Update: I have since learned that the conclusion I make in this post is incorrect, and as a science hobbyist, quantum mechanics is still far too difficult for me to understand. I leave this article published as a thumbtack in the history of my foolishness, and also as a way to hopefully instill curiosity of the subject in the reader. (See footnote for brief explanation.)
Several weeks ago, a friend of mine called me with some troubling news: the world of physics is in total disarray. “The best definition we have for how things work, at the quantum level, is magic,” he explained. There was panic in his voice.
“Jeff, what the hell are you talking about?”
He pauses to catch his breath. “Science right now,” he continues, “is stumped.”
“Sure, we understand how life-size things work, how planetary-size things work, and even how cell-size work. But go even deeper, to a subatomic level, and we are absolutely clueless,” he explained. It turns out, my distressed friend was not alone in harboring this eerie sentiment towards the laws of physics which I had until that point assumed we had a pretty good understanding of — it troubled many smart people, including Einstein, as well.
“Slow down Jeff – what the hell do you mean it’s ‘magic’?” He began explaining his late night obsession with a branch of physics called quantum mechanics. Quantum mechanics is mind-bendingly difficult to wrap your head around, and human language falls short in properly explaining it. He began his explanation thus: “Imagine there is a table in front of you. This table has a coordinate in 3D space, and you know that if you closed your eyes, or turned your back to this table, that it would still be there with 100% certainty. You would know that its color, position, and size has not changed just because you’re no longer observing it.”
“Well, at the quantum level, you can no longer be so certain.”
Quantum mechanics, amongst other things, says that you cannot make any assertions about certain attributes of a particle until you measure those attributes. For example, a particle has a spin. For simplicity’s sake, a particle’s spin can take on a negative or positive value. However, this particle does not have an “inherent” spin, and only takes on a value when you (an observer) measures it.
“What about before it’s measured? It still has a spin value right? We just don’t know its value because we haven’t measured it, but it still has a definite, inherent value, whether or not we are looking at it. Right?”
He continues his explanation, half in disbelief himself. “Before we measure it, its spin is ‘random’. Indeterminate. And not due to human ignorance; just literally random. It could be anything. Only when you measure it does it become something.”
At this point, my eyes are squinting and my fingers are anxiously brushing through my hair. “But— what if— how does— doesn’t it—it’s because—what.”
I was stumped.
“What the hell do you mean its spin is ‘random’ before you measure it? What does that even mean?”
That wasn’t even the spookiest part.
“Have you heard of quantum entanglement before?” he asks.
“Sounds familiar, but no not really.”
“Well,” he laughs, “you might want to sit down for this.”
“Ok, so, you know how I just told you that we don’t know a particle’s spin for sure until we measure it?”
“Well, Quantum Entanglement says that once two particles become entangled [through interaction], that if you were to separate these two particles a million miles apart, and measure one of the particle’s spin and find it to be positive, you then immediately know the other particle’s spin is negative.”
“But I thought the spin of a particle is random until you measure it? Why does measuring one particle’s spin immediately cause another particle, millions of miles away, to all of a sudden be non-random and definite?”
Being the modern homosapien that I am, I wasn’t going to take “magic” for an answer.
I struggled with this concept for several weeks after that bizarre phone call. I read article upon article, watched hours of YouTube videos, and struggled with dozens of analogies and metaphors that try to explain the concept at a five year old level. I still could not make sense of it. How can something be random? What does it mean for a physical attribute to be random? To be nothing? To be uncertain?
I found an answer to this question in the most unlikely of places.
I took a strange trip this Sunday with my wife to Target. She said we needed matching towels for the bathroom.
“What’s wrong with our current towels?” I asked.
“They’re gross. They’re like old hand-me-downs from your parents.”
The aisles of Target were brightly-lit and vibrant as ever. I never liked Target much, since every time I went only looking for a toothbrush, I would leave with $120 worth of goods I never knew I needed. This time around, I was less interested in comparing towels and more so with my continued preoccupation with quantum entanglement. I paced the wide aisles with hands behind my back and gaze straight towards the ground, anxiously pondering what it meant for something to be random; what entanglement can possibly mean.
“…doesn’t have a spin…observe through arbitrary distance…random…,” I mutter to myself like a mad-man.
“Do you think this purple would go nice with our shower curtain?” my wife asks.
“…observe one…other constricts to same reality…”
“What about the color of this blue hand towel?”
“…perspective…alternate version of reality…relative to observer…”
“Are you just saying yes to anything?”
She smiles. I buy myself some time.
In that moment, through my pacing back and forth, I was utterly unaware of myself. I was nothing more than a brain floating through space and time without a body. I wasn’t six feet tall, nor was I 170 pounds, and I didn’t have black hair. I was nothing but thought and motion.
Deep in perplexed and spaghetti thought, I glance to my right and am instantly taken aback by what I see.
I was spooked. There I was, meat and everything. Before then, I was infinite. The moment I looked in the mirror, I instantly became six feet tall, 170 pounds, and sure enough, with black hair.
