When people hear the phrase “quantum physics,” it’s likely they imagine scientists deciphering equations about aspects of nature that are so mysterious they might as well be magic. As a result, when believers hear quantum physics (or quantum mechanics, as its often called) refutes our Faith, they may not know how to respond.
First, remember that physics is the study of how matter and forces interact with each other. It tells us, for example, what angle and force is necessary to get the eight ball in the corner pocket in a game of billiards. Quantum means simply “tiny,” so quantum physics is simply the study of how the smallest parts of the universe—such as atoms and electrons—interact with each other.
However, unlike billiard balls, these tiny parts of our universe behave in strange and unexpected ways. In order to see just how weird quantum physics can get, let’s take a look at one of its most famous experiments.
In order to understand the weirdness of the quantum world, we need to review how objects “normally” behave.
Imagine you and I are in a room armed with paintball guns whose pellets splatter on impact. Along with us are two white paint canvases, one placed in front of the other. They are identical except for one difference: the front canvas has two small, rectangular openings or slits cut out of the middle. When you and I shoot the front canvas with paintballs, some of the paint will pass through the slits and hit the rear canvas. This will leave two rectangular patterns on it.
Now, imagine the two canvases are half submerged in a tank of water. If you drop a heavy weight at one end of the tank, it will create a wave that travels to the other end of the tank. When this wave hits the double slits in the front canvas, it will break apart and then recombine on the other side.
If you’ve ever been to the ocean, you’ve probably seen waves interact with each other to form larger, more irregular waves. The same thing happens as the waves pass through the slits and interact with each other on the other side. Unlike the two identifiable rectangles the paintballs made, the waves will create a longer series of smaller rectangles and indentations called an “interference pattern.”
Alright, now let’s move this thought experiment to the quantum realm of electrons, which are the particles that orbit the nucleus of an atom. For a long time scientists wondered, “Are electrons little particles that bounce around like paintballs, or do they travel and dissipate like waves?”
If we fire electrons like a stream of paintballs through the double slits, what will show up on the rear canvas? If we see two rectangles, that would prove electrons are particles. But if we see an interference pattern, that would prove electrons are actually waves of energy.
It turns out that when electrons are fired like a stream of paintballs through the double slit, they form an interference pattern. So electrons are really waves, not particles, right?
Not so fast.
Enter the quantum realm
Imagine you and I are firing paintballs at the double slits on the canvas but we fire our paintball guns in an extremely fast, rapid-fire sequence. It’s possible that so many paintballs would crowd the slits that they would bounce off each other. This could form what looks like an interference pattern, even though paintballs are tiny pellets filled with liquid, not waves of energy.
In order to avoid this possibility with electrons that are fired in a similar way, scientists repeated the experiment. However, this time they fired the electrons one at time toward the double slits. As hundreds of electrons individually passed through the slits they hit the rear canvas and left an impression that could be recorded. But, as the areas of where they hit became visible, the scientists couldn’t believe what they saw: an interference pattern!
That seems to be impossible. Interference patterns occur when wave energy forms an interaction, yet the electrons were fired one a time a time. How could they be “working together” to form an interference pattern even though they are not causally connected to one another? One theory was that each individual electron turns into a wave of energy after it is fired. It then passes through both slits, interacts with itself, and then hits the rear canvas where it forms the interference pattern.
In order to test this hypothesis, detectors were placed on each slit to see which one (or possibly both) served as the electron’s path. But here is where “quantum weirdness” rears its paradoxical head. When the electrons were fired one at a time through the slits while the detectors were turned on, they formed only two rectangular patterns, not an interference pattern.
The very act of observing the electrons caused them to stop acting like waves that passed through both slits. The detectors caused them to act like particles that went through only one of the slits! This experiment beautifully illustrates the essence of quantum physics and why observation and duality make this branch of science so strange and unique.
When you look at a tree, what you “see” is a light particle (or photon) bouncing off the tree and hitting your eye. This interaction then sends a signal to your brain that is decoded to reveal what the tree looks like. Since trees are so big, they aren’t affected by a few photons hitting them.
But atoms and electrons are different. Because they are so small, any way of observing them will result in interactions with other particles such as photons or electrons. This makes it impossible for any scientist to be “neutral” and observe a quantum system without affecting it. Observations also have the capacity to change the qualities of what is being observed.
