In Search of a Theory of Everything
Page 12
This principle has in fact a counterpart in modern physics in the notion of energy, which includes mass, since for relativity mass and energy are basically the same, as implied by E = mc2. Like Being, energy can neither be created (it does not come to be from nothing) nor destroyed (it does not pass away into nothing). It just is and its total amount is unchangeable and enduring. Particles of matter and antimatter are constantly being created and annihilated, for example, but not out of nothing and into nothing. To occur, these processes require something to already exist—namely, energy. They are created from energy and annihilated into energy. There is no mechanism in modern physics that violates the basic Parmenidean idea that something can neither be created from nothing nor pass away into nothing. All interactions require something, energy (or matter, since they are equivalent), but also space and time. In fact, while space contracts and time dilates in Einstein’s relativity, the combined space-time interval is invariant (conserved), too (like the combined matter-energy). Indeed, nonexistence is an impossibility even in modern physics, and the uncertainty principles of quantum theory (see next paragraph) may be considered as additional statements (in addition to those of relativity) in support of that. Why use these principles? These principles are relationships between space, time, matter, and energy, concepts that constitute the essence of nature (of something-ness). And if we hope to “prove” that the notion of nothingness is an impossibility—that nothingness is not derivable from something-ness—well, we had better begin from an analysis of principles that describe the essence of something-ness.
So to argue for this (that nonexistence/nothingness is an impossibility), we first recall the position-velocity uncertainty principle: the product of the uncertainties in the position and in the velocity of a particle must be greater than Planck’s constant divided by the particle mass—that is, such product is greater than zero. Analogously there exists the time-energy uncertainty principle. It states that the product of the fluctuations in the energy of a particle and the time interval that the particle endures must be greater than Planck’s constant—again such product is greater than zero. For these uncertainty principles to hold spatial distances, time intervals, velocities, and energies are forbidden from ever being absolutely zero—that is, their nonexistence is forbidden. For example, the smaller the confining space of a particle is (or the briefer the time interval the particle endures in such confinement), the more frantic its motion and energy are. But neither the confining space nor the time interval can ever be exactly zero, for if they were, the uncertainty in position and the uncertainty in time would have been zero, too, and consequently both uncertainty principles would have been in violation—the product of the uncertainties in position and velocity, and in time and energy, would have been zero, too (instead of greater than zero). Similarly, both uncertainty principles would have been in violation if a particle had zero velocity or energy. The principles hold only if spatial distances, time intervals, velocities, and energies are nonzero; they must exist; they cannot be nothing! (In a sense, such a result is expected because our physics relationships, equations or inequalities, are in the first place conceived to describe something, not nothing; the notion of nothingness is indescribable.) Hence, as per Parmenides’s reasoning and as per the uncertainty principles, nothingness is not only not allowed to exist—for nothing comes from it (e.g., the uncertainty relationships are violated and thus cannot be used to account for what exists)—but, equally profoundly, existence is required, that is, spatial distances, time intervals, velocities, and energies must be nonzero (for only then do the uncertainty relationships, which describe something-ness, hold).
In fact, one of the fundamental tenets of quantum theory is that information cannot be lost from the universe (recall the section “Black Holes: Challenges in the Quest for Sameness” in chapter 3). In Parmenidean terms this means that what is (Being, information already present) cannot become Not-Being (information cannot be lost).
Quantum theory (the essence of which is the uncertainty principles) is then in accordance with Parmenidean philosophy, “for the same is the thinking and the Being”: for we can think only about that which exists; in other words, the uncertainty principles describe only something-ness and forbid nothingness. With this in mind Parmenides’s main question, How can something exist? may now be answered: within the context of modern physics, something (Being) must exist because nonexistence (Not-Being) is impossible.11 Although still, science cannot answer why this universe with these laws, why not some other type? Anyhow, what is the nature of that which exists?
An Indivisible Whole
Relativity
The view of Being as an indivisible whole is supported by Einstein’s theory of general relativity: for everything that there is, space, time, matter, and energy are no longer independent of each other (that is, they are not absolute), as was the case with Newtonian physics, but are intimately interwoven, affecting one another constantly. “Time and space and gravitation have no separate existence from matter.”12 Space-time is a malleable continuum distorted by matter.
Yes, it is true that for the sake of practical calculations in physics we often isolate, in our mind, a phenomenon of interest by assuming that it is disconnected from the rest of nature (disconnected from the whole). For example, we study the gravitational interaction between the sun and the earth by neglecting the gravitational effects of the rest of the heavenly bodies. But as in the philosophy of Parmenides modern physics is about oneness, not isolation. And in reality all things in nature are part of the whole and are entangled far more intricately than the theory of relativity alone could discover.
