Richard A. Muller’s Now offers a bold, testable theory of time that challenges conventional physics and redefines our understanding of the present moment.

In Now: The Physics of Time, Muller confronts one of the most elusive concepts in science: what exactly is “now”? While Einstein’s theories of relativity revolutionized our understanding of time’s flexibility and its link to gravity, they failed to explain the subjective experience of the present. Muller argues that physics must account for this phenomenon rather than dismiss it as illusion. He proposes a groundbreaking idea: just as the universe expands spatially, it also expands temporally—and the leading edge of this expansion is what we perceive as “now.” Drawing on relativity, entropy, quantum entanglement, and the Big Bang, Muller builds a framework that not only reinterprets time’s flow but also opens new debates about free will and the nature of reality. With clarity and intellectual rigor, Now invites readers to rethink time not as a static dimension, but as a dynamic frontier of existence.