The double-slit experiment showed that individual atomic elements such as electrons (and even some larger atoms and molecules) can be described in “particle terms” and “wave terms” (this is called “wave-particle duality”). Also, unlike in classical physics, the motion of these elements can be described only probabilistically, and definitive answers are possible only once these elements are directly observed (see “Schrödinger’s Dilemma,” below).
Unfortunately, this scientific conclusion has given rise to a pernicious form of pseudo-science and “new age” thinking that says we can create our own realities, and God is simply something inside each of us and not the transcendent creator of the universe.
Quantum consciousness?
Deepak Chopra is a self-help guru known for offering advice that some find profound. For example, in one article Chopra says:
Quantum theory implies that consciousness must exist, and that the content of the mind is the ultimate reality. If we do not look at it, the moon is gone. In this world, only an act of observation can confer shape and form to reality—to a dandelion in a meadow, or a seed pod, or the sun or wind or rain. Anyway, it’s amazing, and even your dog can do it too (“The Illusion of Past, Present, Future”).
Chopra misunderstands how quantum theory works. Observers are capable of reducing the probabilistic state of particles into definite states, but so can any interaction at the quantum level. A quantum state doesn’t ask if a particle affecting it comes from a conscious observer such as us or an unconscious force such as the sun.
More importantly, the conclusions of quantum physics do not apply to objects that are bigger than a molecule. The wave property (or wavelength) of these objects is practically zero (as factored into the de-Broglie’s equation), so they do not behave like sub-atomic particles. If you sent moons or dandelions through a double slit, they wouldn’t act like electrons do.
Chopra uses these aspects of quantum physics to argue that the ultimate reality is consciousness and so we can “create our own reality,” because our minds are conscious. Now, one can argue that a non-physical observer was necessary at the beginning of the universe to actualize the first quantum state. But it doesn’t follow that our minds create and sustain the universe as it currently exists.
Our minds are conscious because we are made in the image of God, not because we are God. In its reflection on the New Age called Jesus Christ the Bearer of the Water of Life, the Pontifical Councils for Culture and Interreligious Dialogue taught, “God is not identified with the Life-principle understood as the ‘Spirit’ or ‘basic energy’ of the cosmos, but is that love which is absolutely different from the world and yet creatively present in everything, and leading human beings to salvation” (4).
Something from nothing?
While gurus like Chopra try to use quantum physics to prove there is only a spiritual reality, skeptics sometimes use it to argue that only the material exists, and God is not necessary to explain why there is something rather than nothing. They claim, for example, that scientists have observed so-called “virtual particles” emerging, apparently without a cause, from a vacuum. This supposedly shows that the universe’s existence can be explained without God, because quantum physics proves “something can come from nothing.” In an interview with National Public Radio, physicist Lawrence Krauss said, “Nothing can create something all the time due to the laws of quantum mechanics.”
However, this phenomenon does not refute the metaphysical principle that something cannot come from nothing. That’s because the quantum vacuum from which these particles spring is not “nothing.” Rather, it is a field with a very low energy level that can fluctuate. Unlike nothing, this field has properties and can be positively described. This makes it more than capable of producing “something” like a virtual particle. Philosopher and theoretical physicist David Albert writes:
Vacuum states—no less than giraffes or refrigerators or solar systems—are particular arrangements of elementary physical stuff. . . . [T]he fact that particles can pop in and out of existence, over time, as those [quantum] fields rearrange themselves, is not a whit more mysterious than the fact that fists can pop in and out of existence, over time, as my fingers rearrange themselves. And none of these poppings—if you look at them aright—amount to anything even remotely in the neighborhood of a creation from nothing.
Albert says that Krauss’s claim that quantum fields have the property of being able to create universes doesn’t resolve the issue at all. He maintains that physicists such as Krauss “have nothing whatsoever to say on the subject of where those fields came from, or of why the world should have consisted of the particular kinds of fields it does, or of why it should have consisted of fields at all, or of why there should have been a world in the first place. Period. Case closed. End of story.”
(Krauss subsequently dismissed critics such as Albert as “moronic philosophers,” even though Albert holds a PhD in theoretical physics along with a PhD in philosophy.)
The end of causation?
A critic could say in response that even if these fields aren’t “nothing,” quantum physics still shows the universe could have come into existence without God. After all, quantum events like particle decay in atomic nuclei do not have causes and are entirely unpredictable. It may simply be the case that the emergence of our universe from nothing was a similar, uncaused quantum event.
