A number of interpretations of quantum mechanics postulate a “quantum realm.” These include the Transactional Interpretation.* One of its developers, Dr. Ruth Kastner, calls it “Quantumland.”
Here’s a drawing of Quantumland that Dr. David Chalmers, the noted philosopher of physics, presented in a lecture :
The quantum realm on the left underlies our everyday world on the right. [Image source: David Chalmers and Kelvin McQueen, “Consciousness and the Collapse of the Wave Function” http://consc.net/slides/collapse.pdf]
In this drawing, the waviness on the left is a metaphor for the quantum realm. It is a metaphor because these waves are not in a known physical medium. We are accustomed to water waves traveling through the medium of water and sound waves traveling through the medium of air. For example, below is an animation of a wave traveling through the medium of some kind of mesh.
Classical wave traveling through a mesh. This is not a quantum wave due to its traveling through a medium made of matter. [Animation by: Christophe Dang Ngoc Chan (cdang) – Own work, CC BY-SA 3.0; https://en.wikipedia.org/wiki/Se… ]
Somehow, in the quantum realm, there are waves with no medium or, possibly, a medium that we can’t detect. I, for one, cannot imagine a wave travelling through no medium at all. The quantum realm, for us, is mathematical equations to which we assign physical meaning by creating metaphors.
The quantum realm is ever-changing wavinesses evolving into new wavinesses. It underlies our everyday physical reality. Changes in the wavinesses of the quantum realm result in changes in the probabilities of what we will observe in our physical reality.
Should some part of the quantum waviness be detected, it immediately takes form as a real particle. For example, let’s say that a part of the wavy quantum realm represents a photon from the sun. Let’s say that the math representing the waviness describes the probabilities that we will see a red photon or a yellow photon, with high probabilities that we will see a yellow one. As it hits our eye, let’s say that we see a yellow one. The waviness in the quantum realm has had real life results in our everyday physical universe.
The moment that the probabilities result in a yellow photon in our eye is the “collapse of the wave function” (as labeled in the above drawing).
Entanglement in the Quantum Realm
[Image source: NASA/JPL/Cal Tech]
If we were in the quantum realm, not only would we experience ever-changing waviness all around us, we would also, in certain situations, experience a one-ness with waviness at great distances from us. This is quantum entanglement. In quantum entanglement, waviness in one area can correlate its behavior with waviness on the other side of the universe. It’s as if time and space, as we know them, do not exist in the quantum realm.
Just as in a mystical experience, two wavinesses across the universe from each other are one. This results in two particles in physical reality correlating their behavior across the universe instantaneously. For example, two spinning electrons on opposite sides of the universe can coordinate the directions of their spin instantaneously.
Quantum entanglement is a phenomenon well-supported by mathematical calculations and experimental evidence. Though, the experiments are not conducted on opposite sides of the universe—the “opposite sides of the universe” idea is extrapolated mathematically from laboratory results.
Living in “The Matrix”
I think of the quantum realm as underlying our physical reality similarly to the way that computer code underlies what we see on our computer monitor. The code is a sea of ever-changing numbers as electricity zips through it and equations are solved. But those numbers are meaningless to most of us. For our convenience, the changing numbers of the code light up pixels on the screen. We see the changing images and text on the screen, and we grasp the meaning of the underlying computer code.
The coding of virtual reality as in “The Matrix.” [Image source: By Jahobr – Own work, CC0, File:Digital rain animation medium letters shine.gif]
Our everyday reality is something like “The Matrix,” with the quantum world being like the computer coding underlying it all. This is not to say that we’re living in a virtual reality produced by a computer. It could, for example, be a virtual reality created in consciousness. This idea is at least as old as Buddhism but has been gaining new currency, as in the work of Dr. Donald Hoffman.
*The Transactional Interpretation was first developed by John Cramer in the 1980’s with further development by Ruth E. Kastner in recent decades. For a lay explanation, see Kastner, Understanding Our Unseen Reality, Solving Quantum Riddles, Imperial College Press, London, 2015. Also see Kastner’s mathematical presentations for physicists in books and journal articles.