Overview: Could Life And Consciousness Be Related To The Fundamental Quantum Nature Of The Universe?
Consciousness defines our existence and reality. But how does the brain generate thoughts and feelings? Most explanations portray the brain as a computer, with nerve cells ("neurons") and their synaptic connections acting as simple switches, or "bits" which interact in complex ways. In this view consciousness is said to "emerge" as a novel property of complex interactions among neurons, as hurricanes and candle flames emerge from complex interactions among gas and dust molecules. However this approach fails to explain why we have feelings and awareness, an "inner life". So we don't know how the brain produces consciousness.
We also don't know if our conscious perceptions accurately portray the external world, or if we all have similar pictures of what lies outside our conscious minds. In fact, the fundamental nature of reality remains as mysterious as the mechanism for our conscious perceptions.
Reality seems to be described by two sets of laws. In our everyday ("classical") world, the physics of Newton and Maxwell accurately and logically predict the behavior of objects and energy. However at very small scales (e.g. that of atoms and sub-atomic particles), the seemingly bizarre and paradoxical laws of quantum mechanics reign. For example in the quantum world, particles may be "schizophrenic", occupying two or more places or states at the same time (quantum superposition). And quantum particles separated in distance may be intimately connected (nonlocal quantum entanglement) and/or unified into common entities (Bose Einstein condensation).
Despite our lack of understanding, these strange quantum properties are utilized in quantum computation and other forms of quantum information technology (e.g. quantum cryptography, quantum teleportation) which are likely to revolutionize science.
Quantum computers differ from conventional computers which represent information as e.g. binary bits of either 1 or 0. In quantum computers information may also be represented as simultaneous quantum superposition of both 1 AND 0 (quantum bits, or "qubits")! While in superposition, qubits interact/compute with other qubits via nonlocal quantum entanglement. Eventually each qubit "collapses" from its quantum schizophrenia and chooses either 1 or 0 as its classical form. The classical bits resulting from the previously entangled qubits are the solution, or answer to the quantum computation. Because the quantum interactions among qubits occur in near infinite parallelism, quantum computers have enormous potential advantages over conventional computers, at least for certain applications.
But why are there two separate realities, and how are they related? The boundary between the quantum and classical worlds is unclear, and the transition between the two is commonly described as quantum state reduction, collapse of the wave function, or decoherence. Although quantum effects generally occur at small scales there is no apparent transition or cutoff due to size or scale, no absolute reason why large objects may not be in superposition.
Early quantum experiments led to the conclusion that quantum superpositions persisted until measured or observed by a conscious observer, that "consciousness collapsed the wave function". This became known as the "Copenhagen interpretation", after the Danish origin of Nils Bohr, its primary proponent. The Copenhagen interpretation placed consciousness outside physics!
To illustrate the apparent silliness of this idea, Erwin Schrödinger in 1935 formulated his famous thought experiment now known as Schrödinger's cat. Imagine a cat in a box. Outside the box a quantum superposition (e.g. a photon both passing through and not passing through a half-silvered mirror) is coupled to release of a poison inside the box. According to the Copenhagen interpretation the poison would be both released and not released, and the cat would be both dead and alive until the box was opened and the cat observed. Only at that instant would the cat be either dead or alive. Schrödinger intended his thought experiment to show how ludicrous was the Copenhagen interpretation, however to this day there is no accounting for reduction or collapse of a large scale, isolated quantum superposition.
Experiments also seemed to show that when quantum superpositions do reduce/collapse, the particular choice of classical states among various possible superpositioned states was random. This presumption displeased Einstein: "God does not play dice with the universe". (Randomness in quantum computers is averaged out, so that results reflect quantum algorithmic processes.)
There are several modern interpretations of quantum state reduction, or "collapse of the wave function".
Persisting is the Copenhagen interpretation (measurement or conscious observation collapses the wave function) which is consistent with "positivist" philosophies in which the mind constructs reality. The Copenhagen view puts consciousness outside physics, but doesn't account for fundamental reality; it merely accounts for the results of experiments.
The "multiple worlds" or "multiple minds" view follows a suggestion put forth by Hugh Everett that each superposition is amplified, leading to branching off of a new universe and conscious observer; in one universe the cat is dead, and in another universe the cat is alive. There is neither collapse nor reduction, however an infinity of realities (or of conscious minds) is required.
