The Power to Decode Gravitational Waves Can Shape the Society of Tomorrow

When we gaze up at the night sky, stars seem to flicker delicately. Yet deep within the vast universe, dramatic events are constantly unfolding—collisions between stars and black holes, massive stellar explosions. These events cause distortions in spacetime known as gravitational waves, some of which barely reach Earth and leave subtle traces in observational data. Accurately interpreting these signals requires sophisticated analytical techniques capable of extracting meaningful information from massive amounts of noise.
Such data analysis techniques are not limited to space science. They hold enormous potential for applications across modern society—in traffic safety, healthcare, education, and urban planning. At the forefront of this interdisciplinary work is Professor Hirotaka Takahashi of Tokyo City University’s Faculty of Design and Data Science and its Research Institute.

His lab focuses on two major areas: “Big Data Analysis” and “Operations Research,” rooted in physics, mathematical science, and information and communication technology. One of the lab’s key projects is the analysis of gravitational wave data. These waves are generated by short-lived cosmic events such as stellar collisions or explosions, and they arrive on Earth unpredictably. For this reason, continuous observation and data collection are necessary.
Japan’s large-scale cryogenic gravitational wave observatory, KAGRA, gathers enormous volumes of data daily. While “gravitational wave” might evoke images of massive ripples, most are unimaginably small—on the scale of 10 to the power of minus 21. Professor Takahashi is advancing research that employs artificial intelligence (AI) and the latest signal processing technologies to detect such minute signals more efficiently and reliably.

Professor Takahashi is also conducting research on safe driving support. Small wearable devices are placed on drivers’ wrists to gather driving data for analysis. Results have shown that drivers tend to make more frequent and subtle steering movements when their attention is scattered. This finding could lead to real-time alert systems that recognize such behaviors and warn drivers, or to individualized safety strategies based on each driver’s characteristics.He notes that small, smartwatch-like devices can make these systems cost-effective. “We use similar wearable devices to analyze swimming stroke data in athletes,” he adds. “We’re also collaborating on a sleep apnea project. Traditionally, diagnosis has required hospitalization and large-scale equipment, but our goal is to enable simple at-home testing using smartphone apps.”

In the field of operations research, which explores decision-making methodologies, his team tackles a wide range of topics—such as planning evacuation strategies for municipalities, optimizing the placement of public facilities, and designing train schedules. His lab is also working on analyzing learning and behavioral records collected through tablets used in schools, using AI to support teachers in their instruction.During the COVID-19 pandemic, his team developed simulations that modeled artificial societies within computers to replicate daily life and predict how the virus would spread.
“These are all attempts to systematize and model decisions that have traditionally relied on the invisible intuition and experience of skilled professionals—so they can be made by non-experts or even computers,” he says.

Gravitational waves, safe driving, sleep disorders, athletic performance—at first glance, these may seem unrelated. But when asked directly, Professor Takahashi explains that all of them are connected through data.
“The analytical techniques and insights gained from gravitational wave research can be applied across many fields. Taking a broad, scientific perspective is what really matters.”

While his lab explores a wide range of themes, his original passion remains rooted in space. Influenced by his father, he dedicated himself to baseball until high school. But since he enrolled in a prestigious school with many talented athletes, he eventually shifted his focus to academics.
“I liked chemistry back then and considered going into pharmaceutical sciences. But my prep school physics teacher often talked about space after class. I was fascinated by how many mysteries of the universe remain unsolved—and that led me to pursue astrophysics.”

Gravitational waves were once considered too weak to ever be observed. But in 2015, the U.S.-based LIGO project succeeded in detecting them for the first time. Two years later, three key contributors to the project received the Nobel Prize in Physics—testament to how groundbreaking the discovery was.This milestone catalyzed the rise of multi-messenger astronomy, where observatories and telescopes around the world collaborate to unravel cosmic phenomena from multiple perspectives.
“I regret missing the first detection,” Takahashi admits, “but now observatories worldwide are working together to observe celestial events. My goal is to establish gravitational wave observation using Japan’s KAGRA and to further advance astronomical research.”

With a growing shortage of digital talent, Professor Takahashi shares his hopes for the next generation.
“When you work with AI, you realize that what it gives you is not a definitive ‘answer’ but a ‘response’—just one proposed option. The decision must ultimately be made by you. That’s why it’s so important to be able to properly interpret and use AI’s suggestions. And one more thing—always keep a wide perspective. Topics from completely different fields can suddenly connect in unexpected ways. Whether you’re a student or a working professional, don’t dismiss things as ‘irrelevant to me.’ Stay curious, stay learning.”

About 100 years have passed since Einstein predicted the existence of gravitational waves in his general theory of relativity in 1916. Thanks to the accumulated wisdom of humanity, we can now observe what was once considered undetectable—and prove its existence.The methods Professor Takahashi is developing to analyze vast cosmic data may someday improve our everyday lives. Events that occurred hundreds of millions of light-years away may hold the power to transform the world of tomorrow.