It makes sense to squeeze every last drop of milk into our coffee and drizzle the remains of our expensive olive oil over our salad — so we stand in our kitchens, holding bottles or cartons at awkward angles, waiting and watching with varying degrees of patience. How long do we have to wait? That's what two physicists at Brown University in Providence, in the US state of Rhode Island, wanted to find out.  Their findings  were published in the journal Physics of Fluids . Thomas Dutta, a PhD candidate, recalled how his grandmother struggled with getting the last few drops out. And his physics professor, Jay Tang, also knew how it felt to stand in his kitchen, wondering how long it takes for the water to drain off his cast-iron wok after washing it. Probing everyday science  Tang usually researches the biophysics of bacteria — more specifically, how single-celled organisms move and bacteria swarms spread across wet surfaces.…