And it clicked. Before I measured myself in the mirror, I could have been anything. I didn’t feel like I had black hair or hazel eyes. Heck, I could never know what color my eyes were for certain unless I “measured” their color (with a mirror). It’s not until I observe myself that I can make accurate assertions about my attributes.
Now, that might seem like a far-removed example, but riddle me this: what color are you?
You can’t say yellow, or black, or white, because the question is not what color is your skin, but rather what color are you. The answer to this question is obviously that there is no answer since this question is nonsense.
Now, let’s say you have a mole on your face — what color is this mole?
“Easy,” you say, “brown!”
Fine, good. What color is the mole to itself?
Wrong, since this question is similar to me asking you what color you are — nonsense. Going even further, what color is the mole to your nose? Well, our nose doesn’t perceive of color, so this question is again nonsense.
So, the question of “what color is this mole” can best be answered not by “brown”, but by “depends on who you ask”, or, “depends on how you measure it.”
To a human perceiver, it depends on the lighting conditions, the mole’s angle to the light source, the fogginess of the mirror, or the quality of your eye sight. To a non-human perceiver, this question cannot even be posed in the first place.
So, does a mole have an inherent color? The answer is no. It is only when you decide upon the rules of how you will measure its color and perform the measurement does it actually take on a color.
Let’s go over some more fun, but not necessarily literal, examples.
Imagine you’ve woken up to a magnificent sunrise, and you have not yet checked the time.
What time is it?
You don’t know.
Therefore, the time could be anything. Your world is as of yet infinite. The instant you measure the time however, you constrict your version of reality to a very specific interpretation: 8:30am. This time carries with it real world implications and obligations: you now have 30 minutes to take a shower, make coffee, walk the dog, and drive to work. Simply by measuring time have you altered your reality and constricted it to a specific interpretation.
Here’s another example, in true Schrodinger fashion: you send a heart-felt text message to your hopeful-to-be special someone, then immediately hop in the shower. You sing and bust moves while you lather your hair with fruity shampoo, all while images of love and romance conjure in your mind. You dry yourself off and head to check your phone for a response. As of yet, your version of reality is infinite. You don’t know for sure whether you have gotten a response, so you could be anything, happy or sad. The instant you check your phone, however, you’ve constricted your version of reality to a very specific interpretation: you haven’t gotten a response yet, and are instantly saddened. Simply by measuring your environment (checking your phone) have you altered your version of reality.
(You might even see from the above examples the dangers of constantly checking your phone – every time you pull your phone out of your pocket and “measure” your notifications, you constrict your version of reality to a specific interpretation that was before unbiased and infinite.)
Take even mind-altering substances (for example, that is). When you ingest marijuana, you might say that it makes you feel more spiritual, and that it connects you with nature, and it just feels right. The effects of marijuana however are not pre-divined and “deep”, but just a very specific (and ultimately random) interpretation of reality. The fact that smoking weed makes you feel whole is coincidental and not in any way pre-destined. Replace “smoke weed” with “drink alcohol”, “ingest psilocybin” or “take LSD”, and you’ll see the same pattern: every substance provides its own very specific perspective and interpretation of reality. The fact that magic mushrooms connect you to some sort of divine nature is a very specific, and random, interpretation. This implies that there is an infinite number of realities that could exist, each with its own perspective, and thus that there can exist an infinite number of new and novel drugs that will come about in the future that will let you experience a different version of reality. Perhaps one will make you feel like wind, or allow you to conspire with plants, or make you feel transparent, or see clouds as bits and bytes – the possibilities are literally endless, since all reality is perspective. Humanity’s current culture and mode of living? All one very specific interpretation of reality.
So, with this mindset, quantum entanglement is not so mind-bending after all. We’ve known since Newton that the universe tends to balance itself (i.e for every action there is an equal and opposite reaction), and since Einstein that energy is neither created nor destroyed. So the fact that if one object is positive the other must be negative is not a very troubling concept. Now, combine that with what we know about measuring reality, and we see that when we define the rules by which we will measure the spin of a particle (i.e on what axis), then simply by performing that measurement on that axis have we constricted our version of reality to a specific interpretation, i.e positive, and since the universe must always remain in balance, measuring that particle’s respective entangled particle by that same interpretation of reality (i.e on the same axis) will lead to an opposite spin (i.e negative).
Magic? Not so much. Troubling? No. But that every attribute of you and I is not absolute, but only dependent on and relative to who the observer is, has given me some pause. “Black” as an answer to “what color is my hair?” is no longer a valid response, since “relative to x” must be appended to the question.
And really, it seems, “relative to x” must be appended to every physical and metaphysical question that any human has ever posed for there to be a real shot at a valid answer.
Update: My conclusion doesn’t hold up. It turns out that if you measure the spin of a particle several times on the same axis (“same version of reality”), you won’t get the same results every time. This is what makes QE spooky: if you measure the first time and the first particle’s spin is up, then the entangled particle’s spin will be down. If you measure again on the same axis, the first particle’s spin can now be down, and the entangled particle’s spin will automatically be up. Mind = more blown. Looks like I have more reading to do.