“We take gravity for granted,” Pettit said. “Generally, we are unaware of the weight of our hands, or how easily we pour coffee into a cup. We don’t stop to think, ‘Will the coffee rise up and pour ...

A staggering 2.5 billion single-use coffee cups end up in landfill every year, which is bad news for the planet. While technically recyclable, the mix of paper and plastic in most disposable cups ...