Lord Kelvin
Brief Bio: British mathematical physicist and engineer
Lived: 1824-1907
For further info: en.wikipedia.org
Quotes:
“When you can measure what you are speaking about”
I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely, in your thoughts, advanced to the stage of science, whatever the matter may be.
3 May 1883 from the lecture “Popular Lectures”