Perception and reality

Do we perceive the real or what we desire to see? Two observers of the same event often recall differing details. Patanjali prescribed yoga to discipline the mind and dampen its wanderings, chittavritti nirodha; otherwise perception gets clouded by rationale, opposites, alternatives, sleep and memory. A well aware person’s brain emits clean theta waves that maintain long range temporal correlation, but the beta waves of people with confused identity lose such correlation due to interference with neural noise (Sci Rep 11, article number 422 (2021)). Sensors, used by scientists to extend their own, are cooled to reduce inherent noise. Touch, taste, smell, sound and sight are identified as the five physical senses, but the Gita teaches that the mind is the sixth sensor, indriyanam manashchasmi. So the conscious living mind cannot be completely stilled. This issue was thrust upon physicists as they explored the nanoworld of atomic interactions. Planck discerned light as a stream of discrete energy photons in 1900 to usher in the quantum era. Integers in the Balmer formula, for the wavelengths of light emitted by hydrogen atoms, arrived 15 years too early to be realized as quantic. Another 13 years passed before Bohr related it to quantized electronic momentum, which in turn was seen as a standing electron wave by de Broglie a decade later. The 2022 Nobel Prize in physics was awarded to Alain Aspect (France), Anton Zeilinger (Austria) and John Clauser (USA) for experiments supporting quantum randomness over local reality. 

Wave-particle (or spirit-matter) duality of nature is not dialectical but complementary. Delayed choice experiments prove that the two apparitions cannot be seen simultaneously; a quantum immediately erases its wavy history for a particle detector, and vice-versa. Similar waves superpose to make bigger or smaller ones. This led Schrodinger to think of his cat in a live+dead superposed state until let out of the bag. Infinitely superposed general waves collapse randomly into one of the constituent eigenstates at detection. Einstein bemoaned how anyone can believe “that the Moon is not there when you are not looking at it.” Heisenberg’s limit on determinism required the product of uncertainties in conjugate variables like position and momentum to be greater than the Planck constant. A particle is located at best within the wavelength of light that bounces off it; more precision with shorter wavelength transfers higher momentum which becomes more uncertain. Wigner paradox, on seeing a quantum system differently than his friend, is under test. 

Einstein used quantum to explain many effects and got the Nobel Prize for photoelectricity. Skeptical of the randomness, he later declared “God does not play dice with the Universe,” and Bohr retorted, “Stop telling God what to do.” Einstein, with Podolsky and Rosen, proposed the EPR paradox in 1935 to precipitate the issue. A subatomic particle like neutral pion at rest can decay into a photon pair, or any other allowed particle-antiparticle, that fly off in opposite directions with opposite spins and other quantum numbers. Measuring the properties of one immediately tells of the distant partner. Such faster than light “spooky action at a distance” as Einstein called, violates causality that requires cause to precede effect. They thought it suggestive of hidden variables that would preserve local reality. Schrodinger conjoined the decay pair into an entangled state of highly correlated components. Bell proved a theorem requiring the correlation coefficient of measurements in a locally real hidden variable theory to be less than a certain value, while quantum randomness would make it greater.

Clauser modified Bell inequality in 1972 to make it measurable, entangled photons about six meters apart, measured a greater value to reject local realism, and lost his two dollar bet against quantum randomness. In the next decade, Aspect closed the unidirectional loophole of Clauser’s observation, with random directional views of entangled photons traversing through 12 meters. Can a hidden variable impose sequence on what appears random? Then Zeilinger, who had entangled photons about half a kilometer apart, devised a method in 2017 to use light emitted by stars hundreds of light years away to generate randomness. One could still argue that the randomness was wiped out by an encoding in the starlight, about an experiment to be performed by an unborn scientist. Every loophole cannot be closed but becomes ever more fantastic, setting quantum theory on a stronger base. A scientific theory has to remain continually verified by experiments to ever increasing precision till the present; a single contradiction turns it into fiction. 

Entanglement is used in teleportation to produce an exactly similar state elsewhere; but two identical states cannot co-exist, so the original has to be disentangled immediately; hence they can be used for unbreakable encryption in quantum networks. They are also the qubit of  quantum computers. Binary digits (bits) are stored in our classical computer as either of two states represented by 0 and 1. A qubit can store any of the infinitely different superpositions of its two states, all fractions from 0 to 1, making quantum computers many fold quicker. In a recent interview with the Spanish newspaper El Pais (14 June 2023), Zeilinger says that a full quantum computer would require thousand qubits, and the present ones have just about 50. He thinks that quantum computers will enter cell phones in a hundred years. The Austrian Academy of Sciences entangled photons almost 250 km apart in an optical fiber, Max Planck Institute entangled a cluster of 14 photons, and the MIT atomic clock has been stabilized with entangled photons to lose less than one second in 150bn years. The whole Universe could be a single quantum state, entangled in a neural network (doi.org/10.3389/fphy.2020.525731) of the cosmic web that ensnares every mass to comprise the mind of nature. 

As any observation physically affects the observed, absolute reality is unknowable. A surrounding that adjusts to our sense of awareness tells that nature is intrinsically conscious. This possibility will be discussed in subsequent articles. 

The author is a professor of Physics