I’m one of those people who is perpetually, somehow, covered in coffee. After about 30 seconds in my cup, my coffee inevitably comes out of it, turning the whole thing into a dripping mess.
So I was intrigued when I saw this recently published study, which gives a scientific explanation of why you spill coffee — and how you might actually keep it in your cup.
The research was done by South Korean physics student Jiwon Han, who did the study while competing in a physics research tournament in Thailand. Han studied the motion of coffee using oscillators, a mechanical machine that shakes the glass to simulate the motion of walking. He also strapped an accelerometer to the top of his mug and walked around, to measure the exact motion the cup was going through.
Han finds several solutions to the coffee-splashing problem, although only a few of them are likely to be acceptable in your office. His first reassuring conclusion is that it’s not all your fault: It’s partly due to the shape of a coffee cup. At a normal walking speed, liquid held in a coffee cup tends to splash around much more than liquid in a wine glass. So there’s one solution. If your office is like mine, however, drinking your coffee out of a wine glass at work might be frowned upon.
Han also tests out walking backward, and finds that this approach is also effective at decreasing the movement of liquid in the cup. Yet walking backward with coffee also presents its own problems — like drastically increasing “the chances of tripping on a stone or crashing into a passing-by colleague who may also be walking backward,” Han says.
So what’s the best solution? The secret is that the splashes are partly because of the additional motion that your wrist introduces to the cup when you walk. If you strapped your coffee around your waist, you’d be less likely to spill it, but that also seems strange and impractical. So Han suggests the next best thing: carrying your coffee with a “claw” hand, in which you grip the rim of the cup from above. In this position, there’s less movement of the wrist, greatly reducing the oscillation in the liquid.
He finds some other solutions such as: Foam is very effective at dampening oscillations on liquid, as the chart below shows. So you can order a cappuccino. You could also, of course, just get a taller cup or use a lid.
To some, this might seem like very pointless research. But in a TED talk given last year, Han said the research has applications in other aspects of society as well — like how to prevent spilling oil from a fuel tank, for example. But for those in offices, it just might help keep coffee in your cup.
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