Q&A: Richard Muller on why the flow of time is not an illusion

“Now—that enigmatic and ephemeral moment that changes its meaning every instant—has confounded priests, philosophers, and physicists, and with good reason.” So writes Richard Muller, a physicist at the University of California, Berkeley, in the opening lines of Now: The Physics of Time (W. W. Norton, 2016). But Muller thinks he might have a solution to the puzzle—one that can be experimentally tested. In the February issue of Physics Today, reviewer Martin Bojowald calls Muller’s theory “original and intriguing” and says that Now “presents important lessons in physics and beyond.”

Physics Today recently interviewed Muller about space, time, climate change, and how to talk to future world leaders about physics.