Since EPR thought experiment a century ago, there is much confusion about entanglement in modern physics. It is used in a very narrow sense. It is NOT “spooky action at a distance”, as Einstein said. Neither does it an exclusively quantum phenomenon nor does it last infinitely. The same laws of physics govern both the macro and the micro world (यत् ब्रह्माण्डे तत् पिण्डे). Entanglement is a basic property of every solid and liquid in the universe (not only quantum particles), as well as time (entangled as past-present-future) and coordinates (entangled as x, y, z). Along with disentanglement (विभागः), it is responsible for all chemical reactions (“तथा भवतीति सापेक्षेभ्यो निरपेक्षेभ्यश्च” इति प्रशस्तपादभाष्ये संयोगनिरूपणे).

Entanglement requires at least a pair to share spatial proximity (अविरलदेशत्व) and interacting with or without exchange of energy in such a way that, the description of the state of one particle depends on the state of the other. It is a form of coupling that connects two objects (like the two ends of a rubber string). Also conjugate parts of one object (like the hands or legs of the body or a laser beam fired through a certain type of crystal to cause individual photons to be split into pairs of entangled photons), or the relation between two conjugate objects (like a pair of shoes or socks or gloves).

Entanglement (संयोगः – coupling, bond) of the quarks and gluons in different combinations creates all matter. The inertia caused by the coupling of the Consciousness and mind leads to intelligence (आत्ममनसोःसंयोगविशेषात् संस्काराच्च – कणादसूत्रम् 9-2-6). Coupling of the space beyond (longitudinal waves that move the adjacent coordinate point) leads to propagation of sound waves. Etc.

It all began in 1920’s with the failure of physicists to explain quantum phenomena using macro physics. A misinterpretation of Heisenberg’s equation led Einstein to say: “God does not play dice”. Position implies fixed coordinates in a frame of reference, where momentum is zero. Momentum implies mobile coordinates in a frame of reference, where position is zero. Thus, if one has nonzero values, the other will have zero value. Multiplying both will lead to zero result, as one of the two factors will always be zero. Thus, Heisenberg’s equation is mathematically wrong, though uncertainty is inherent in nature. It is our inability to consider/know and regulate ALL effects or factors that affect the probable outcome of any operation or measurement (कर्मण्येवाधिरारस्ते मा फलेषु कदाचन). This is in conformity with the Schrodinger equation, which implies: everything is random at the most basic level and order rises upon randomness – not vice versa.

Schrodinger first expressed energy in both wave and particle forms and then combined them together due to energy conservation. Schrodinger’s equation showed the implications for some entity that was behaving like a particle, but also had the wave properties inherent in it – the wavefunction that exhibited some uncertainty regarding their particle properties. If there are multiple wave sources, all the waves are added up and then squared to get the combined intensities. This is the “superposition” principle. But nothing behaves as a particle AND a wave at the same time. They have totally different properties. Waves involve the transport of energy without the transport of matter. It only passes the momentum. Particles have mass. Often a tiny particle with high energy, moves in waves due to the same principle as sound waves (see the Vedic equation for sound – शब्दः – तत्र शकार बिन्दूः बकार वातः दकार अग्निः विसर्गश्चाकाशः । बिन्दुवातग्न्यम्बराणां तस्मात् साङ्केतिकाः स्मृताः – नामार्थकल्पसूत्रम्).

Schrodinger equation also talk of negative probabilities that do not always add up but can also be negative. If the probability of the Schrodinger’s cat being alive is 100% and that of it being dead is 100%, the probability of it either living or dead can be zero. But if the probability of living is say 70%, then the probability of it being dead can be calculated. That is one type of entanglement.

Consider two waves coming from different directions in a sea front. We could clearly see them. They merge and become entangled. Thereafter, though they were at two places earlier, we can’t distinguish their position separately. Our inability to know the different components of such entanglement is called superposition (something observed earlier, which is not distinctly observable now – अध्यास – स्मृतिरूपः परत्र पूर्बदृष्टावभास). It doesn’t mean something existing at two places at the same time (though it may appear so) – it is impossible due to the following reason.

Measurement is a process of comparison of similars at here-now, with some fixed information called the unit. Observation is the perception of the result of measurement (it is possible only with a sentient being). The object to be measured is scaled up or down with the unit to get a scalar quantity that reports the prevailing state of something at any given moment only and does not interact or interfere with the time evolution of the particles. Hence measurement does not affect the entanglement or superposition or determine the outcome (it only give information about the present state at a given time), as local conditions are not affected. Similarly, superposition doesn’t mean both dead and alive at the same time till the observer finds it out. It is either dead or alive at a given time. There is nothing like “collapse”. Scientists are fooling around with such fictions for over a century.

