Why does coffee slosh?

Speaking of the recent comment by one of our bloggers about topping off you morning coffee instead of starting with a new cup, it reminded me of an article that I came across the other night about sloshing coffee in a mug as you walk.

It turns out that a group of researchers at the University of California Santa Barbara looked into why coffee has a tendency to slosh out of the mug it is filled in. The actual report is here, but you need a subscription, however the best explanation of the study is found at MSN News here. (And it's where the photo is from).

The basic reason why it turns out is that the stride that we make as humans is at the same rate as the slosh of coffee. So it's just like swinging on a swing the movement of our body makes the coffee go back and then forth, and back and forth and then out of your cup on to you clean shirt or pants, which starts your day off right! I guess this really shows that our bodies are really made for coffee that we would both operate at the same frequencies.

In the article they suggest that simply taking your time with a full cup of coffee is the easiest way to prevent sloshing. So if a person is focused in on the cup of coffee they are handling, you can compensate your stride so that you are not going to slosh the coffee out of the cup, but if you are distracted and just walk natually you are going to slosh the cup in about 7-8 steps according to the research. The other solution is not to use a round cup.

Pretty interesting stuff, and amazing that someone would be looking into it!