Apologies Aren't Necessary—Einstein Was Right [1]

This post is a response to a New York Times article of October 21, 2015, entitled "Sorry, Einstein. Quantum Study Suggests ‘Spooky Action’ Is Real". The Times article reports a study conducted at Delft University of Technology in the Netherlands that questions Einstein's defense of the "locality" principle, which insists that an object can be influenced only by events in its immediate surroundings. Einstein had famously labeled any claim to the contrary as "spooky action at a distance." I feel Einstein is correct despite the findings of the Delft experiment. However, in order to understand what is involved in this difference of interpretation, it is necessary to understand three important characteristics of particles and waves: particles in superposition, entanglement of elementary particles, and collapse of a wave function.
One of the simplest ways to illustrate these characteristics is to conduct a two-slit experiment, as described In the post of October 24, 2015. In the classic version of the two-slit experiment, first done more than 200 years ago, light rays passing through two parallel slits displayed characteristic wave behavior (think here of water waves) by interfering with each other, creating a pattern of light and dark patches on a photosensitive screen positioned behind the slits. The patches corresponded to the points on the screen where the peaks and troughs of waves diffracting out from the two slits combined with one another either constructively or destructively. Light patches occurred when the crests of two light waves came together while dark patches occurred when the crest of one wave met the trough of another wave.
Other research findings suggested that under some circumstances light consisted of elementary particles of light called photons. In the twentieth century, physicists performed a variation of the classic two-slit experiment with low-intensity light to show that this interference pattern was evident even when particles of light (photons) passed through the apparatus one at a time. This finding indicated that the photon was interfering with itself by passing through both slits at once! This phenomenon came to be called quantum superposition—the particle simultaneously existed in two possible states at once.
Surprisingly, for the time, when a variation of the two-slit experiment was performed placing detectors at the slits to determine through which slit a particle was passing the wave pattern disappeared and a single photon was observed. (This was an early indication that our world exists only when it is observed.) This interference of the light waves with each other became known as "entanglement" and the particles associated with them became known as "entangled particles". Disappearance of the wave function and the display of an elementary particle when an attempt was made to detect a particle became known as "collapse of the wave function". (These experiments can also be done with other subatomic particles such as the electron with the same results.)
A characteristic of entangled particles that defied common sense and has proven to be very difficult to explain is the central question involved in the Delft University study: when one of two such entangled particles is observed, for example its spin (a characteristic of elementary particles having nothing to do with actual spinning) is measured, the other entangled particle will Instantaneously display the opposite spin. This has proven to be true even as the distance between the entangled particles has increased. Increasing the distance between the entangled particles has been done, for example, by splitting the beam of light with a mirror and, in the Delft study, by using two diamonds with entangled photons and placing the diamonds on opposite ends of the Delft University. This separation, 1.3 km (approximately 0.81 miles) constituted a distance the scientists conducting the Delft study felt insured that the particles could not influence each other without violating fundamental laws of physics. Nevertheless, as reported in the NY Times article cited above (See New York Times), scientists involved in the Delft experiment (see Delft study) concede that other attempts to close loopholes may follow their study but they clearly feel that their study is sufficient proof that the spookiness Einstein derided is real, that action at a distance must be occurring. There is, however, a more credible and satisfactory explanation for what is happening here that does not require action at a distance and is consistent with the known laws of physics: the "many-worlds" interpretation of reality.
The Many-Worlds Interpretation of Reality
A remarkable theory developed by Hugh Everett III, is called the many-worlds interpretation (also called the many-universes interpretation) of quantum mechanics.[2] The many-worlds interpretation views reality as a many-branched tree, wherein every logically possible quantum outcome is realized. All logically possible alternative histories and futures are considered to be real, each occurring in an actual “world” (or “universe”), each with its own observer.
In lay terms, many-worlds posits that as we make certain critical choices in life, branching occurs such that a number of worlds emerge, one for each of the choices we could have made. Everything that could have happened in our future, but will not, will occur in the future of some other world and everything that could have happened in our past, but did not, has occurred in the past of some other world.
To illustrate the application of the many-worlds interpretation to the question of whether action at a distance occurs, assume that we are a group of scientists conducting an experiment. We have two entangled particles and we measure, say, the spin, of one of the entangled particles. We have made a choice and branching occurs so that one of the entangled particles is in our world and the other is in the world of a group of counterpart scientist. In our world we make one measurement—there is no action at a distance since only one measurement is made in our world. We know this, for when we measure a particle in superposition we find only one particle. And none of the fundamental laws of physics of our world are violated. Meanwhile our counterpart team of scientists in another world also make one measurement and again there is no action at a distance since only one measurement is made in their world.
Should you accept the many-worlds interpretation as physics or is it metaphysics. Max Tegmark contends:
"The frontiers of physics have gradually expanded to incorporate ever more abstract (and once metaphysical) concepts such as a round Earth, invisible electromagnetic fields, time slowdown at high speeds, quantum superpositions, curved space, and black holes. Over the past several years the concept of a multiverse has joined this list. It is grounded in well-tested theories such as relativity and quantum mechanics, and it fulfills both of the basic criteria of an empirical science: it makes predictions, and it can be falsified." [3]
You have a choice. You may believe in action at a distance and its difficulties given the fundamental laws of physics or you may believe in the many-worlds interpretation that, while it is not a widely accepted concept with the general public or with the physics community at large,  it offers a credible and satisfactory explanation for the relationship between entangled particles.


Notes
1. This Post is adapted from Donald W. Jarrell, At the Edge of Time: Reality, Time, and Meaning in a Virtual Everyday World (North Charleston, South Carolina: CreateSpace Independent Publishing Platform, 2012, rev 2014), 66-68. See At the Edge of Time.
2. Hugh Everett III, The Many-Worlds Interpretation of Quantum Mechanics: The Theory Of The Universal Wavefunction, doctoral dissertation, Princeton University, 1957, 9. Everett’s doctoral dissertation may be downloaded as a pdf file at www.pbs.org.
3. Max Tegmark, "Parallel Universes", Scientific American, April 14, 2003.

Next post on a bi-weekly schedule: November 20, 2015.


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