Some scientists have drawn attention towards Bell’s inequalities to counter EPR’s postulation of the hidden variables. Bell showed that if two observers randomly and independently choose between measuring one or another property of their particles, like position or velocity, the average results cannot be explained in any theory where both position and velocity were pre-existing local properties. This raises the question: what is so special about “measurement”?

Also there are some confusing but related issues. Wigner devised a thought experiment, in which his friend measures some quantum properties – say position – in a tightly sealed laboratory by using polarized photons. For the observer from outside, the friend becomes entangled with the particle and is infected with the uncertainty like the Schrödinger’s famous cat. Since it is absurd, he believed that, on observation by an intelligent observer, the “superposition” has “collapsed”. This conclusion was based on the role of one of two paths each photon may take in the setup, depending on the “polarization” of the photon. The “path” “measures” the polarization. (Wigner wrote “The Unreasonable Effectiveness of Mathematics in the Natural Sciences”. My paper on “REASONABLE EFFECTIVENESS OF MATHEMATICS” can be seen at http://fqxi.org/community/forum/topic/2325).

Others built upon it with two hypothetical scientists Alice and Bob with their friends Charlie and Debbie, measuring a pair of entangled particles in two laboratories. Yet others like de Broglie-Bohm postulated “action at a distance” – actions can have instantaneous effects elsewhere in the universe – which conflicts with relativity. Some postulated “backwards causality” or “super-determinism”. I will not discuss these fantasies for the reason given below. Those interested may read it from texts or the internet.

We may send a light pulse to some body, but after interacting with the body, the SAME light pulse will NOT come back to us. Part or whole of it may be absorbed by the body or deflected by other effects. Information is the result of measurement of the “received impulse” (emitted by a body) and not the “initial impulse” bounced from a body. What we measure through observation is the emission by the body received by us and not the state of the body that emits it (अनवर्णे इमे भूमी – Taittiriyaranyakam – Prathama Prashna). Thus, the speed of light is not relevant here. At one moment we can look at a distant star and the next moment another in the opposite direction thousands of light years away. We can know their position instantaneously. They are not entangled (इयं चाऽसौ च रोदसी – ibid). The same principle applies to polarized photons also. No information is transferred between polarized photons. There is no proof. As already explained, superposition is only our inability to know the present state accurately.

Often it is said that Schrödinger also came across the uncertainty principle from his wave mechanics. He represented the momentum p by a differential operator – iħ d/dx, which does not commute with the position operator x. Schrödinger based his proposition on the wave-function ψ, which gives the probability |ψ|^2 of finding a particle at a particular point. Since the position of the electron cannot be determined with certainty (which is true), the probability refers to the location within an interval of space of length δx (which is misleading). This implies that only those values of ψ have to be chosen which become non-zero within the range of δx and cancel each other out to become zero outside it. These are done through Fourier analysis. Thus, the narrower the space δx is, the more stringent is the cancel requirements outside it. As a consequence, a greater number of different waves will have to be added together to achieve this. In other words, the width of the band of wavelengths thus required will be inversely proportional to δx.

It is known from de Brogli’s formulation relating to matter waves that the wavelength and the momentum of the particle are related by the equation: p = h/λ. Thus, a broader band of wavelength means a wider range of momentum values. In other words, as δx decreases (location is better specified), the uncertainty δp increases (the momentum is further spread out). Thus, δx. δp ≥ h. It can be seen that in the event of x being precisely known, i.e., δx = 0, which implies a fixed position, δp = 0 and vice versa. This is because, particles have fixed dimensions and momentum requires displacement from their position to a position outside it. Since only those values of ψ have to be chosen which become non-zero within the range of δx and cancel each other out to become zero outside it, when δx is narrowed down to 0, which means that it has a fixed position, then  outside its position δp = 0 also and vice versa.

