Introduction: Touching the Invisible World with My Own Hands
What comes to mind when you hear the words ‘Quantum Physics’? You probably picture complex equations, the bizarre world of subatomic particles, and theories far removed from reality. But what if I told you that a magical phenomenon of this strange physics, specifically ‘Quantum Tunneling,’ could be witnessed right in your kitchen with just a simple glass of water?
The goal of this article is to weave four of the most astonishing and counterintuitive facts about quantum computing into one easy-to-understand story. You are about to witness light passing through an invisible barrier and gain a new perspective on the quantum world.
1. Surprising Fact: Quantum Phenomena Also Occur in the ‘Palm-Sized’ Macro World
The theme of the 2025 Nobel Prize in Physics is the discovery of ‘Macroscopic Quantum Tunneling’ and ‘Energy Quantization.’ We’ve long thought that quantum phenomena were confined to the microscopic world of atoms and electrons. However, this research shattered conventional wisdom by proving that quantum effects can also operate in electrical circuits the size of your palm—the ‘macroscopic world.’
How is this possible? The secret lies in ‘superconductors.’ In an extremely cold superconductor, individual electrons (fermions) pair up to form ‘Cooper pairs.’ These pairs act like different particles called ‘bosons,’ and billions of them can ‘condense’ into a single, massive quantum wave. This macroscopic quantum state became the foundation for the ‘superconducting qubit,’ the core of modern quantum computers.
This giant quantum wave demonstrates two miracles. First, it ‘tunnels’ entirely through energy barriers that are classically impossible to overcome. Second, like an atom, it possesses ‘quantized energy levels,’ where energy is divided into discrete steps. By defining the lowest energy level as ‘0’ and the next as ‘1,’ we were able to create stable qubits that are much easier to control than single particles.
2. Experience It: An Invisible Man in a Glass? Witness ‘Quantum Tunneling’ Yourself
Now, it’s time to experience this bizarre quantum tunneling phenomenon for yourself. All you need is a clear glass of water and your finger.
Step 1: Create the Barrier (The Disappearing Finger)
First, hold the glass of water upright. From this angle, you can't see your fingers holding the outside of the glass. This is due to a phenomenon called ‘Total Internal Reflection.’
The ‘barrier’ that light (photons) cannot cross here is the thin ‘air gap’ between the glass and your finger's skin. The light reflecting off your finger is blocked by this air gap, unable to enter the glass and reflecting 100%. That's why your finger becomes invisible to your eyes.
Step 2: The Principle of Breaching the Barrier (Evanescent Wave)
In classical physics, it’s impossible for a particle to pass through a barrier. But in the world of quantum mechanics, the story is different. A particle is also a wave, so it has a ‘probability’ of passing through.
When total internal reflection occurs, the light wave doesn't actually vanish completely at the air gap's boundary. Instead, it seeps faintly into the barrier as an ‘Evanescent Wave,’ which then decays exponentially. This wave is normally too weak and short-lived to be detected, but its very existence is the key to tunneling.
3. The Tunneling Demonstration (The Reappearing Finger)
Now, press your finger very firmly against the glass. As the ‘air gap barrier’ between the glass and your skin becomes extremely thin, something amazing happens.
The outline and fingerprint of your once-invisible finger begin to faintly appear. This is an analog of ‘Quantum Tunneling.’ As the barrier (the air gap) became thin enough, the tail end of the evanescent wave, before it completely decayed, reached the other side. As a result, photons from your finger probabilistically ‘tunneled’ through the classically impossible air barrier to reach our eyes. You have just experienced the quantum tunneling phenomenon with your own hands.
3. Debunking a Myth: Quantum Computers Are Not a ‘Magic Bullet’
One of the biggest misconceptions about quantum computers is the belief that they are ‘super-supercomputers’ that will replace all existing computers. This is fundamentally incorrect.
A quantum computer is not a computer that ‘solves all problems faster.’ Rather, it is a ‘specialized computer’ optimized for solving ‘specific types of problems,’ such as factorization or breaking certain types of encryption. Only for these specific problems do quantum computers show overwhelming efficiency, solving in an instant what would take a classical computer billions of years. For everyday tasks (sending emails, watching videos), classical computers are still far more efficient.
4. On the Shoulders of Giants: Quantum Computing is a Culmination of Decades of Nobel-Winning Technology
The quantum computer we talk about today isn't a technology that appeared overnight. It is the crystalization of human intellect, built up over decades, even a century. This journey has been a history of steps taken on the shoulders of giants. Scientists first learned how to trap a single ion in mid-air with electromagnetic fields (Nobel Prize 1989), then developed techniques to cool atoms to almost absolute zero using lasers (Nobel Prize 1997). Finally, they experimentally proved the bizarre phenomenon of ‘quantum entanglement,’ where two particles remain connected no matter how far apart (Nobel Prize 2022). All of these were essential building blocks for controlling qubits.
And the very ‘quantum tunneling’ principle we experienced today led to the creation of the ‘Scanning Tunneling Microscope (STM),’ which allows us to see individual atoms, earning a Nobel Prize in 1986. As you can see, quantum phenomena are not just theories; they are powerful tools for seeing and controlling the microscopic world.
Conclusion: Toward a New Paradigm of Computation
Today, we witnessed quantum tunneling with just a glass, learned this phenomenon also occurs in the palm-sized macro world to form the basis of qubits, debunked the myth of the all-powerful quantum computer, and understood that this technology is a culmination of numerous Nobel Prize-winning achievements.
A quantum computer is not a magic wand that will solve every problem. But it is undeniably a ‘new tool that surpasses the limits of classical computation.’ The entire global physics and engineering community is striving to realize that tool.
If classical computers defined the 20th century, what intractable problems of the 21st century will this new paradigm of quantum computing solve to define our future?
References
- ActionLabShorts, “Quantum Tunneling At Home,” YouTube (Aug. 1, 2020)
- Physics Videos by Eugene Khutoryansky, “Quantum Tunneling (animated),” YouTube (Mar. 4, 2015)
