Everything is made of Fields

Space and time are typically defined using a familiar and somewhat implicit abstraction that prefigures a dichotomy between bodies/entities and physical space. Bodies/entities are characterized by a position, may move throughout space, interact and transform into each other. In this abstraction, empty space plays no substantial role, apart from providing a "natural" notion to distinguish between various systems and allow one to calculate their spatial distance.

But -in fact- a reasonable description of reality needs to consider space itself as a system, and all entities we observe (including ourselves) as its components or its properties.

For instance, let's consider empty space as nothing. This immediately leads to a wide range of paradoxes: how is it possible that systems (like us and the Earth) move through nothing? What exactly is nothing? Does nothing exist or not?

Beyond this "intuitive" resoning, there is a much sounder one. In the course of countless trial and errors, Scientists have been forced to use this concept in order to be able to adequately explain natural phenomena. In fact, all most precise fundamental theories of physics treat space itself as a system. This naturally leads us to the concept of field.

What is a field?

In physics, a field is a physical property associated to each point in space and time (spacetime). The basic concept is indeed well-known to everyone. Think about weather forecast: the presenter graphically shows the value of physical properties such as temperature or wind in different points/areas of space (earth surface) and time (day by day). In this case, temperature is a so-called scalar field, i.e., identified by a simple number, while the wind is a vector field (represented by a little arrow) because characterized by an amplitude (wind strenght) and a (spatial) direction, for each point in spacetime. In general, a field is a mathematical object used to represent physical (measurable) properties of interest at every point in spacetime.

Reality at elementary level

The most elementary and accurate descriptions of nature are currently expressed in terms of fields (although quite different from the ones we are accustomed to in our daily experience), simultaneously present at each spacetime point and able to interact, and affect each other according to precise rules. These rules are written in a mathematical language (theories), known as General Relativity (gravitational field) and Standard model of particle physics (all fields today considered as elementary except the gravitational field). Specific predictions of the standard model have been verified in laboratory with an unprecedented precision of about one part out of 1000 billions! Although it is certainly not the final answer, given the current agreement with experimental results, the standard model can be considered the best theory ever built by humankind.

In agreement with the standard model, empty space is very different from nothing. It simply corresponds to the lowest energy state (fundamental state) for all the underlying fields, while systems that we can measure and observe (including us) correspond to excited states, that is, characterized by a higher energy level than empty space.

An analogy

A very intuitive (although imperfect) analogy is provided by the famous cartoon "La Linea" (The Line) di Osvaldo Cavandoli, in which space is simply a continuum (flat line), and every object, including the character can be distinguished as lines with different height/shape (that is, different energy levels):

Hence:

I don't know about you, but for me this aspect means a authentic paradigm shift of the concept of reality as we know it from our daily experience. While it is well-known to physicists, it is much less known to the public. This article, as well as my recent book (sorry, only in italian for the moment - I am working on an english version, stay tuned...), is my small contribution to fill this very relevant gap.