"What Is the Largest Sofa That Can Pass Through a Right-Angled Corridor?"... 60-Year Mathematical Puzzle Solved by a Korean [Video]

[Financial News] "What is the largest sofa that can pass through a right-angled corridor?"This unusual problem, posed by Canadian mathematician Leo Moser in 1966, remained unsolved for decades. In 1992, Joseph Gerver, a professor at Rutgers University, proposed 'Gerver's sofa,' a shape composed of 18 curves that considered the sequence in which the sofa touches the walls. However, he was unable to prove that this was the optimal solution.
This long-standing mathematical challenge, considered one of the world's great unsolved problems, has finally been solved after more than 60 years—by a 31-year-old Korean mathematician.
According to the mathematics community on the 4th, the American science magazine Scientific American recently selected Dr. Baek Jin Eon's research on the moving sofa problem as one of the 'Top 10 Mathematical Innovations of 2025.' Dr. Baek is affiliated with the Heo Joon-Yi Institute for Mathematical Challenges at the Korea Institute for Advanced Study (KIAS).
Scientific American explained, "While this solution may not help you move a sofa on moving day, it demonstrates that as cutting-edge mathematics becomes increasingly complex, mathematicians retain a special affection for unsolved problems that anyone can understand."

In fact, on MathOverflow—a mathematics forum—'the moving sofa problem' currently ranks second on the list of 'longstanding unsolved problems that are not particularly famous but are understandable to everyone,' underscoring its status as a persistent challenge for mathematicians.
Through seven years of research, Dr. Baek mathematically proved that Gerver's sofa is indeed the optimal solution. Scientific American highlighted that Dr. Baek arrived at the answer without any reliance on computers. The results were posted on arXiv, a preprint server, at the end of 2024 and have also been submitted to the international journal Annals of Mathematics.
In August of last year, Dr. Baek was also selected for the June Huh Fellowship, which supports mathematicians under the age of 39 for up to 10 years. The June Huh Fellowship was established in honor of June Huh, a Fields Medalist and professor at Princeton University. Recipients of the fellowship receive annual funding of 100 million won for five years to pursue their research.
y27k@fnnews.com Seo Yoon-kyung Reporter