How does soap make greasy dirt rinse off with water?

Water and oil do not mix because oil is hydrophobic, or water-fearing, while water molecules are polar and hydrophilic, or water-loving^[1]. Soap acts as a bridge between these two because its molecules have both a hydrophobic tail and a hydrophilic head^[1]. When you wash your hands, the hydrophobic tails latch onto the oily dirt, while the hydrophilic heads remain in contact with the water^[1]. This creates tiny clusters called micelles, which trap the oil inside^[1][5]. Because the outer heads are soluble in water, the entire micelle is easily rinsed away down the sink, taking the trapped germs and grease with it^[1].

Did you know that this same process is essential for your body to absorb vitamins?