The Debate Over Time's Place in the Universe
Physicists can’t agree on whether the flow of future to past is real or a mental construct.
theatlantic.com
Einstein once described his friend Michele Besso as “the best sounding board inEurope” for scientific ideas. They attended university together in Zurich; laterthey were colleagues at the patent office in Bern. When Besso died in the springof 1955, Einstein—knowing that his own time was also running out—wrote anow-famous letter to Besso’s family. “Now he has departed this strange world alittle ahead of me,” Einstein wrote of his friend’s passing. “That signifies nothing.For us believing physicists, the distinction between past, present, and future isonly a stubbornly persistent illusion.”
Einstein’s statement was not merely an attempt at consolation. Many physicistsargue that Einstein’s position is implied by the two pillars of modern physics:Einstein’s masterpiece, the general theory of relativity, and the Standard Modelof particle physics. The laws that underlie these theories are time-symmetric—that is, the physics they describe is the same, regardless of whether the variablecalled “time” increases or decreases. Moreover, they say nothing at all about thepoint we call “now”—a special moment (or so it appears) for us, but seeminglyundefined when we talk about the universe at large. The resulting timelesscosmos is sometimes called a “block universe”—a static block of space-time inwhich any flow of time, or passage through it, must presumably be a mentalconstruct or other illusion.... |
