Challenging the Idea that Space and Time are Fundamental Constituents of Nature

September 21, 2013 - Amplituhedron / art / mapping / physics / quantum / reality screen / science

A recent article in Quanta Magazine, which has been circulating around the internet through social media, reviews recent challenges to the idea that space and time are “fundamental components of reality.” A few sections of the article stand out to me as especially interesting when considered in light of spiritual and religious traditions across human culture. I’m including the quotes here without any further commentary other than to emphasize some phrases in bold.

“Locality is the notion that particles can interact only from adjoining positions in space and time. And unitarity holds that the probabilities of all possible outcomes of a quantum mechanical interaction must add up to one. The concepts are the central pillars of quantum field theory in its original form, but in certain situations involving gravity, both break down, suggesting neither is a fundamental aspect of nature.

In keeping with this idea, the new geometric approach to particle interactions removes locality and unitarity from its starting assumptions. The amplituhedron is not built out of space-time and probabilities; these properties merely arise as consequences of the jewel’s geometry. The usual picture of space and time, and particles moving around in them, is a construct.


Artist’s rendering of the amplituhedron. (Andy Gilmore)

“They have also found a ‘master amplituhedron’ with an infinite number of facets, analogous to a circle in 2-D, which has an infinite number of sides. Its volume represents, in theory, the total amplitude of all physical processes. Lower-dimensional amplituhedra, which correspond to interactions between finite numbers of particles, live on the faces of this master structure.”

Amplituhedron Drawing

A sketch of the amplituhedron representing an 8-gluon particle interaction. (Nima Arkani-Hamed)

“Beyond making calculations easier or possibly leading the way to quantum gravity, the discovery of the amplituhedron could cause an even more profound shift, Arkani-Hamed said. That is, giving up space and time as fundamental constituents of nature and figuring out how the Big Bang and cosmological evolution of the universe arose out of pure geometry.

‘In a sense, we would see that change arises from the structure of the object,’ he said. ‘But it’s not from the object changing. The object is basically timeless.‘ “

Read the full article here.