You've got your fancy new suitcase and you're ready to take it with you on your travels across the globe.
You get to the airport, quickly moving through the crowds on the uneven pavement, rushing to check in. Then, your heart sinks when you realize your new suitcase has got a serious case of the wobbles.
Why does this happen?
Scientists from the Universite Paris-Diderot in France investigated this matter and published their findings in the science journal Proceedings of the Royal Society A. They also suggested some solutions to overcome this modern-day problem.
To learn more about the issue, they put a suitcase on a treadmill (跑步机) and observed what happened.
It was soon noted that the "wobble" was actually a result of repeated actions that caused the suitcase to sway (摇晃) from side to side. They discovered that if one of the wheels encountered an obstacle such as a small bump, it jumped into the air for just a moment and then banged back down to the ground. That second action caused the opposite wheel to lift off the ground and then to bang back down, causing the first to lift again and so on. This swaying increased as the luggage was pulled along.
"The suitcase is a fun way to tackle the problem, but the study would be the same for any trolley with two wheels or blades (桨叶)," Sylvain Courrech du Pont, lead author of the study, told BBC News. "So it will be the same for a caravan (大篷车) or maybe also for airplanes."
Instead of slowing down when we see a rocky part of the path, the scientists recommended doing the exact opposite and speeding up. This is because going faster gives the wheels less time to rise and fall, preventing the case from swaying. They also said that reducing the angle of the suitcase by lowering its handle to the ground would help keep it steady.
"These findings could help researchers simulate and design better rolling suitcases and other pulled trolleys, such as towed trailers (牵引车)," Courrech du Pont added.
With these masterminds working on perfecting our suitcase problems, wobbly luggage may soon be a thing of history, leaving us to enjoy our travels.
