New Twist on Sofa Problem That Stumped Mathematicians and Furniture Movers

Hobby 3-D Printing Leads to New Insights into Moving Sofa Problem

By Becky Oskin

Most of us have struggled with the mathematical puzzle known as the “moving sofa problem.” It poses a deceptively simple question: What is the largest sofa that can pivot around an L-shaped hallway corner?

A mover will tell you to just stand the sofa on end. But imagine the sofa is impossible to lift, squish or tilt. Although it still seems easy to solve, the moving sofa problem has stymied math sleuths for more than 50 years. That’s because the challenge for mathematicians is both finding the largest sofa and proving it to be the largest. Without a proof, it’s always possible someone will come along with a better solution.

Calculating just how fast Usain Bolt runs

With gold medals in three sprinting events at three Olympic Games, Usain Bolt has written himself into the record books as arguably the fastest human of all time. But just how fast is the Jamaican sprinter?

Three mathematicians, Sebastian Schreiber of UC Davis, Wayne Getz of UC Berkeley and Karl Smith of Santa Rosa Junior College, show how to calculate Bolt’s maximum velocity in the 100 meters at the 2008 Beijing Olympics in their 2014 textbook, “Calculus for the Life Sciences.”

This plot shows Usain Bolt's velocity measured at 10 meter intervals.

This plot shows Usain Bolt’s velocity measured at 10 meter intervals.