Google on Tuesday celebrated Danish chemist Soren Peder Lauritz Sorensen who introduced the pH scale to the world with an interactive Doodle. Sorensen's method of expressing acidity -- the negative logarithm of hydrogen ion concentration (pH) -- still has a wide range of real-world uses. For example, in agriculture, the pH value can indicate the moisture associated with a soil, which can reveal what crops are suitable for the soil and what adjustments farmers must make to adapt it for growing any other crops. This is what pH value means. Born in Haurebjerg in 1868, Sorensen was initially interested in studying