First, the “uncaused” or, more precisely, indeterminate nature of quantum events is not a proven fact. Instead, it is a feature of some interpretations of the mathematical formulas used in quantum physics (usually the Copenhagen interpretation). These interpretations describe the world depicted in these equations but, as the late atheistic physicist Victor Stenger admits, “Other viable interpretations of quantum mechanics remain with no consensus on which, if any, is the correct one.” Stenger says we have to remain “open to the possibility that causes may someday be found for such phenomena” (Has Science Found God?, 188-89).
For example, David Bohm’s interpretation of quantum physics does not have uncaused events. Under Bohm’s view (or the deBroglie-Bohm interpretation), the way particles behave is completely determined by the physical events that happened earlier in time. Quantum events appear to be random even though they have a determined cause in the form of a “hidden variable” physicists have not (and possibly cannot) discover.
However, even if quantum events like the emergence of particles from vacuums or the decay of atomic nuclei do not have determined causes (i.e., identifiable, physical conditions that brought them about), it doesn’t follow that they are uncaused. They may simply be the result of indeterministic causes, or structures that explain the origin of an event without explaining why a particular event happened instead of another event.
For example, we might wonder why a speaker chose to utter a certain series of words, but we would not question the fact that he caused those words to be uttered. John Jefferson Davis shows how this same reasoning applies to quantum systems:
Quantum-mechanical events may not have classically deterministic causes, but they are not thereby uncaused or acausal. The decay of a nucleus takes place in view of physical actualities and potentialities internal to itself, in relation to a spatiotemporal nexus governed by the laws of quantum mechanics. The fact that uranium atoms consistently decay into atoms of lead and other elements—and not into rabbits or frogs—shows that such events are not causal but take place within a causal nexus and lawlike structures (Frontiers of Science and Faith, 55-56).
In short, quantum systems may be without causal determinacy, but they still have predictable causal conditions that lead to certain results. If they did not and were truly without casual properties, then scientists wouldn’t be able to replicate quantum experiments. In fact, scientists often describe quantum fields or nuclei as “producing” particles or effects, but the word produce is a synonym for cause. This shows that even these peculiar systems adhere to some form of the metaphysical principle of causality and do not prove that “something can from nothing.”
Wisdom from on high
There are still many mysteries within the realm of quantum physics for scientists to explore. For example, Einstein’s theory of relativity describes the effects of gravity using classical physics, but the theory doesn’t describe how gravity works at the quantum level. That’s why physicists are currently working on a “quantum theory of gravity” to study things like the first moments of the universe’s expansion after the Big Bang.
As future discoveries in quantum physics continue to be made, we should not let them be a cause of concern. Instead, we should echo the Catechism’s declaration, “These discoveries invite us to even greater admiration for the greatness of the Creator, prompting us to give him thanks for all his works and for the understanding and wisdom he gives to scholars and researchers” (283).
Sidebar 1: Wisdom of Chopra?
Consider these two Deepak Chopra quotes:
“Attention and intention are the mechanics of manifestation.”
“Your consciousness quiets an expression of knowledge.”
The first is a real Chopra quote; the latter is a random combination of words strung together by an online “Deepak Chopra quote generator” (wisdomofchopra.com).
It’s hard to tell them apart, because Chopra’s “wisdom” is just a vague assertion that the mind creates reality combined with scientific jargon related to quantum physics in order to give it an air of legitimacy.
Sidebar 2: Schrödinger’s Dilemma
In 1935 Erwin Schrödinger created a thought experiment involving a cat that was locked in a steel box with a vial of poison. The vial would be broken if a radioactive molecule called an isotope underwent decay and set off a detector. Since atomic decay happens at the quantum level it’s impossible to predict when an isotope will emit a sub-atomic particle.
According to one popular interpretation of quantum physics called the Copenhagen interpretation, these particles exist in a super-position, or “merged state.” This probabilistic state would not become a definite reality until it is observed (similar to how the electrons in the double slit experiment don’t pass through a single slit until they are observed).
Schrödinger said that if the Copenhagen interpretation were correct then the quantum effects of the isotope would be uncertain until an observer collapsed this state (or “wave-function”). This would mean the cat, whose life depends on one of two states being made definite, would exist in an uncertain state and be both alive and dead until someone looked in the box.
It’s important to remember that Schrödinger did not think the cat could actually be alive and dead at the same time. Instead, he used this experiment to highlight what he saw as a weakness in the Copenhagen interpretation of quantum physics.