself and thus the Earth moves like a marble that rolls in a funnel. > - No particle has a definite position, except when colliding with another one. Thus, particles don't exist in a continuous way, but in leaps. These are linked to each other, forming a network of relations which weaves the texture of space. > - These leaps don't occur in a predictable way, but at random. We can only calculate the probability that one particle will appear here or there. > - There is no such thing as real void. Particles always move, for little that it is. Reality is formed of particles having brief existences, continually appearing and disappearing, colliding with others. > - The relations don't follow an order, or tempo. Each process dances independently of others. This means that processes cannot be ordered in a succession of instants. > - There is thus no longer space which contains the world, and there is no longer time in which events occur. There are only elementary processes wherein quanta of space and matter continually interact with each other. > - Atoms and molecules are always moving. A hot substance is one in which atoms move more quickly. Cold ones, the opposite. > - Heat always moves from hot things to cold. The reason for this is that it is statistically more probable that a quickly moving atom of the hot substance collides with a cold one and leaves it a little of its energy, rather than viceversa. > - We know something about physical objects, but not everything about their state, so we can only make predictions based on probabilities, but only considering the variables we can observe. > - For a supersensible being there would be no flowing of time: the universe would be a single block of past, present, and future. But due to the limitations of our consciousness we only perceive a blurred vision of the world, and live in time. > - When we say that we are free, this means that how we behave is determined by what happens within us, within the brain, and not by external factors. To be free doesn't mean that our behavior is not determined by the laws of nature. It means that it is determined by the laws of nature acting in our brains. There is not an I and the neurons of my brain. They are the same thing.