The Coffee Walkers. It sounds like some creepy Steven King inspired blog post today (reminds us of the Tommy Knockers). However, the truth of the matter is that this is a gait blog post on walking.
Why is it so hard to walk with a cup of “joe” or a coffee mug of anything liquid for that matter ? It is all about physics and wave frequency.
In a neat little article written by Natalie Wolchover for CNBC.com she says,
“New research shows that "the properties of mugs, legs and liquid conspire to cause spills, most often at some point between your seventh and tenth step. So says a pair of fluid physicists at the University of California at Santa Barbara.”
This is a physics problem actually. It is one of frequencies to be precise. Apparently the human stride has almost exactly the right frequency and amplitude to drive the natural oscillations of a liquid when it is in a classic shaped and sized coffee mug. The frequency of the liquid sloshing to and fro in your mug has the same frequency as your gait. So, when you are walking with your mug-of-Joe there is an additive effect of the two frequencies and apparently the more steps that are taken the effect eventually summates until the lip of the mug is exceeded. Stopping or slowing down once the ride is underway and the summation effect is changed, but not necessarily reversed. A sudden change in the frequency, such as you suddenly stopping, slowing or speeding up, can abruptly change the effect on the mug however the fluid within the vessel is not changed at the same rate and thus it can breach the edge of the mug.
According Wolchover, of one of the linked articles,
“Coffee drinkers often attempt to walk quickly with their cups, as if they might manage to reach their destination before their sloshing java waves reach a critical height. This method is scientifically flawed. It turns out that the faster you walk, the closer your gait comes to the natural sloshing frequency of coffee. To avoid driving the oscillations that lead to a spillage, walk slowly.” The other valid suggestions were to watch the mug and to accelerate slowly.
We take the easier route. Maybe we are smarter, maybe lazier, and maybe just tired of always analyzing things … . . we choose a container with a damn lid. Can you say “Einstein-ian” ? We don’t like coffee sloshing on our clothes or rugs.
Shawn and Ivo ………… jacked up on Joe. Get you never thought we would be able to turn coffee-talk into a gait article huh ? And you thought we would run out of gait stuff to talk about !
Article links that provided the inspiration for today’s post, and that we referenced.