This also implies that within the space occupied by the particle, δp ≠ 0, which means, all particles have internal “momentum”, which arises due to its internal structure. We will prove that all particles, however small they might be, have an internal structure till they decompose to a state where particles and fields become indistinguishable and the concept of position and momentum vanishes. This also means that when the particle has a fixed position, it does not have a momentum in the same frame of reference. But this does not mean that the object is at rest. It may be in motion with reference to other frames of reference, which cannot be ascertained without referring to those frames of reference. Similarly, if the object has a known momentum, it does not have a fixed position in the same frame of reference. But it may be at rest with reference to some other frame of reference.

The description of measurement in these examples misses some vital factors. Measurement is a process of comparison between similars. We measure length with a rod – by comparing its length (unit) with that of the object (according to Einstein, the length is what we measure by a measuring rod). We measure volume by comparing it with containers of unit volume. We measure velocity by comparing the distance traveled in unit time (irrespective of mass).

If the particle has momentum (mass times velocity), its velocity can be measured by comparing it (and not bouncing light off it, as Einstein and others suggest) with the velocity of a photon, whose velocity per second can be treated as the unit. But this measurement, which is time variant and different from the measurement process of the spread components of the respective coordinates representing dimensions, will not give us position, which is a fixed co-ordinate in the specific frame of reference and time invariant. To that extent, there is no “uncertainty”, as, while measuring momentum we do not measure position and vice-versa. In other words, the so-called “uncertainty” is not in the process or the result of measurement, but it is a description of exclusive information (since time invariant fixed co-ordinates of position and time variant mobile co-ordinates of momentum are mutually exclusive). Thus, the so-called “uncertainty” is a logical conclusion wrongly described. Logical because other factors beyond our control may affect the outcome.

The problem with the Schrödinger equation is that no one is clear about what exactly the wave-function represents. The confusion was compounded when Poincare came up with the equation: e = mc^2. Einstein also arrived at the same equations five years later through a different route. In spite of the evident contradictory properties of mass and energy, they were thought to be interchangeable. It is like telling the cost of 1 kg of apple is $1. Hence 1 kg of apple = $1.  All the equation shows is that the rate of mass and energy interaction (distribution of mass by energy over an area) is related as e/m = c^2 or m/e = 1/c^2. This is not the same as e = mc^2 because c also represents energy of the photon, which is a part of electromagnetic wave and velocity is time variant. The energy does not go up with time.

The value of the parameter c is defined in the above equation from the fundamental concept requiring an absolute constant K, which is a constant of proportionality between mass and energy. Thus, we can say: e = Km. It has been observed experimentally that the value of K is equal to the square of what is interpreted to be the velocity of light. Whatever c stands for, we can define it as: c = √K. If mass and energy are convertible, then total mass can be converted into energy and vice versa. In such a case, total energy should have been in one side of the equation to make it convertible with mass in proportion with K. Substituting c^2 for K, we can write e/c^2 = m or e = mc^2. But the equation e/c^2 = m or e = mc^2 is meaningless, as there is nothing like bare mass or bare charge. Thus, the equation must have some other meaning. It can only be the constant rate at which unit mass is displaced by unit energy or unit energy is confined by unit mass, i.e., e/m = K or m/e = 1/K.

अतिदूरात्सामीप्यादिन्द्रियघातान्मनोनवस्थानात् ।

सौक्ष्म्याद् व्यवधानादभिभवात् समानाभिहाराच्च ।

Perception (result of measurement) is affected by the following factors:                                                                                                                   

1) distance scale – too long, 2) distance scale – too short, 3) defective instruments, 4) non-contact with the observer, 5) quantum scales, 6) due to intermediate partitions, 7) blockade or coverings, 8) superposition, etc.

Some of these concepts have been overlooked by modern scientists leading to wrong interpretations of right observations. Let us examine the concepts used in modern science of the last 100 years in developing Quantum Mechanics till Bell’s experiment. I will deal with Bell’s, Aspect and Legget experiments separately because of their implication.

Earlier, it was supposed that until a quantum system is observed, it does not necessarily have definite properties. Schrödinger’s famous thought experiment used a cat trapped in a box with poison that will be released if a radioactive atom decays. Since radioactivity is a quantum process, before the box is opened, the atom was supposed to be both decayed and not decayed, leaving the cat in a so-called superposition between half alive-half dead. But does the cat itself experience being in superposition? No one knew.

