When the laws of physics shift slightly in the world of mirrors Exploring why the universe and we "exist without vanishing"

When we gaze up at the night sky, the countless stars we see—and even you, the one reading this right now—might actually be miraculous products born from a “bug” in the history of the universe, one with an improbable probability.

Appearing on TBS’s YouTube program ‘CROSS DIG 1on1’, Dr. Shion Kubota, a Harvard University physics doctoral candidate researching neutrino physics, discussed the cutting edge of research tackling the fundamental cosmic mystery: “Why do we exist without disappearing?”In this article, using her explanations as a guide, we will delve deep into how the workings of elementary particles—the smallest units of the universe—are intrinsically linked to our very existence.

Neutrino Physics: Unraveling the Mystery of the Universe and Our Existence

One conclusion reached by modern physics is that everything in the universe is made up of “elementary particles” – indivisible building blocks (think of them as the ultimate Lego blocks). Currently, 17 types of elementary particles have been confirmed within the theory known as the Standard Model. Among these, the “neutrino” remains shrouded in mystery.

The massive “DUNE” experiment, in which Mr. Kubota is involved as part of a U.S. national project, aims to unravel the properties of these neutrinos. At first glance, this might seem like a story from the microscopic world, seemingly unrelated to our daily lives. However, at the core of this research lies a philosophical question that everyone has pondered at least once: “Why do humans, and this universe, retain their current form?”

Immediately after the birth of the universe, the so-called Big Bang, we were destined to vanish in an instant, transformed into “light.” Yet, that did not happen. What created this critical turning point was the minute “difference in behavior” among elementary particles.

The Miracle of the World Born from the Imbalance of Matter and Antimatter

To understand why we exist, we must first grasp the concepts of “matter” and “antimatter.”

According to Kubota’s explanation, at the beginning of the universe, the matter (particles) we know and antimatter (antiparticles) – which have the same mass and appearance but opposite properties like electric charge – are thought to have been born in equal proportions, as one-to-one pairs. They are, in a sense, “strange twins.”

However, these twins possess a fatal characteristic. When matter and antimatter collide, they undergo “pair annihilation,” releasing immense energy (such as light) and vanishing without a trace.

“Imagine taking all my particles, flipping them all over, and creating ‘Anti-Kubota Shion’. Now, if this Kubota Shion and Anti-Kubota Shion were to meet, what happens? They’d go ‘boom’ and explode, vanishing into nothing.”

Kubota Shion (from ‘CROSS DIG 1on1’)

If matter and antimatter had remained in a 1:1 ratio as in the early universe, all matter would have collided with antimatter and vanished, leaving only light in the universe. Stars, Earth, you, and I would never have come into existence.

However, in reality, antimatter is almost entirely absent around us. Today, only “matter” remains overwhelmingly, with an immense disparity in the ratio compared to antimatter. It is precisely because this imbalance occurred somewhere that the surviving matter formed stars and created life.

The slight warp in the mirror world revealed by CP symmetry breaking

So, in a world that should have been perfectly balanced one-to-one, when and who exactly “cheated” to ensure only matter survived?

The key to solving this mystery lies in a phenomenon called “CP symmetry breaking.”
Physicists fundamentally prefer a “symmetrical” world. For example, when a phenomenon is mirrored (parity inversion: P) and then its positive and negative charges are swapped (charge inversion: C), it is natural to expect that “exactly the same physical laws apply (the same behavior occurs)” in both the original world and the mirror world. This is the state where “CP symmetry is conserved.”

However, nature was not perfect. Under specific conditions, a minority of elementary particles existed that exhibited “slightly different behavior” between the mirror world and the real world. A kind of uneasiness where the laws do not mirror each other. This is “CP symmetry breaking.”

This extremely microscopic, imperceptibly slight “warp (bug) in the laws of the universe” is believed to be the reason matter survived just a tiny bit more than antimatter. And now, the prime suspect for being the “culprit (or accomplice) who broke the symmetry” is the neutrino.

Neutrinos are mysterious entities that swarm around us, one of the most abundant particles in the universe, yet they possess extremely light mass and no electric charge.They possess the peculiar property of changing their form (neutrino oscillation) as they travel through space, shifting between three types: electron neutrinos, muon neutrinos, and tau neutrinos. At the forefront of physics, it is hoped that decisive evidence of CP symmetry breaking lies hidden within these neutrino oscillations.

The Full Scope of DUNE: A Giant Project Transcending Observational Limits

If we can observe neutrino behavior, particularly CP symmetry breaking, we could grasp decisive evidence for why we exist. However, observing neutrinos is one of the most challenging tasks in physics.

