Your Brain is a Time Machine: The Neuroscience and Physics of Time

by Dean Buonomano

Stephen Hawking states, “The reason we say that humans have free will is because we can’t predict what they will do.”15 Similarly, for Roger Penrose, “The issue of free will is discussed in relation to determinism.”16 In other words, if the laws of physics establish that it is possible to predict the state of any system at time t, including the human brain, from previous moments in time, then free will does not exist. As explained by the philosopher Michael Lockwood: “Universal determinism is so widely held to be incompatible with the existence of free will. For universal determinism is the thesis that the universe is subject to a set of rigid laws that, in conjunction with the state of the universe at any given time, prescribe precisely what state the universe will be in at any subsequent time. If the universe really is deterministic in this sense, it follows, . . . that all future outcomes—including, therefore, all our own future choices and actions—are already fixed.”