Wigner imagined a friend shut in a lab, measuring a quantum system. It was absurd to say that his friend exists in a superposition of having seen and not seen a decay unless and until Wigner observes him – the observer himself is observed. Copenhagen interpretation says that until a system’s properties are measured, they can encompass myriad values. The superposition only collapses into a single state when the system is observed. Physicists can never precisely predict if there is such a state and if yes, what that state would be. The essence of theories are their deterministic value. Quantum theory was claimed to be inherently probabilistic – making it questionable. Wigner held the then popular view – consciousness somehow triggers a superposition to collapse – is neither proven nor its mechanism explained. Thus, his hypothetical friend would discern a definite outcome when he or she makes a measurement and Wigner would never see him or her in superposition.

Wigner’s view is rightly dismissed as spooky and ill-defined because it makes the observers unique. In reality, the Observer (द्रष्टा), the observed (दृश्य) and the mechanism of observation (दर्शन), makes one system. Some physicists concur that inanimate objects can knock quantum systems out of superposition through a process known as decoherence. Researchers attempting to manipulate complex quantum superposition in the lab can find the result affected extraneous factors like speedy air particles colliding with their systems – over which they have no control. Hence they carry out their tests at ultra-cold temperatures and try to isolate their apparatuses from vibrations. That only minimizes the effect of uncertainty – the external effects that affect the outcome of the experiment. But it does not rule it out completely.

Several competing quantum interpretations employ decoherence to explain how superposition breaks down without invoking consciousness. Others hold that there is no collapse at all. The “many worlds” view says that whenever a quantum measurement is made, reality splits, creating parallel universes to accommodate every possible outcome. Wigner’s friend would split into two copies and in one frame, he could measure his friend to be in superposition from outside the lab.

But this is nothing but fantasy. There is nothing as Observer created reality. Reality is that which is:                                 

1) Perceptible through measurement,                                                                                                                                                                                                                                           2) Is knowable and                                                                                                                                                                                                                                                                           3) Describable using any language.

Thus, measurement is not affected by the Observer who measures the state of a subject or an object (an operation) at a given moment using a unit of equal class, but with a fixed magnitude. Though the measurement – like all operations – is carried out in the present moment, description of the state of the object is always related to the past. Because by the time measurement is complete, the result shows the state as it was during the measurement and not as here-now. Being at a different time scale, the observer cannot influence a fixed state of the past. He can only report it.

When the measurement relates to only two states (alive or dead here) which are present continuous with a boundary dividing the two (the cat may die due to many reasons. It can continue to live till it dies, but once dead, it can’t be alive again), the timing of the observation becomes important. If the observer observes before the gas leaked, he will report the cat as alive. If he observer after the gas leak, he may report the cat as dead (the cat may not die even after the leak due to many reasons like the poison not reaching it due to other leaks or partition or it has strong immunity to resist death for some times, etc.). 

In all such cases, uncertainty is inherent because of our lack of information about the other incidents. It is only measuring whether the cat is alive or dead. But it is not measuring the state of the trigger or the poisonous gas, which are vital determinants for the state of the cat. Hence, Heisenberg’s postulate does not affect Quantum Mechanics. In fact, there is only one mechanism applicable to all systems subject to variations due to different factors. Quantum Mechanics differs from the macro world due to scale difference. This also makes it difficult to perceive giving rise to weird speculations.

The “Bohmian” model says that at the fundamental level, quantum systems do have definite properties, which is correct. Our knowledge about those systems is limited enough to precisely predict their behavior. Wigner’s friend has a single experience at a particular time. If Wigner thinks his friend is in a superposition of different states, it is his own ignorance.

The QBism (short for Bayesianism of 18th-century) argue that a person can only use quantum mechanics to calculate how to calibrate his or her beliefs about what he or she will measure in an experiment. Measurement outcomes must be regarded as personal to the agent who makes the measurement. Simultaneous measurement of position along x-axis and momentum along y-axis is possible. Quantum theory can’t tell us anything about the underlying state of reality till it is physically measured, nor can Wigner use it to speculate on his friend’s experiences.

Retrocausality allows events in the future to influence the past. What Wigner’s friend experience at the moment of measurement, can depend upon Wigner’s choice of how to observe that person later. But it gives rise to grand-mother paradox. It also contradicts collapse theories. Once a state is measured and known, can it be changed by a future event? This brings into question the nature of time. Past is where the state is frozen and we can remember it without any change (अनुभूतिव्यञ्जक). Present builds on the past and is what is happening at here-now (स्वव्यापारारुढ). Future is only the possibility of what can happen based on the present state (भवितव्यव्यञ्जक). There is no reason to reverse this definition or extend the indeterministic characteristic of future to past and present as well.