Learning the Physics of a Creaking Step

Dear Delyara, The very last step before the top landing has a deep, wooden groan that changes pitch depending on where you place your weight. If you step on the left corner, it’s a sharp whine; if you hit the center, it’s a heavy, solid thud. I’ve spent months trying to learn the exact physics of skipping it entirely when I come home late, trying to move through the house like a shadow that leaves no trace behind.