A game of quantum mirrors

Imagine you sit down and pick up your favorite book. You look at the image on the front cover, run your fingers across the smooth book sleeve, and smell that familiar book smell as you flick through the pages. To you, the book is made up of a range of sensory appearances.

But you also expect the book has its own independent existence behind those appearances. So when you put the book down on the coffee table and walk into the kitchen, or leave your house to go to work, you expect the book still looks, feels, and smells just as it did when you were holding it.

Expecting objects to have their own independent existence - independent of us, and any other objects - is actually a deep-seated assumption we make about the world. This assumption has its origin in the scientific revolution of the 17th century, and is part of what we call the mechanistic worldview. According to this view, the world is like a giant clockwork machine whose parts are governed by set laws of motion.

This view of the world is responsible for much of our scientific advancement since the 17th century. But as Italian physicist

Carlo Rovelli argues in his new book Helgoland, quantum theory the physical theory that describes the universe at the smallest scales almost certainly shows this worldview to be false. Instead, Rovelli argues we should adopt a "relational" worldview.

What does relational?

During the scientific revolution, the English physics pioneer Isaac

Newton and his German counterpart

Gottfried Leibniz disagreed on the nature of space and time.

Newton claimed space and time acted like a "container" for the contents of the universe. That is, if we could remove the contents of the claimed that space and time were universe - all the planets, stars and nothing more than the sum total of galaxies - we would be left with distances and durations between empty space and time. This is the all the objects and events of the "absolute" view of space and time. world. If we removed the contents

Leibniz, on the other hand, of the universe, we would remove

it mean

to be

‘‘According to orthodox quantum theory, the cat is neither dead nor alive until we open the box and observe the system. A puzzle remains concerning what it would be like for the cat, exactly, to be neither dead nor alive.”