
Søren Peder Lauritz Sørensen or S.P.L. Sorensen – the Danish biochemist, most remembered for his introduction of the pH scale, was honoured by search engine Google on its animated doodle. The google doodle also involves an interactive game that allows you to figure out whether a given specimen is acidic/basic.
The pH scale (potential of hydrogen) is a scale that determines the acidic or basic character of an aqueous solution on a range of 0 to 14. The markings below 7 ascertain the acidic character of the solution with those nearing 0 as most acidic. As the number increases from 0 to 14, basic or alkaline character of the solution increases and acidity gets reduced.
Son of a farmer, Sørensen, was born on January 9, 1868 in Havrebjerg (Denmark). Initially, Sørensen was interested in pursuing a career in medicine rather than chemistry but a fellow chemist, S M Jorgensen influenced him to take up chemistry and Sørensen rose to fame and became a figure whose introduction of pH scale is something that remains instilled in every high-school student.

Sørensen was also involved in chemical technology and made contributions to the Danish spirits, yeast, and explosive industries. He was awarded several honours from scientific and technological societies. Sørensen retired in 1938 after a period of poor health and passed away the following year.