How To Never Spill Your Coffee Again & Save Yourself A Dry Cleaning Nightmare
I start every morning with a cup of hot coffee, but it's not just the caffeine that perks me up. When it comes to filling up my mug and taking a sip you might as well call me Kramer cause some of it inevitably winds up on my hand or shirt. Thankfully, there's a hack to never spill coffee again especially developed for clumsy people like me. It promises that by employing simple principles of physics you can keep that piping hot coffee safely in your mug where it belongs!
Student researchers in South Korea tackled this seemingly mundane problem and published a paper of their findings titled The Coffee Spilling Phenomena in the Low Impulse Regime in the Achievements in Life Sciences journal. Author Jiwon Han investigated "the physical properties of the fluid-structure interaction of the coffee cup" to find out why it is so very easy to spill coffee over the lip of the mug while walking. According to his research, we've been holding our steaming cups wrong this entire time and in order to reduce liquid spillage (and dry cleaning bills) Han has developed the "claw-hand" method of carrying coffee — and it looks exactly what it sounds like.
Instead of holding your favorite cat mug by its handle or wrapping your hand around its body, Han recommends gripping the top of the mug with your finger tips in an over-handed posture. Carrying the cup by the rim reduces "the magnitude of acceleration," which means that we are not swirling the coffee around unintentionally with so much force as we move.
I attempted this strategy, and while it did reduce the movement of the coffee in the cup, I was paranoid that the mug would slip out of my hand at any moment leaving a much bigger mess to clean up. (Note: do not attempt this carrying method with wet hands. You will drop the coffee unless you have Hulk-like finger strength.)
If utilizing the claw doesn't stop you from a frequent scalding, Han recommends that coffee-drinkers change the way the walk from the break room back to their desk. "Since we are not accustomed to backwards walking, our motion in the walking direction becomes irregular, and our body starts to heavily rely on sideways swinging motion in order to keep balance," Han explains in the paper, adding that he understands that backwards walking may be impractical for most; though I would love to see someone in the office attempt it!
So what do all these suggested methods boil down to? "The thrust of most of them is that both the claw grip and backwards walking create a more circular motion that moves the liquid around the cup rather than careening into the sides," Food And Wine explains. For those caffeine-addicts more scientifically inclined, there are plenty of charts, graphs, and equations explaining cup motion properties and the frequency spectrum of backwards walking in the study.
Han, a high school student, even gave a TEDx Talk last September illustrating his "pointless" research.
There you have it folks. It's not that your cup is too full or that your mug is the wrong size, we've just been holding are coffee in a way that is against scientific common sense.