The following is an extract from our Lost in Space-Time newsletter. Each month, we dive into fascinating ideas from around the universe. You can blame my youngest child for the existential crisis that I’m about to drag you into.
When he gazed up with his innocent wide eyes to ask, “Mum, do you think we could be living inside a computer game?”, little did I know that my search for an answer would require a three-year journey of discovery! Could this all in fact be a computer simulation of a virtual reality so perfect that it appears to be real in every sense? Day one of my quest started with an epic internal battle between the part of me that wears my Astronomer Royal for Scotland hat, and the other part of me who is still a toddler.
Astronomer Royal: “If a scientific question cannot be directly tested, it is, by definition, worthless. Move on.” Inner toddler: “Why? What is real?” It took a week before I settled on a position.
The ability to simulate reality hinges on the question of whether everything in our universe is mathematical – maths is the only language that computers speak – and the Astronomer Royal could certainly interrogate that. Let’s start by celebrating the particle physicists who revolutionised our understanding of the building blocks of reality with their “shut up and calculate” prescription for quantum mechanics, (an approach that handily evades all the problematic philosophical questions that arise when you zoom into the quantum realm). In the 1970s, they gave birth to a single algebraic equation, the so-called standard model, that predicts the number of subatomic particles, their properties and how they interact with each other.
Using this mathematical model, they predicted what should be observed when two protons smash into each other at close to the speed of light and break apart to reveal their innards. To carry out this challenging particle-smashing experiment, they built CERN, a 27-kilometre ring of superconducting magnets buried 100 metres under the France-Switzerland border. The perfect accuracy of the theorists’ predictions compared with the precision of CERN’s experimental measurements is breathtaking.
The resulting discovery of the long-searched-for Higgs boson affirms our hypothesis that the universe is very mathematical. Why banishing irrational numbers could trigger a revolution in quantum theory But then the astronomers came along, throwing several spanners in the works. For example, particles called neutrinos change their personality – switching from one so-called flavour to another – in the eight and a half minutes it takes them to travel from the sun’s core to our detectors.
Extract — continue reading at the source.
