At least once in our lives, we have all heard a physics teacher say, “Physics is everywhere!” And undoubtedly, it is. Yet, we nod in agreement while absentmindedly sketching in the corners of our notebooks. Whether we realize it or not, physics continues to operate even in the most mundane moments of our daily lives.
To break this down into something simpler than complex equations and concepts, we can see that physics has even made its way into our language. When something is unnecessarily complicated, we say, “It’s not rocket science.”. Well, if the topic has started to involve quantum…
Before diving into quantum mechanics, let’s start with the things that we observe as daily surroundings. If we take a stone in our hand and release it, we see that it falls to the ground. Similarly, when driving a car and pressing the brakes, we know that the car will slow down. All of these phenomena fall within the domain of classical physics, which operates following our intuition and observations—just as we know that a stone we let go of will eventually hit the ground.
Humans believe in what they see and can predict events, as long as they are not absurdly unexpected. Our daily lives are built upon this predictability; we instinctively understand cause-and-effect relationships. Now, imagine this ability is suddenly taken from you. You are a pedestrian waiting to cross the street. The traffic light in front of you turns yellow, but you have no idea whether it will turn green or red next. Will the change happen randomly? Or will the color be determined only when someone looks at the light? This is exactly how the quantum world operates.
In quantum mechanics, we can not precisely determine how particles will behave in the future; we can only make probabilistic predictions. Just as we might not know whether the light will turn red or green next, but we do know it won’t suddenly turn the color of purple…
Of course, in real life, we often know what will happen next because we have seen the previous state—just as we can anticipate the next color of a traffic light based on our experience. This is why quantum mechanics seems so different from our everyday reality, making it more difficult to grasp.
So, what exactly is quantum mechanics? Can it truly be understood, or does Richard Feynman’s famous remark hold—that if we think we understand quantum mechanics, then we don’t?
The word “quantum” comes from the ancient Greek word “quanta,” meaning “discrete” or “divided into portions.” To understand what quantum mechanics is, we must first examine what it means for something to be discrete in a physical sense.
To do this, let’s take a journey back about 80 years and imagine ourselves as a projectionist in an open-air cinema. We load the reels of a film that is about to premiere and, once the audience has settled in, we start the movie. Frame after frame, the film plays before our eyes…
These frames are played at a certain speed, and because our eyes cannot perceive the gaps between them, we believe the motion to be continuous. However, if we slow things down and examine the frames one by one, we realize that each moment is made up of separate, distinct images.
This analogy helps us distinguish between classical physics and quantum mechanics. Classical physics sees nature as a continuous flow—just as we perceive a film as a smooth, uninterrupted experience. Quantum mechanics, on the other hand, reveals that nature is composed of discrete units, like the individual frames of a film.
Of course, the concept of quantum mechanics was not developed while watching movies. So where did it come from?
As mentioned earlier, classical physics aligns well with our observations—or at least, that was the belief. However, at the end of the 19th century, this seemingly perfect understanding of the universe began to crack. Just as physicists were convinced that all the secrets of the universe could be captured in a few equations, the unthinkable happened. Experimental results began to contradict theoretical predictions, and this discrepancy was far greater than a simple margin of error. It was enough to shake the very foundation of classical physics.
It was discovered that energy was not continuous, as previously assumed. Instead, it was quantized—existing in discrete packets, much like the individual frames of a film. This marked a turning point in physics. But where do we, as observers, fit into this transformation?
This turning point is not as distant as it seems, nor does it operate under completely different rules. Sometimes, the things closest to us remain unnoticed—just like a hidden detail in plain sight. Now, imagine stepping into a new cinema, sitting down in the audience, and putting on 3D glasses. The movie begins, and suddenly, the images gain depth. The characters seem to step out of the screen as if they are right beside you. But how do your 3D glasses “know” that these scenes are three-dimensional?
This is where one of the fundamental principles of quantum mechanics comes into play: the dual nature of light. Light behaves both as a wave and as a particle. 3D glasses exploit this wave property to separate the images seen by each eye, creating the illusion of depth.
In cinemas, on the streets, even in the lenses of our glasses… Just as we said in the beginning, quantum is everywhere!
Now, let’s step back into our childhood, to the games we used to play outside. Imagine a moment when we played house with our friends. But this time, we changed the rules: we are not playing house—we are playing “Quantum House!”
In traditional house-playing games, roles like “mother,” “father,” and “child” are assigned, and sometimes we end up in roles we don’t want. In Quantum House, however, things work a little differently—here, everything is everything at the same time! A child can be both the mother and the father; perhaps even a cat! But until someone observes, their role remains uncertain. They can exist in all states at once…
If a child can play Quantum House, then quantum mechanics must be child’s play!
As our journey comes to an end, after this long and exhausting day, we decide to relax and take a dip in the sea under the evening sun. But we are still children, and it’s our first time in the water. A sense of fear arises—the water is cold and pulls us downward. But in reality, it is also pushing us upward, and with time, we will get used to it. Eventually, on hot summer days, we won’t even want to get out of the water, even for five minutes.
We don’t need to understand every detail to experience something. Just as we learn to swim without calculating buoyant force, we can also grasp the essence of quantum mechanics without solving every equation.
Many aspects of quantum mechanics seem to have been understood, but there are still many mysteries waiting to be uncovered. We find ourselves in the middle of a grand film—frozen in a single frame. But the film continues to roll, and in the next scene, perhaps YOU will be the one to unlock the secrets of quantum mechanics.
But we’ll only know once we see it—because, after all, this is Quantum House, and you might be the mother, the father, or even the cat!
Wait until the next frame!
- Cover Photo Image Credit: Photo by Eric TERRADE on Unsplash
- Quantum Technologies Research Team (HARMONY) Page
