In the field of physics, there has been much talk for many decades about additional dimensions of the universe we inhabit and experience. The first time people began considering this was ancient. Early human folklore is full of legends and myths of alternate realities, including god-realms, fae-realms, and realms of magic. Many include bridges or portals of travel between these multiple realms by such devices as the rainbow. In the mythology of Northern Europe, for example, we see a cosmos consisting of multiple worlds connected by the meta-medium of a great invisible world tree. Midgard or the world of earth exists in simultaneity with Asgard, the home of the Aesir or gods, Alfheim, the world of the Alfar or elves, and the realm of the Vanir a lesser race of divine beings. Below Midgard exists the underworld, which includes the realm of the dead where Hella reigns and Nifelheim, the realm of the earth-folk or dwarfs.
Stories of abduction by the fae, be they elves, fairies, goblins or whatever, involve enchantment or passing through some portal, to find oneself in a different world. Fantasy authors such as C.S. Lewis capitalized on this long folklore tradition in works of fiction, such as the alternate reality of the world of Narnia, accessed by magic or magical portals. Lewis even included a kind of meta-reality in the form of a timeless “wood between the worlds” full of pools of water, each of which was a portal to another reality. Digory and Polly in Lewis' first novel in the Chronicles of Narnia, The Magician's Nephew, enter this mystical meta-world by magical rings, and from there they teleport into the worlds of Charn and later Narnia. In the remaining novels, teleportation happens either from walking through the mystic wardrobe, a portable clothing closet made from wood grown from a seed from Narnia, or they are summoned there and later sent home by Aslan's mystical/divine power.
In the genre of science fiction, we see alternate realities explored even more thoroughly, with characters traveling or teleporting to such dimensions as subspace, pocket-universes, alternate timelines, mirror universes, the past or future of this universe, and the meta-verse of the Mycelial Network, featured in Star Trek: Discovery. And back to modern physics, theory and experiment suggest very strongly that alternate timelines and other additional layers of reality may in fact exist. I was always entranced by this notion of alternate realities and have ruminated a great deal about this in my lifetime. I would like to explore this in this essay, and share my thoughts on it.
Beginning with everyday experience, we consider dimensions of space, or degrees of freedom in travel or translational movement, that are independent of one another, meaning if I travel along only one, I do not travel along the other. Clearly I can head north or south without going east or west at the same time, and vice versa. This means for horizontal travel there are two dimensions. I can also drop a stone from a tower and it will fall to the ground without moving horizontally. This adds a third dimension of freedom in travel. Most people think of our world as three-dimensional and in virtual realities, such as a stage production, movie, or virtually-real interactive game, efforts are always made to model these three dimensions of existence. Sound systems are considered superior if they can project sound from all directions and thus reproduce and 3-dimensional sonic environment for television or film-viewers.
But what of time? We know we experience a dimension of cause and effect, which we call time. If I do something now, it will determines things later. In fiction, people often go back in time to alter events and upon returning home, find that reality has changed as a result. One of the first thinkers to wrestle with the dynamics of time was Albert Einstein. This physicist and scientific philosopher proposed a then-radical theory that time is a fourth dimension and that its rate of progression is not only flexible, but depends on the reference frames of the observer and the observed. These axioms were later supported by laboratory experiments. High-speed particles that are known to decay at a certain intrinsic rate of probability demonstrate a “slowing down” of causality and a drop in their rate of decay when traveling close to the speed of light. The rate of progression along the dimension of time thus depends closely on ones speed of travel and by extension within general relativity, on acceleration, rate of change in acceleration and other higher-degree parameters of motion. So without any more discussion of Einsteinian relativity, we can say that time is a fourth dimension or degree of freedom in existence.
At about the same time as Einstein was developing his Theory of Relativity, other scientists were exploring the theory of Quantum Physics. Experiments had demonstrated that energy does not increase or decreases in a continuous manner, but rather jumps suddenly to a higher or lower level. One way to model this is to consider the behavior of waves on a violin string. Any vibration along such a string must be self-sustaining, and therefore cannot be of a frequency or wavelength that produces reflective waves at the fixed ends of the string that upon returning weaken or cancel out the wave. Only certain frequencies of vibration can then exist on the string and these are called harmonics. The same behavior is observed with sound waves in organ pipes and other wind instruments, with waves in water, and with waves of light. The energy on a such a bounded medium is said to be “quantized” and an impulse of energy so quantized is called a “quantum”, the plural being “quanta”.
Further experiments demonstrated that not only is the energy of wave phenomena quantized, but so also is the energy of so-called particles, or bits of matter. Modeling this required consider particles to have a wave-like second nature. The position or energy of a particle then is governed by quantization of wave-frequency in the particle's position or energy probability. This theory has become perhaps the most well-supported and “proven” physical theory of all time.