Another interpretation which avoids reduction/collapse is that of David Bohm in which objects have both a particle aspect and a "pilot" wave aspect (non-local hidden variable or quantum potential) which acts on and guides the particle. Bohm's approach shows that the quantum world can exist independently of the human mind, offering a "realist" alternative to Bohr's prevailing "positivist" Copenhagen view. But Bohm's view requires another layer of reality.
The theory of decoherence reconciles the Copenhagen interpretation with quantum superpositions in the absence of measurement or conscious observation. Any interaction, or loss of isolation, of a quantum superposition with a classical system (e.g. through heat, direct interaction or information exchange) would "decohere" the quantum system to classical states. But decoherence theory doesn't define isolation (no quantum system is truly isolated from its classical surroundings) nor deal with superpositions which are isolated.
Finally, several proposals posit an objective threshold for reduction ("objective reduction", "OR"). British mathematical physicist Sir Roger Penrose suggests that each superposition corresponds with bifurcation/separation of the universe at its most basic level (quantum gravity, or fundamental spacetime geometry at the Planck scale). This is akin to the multiple worlds view, however according to Penrose the separations of the universe at its most fundamental level are unstable and spontaneously reduce ("self-collapse") due to an objective, intrinsic feature of spacetime geometry ("objective reduction"). Moreover the larger the superposition, the more rapidly it reduces. For example an isolated electron in superposition would undergo objective reduction only after 10 million years; a one kilogram cat in superposition would self-collapse in only 10-37 seconds. Penrose's proposal is currently being tested experimentally.
In his 1989 book "The emperor's new mind" Penrose suggested that the choices resulting from this quantum gravity mediated form of objective reduction are not random, but influenced by Platonic information embedded at the Planck scale, the fundamental level of the universe. Moreover this particular type of non-random ("non-computable") choice is characteristic of choices made in consciousness. Therefore Penrose proposed that quantum computation which reduces by quantum gravity-mediated objective reduction must be occurring in the brain. Thus human thought differed in a very basic way from the output of classical computers. Penrose's book was (appropriately) seen as a slap in the face to artificial intelligence ("AI") proponents who claimed to be able to develop conscious computers by simulating neural and synaptic activities in silicon.
As qubits in the brain Penrose suggested superpositions of neurons both firing and not firing. There were two rational objections to this suggestion. First, quantum superpositions are disrupted by interactions with the environment ("decoherence"), requiring isolation and ultra-cold temperatures in laboratory situations. How could superpositions avoid decoherence long enough to perform useful functions in the warm, wet brain?
Second, neurons and synapses seemed rather large and complex for delicate quantum effects. Single cell organisms like paramecium are able to swim gracefully, avoid objects and predators, learn and remember, find food and mates and have sex!
If we look inside neurons, paramecium and other cells, we see highly ordered networks (the "cytoskeleton") comprised of microtubules and other filamentous structures which organize cellular activities. Paramecium sensory input and movement, cell division ("mitosis"), cell growth, synapse formation and all aspects of coordinated functions are accomplished by microtubules, cylindrical polymers of the protein tubulin arranged in hexagonal lattices comprising the cylinder wall.
For twenty years I had been studying how microtubules could process information, acting like computers. In the 1980s along with colleagues Rich Watt, Steen Rasmussen and others I had suggested that cooperative interactions among tubulin subunits acted as molecular scale "cellular automata". Our work had shown that the tubulins switching in microtubules provided the same potential information processing capacity in each neuron as the entire brain at the synaptic level. But an enormous increase in classical information processing didn't help with the enigmatic issues of consciousness.
However microtubules seemed to be excellent candidates for the quantum computers Penrose was seeking. As the states of tubulin are controlled by quantum mechanical internal forces (van der Waals London forces), they may exist in quantum superposition of multiple states ("quantum bits, or "qubits"), and microtubules may be seen as quantum computers involved in cellular organization.
The Orch OR model. Insert shows an axon (top) synapsing on a dendritic spine on a dendrite. Within the dendrite are a bundle of microtubules shown telescoping in scale (upper right). Each tubulin may exist in two possible classical states (blue, red) or a quantum superposition of both states, forming a protein qubit. Tubulin qubits interact/compute by nonlocal entanglement and reduce to classical output states as the solution of the quantum computation.
