The diameter of a human hair is 9 \cdot 10^{-5}9?10 ?5 9, dot, 10, start superscript, minus, 5, end superscript meters. The diameter of a spider's silk is 3 \cdot 10^{-6}3?10 ?6 3, dot, 10, start superscript, minus, 6, end superscript meters. How much greater is the diameter of a human hair than the diameter of a spider's silk? Write your answer in scientific notation.