What bearing does this have on the question of additional dimensions? Experiments with diffractive interference of light and electrons have born out the hypothesis that both are both wavelike and particle-like in nature, a seeming contradiction, but in truth self-consistent. If we consider an unbounded string, one extending infinitely in both directions, and we set that string vibrating, because it is not bounded, it can vibrate with any frequency. However, as more and more frequencies are super-imposed, the vibration becomes more and more focused upon on position on the string. While this experiment cannot be carried to conclusion in the lab, due to our inability to create or manipulate a string of infinite length, the mathematics of waves demonstrate that as we increase the range of simultaneous vibrational frequencies on the string, with the amplitude or intensity dropping as the frequency increases infinitely, in a manner that keeps the total energy finite, the vibration approaches a single point, or singularity, or in other words, it becomes a particle.
Experiments with diffractive interference demonstrate that a wave of light allowed to pass simultaneously through two small apertures spreads out after passing through, like ripples from a stone dropped into a pond, These two ripple-patterns overlap and depending on the angle from the midpoint between the apertures, either weaken or strengthen each other. At some angles the result is a bright point of light and at others total darkness. Such interference can also be observed in the acoustics of poorly-dampened music halls and in the height of ocean waves along a shoreline behind a breakwater of finite length. Electrons, although particles, demonstrate such interference as well due to wavelike interference in their probabilistic movement. The really shocking thing, however, is that even if I send only one electron or one photon of light every second so that no two quanta are in the chamber at the same time, the pattern of interference still emerges. It would almost seem that difference in time is irrelevant, or that the particles are still interacting, but with particles in other parallel realities. Many physicists are drawn to the notion that all possible timelines or realities, differing from one another to one extent another in events, exist simultaneously and interact with one another. Simultaneous alternate realities exist then within a fifth dimension, or degree of freedom. In Star Trek: Discovery, the mirror universe of the Terran Empire is accessible by means of an engine that allows the ship to travel along a meta-reality called the “mycelial network”, which bridges between all timelines along a fifth dimension. Alternate realities are infinite in number because energy, position and movement within the universe has an infinite variety.
Star Trek also explores the notion of alternate realities of higher and lower energy within our own 4-space. “Subspace” is a kind of underground of our physical reality, made of energies and even particles with energies lower than that of empty space, called negative or dark energy and matter. In real-world physics, empty space or the pure vacuum has been shown to be full of energy, manifesting itself constantly in the form of temporary or virtual particles that carry forces like gravity or electromagnetism across space. These particles to not exhibit properties like inertia or momentum, because they exist at energies below that of the vacuum. The possibility of alternate realities existing simultaneously but invisibly with our own at low energies and either independent of it or in interaction with it creates a kind of sixth dimension.
Any meta-dimension containing all of these realities, differing in time, causal history, or energy level, would then be of seven dimensions. It's very interesting to note, that in Middle-eastern mythology, the divine number is seven or eight, depending on the culture. One might say that God in such mythologies, exists in the Seventh or Eighth Dimension. If we consider all the possible timelines and energy level-realms of our universe as a packet or single sixth-dimensional reality and then consider other independent 6-space universes that could exist, then that introduces a seventh dimension and the meta-dimension would then be eight, the divine number in Arabic tradition and modern Islam.
Additional degrees of freedom are also theorized, but existing in more limited or lower domains of our universe. What makes two protons share a repulsive force of electrical repulsion, while simultaneous attracted to one another by gravity? Why do two particles of matter attract one another, while being repelled by negative or dark matter? These forces and the nature of the intrinsic properties of mass and electric charge can be explained as additional dimensions of energy. Some suggest there maybe thirteen or more dimensions, six or more in addition to the 5 or 6 macro-dimensions I have already laid out and the dimension of dark energy also explained above, which is a micro-dimension or intrinsic property of the quanta considered.
I am not a theist and do not believe in personal or individuated gods. But as a Buddhist, I have pondered deeply the reflections of higher-dimensional physics upon the framework of Buddha-consciousness, an ultimate reality of pure consciousness beyond time and space. Reality, as we call it, is considered in Buddhist thought to be a kind of dream, a matrix, or virtual dream reality, existing not in a computer, but within the all-mind energy of Buddha-consciousness. Individual consciousness. “spirit” or “soul” if you wish to call it that, is a temporary condition within this framework. An individual consciousness exists continuously and intimately interconnected with others and together with all consciousness. A person may return after death through rebirth, but may become several people, or several upon death may return as one person. Like a subroutine “personality” in an AI, or like individual personalities in a person suffering with multiple-personality disorder, of which the characterization of “disorder” then becomes questionable, these “souls” exist for a time, learn and grow in wisdom and memory, and eventually “ascend through enlightenment”, awakening from the virtual dream and returning to full awareness of the collective. Individuation within the collective all-mind is fluid and dynamic, totally free, and under no compulsion to merge or individuate, any more than bacteria, planarian worms or sea anemones splitting themselves in two through binary fission or two gametes joining into one cell during fertilization. The all mind is both one and many at the same time, never going to either full separation or full absorption, but in constant dynamic and kaleidoscopic variation between them. Physics has become for me a scientific reflection of my earliest and most deeply held philosophical convictions and they in turn are a reflection of observation and of making sense of physical observations and experience.