Quantum Entanglement
One of the most fascinating consequences of quantum theory is the phenomenon of quantum entanglement. According to it, there are no perfectly isolated particles (or systems). The notion of an individual particle disconnected from the rest of the universe is inaccurate. Rather, all particles in the universe are part of a unified whole. They are in constant and instant interaction, affecting and determining the behavior of each other regardless of how far apart they are. Quantum theory suggests that everything that happens in the universe influences instantly everything else. In this sense the universe is indeed a Parmenidean indivisible whole. To explain this concept further, we use the following thought experiment.
Suppose, for simplicity, that a mother particle could initially be at rest and with zero spin, and that later it decays into two daughter particles, A and B. To conserve momentum (linear and rotational), the daughter particles must take off away from each other as well as spin in opposite directions. In 1935, Einstein, with Boris Podolsky (1896–1966) and Nathan Rosen (1909–1995), argued through this thought experiment (which is known as the EPR, from the initials of their last names), that the daughter particles must have a fixed spin since the moment of their creation. To conserve rotational momentum, one must spin clockwise and the other counterclockwise. Which particle spins in what direction is determined with a measurement. So if Alice measures that particle A spins clockwise, she is also certain that particle B must spin counterclockwise, as it is so confirmed when Bob measures it. Einstein’s view is really the deterministic view of classical physics: that a particle has a fixed property even before we measure it.
But according to quantum theory, the spins of the particles A and B become fixed only when an observation (a measurement) is made. Until then, not only do we not know how the particles spin, but even worse and unlike Einstein’s view, the particles do not have a fixed spin; each particle is assumed to spin simultaneously in both directions until a measurement is performed that will force them to take on a fixed spin—a peculiar concept, which is known as the Copenhagen interpretation of quantum theory.13 It is this interpretation that Einstein found illogical and aimed to refute. And so did Schrödinger (one of the main creators of quantum theory): to capture the peculiarity of the indeterminate spin state that particles A and B were assumed to be in before the act of measuremen
t, he used a metaphor, the famous Schrödinger’s cat. Briefly, he argued that according to the Copenhagen interpretation, until an actual observation is performed, a cat in a sealed opaque box, which also contains radioactive atoms with a chance to decay and spread poison, is both dead and alive at the same time. Namely, the state of existence of the cat before the observation is a mix of two possible outcomes because the status of the cat depends on the status of the radioactive atoms, which, per the Copenhagen interpretation, themselves are in a mixed state of two quantum probabilities, that of the decay outcome, which will kill the cat, plus that of the nondecay, which will preserve the cat. Only after opening the box and observing can the observer actually determine whether the cat is definitely either dead or alive—and that knowledge is of course true only at the moment of observation, not before. So reality, in quantum mechanics, is subjective; it is created only by the act of observation—the moon14 exists only if we look at it, and a tree falling in a forest makes a sound only if we are there to hear it. Before the observation, the cat doesn’t even exist in the Copenhagen interpretation, but its probable existence is expressed mathematically with all opposite qualities simultaneously, such as being both dead and alive (or being both here and there). But according to classical physics, even before opening the box, the cat is in a definite state of existence: it is either only dead or only alive and only at one specific location. So reality, for classical physics (for Galileo, Newton, Einstein) is objective—the moon exists even when we don’t look at it, and the tree makes a sound even when no one is there to hear it. (The nature of reality, a much contested topic, has not been settled yet, if ever, for we lack a theory of everything.)
So, according to the quantum view, the spin direction of each particle is fixed by the very act of measurement. For example, if Alice measures that particle A spins clockwise, then and only then the spin of particle A becomes fixed (contrary to Einstein’s view, for which A would have been spinning clockwise since its creation); and, equally important, then and only then the spin of particle B becomes fixed, too, and it is counterclockwise (also contrary to Einstein’s view for which B would have been spinning counterclockwise also since its creation). In general, measuring a property of particle A instantly forces a certain fixed property for particle B, even though particle B is not measured directly. This view, which is really the phenomenon of quantum entanglement, appeared absurd to Einstein because it meant, he argued, that the measurement of the spin of particle A affects and fixes instantaneously the spin of particle B, even when such measurement is performed while the particles are light-years apart and across the universe. This instantaneous “spooky action at a distance,” as nicknamed by Einstein, was not required by his analysis since according to it the particles had presumably fixed spins since their creation. How can such instantaneous influence exist, Einstein thought. How is it that measuring a property of one particle instantly affects and fixes an earlier indeterminate property of another particle? How is it that the very moment that the spin of particle A is measured, A communicates instantly how it spins to particle B so that particle B can spin opposite (to conserve momentum)? It is a strange type of communication that occurs faster than the speed of light, in fact instantaneously, and appears to violate one of the main principles of relativity, that information cannot be transferred with a speed faster than that of light because it would violate causality. This bizarreness caused Einstein to believe that quantum theory was not a complete theory of nature despite its immense technological success, which today includes computers, cell phones, and so on. Analogously, Newtonian gravity is abundantly useful in plotting orbits to the moon or building skyscrapers, but its philosophical essence is really incorrect. Observing solely particle A would not in any way influence particle B, which is spatially separated from A, Einstein thought.