In the early 1990s Sir Roger Penrose and I teamed up to develop a model of quantum computation in brain microtubules responsible for consciousness. The quantum computations are isolated from environmental decoherence by specific evolutionary mechanisms, and reduce to classical states by Roger's objective threshold related to quantum gravity ("objective reduction - OR"). This links the process to fundamental spacetime geometry—the fine structure of the universe. The quantum computation is "orchestrated" by feedback from microtubule-associated proteins, hence we term the process "orchestrated objective reduction" ("Orch OR").
Consciousness is thus a sequence of discrete events, arising from alternating phases of 1) isolated quantum coherent superposition (in which microtubule quantum states are isolated by actin gelation), and 2) classical input/output in which microtubule information communicates with the non-conscious portions of the brain, nervous system and outside world. The alternating phases correspond with brain neurophysiology, e.g. the well known "40 Hz" gamma EEG oscillations.
We account for feelings and conscious experience by philosophical pan-protopsychism in which the components of conscious experience are irreducible, fundamental entities embedded in the Planck scale of fundamental spacetime geometry. Our proposal is consistent with the philosophy of A. N. Whitehead who proposed that consciousness was a sequence of "occasions of experience" occurring in a "basic field of proto-conscious experience".
Thus the infinitesimally tiny Planck scale, described by loop quantum gravity, string theory, quantum foam etc., is the authentic Matrix whose configurations give rise to conscious experience (and everything else).
The vast majority of brain activity is non-conscious; consciousness is the "tip of an iceberg". However no specific brain regions houses consciousness. Neurons may be non-conscious at one moment, and support conscious activities at the next. The transition, we propose, is Orch OR. This implies that pre-conscious activities including Freud's subconscious and our dreams are manifest as quantum information, e.g. as schizophrenic superpositions of multiple possibilities. The bizarre nature of the dream world has been described (Matte Blanco, 1971) as "where paradox reigns and opposites merge to sameness", also an apt description of the quantum world.
Thus we see consciousness is a self-organizing process on the edge between the quantum world and the classical world, and a connection between biological systems and the fundamental level of the universe. Orch OR is consistent not only with neurobiology and physics, but with spiritual traditions such as Buddhism, Hinduism and Kabbalah.
Orch OR/consciousness can occur only in very special circumstance: quantum superpositions must be isolated from environmental decoherence long enough to reach threshold for Penrose OR. Neural activities in the brain are typically in the time scale of tens to hundreds of milliseconds, requiring isolated superposition of microtubules occupying thousands of neurons. Simple organisms may be conscious, but would require longer periods of isolated superposition, and have infrequent moments of consciousness. Whereas we may have e.g. 40 conscious moments per second, a simple worm may have only one conscious moment per minute (and of far less intensity than ours).
OR may also possibly occur in cosmological situations such as gigantic Bose Einstein condensations in neutron stars. By our definition, such OR events would be conscious, but lack cognition (OR without Orch). Astrophysicist Paola Zizzi has suggested that the period of inflation during the Big Bang represented a quantum superposition of the incipient universe which was terminated by OR. Thus the universe at its birth had a moment of cosmic consciousness (the "Big Wow") - the macrocosm of our individual conscious microcosms.
I work as an anesthesiologist, and routinely erase and restore the consciousness of my patients. The anesthetic gases I administer pass through the lungs, into the blood and brain where they localize in tiny pockets inside certain neuronal proteins. The critical proteins whose disrupted function causes anesthesia/loss of consciousness include tubulins as well as various membrane protein receptors. The tiny intraprotein pockets where anesthetics bind are "hydrophobic" regions, nonpolar areas where the dynamics of the proteins are controlled by quantum forces called van der Waals London forces. Unlike any other drugs, anesthetics act only by these same extremely weak quantum mechanical London forces, apparently preventing/impairing normally occurring London forces whose collective coherence is necessary for consciousness.
Despite intense criticism by scientific, computational and philosophical establishments, Orch OR remains a viable theory, and perhaps the only complete model able to deal with the enigmatic features of consciousness and provide testable predictions. Recent evidence shows that some forms of quantum processes involving organic molecules are enhanced by increased temperature, suggesting that decoherence may not be a significant problem.
Many view the idea of quantum consciousness (and Orch OR in particular) as unlikely. But I view it as a "speck on the horizon", a paradigm that will eventually dominate our view of brain, mind and reality. It is the only approach which seems capable of tying everything together. Moreover the connection to a Platonic fundamental reality provides a scientific avenue to spirituality.