This is because neutrinos interact so rarely with other matter that they are often called “ghost particles.” Even at this very moment, hundreds of millions of neutrinos per second pass through our bodies and the Earth without causing so much as a scratch. According to Mr. Kubota, even over the course of a human lifetime (70-80 years), neutrinos might interact within the body “once, if at all.”

New-Age Pixel Technology Tracking Faint Traces

To capture these elusive particles, the United States launched the DUNE Project, mobilizing the nation’s full resources. At Fermilab in Chicago
, a high-energy neutrino beam is artificially generated and fired toward a massive detector installed 1,300 kilometers away in an underground mine shaft (the Sanford Mine) in South Dakota.

During this immense journey, neutrinos change their properties (neutrino oscillation). To detect this “wobble,” the target detector is filled with 40,000 tons of liquid argon (equivalent to several buildings). When a neutrino very rarely collides with an argon atom, the ejected electron leaves behind a faint “charge trail” in the liquid, which is observed.

“When an electron—meaning the particle produced by the neutrino—moves through the argon, it leaves a trail of charge along its path. It’s like Hansel and Gretel’s breadcrumbs. Our job is to project these breadcrumbs.”

Shion Kubota (from ‘CROSS DIG 1on1’)

To capture these tracks more precisely, Kubota’s team is developing an entirely new “pixel-type readout technology (Q-Pix).” Previously, we inferred 3D data by combining 2D shadow images. With pixel-type detectors, we can record the neutrino’s trail as accurate 3D data from the start, aligned with the time axis.

This represents more than just a technical advancement. It enhances the resolution of science—the “language for understanding the universe.” It holds the potential to reveal previously invisible low-energy events and even clarify the entire cycle from the death of stars to the birth of life.

The existence of “I” standing at the end of 13.8 billion years of exquisite balance

The more we unravel the history of the universe, the more we realize that our very existence here and now rests upon a succession of astronomical miracles.

13.8 billion years ago, the perfect symmetry between matter and antimatter was broken by the tiniest margin. As a result, matter prevailed, forming stars over vast spans of time and creating an environment where life could flourish within the laws of gravity and electromagnetism. Had
the laws of the universe differed even by the width of a grain of sand from their current form, we could never have come into being.

“After all, the fact that this ratio emerged from that one-to-one balance is also something like a miracle. When I think about how this universe, and my very existence, came to be through this accumulation of miracles, I just feel like saying ‘thank you’ to everything.”

Kubota Shion (from ‘CROSS DIG 1on1’)

Cutting-edge physics explores the microscopic world using equations and massive experimental apparatus, yet its ultimate destination is an overwhelming philosophy that compels us to reexamine the very foundation of our existence. A bug in the laws of the universe built the very foundation of my life. Recognizing this, the everyday scenery before our eyes should appear tinged with colors entirely different from yesterday.

Taking this thought further, the very fact that “you and I exist” is itself the result of how much the quantum world fluctuates and how much it is imbued with accidental collapses.In the world of quantum mechanics, states exist only probabilistically and remain undetermined until observed. Perhaps even at that decisive moment when matter overcame antimatter, some sort of “macroscopic convergence of probability” occurred. Or perhaps the very consciousness that allows us to ponder the universe’s mysteries is an extension of the minute functions of elementary particles.

The Frontiers of Knowledge Pioneered by Fundamental Science and Our Daily Progress

In modern society, investment often prioritizes “solutions with immediate utility.” However, as Mr. Kubota points out, fundamental science is not about “solving specific problems right now,” but rather an endeavor to “expand the very circle of human knowledge itself.”

Just as knowledge once gained by exploring cosmic truths later became essential tools for humanity’s expansion into space. Or as fundamental research on viruses and immunity later led to vaccine development that saves countless lives. Knowledge accumulated through basic science continues to underpin the possibilities of our future beneath the surface. The pixel readout technology developed in the DUNE project also holds the potential to be applied in unexpected ways in the future, such as in medical device image processing or new material development.

“Why is the world shaped this way?” The efforts of researchers
driven by this pure romance continue to gradually reveal the contours of the universe, day by day.

This “everyday life” we take for granted today—breathing, eating, interacting with others—stands upon the extraordinary luck of a tiny “symmetry breaking in the laws of physics” that occurred just after the Big Bang 13.8 billion years ago.
The next time you gaze at the night sky, or pause in thought, remember that you yourself are a product of this miracle. Doing so might make even your troubles and hardships feel precious, as part of the grand history of the universe. Your very existence is what could be called the “most beautiful error” born from a cosmic glitch that should have been lost.