Ideas

Space, the multiverse and quantum mechanics at the Festival dei Sensi

The infinitely small and the infinitely large are the focus of the exhibition in Itria Valley from 22 to 25 August

by Gian Francesco Giudice

20 August 2024

3' min read

In the early 20th century, physics experienced an overwhelming revolution. While Picasso shattered the pictorial image, Joyce disrupted narrative technique and Freud delved into the human psyche, the advent of the theory of relativity and quantum mechanics demolished the classical conception of physical reality. Just as art would never be the same after the avant-garde movements of the early 20th century, physics changed forever.

A new vision of the physical world emerged, completely different from the one we derive from sensory perception and common intuition. Nature revealed an unfamiliar face when observed at near-light speeds, subatomic distances, or exceptionally intense gravity. Under these extreme conditions, space and time merge into a single malleable entity, which deforms and contorts under the effect of matter and energy.

Einstein

This is the world of Einstein's relativity. At microscopic distances, the contours of reality blur into inevitable indeterminacies, matter and energy fragment into distinct lumps, and the mechanistic conception gives way to chance, governed by probabilistic laws. This is the world of quantum mechanics.

"The faces in my portraits are more real than the real ones," abstract painter Paul Klee noted in his diary in 1901. The same can be said for modern physics, which describes an apparently abstract world, but in reality reveals the essence of the fundamental laws that govern nature. Classical physics, prior to the 20th century revolution, barely scratches the surface of objective reality. To penetrate the depths of the natural order, one needs relativity and quantum mechanics. These theories are not an abstract description of phenomena that only occur under extreme conditions, but paint the true face of nature.

Relativity and quantum mechanics

Understanding the language of nature, based on relativity and quantum mechanics, has paved the way for the exploration of territories inaccessible to direct observation. The secret is the deductive power of the scientific method, which allows the limits of perception to be overcome with a clever blend of theoretical reasoning and experimental measurements.

The most fascinating example of the exploration of phenomena that cannot be reproduced in the laboratory is the study of cosmic origin. As I recount in the book Prima del Big Bang, published by Rizzoli, science has recently made enormous progress in understanding what gave birth to that special mixture of space, time and matter that we call the universe.

It was surprising to discover how the necessary ingredients for a cosmic origin come from precisely those seemingly abstract theories, namely relativity and quantum mechanics. The result is paradoxical: how can quantum mechanics, the theory that governs the microscopic world, determine global properties of cosmic space?

The answer lies in the theory of relativity that distorts space during the evolution of the universe, greatly diluting the microscopic quantum effects. The infinitely small and the infinitely large become blurred during cosmic history. This mutual collaboration between quantum mechanics and relativity is entirely tangible because it generates the galactic structures that are observed in the sky today. If quantum mechanics did not add that hint of inhomogeneity to the cosmic recipe, the universe would today be a uniform gas without any form of life.

Recent astronomical observations have supported the hypothesis on the quantum origin of celestial structures. The Euclid project, coordinated by the European Space Agency with a decisive Italian contribution, will soon provide new clues on the role played by quantum mechanics in cosmic infancy.

The quantum hypothesis opens up staggering perspectives when our imagination propels us to explore the universe to enormous distances. The same phenomenon that produces galactic structures could be repeated at much larger scales. The universe in which we live would then be just an island of matter, immersed in a gigantic empty space, dotted with other universes, each with its own characteristics. This is the image of the multiverse, i.e. a complex cosmic structure made up of a multitude of isolated universes wandering in space. It is a magnified version of the image that appears to us on the night sky, dotted with stars immersed in a cosmic void.

This and more will be discussed at the Festival of the Senses, which will be held in the Itria Valley from 22 to 25 August and has Space as its theme. The starry summer sky will be the backdrop to the journey through space and time, beyond the limits of sensory perception, amidst the scents of olive trees and the sight of the distant sea. With the Festival dei Sensi, the enchanting places of Apulia will be transformed into a multiverse of curiosity and knowledge.