The time paradox: How your brain creates the fourth dimension (2024)

SOME time ago, students at the University of Tennessee were handed an unusual assignment. Imagine yourself as a Lilliputian, they were told, as they stared at a miniature model of their communal lounge, complete with furniture and figurines. The students were asked to put themselves in the little people’s shoes, relaxing on the tiny chairs with minuscule cups of coffee. Then they had to say when they felt 30 minutes had passed.

For the notionally shrunken students, time flew. Their estimates fell well short of clock time. Even more curiously, the acceleration in their felt time was proportional to the scale of the model lounges in which they were immersed.

This bizarre result, reported in Science in 1981, is occasionally invoked by neuroscientists to suggest that space and time are folded together in the brain as they are in the universe. It is also one of many intriguing demonstrations of how malleable our perception of time is – and how mysterious.

Time’s passage is perhaps the most fundamental feature of our experience, and yet modern physics can’t decide if it is a fundamental property of the universe. So what is time, and why does it flow? How come it seems to slow and surge? And what, if anything, does the time we experience have to do with the time defined by the laws of nature?

The search for answers takes us into the strange borderlands between neuroscience and physics – a foggy, treacherous place that exposes the limits of our ability to see reality as it really is, forcing us to confront the idea that time is all in the mind.

It…