But he was wrong. These opposite views appeared for a while to be part of the unverifiable realm of metaphysics. But in 1964 physicist John Bell (1928–1990) found a way to convert each point of view into an experimentally testable calculation (a number that can be measured), which is known as Bell’s inequality.15 The experimental verdict found Einstein’s view false and favored the spooky action at a distance of quantum entanglement! Indeed, by measuring the properties of particle A, we instantly affect the properties of particle B regardless of how far apart they are. And so, generally speaking, by measuring a property of one particle in a system, what we actually measure is a property of the whole system—which includes us, the observer, too—or, more precisely, of the entire universe. The universe is indeed an indivisible entangled whole. In the Copenhagen interpretation the observer is really part of what he observes—there is a mutual influence between observer and what is being observed. However, in classical physics the observer is thought of as an outsider separated from what he observes—there is no influence at all between observer and what is being observed. The classical-physics view of an observer is therefore like someone watching a movie—if the movie is nature, then an observer eating popcorn and drinking soda while watching has no influence on the movie plot (on nature). Whereas the quantum view of an observer is like someone being in the movie—his actions are part of the plot.
Of course, this constant and instant interconnectivity between things in the universe, this quantum entanglement, exists not just when we curious observers of nature exercise our “free will” (chapter 14) and decide to make a measurement but is an intrinsic property of nature. For just as in an act of measurement, for which we observers cause willingly particles to interact in order to satisfy our inquisitive mind—for example, photons are shined upon electrons to see where they are and how they spin—particles in nature are in constant interaction anyway (without us having to cause it at will), as if nature itself is constantly self-measuring (self-observing). Now, with self-measuring in mind, we have an additional reason to reinforce a previous conclusion, that, not only are the phenomena observed to occur discontinuously (as a result of the very act of observation, as argued in chapter 7), but the phenomena themselves might occur discontinuously even when we are not observing, for nature is self-observing.
The whole universe experiences the phenomenon of quantum entanglement. If two particles have a chance to interact initially (that is, to become entangled like particles A and B that were created from the decay of the same mother particle), they continue to interact (they remain entangled) even when they are later separated. With this in mind, the entire universe may be considered an entangled whole (where everything in it is in constant and instant interaction with everything else, a perfect Parmenidean whole), for initially, according to the big bang, the entire universe was a mere microscopic size, possibly just a single point, where certainly everything was in close interaction and thus entangled with everything else, and so must then continue to be so today even with everything so far apart. The cosmic interconnectivity of mathematical nature anticipated by the Pythagoreans is now taking a concrete form through quantum entanglement.
Let’s justify quantum entanglement. Recall the wave-particle duality (chapter 6). A particle is both a particle (a localized entity) and a wave (an extended entity). The probable existence of particle A is represented by a wave function, and so is the probable existence of particle B. Although of a more complex shape, a wave function is like a straight line, it extends throughout the universe. Since both particles are—in the sense of the wave function—simultaneously everywhere, they are also simultaneously together at any one location; thus, they are constantly entangled.
In concluding this section, I would like to emphasize that information that travels faster than the speed of light is still impossible, as stated in the theory of relativity. That is, while Alice’s measurements of the properties of particle A influence instantaneously the properties of particle B, still information, that is, what Alice knows concerning the properties of either particle A or B, cannot be communicated to Bob faster than the speed of light; each person’s knowledge can be communica
ted to one another at best at the speed of light, say, by a radio signal. Only then can Alice and Bob verify the remarkable correlation between the properties of particles A and B due to the phenomenon of quantum entanglement. Before such communication, the outcome of Bob’s measurement concerning the spin of particle B would appear to him as random, as dictated by the laws of quantum probability, even when Bob does his measurements after Alice has done hers.
So as attested indirectly by the motion, change, and plurality of everyday experience—when these, of course, are investigated rationally by the human mind—the universe is indeed an indivisible whole. But there is a hypothesis that such universal oneness was once truly absolute.
The Absolute Oneness
The ultimate example of Parmenidean oneness, wholeness, and completeness, as properties of the universe, comes perhaps from the cosmological model of the big bang. It speculates that all matter and energy, all of space and time, the absolute wholeness of the universe of today, was once, about 13.8 billion years ago, contained in just a singular point. This primordial point, we must emphasize, was not within the universe; this one point was the universe, the whole universe; infinitely small, hot, and dense, containing a single type of particle and obeying one grand law—the absoluteness of oneness, with no sense of location or flow of time, with neither here nor there, neither now nor before or after: the whole universe then (and “there”) was but one place of space and one moment of time, a single space-time point.
Unfortunately, the properties of the universe at this hypothetical primordial singular state cannot be described even in principle by our current physical theories. At this singularity—when the universe’s size and age are both identically zero—all our physics equations break down; they are meaningless. Could this breakdown be an indication that such a singular state of the universe is really an impossibility, a Not-Being? If so, the universe might have been very small but not point-like. But was it born?