Half a century of math mystery finally meets Baek Jin-eon
After almost sixty years of stumping progress in geometry, a Korean mathematician has cracked a problem that generations of scholars left unsolved.
After almost sixty years of stumping progress in geometry, a Korean mathematician has cracked a problem that generations of scholars left unsolved.
The so-called moving sofa problem asks how large a rigid shape can be while still being able to pass around a right-angled corner in an L-shaped corridor of a constant width of 1 meter.
First posed in 1966 by Austrian-Canadian mathematician Leo Moser, the puzzle became widely known because it can be understood without advanced mathematics and has appeared in US textbooks.
Over decades, researchers proposed increasingly efficient shapes while narrowing the possible range of solutions, but were unable to prove where the upper limit lay.
…
Baek’s work aimed to settle that question.
After seven years of research, he released a 119-page paper in late 2024 on the preprint server arXiv, arguing that Gerver’s figure represents a hard upper limit.
Unlike earlier studies that relied heavily on computer-assisted estimates, Baek used logical reasoning to establish optimality.
While much of public attention in science and tech tends to gravitate toward flashy hardware or AI breakthroughs, this achievement is a reminder that foundational work, proofs that clarify what is true rather than what is possible, still matters. Geometry underpins areas from digital imaging to physics to cryptographic algorithms in everyday use.
Math may not come with much fanfare, but when a puzzle resists solution for generations and then yields to a new insight, it’s a reminder that some mysteries are worth the wait.
Thanks, Theophrastvs