Until the End of Time: Mind, Matter, and Our Search for Meaning in an Evolving Universe

by Brian Greene

To sum up: We are physical beings made of large collections of particles governed by nature’s laws. Everything we do and everything we think amounts to motions of those particles. Shake my hand and particles constituting your hand push up and down against those constituting mine. Say hello, and particles constituting your vocal cords jostle particles of air in your throat, setting off a chain reaction of colliding particles that ripples through the air, knocking into the particles constituting my eardrums, setting off a surge of yet other particles in my head, which is how I manage to hear what you’re saying. Particles in my brain respond to the stimuli, yielding the thought that’s a strong grip, and sending signals carried by other particles to those in my arm, which drive my hand to move in tandem with yours. And since all observations, experiments, and valid theories confirm that particle motion is fully controlled by mathematical rules, we can no more intercede in this lawful progression of particles than we can change the value of pi. Our choices seem free because we do not witness nature’s laws acting in their most fundamental guise; our senses do not reveal the operation of nature’s laws in the world of particles. Our senses and our reasoning focus on everyday human scales and actions: we think about the future, compare courses of action, and weigh possibilities. As a result, when our particles do act, it seems to us that their collective behaviors emerge from our a...