Time’s absence may make the universe easier to understand

19 April 2022

Writer’s on a tight deadline might disagree, but some physicists are beginning to believe that time may not exist. It’s a heady concept that there’s no such thing as lunch at one o’clock, because there’s no such thing as time, but when scientists talk about time, it’s on a cosmic scale, not a human one, says Dr Sam Baron of the Australian Catholic University, writing for The Conversation.

In the 1980s and 1990s, many physicists became dissatisfied with string theory and came up with a range of new mathematical approaches to quantum gravity. One of the most prominent of these is loop quantum gravity, which proposes that the fabric of space and time is made of a network of extremely small discrete chunks, or “loops”. One of the remarkable aspects of loop quantum gravity is that it appears to eliminate time entirely. Loop quantum gravity is not alone in abolishing time: a number of other approaches also seem to remove time as a fundamental aspect of reality.

The absence of time in this context though may account for discrepancies in some of the theories that scientists use to understand the universe, such as general relativity, quantum mechanics, and string theory.