In physical realism, matter objects are real but the space between them isn’t, so it is just nothing and nothing, by definition, should do nothing. Yet light waves travel in even the purest vacuum so space doesn’t do nothing, it hosts light. If light waves travel in a vacuum, space as the medium of those waves can’t do nothing. Likewise, that gravitational waves travel in space implies it is something with the sort of elasticity to allow that.
A space of nothing should have no properties but space enables the property of distance, as if there is nothing between the earth and the moon, why aren’t they touching? That space allows the property of distance even without matter present suggests again that it isn’t nothing.
If empty space was really empty it would have no energy but the evidence is that:
“… space, which has so much energy, is full rather than empty.” (Bohm, 1980) p242.
That empty space isn’t empty(Cole, 2001) is illustrated by The Casimir effect. Two uncharged flat plates held close together in a vacuum register a force pushing them together. Current physics attributes this vacuum pressure to virtual particles that pop out of the “empty” space around the plates but how can emptiness create particles? Quantum theory allows the Casimir effect because it says that a point of space can’t constantly have zero energy. The dynamic nature of space causes the energy of the vacuum but a truly empty space couldn’t have this property.
Martin Rees suggests how space could be something as follows:
“Empty space seems to be nothing to us. By analogy, water may seem to be nothing to a fish – it’s what’s left when you take away all the other things floating in the sea.”
He suggests that space is something although it seems nothing to us because it is a constant background. Empty space isn’t a physical thing but as Einstein said it has to be “something” for relativity to work:
“…there is a weighty argument to be adduced in favour of the ether hypothesis.” (Einstein, 1920).
And quantum theory itself implies some sort of quantum ether:
“The ether, the mythical substance that nineteenth-century scientists believed filled the void, is a reality, according to quantum field theory” (Watson, 2004) p370.
The current answer to this conundrum, that space is something and nothing, is field theory. In the case of light, space hosts an electromagnetic field that rotates into an imaginary fourth dimension as described by Maxwell’s equations. The “nothing” of space now hosts non-physical fields that cause physical effects but how does empty space do that? In physical realism, physical effects have physical causes but field theory’s fields aren’t physical any more than space is. That non-physical fields have physical effects works as long as no-one asks “What is really going on?” How can the “nothing” of space plus an imaginary field create the “something” of a physical force?
In quantum realism, empty space is the quantum network running a null process and matter is the same network running another process. The network shows nothing or something in the same way that a screen can show blank or an image. When the network presents as empty space, it runs a positive-negative null process that sums to zero. When it hosts light, a non-zero displacement moves across it, and when it hosts matter, that displacement remains at a point, as the following chapters explain in more detail.
Space as network null processing has a distance property so the earth doesn’t touch the moon because there are null nodes in between. Space as the network doing nothing can also be that through which matter moves but how can empty space as null processing have energy? If empty space is null processing, why isn’t the result all zeros?
The answer is that a null process is a positive-negative displacements that is only zero at the end of each cycle. On a synchronized network, all the nodes would be zero at the same time but the quantum network is asynchronous so that isn’t so. Thanks to light, it is mostly synchronous but not perfectly as each node cycle runs independently, so all the nodes of empty space aren’t zero at the same time. The quantum theory statement that points of space fluctuate in energy reflects the essential asynchrony of the quantum network. The points of space average zero over time but at any instant they aren’t simultaneously zero, as quantum theory says. Like the static on a blank screen, space averages to nothing but isn’t constantly so. The quantum network is the non-physical medium that Einstein suspected had to exist.
Newton saw space as like a tablecloth that presents the cutlery of objects but quantum theory sees dynamic states that only average to nothing. That space is more like what Wheeler called a quantum foam than a passive surface is evidenced by the Casimir effect but if empty space is “full” not empty, what is it full of? Physical realism has no answer but quantum realism says it is full of quantum processing.
When one looks through a window, one sees the view but not the glass transmitting it. One only sees the glass if it has imperfections, a frame around it, or if one can touch it. Now suppose the “glass” transmitting physical reality has no imperfections so it can’t be seen, is all around so there is no frame, and it transmits matter as well so we can’t touch it. The quantum network is like a perfect glass that flawlessly reveals the images of physical reality without showing itself. It is the fullness that we call emptiness.